Hey all, just got my Ludespeed kit on last weekend and have been having a hell of a time with my EGT's (because I'm still a moron in the tuning department).

Current settings :
Boost - 7psi through Deltagate (with large TMIC)
Fuel Mgmt. - RRFPR/Fuel Pump/Zener Diode
Timing Mgmt. - ITC
EGT Probe - Autometer competition series

Now the EGT probe is about 3-4" out of cyl. #3, right at the collector. For some reason I can't get the EGT's down no matter what I do. From 4500-redline in 3rd-5th it will push about 1650 EGT's (note: I'm being nice on it because I know it's so high... can't blow it up just yet). At cruise I push around 1200-1300.

I've talked to two people today, one said that that location should be reading that high and that I should start to worry around the 1700 range. Another said that I should be starting to worry at around 1500 - seems slightly odd since I pushed nearly 1500 in stock form at WOT in higher gears.

My timing is set on the ITC to ramp up from 0° at 4000 to -6° at 5600 and to hold it all the way up. WOT 7psi fuel pressure is around 85-90psi.

This is driving me absolutely nuts... I thought that EGT's should be 1550 MAX, the fuel pressure rising rate is around 4-5:1, which I thought would be optimal (though the A/F reads full rich at all times... starting to question this sensor), and I have pushed the fuel up around 95psi at WOT under full boost. I'm not getting any audible detonation, and I have a VERY low restriction exhaust (read: one 2.5" high-flow cat leading to a 3" straight pipe out).

The only thing questionable is the plugs, which are the stock Champions (burnt up one of the NGK's on the first test run without timing control, damnit!). I've got NGK's coming that are 2 steps colder, so I'm just hoping that's going to make all the difference.

Any suggestions? I mean besides dumping the cash on a programmable ECU (coming soon, though... just want to be safe in the meantime). I'm going to put in a lower pressure spring in the Deltagate as soon as I get the chance, hopefully that'll help as well. :-/

8 -

How are you seeing 1650 as a temp? I thought the Autometer's topped out at 1600?

At any rate, that number is way too high.

You are seeing 1200 at cruise, which would be about right.

I would guess your RRFPR is not doing what it is supposed to do, but you say the Fuel pressure is 85-90 psi at WOT (is that measured with a FP gauge?).

That would leave the plugs maybe?

1650 F is a little too high, but not much if you are seeing this just before shifting into 5th. I think you would like to see this about 100 F lower, though. Once you hit over 1600 F, things are about ready to start getting soft in the engine.

Don't know if you've done this already, but make sure that your RRFPR is working. Hook up a pressure gauge and verify your WOT pressure. Also, try turning the boost down a hair and then see what happens to your EGT readings.

Steve http://www.forcefed4.com/

blaster88 - The guage may go to 1600, but the needle goes beyond that what would be about 50° or so.

Yeah, my FP guage is measuring around 85-90psi at least, that sender is located between the filter and the rail. Now that I've replaced the soft fuel hose supplied, I may be able to kick the FP over 100psi, though I've heard that around 95psi is when your injectors can't handle it and they just stay open. :eek: Not sure if that is true or not though.

SteveS - No no, it climbs to 1650° at 4500rpm and sticks there until redline. I've only done it a couple of times to see, I've been partial-throttling it since then.

I just got another wastegate spring, so that is going to go in and hopefully my boost will be down quite a bit. I'm down as far as possible on the current spring that I've got in there. I'll probably pick up a boost controller as well real soon.

Ok, I may not know what I'm talking about, but here goes:

From what I understand, you go 1 range colder on plugs for every 50 (?) hp increase, hopefully that is your problem. Never use champion plugs in a car, they are only good for lawnmowers.

Should the fuel pressure be that high? That seems too high. From my 5.0 mustang days, I remember that about 35-40 psi was good. I know BMW's run about 3 bar stock (which is about 40-45 psi) running too rich will keep power down, from what I understand, optimum power is just before the point of detonation. I wouldn't think that too much fuel pressure would cause high egt's though, but anything is possible. Possibly try lowering the pressure and see what happens. Obviously if you hear pinging, stop.

Other than that, I have no idea. Good luck and get that thing tuned.

Erik

BTW I saw your car last night and I didn't get to look under the hood. :(

hmmm I've got almost the same setup as you do:
BEGI RRFPR running ~70 psi at WOT.
TMC1 - not adding any retard at 6 psi boost - no pinging yet.
Zener diode holding WOT voltage at 4.72.
A/F meter reading mid-full rich - no hi-flow cat yet.
1 step colder plugs.
2.5" exhaust /w minimal bends.
EGT gauge is 2" away from #3 cylinder exhaust port.

EGTs are a cool 1400 to 1500 max at WOT even to 5th gear redline. :D Though EGTs cruising at 60 MPH are a steady 1350 and rise to ~1500 at 80-90 mph cruising which is considerably hotter than what you're reading. During that time, the AF meter is still doing its happy lean-rich dance indicating that it's still running in closed loop.

I'd definately get the colder plugs installed asap because everything else you've posted seems to indicate that:

1) you're running rich
2) plenty of fuel pressure - I'd double-check with a mechanical gauge to verify it
3) ITC isn't retarding - though if it would, that would shoot up EGTs considerably
4) EGT gauge was installed before turbo and never saw that kind of heat - seems like it's working properly.

Stay off WOT till then :rolleyes: Yeah, I know it's tempting, but what is a week's delay to run safely? Let us know how it goes :)

Godmal - Yeah, I ordered 2 steps colder plugs on Wednesday (2-day'ed, but of course shipping companies don't understand the 2-day concept so I still don't have them).

The fuel pressure should be about that high, I believe. I can't use an S-AFC in my car since it'll lose it's settings as the ECU relearns (MY00 problems...), so the solution to more injector duty is to crank up the pressure upon boost.

Rick Hunter - Does your profile say your car is pink? LOL that is what I get for taking my contacts out. :)

Interesting that you aren't getting detonation, you must be right on the edge there. Strange that the EGTs raise under cruise though, maybe your ECU is compensating and you're getting non-audible detonation?

I may just have to drop the fuel pressure and timing retard and see what I get... hopefully not detonation, lol.

8: I tried the 2-steps colder plug experiment on my EJ22. It didn't make a difference. It still pinged, and I still got 1600+ EGT's at 7+ psi boost. I had to upgrade my 220 cc injectors with 280 cc injectors, and reduce boost to 5 psi to get everything under control. Now I'm running hardly any S-AFC corrections with 80 psi fuel pressures. (I also noticed that my EJ25 injectors go static at 85+ psi fuel pressures, and the engine will bog.)

May I suggest that you look at bigger injectors? Something like a 360 cc injector should do the trick, and will be much cheaper than an aftermarket ECU. Unfortunately, I don't know which cars have compatible top-feed (saturated) injectors that you can transplant.

You can ignore the A/F gauge under boost - our engines love to run rich.

How did you come up with the 6° retard on the ITC? Trial-and-error to eliminate detonation?

-WaC
Wayne

wac - I was fearing that it may be fuel-related, but I'm going to try the plugs as well and see if it even makes a minor difference.

I was planning on going with some type of ECU, possibly the Unichip that Cobb sells (though I don't much like the idea of going back for reprogramming if I switch turbos or something), with a set of 420cc injectors.

The 6° was basically just playing around with it. If it is at 0° retard, I get pinging. If I drop it to where I don't ping, I get REAL high EGT's.

For the record, I have in my possession a blue wastegate spring that I'll be putting in in place of my 7-9psi spring, so boost will be going down soon. Funny thing is... the kid I got it from said that he was told it was a 4psi spring, but if I go to look up the colors online, it is 5-7psi, and mine that was red (orange?) when I put it in, is silver online. Strange.

Must be the bigger turbo or something.

My MY00 will run 10 psi on a 190 lph fuel pump, a Vortech 4:1 FMU, and stock everything else. (this was a mad experiment with a valve I was trying to make into a MBC - thinking it would turn my transmission into metal confetti if always available.)

With that, it was making 1525 or so on EGTs.

Since we've kinda eliminated everything else, what about your zener diode? Which one are you using? Have you checked what voltage you are clamping at? If you use the wrong one that clamps down in the 3v range, then the MAP signal probably isn't getting far enough into the injector duty cycle, and even with increased pressure, you aren't getting enough flow.

Field expedient check - unhook your diode - the car will still run, just get a little part throttle stumbling under boost. No biggie. Look at your temps.

Well the diode that I am using was the 5.1V one that'd clamp at 4.82V (IIRC from the thread). The other one I have sitting around is the 4.7V one that clamps at 4.3V or so, which is what Ludespeed is running on their test car and says it's working fine at the same boost levels. Peculiar, eh?

I'll have to pull the ECU cover and try a few things while driving around and see what I come up with. I'll also have to get an actual multimeter and read that voltage as well... the most electronic I usually get is soldering. *shrug*

Plugs aren't going to help this problem.

I assumed you're running a 98-01 2.5L, right? If not, bigger injectors may indeed be what you need, as Wayne pointed out. Anything smaller than the 280cc injectors will make it very difficult to run 7+psi, even with those high fuel pressures.

Steve
http://www.forcefed4.com

...lowering your fuel pressure? There's a point where your fuel flow is too high and it's still burning on its way out. You will probably have to mess around w/ your timing, but that could be it. Other than that, I would say larger injectors if you're really not getting enough...

SteveS - Well... I guess all I can do is hope until I'm proven wrong. The boost should be dropped within a few days, I just have to get under there and pull the wastegate to change the spring.

mrbell - I haven't tried going too low on it, I planned on playing with it as soon as I get the new FPR in place since my stock one can't keep up with the flow of the new fuel pump (idle pressure is 44psi). I'll give that a shot, maybe even on my way home from work tonite (I only get one or two chances to really get on it, so it's ideal for testing without being in heavy danger).

I can see how too little fuel can give me high EGT's, though wouldn't I be pinging if it wasn't enough?

And if I had too much fuel, would it actually do that? Burn and continue to burn as it's leaving the cylinder?

Yeah, if you've got too much fuel, it burns slower and therefore can still be burning on it's way out as it passes the EGT probe. As you can imagine, this makes the EGT probe VERY hot. It's also not good for the rest of the exhaust system. Another thing you have to worry about here is that the fuel will wash away the oil in the cylinder walls which is, what I like to call, bad.
On the other hand, if you are still not getting enough fuel, your EGT's are high, and you may not ping. The problem here is that when there is a lean condition, the gas burns quickly and very very hot. Some of the excess heat will usually stay around long enough for the next compression stroke and will ignite the mixture. You can still be running lean w/o this happening, tho, especially if your timing is set back enough to offset the pinging.

...of course that's just my opinion, I could be wrong.

Pink... LOL you caught that one quickly :D Yep, Pink... well yeah the front badge is pink and my friends love to bug me about it. :rolleyes:

8, as far as I can tell, I'm not pinging at all. At WOT, my EGTs are quite low. It's just under cruising when the engine is running in closed loop mode, that they can get high at 80-90 mph. I checked out Vishnu's forums and I believe Shiv mentioned that it's normal for such temperatures to show up on the highway under light loads.

Ah I forgot to mention that I've got a WRX pump. My idle pressure is 34 psi.
What MrBell mentioned about too much fuel sounds quite possible. I still find it strange that you have to pull your timing back so much to avoid audible pinging while I don't at all. Course, my boost gauge could be reading generously at 6 psi when in fact it's running at 5, thus the lack of pinging. I don't have much confidence in the quality of their boost gauges.

Furthermore, I'd try to check out the Zener once more.

Well I had an active day today in getting the car going the right direction...

I installed the SVX fuel pressure regulator I got, now the car's idle pressures are a perfect 33psi and around 43psi at WOT without boost.

Also I was talking with a friend of mine up here, goes by HndaTch67 on the board, and he turned down the fuel for me... I thought it was the thumbscrew that adjusted the rate and the nut/allen threaded section that adjusted when it kicked in. No, I was wrong, it was the other way around. So I'm still running 95psi at full boost, but now my EGT's are down to 1600, even 1580-ish. I need to turn it down a bit more (until the fuel pressure guage REGISTERS that it's going below 95psi) and I think I'll be set. Thanks again, Jeremy. :)

Also, I ordered a Split Second VC1 voltage clamp to remove that zener diode once and for all.

I also ordered a 3-5psi spring for my wastegate, so eventually I can run a boost controller in the car (looking for good deals on some, but can't make up my mind on which... still love that Blitz SBC-id).

So I think I've got it almost figured out. I think mrbell hit it on the nose with too much fuel. I'll find out more as soon as I get some solid time to tune. :)

so Nick when are you going to start doing some serious tuning?
You know you want to join the light too. Stay away from the dark t2 side ;)

i was told that i should watch out if my EGTs go higher than 1450.... my egt probe is on the headers near where it connects to the uppipe.

Andrew,

You probe is much further downstream than 8's from your text description. I wouldn't be too surprised if there were several hundered degrees of difference between the two locations. I would be concerned at 1400 or so at your location. What are your readings at sustained cruise of 75mph or so? That is when my car gets the hottest. When I jump on the gas the EGT drop due to the extra fuel.

Aaron
http://www.scoobymods.com
http://www.azscooby.com

So are you saying the problem was too much fuel?

When I've been "tuning" and have turned up the RRFPR too much it has been obvious. The car will stumble and not be as powerful. It's pretty obvious when this happens.

Steve
http://www.forcefed4.com/

Yeah, it was too much fuel, but I didn't have any... well, much, stumbling. I just thought that it was part of high compression + forced induction. Doh.

I'm going to take an allen key with me to work so that I can play a bit more on the mixture during lunch break.

IIRC, if it was cranked all the way up, that'd be 15:1. :eek: No clue WHY it'd be shipped like that...

And for the record, it's not that I couldn't read the directions, it's that the directions I got with them were written mangled, and it said the top and the side adjustment when I have a bottom and a side adjustment. Even in it's opposite orientation, they would have been backwards instructions. :rolleyes:

I'm with Steve on this one. I've never seen high EGT's from too much fuel.

Are you using a Bell RRFPR (you didn't say)? If so, the hex adjustment is for baseline pressure, and the small vacuum thumbscrew is for rate.

-WaC
Wayne

Edit: spelling.

Yeah, I'm using a Bell RRFPR, but for some reason I turned the hex out a bit more and the pressure at full boost has dropped accordingly. Hmmmm... time to call Bell/Cartech....

Aaron, when cruising at 75 I'm at ~1300. I think I have too little of fuel for 5psi and plan to drop the boost a bit until I get some 550cc injectors or something of that nature...

also I'm running the vortech FPR

8, sounds like you're heading in the right direction. Do you think you could take some voltage readings once you've got the Split Sec Voltage Clamp installed? I'm interested to see what it clamps at.

According to the SplitSec site, they have different models that clamp at different voltages - they don't list what voltages they have available.

However, seems like a waste to pay $70 for that thing when it is doing the exact same thing as a zener - it probably is just a zener.

I got the 5v model that is supposed to clamp at exactly 4.85v without variance. They said that they can install a piece to make it adjustable, but it would make it vary with weather, which would just be a PITA, IMO.

I'm going to pop it open when I get it and check it out. If all I find is a zener, I'll definitely send it back, but with all the variance we've seen in zener diodes, I doubt that is what it is.

My zener actually spikes occasionally and pops over the limit, throwing a MAP sensor voltage CE light.

4.85 is going to be out of range, but it may not be an issue.

You want to catch it under 4.8

I thought that 4.85 was the ideal cap? I know Kastle is using the VC1 without any troubles...

My injectors were cutting out at 4.85V when I tried one of the 5.6V 500 mW Zeners. In fact, when I removed it, it still read 4.85V. At 4.72V (5.1V 400mW), I have no problems, don't throw any CEL codes except for the "Catalytic Converters functioning below optimium efficiency"...:rolleyes: hmmm What cats? :D

LOL, I've got the Cat. Code as well, plus 4 misfire codes from the ITC, but those just happen. Can't wait to get the J&S and ditch the ITC so I don't throw any codes.

8,

I have the SplitSec voltage clamp. It works fine. No problems. When I got it there wasn't any diode theory yet. It should work perfect.

Andrew,

Do you have a hi-flow fuel pump? When I swapped my fuel pump I got another 15psi of fuel pressure with the same settings on the Vortech SFMU. I feel the stock pump is seriously weak. My egt's would drop 100 degrees or so from freeway cruise speed if I got intop boost from the extra fuel. I never stay into it long as I don't need that level of a speeding ticket. ;)

Aaron
http://www.scoobymods.com

ISR supposedly put in a new fuel pump when i took it in.

i dont know how they hooked up my fuel pressure gauge either because it is very strange. it matches the boost pressure exactly. its like just a bigger version of the boost gauge. i was under the impression that it shouldnt be doing that but maybe im wrong.

i'll call them up in a little and ask them about it.



well, i just called them up....looks like i have a stock fuel pump. i ordered one from them and will be getting it along with my exhaust and spark plugs.

so hopefully that will take care of the high EGTs and maybe get me another psi of boost (wheres that devil smiley when you need it :))

i also talked to them about my odd fuel pressure gauge, he said its working fine becuase of the vortech fuel pressure regulator. so i guess whatever.

Andrew - Yeah, it raises fuel pressure by boost (4:1 regulator will add 4psi of fuel for every 1psi of boost), so it'll appear they're working the same.

I still can't get my EGT's down... I'm getting a new wastegate spring so I can crank the boost down and tune from like 3psi, then I'll add a boost controller and tune up from there.

I currently have 1 step colder plugs in the car (BKR7E-11) and am waiting on 2-steps colder plugs. I don't have any pinging and I am at a max retard of -3° on the ITC while my fuel pressure is around 80-85psi. Still running 7psi though, so who knows if it is my injectors that are crapping out on me.

Are you sure you're using the ITC correctly? doesn't the ECU start to compensate and basically make the ITC useless?

I don't think so... I'm sure it is working at least at WOT, though. I know it throws misfire codes for all 4 cylinders, so it must be doing something... lol.

Here is some EGT info for you:

PART I - EGT LOCATION:

I have a MY2000 turbo and ran a similar setup for a while. I had a TMIC, Legacy RHB5 compressor, Bell 20007 RRFPR, 255L/hr fuel pump, S-AFC and later a JCS torque chip instead of the AFC. I had NO timinng retard, as we can run 7 psi here at 6,000 feet without any (like 5.5 psi at sea-level).

(A) I had the EGT initially in the turbo up-pipe right before the compressor, and it ran best with:

1) EGT at idle were 500-700 degrees
2) EGT about 1,200 - 1,250 degrees between 65 - 100mph at vacuum while cruising.
3) EGT's about 1,300-1350 at WOT at 5 psi
4) EGT about 1400 WOT at 7 psi.

I was worried about these number because I was told to add 200 degrees to the EGT's at my location. That would have meant is was really 1,600 and I didn't want to believe that. So, to be safe, I chose a more conventional location.

(B) I then moved the EGT to the #3 exhaust about 2" off the head, and stuck an O2 sensor in the old EGT probe location. With no other changes, the

1) EGT at Idle were 700-900 degrees
2) EGT's went to 1,350 - 1,400 cruising,
3) EGT were 1450 WOT at 5 psi, and
4) EGT were 1,475 at WOT at 7 psi.

So, it was clear that the EGT's in the up-pipe just in front of the turbo more closely approximate the head when the car is WOT under load and the exhaust gas velocity is up. There is only a 75-100 degree difference between the locations, but there is a 200 degree difference when cruising at vacuum or at idle.

using numbers at the exhaust port, everyone seems to agree that cruising EGT should be about 1,400 - 1450 and WOT should stay under 1,550 if well tuned, and over 1,600 is getting bad. I have never been over 1575, and as that number comes up I am already getting freaked out ;)

PART II - IGNTION RETARD and EFFECT on EGT's vs FUEL:

Now, I am now running a larger VF22 (thus cooler) with dual 480cc TB injectors run by an SDSEFI EIC controller - still no timing control, except for a prototype I am testing a few times a week. With this new setup, EGT's dropped to 1,400 at 6,300 rpm in 5th gear, and the Rich/Lean meter was where it always likes to be.

Once I added some ignition retard into the equation over the past month, I am amazed at how much the EGT's will rise with just a little retard. Fortunately, I can just add fuel from inside the car.

i.e. At 10 psi, and seting some mild retard (the amount is classified, sorry) to start from 5,000 rpm and up, My EGT's are 1,400 - 1,500 in the first 4 gears, and only 1575 by 5,500rpm in 5th, and that is IF I leave the extra injectors alone and just drive the car! Yes, this is 100-150 degrees hotter than 7 psi with no retard, but it is still safe, and is a lot more power too. And, max OBDII readings on post IC air temp were 145 degrees F in 5th gear under load, which means I have more room to play with the boost.

This was with the Autometer Rich Lean meter reading at 3 o'clock like it does at any other boost level. That equates to enough fuel for 257hp if the stock 280cc injectors are good for 170hp like Shiv says. (Shiv has also stated in the past that four 320cc injectors are enough for 256hp, so that would mean I was using enough fuel for 339 HP, which I don't believe)

However, turning the extra injectors up from about 60% duty cycle to 75% duty cycle drops the EGT's to 1,500 in 5th at 6,000 rpm. That would be enough fuel for 286hp, but I could see on the Autometer R/L meter that I was now rich. However, it pulled a lot harder from 5,000 - 6,400 rpm in 5th gear also.

From previous SCC articles, to run 5-6 psi you shouldn't need any retard, and I recall that you only need -5 degrees to run 7-8 psi. That level of boost is about the limit of your 280cc injectors at 80 psi fuel pressure which will flow as much fuel as 330cc injectors would. That puts you right there with SHIV's first SCC article at 250 hp to the flywheel and 183 to the wheels, or close to that. I believe he was running 1,550 EGT's for that. Note I have to run 25% more boost at 6,000 feet to match those power levels...

Also, I understand that the injectors wont go 100% duty cycle with a MAP voltage clamp, and that you want to run as high of a MAP voltage as you can before the clamp is in effect. But I understand the injectors can stick open at over 75 psi fuel pressure. This is from a post from the gentleman in Argentina who had discovered that with his SC Impreza. So, if the MrBell's post is correct about running too much fuel, and having burning fuel leaving the exhaust and raising EGT's, then that could be the case. Maybe?

Try less retard if you can, or 93 octane or both, with only 80 psi fuel pressure.

Larry
www.ImprezaRS.com

PS: To run 14 psi boost I had to turn the injectors up to 90-100% to keep EGT's at 1,500 at 5,500 rpm in 5th gear, and again it was slightly richer than normal. By Shiv's conservative calcs that is enough fuel for 340-350hp.

Also, I dredged up a dinosaur post from my saved files, see below - I have to split it into two posts:

Larry

-----------original iclub post unedited------------

Author Topic: Making 300hp. Full disclosure (very long)
shiv
Scooby Specialist
Posts: 1234
From:SF Bay Area, CA
Registered: Dec 1999
posted January 17, 2000 06:04 PM
--------------------------------------------------------------------------------
I'm currently in the middle of writing an SCC Project Impreza installment covering all the work I've recently done to the turbocharged 2.5RS. I've been busy this past month testing different upgrades and trying to establish a safe and conservative upgrade path. That said, I'm very happy with the car's current configuration. It's running safely with an estimated 300 engine horsepower. That's a significant step up from the dyno-proven ~255hp (183 wheel hp) the car generated not too long ago.
How does 183 wheel horsepower equal 255 engine hp? Good question. I'm sure most of you know this already but I'll address this again before moving on...

Tested on UPRD's dyno a stock 2.5RS dyno'd at 95 wheel hp. A few weeks later, when tested with the as-is 7psi Minnam set up (with a 2.25" Stromung cat-back), the project car dyno'd at 183 wheel hp. All on 92 pump gas. From the looks of the monitoring equipment, that is as far as the stock fuel system would take it. But still, the Stage II offered a remarkable 88hp gain to the wheels. So conservatively, engine output is *at least* 165 plus 88 = 253hp. Of course, this assumes that the stock car really does make 165hp. That's the only big assumption I'm going to make here.

Now, a more optimistic tuner may say (and I WON'T agree with him)... "Wow, wheel output increased by 93%. That must mean that engine output is 93% greater. So, 165*1.93=318hp! Holy *****!"

Obviously, there is a problem with that tuner's calculation. He would be incorrectly assuming that drivetrain loss is proportional to engine output. Evidence (and a little common sense) suggests that this is not true. While engine ouput does influence drivetrain loss, my guess is that it does so to a small degree (esp. when talking about these non-obscene hp levels).

So let's go back and be grossly conservative. Meaning that engine ouput does NOT effect drivetrain loss. So, with this in mind, it's VERY safe to say that the stock Minnam Stage II system makes (at the least) a fuel-limited 253hp. Not coincidentally, the calculated safe and efficient limit (80% duty cycle) of four 320cc injectors is approximately 256hp. Also not a coincidence are the air flow meter readings from the AFC. Stock was 44% peak. The standard Minnam Stage II was 68% peak. That's a 50% increase in air flow. So, theoretically, that's a 50% increase in engine ouput. 165*1.55=255hp. We're right back to that magic number! Of course, there are other hp-influencing factors involved but I think their cumulative effects are minor and would likely come close to cancelling themselves out if factored in. Also, the math and physics behind it are beyond me so I'm just going to play dumb (well... it's not really playing, is it?) until someone beats me over the head with them.

But wait, we are still a healthy 45hp away from the big 300hp I'm claiming.

WHERE DID THE EXTRA HP COME FROM? The rest of this message will document the mods I believe necessary to make additional safe and reliable horsepower without resorting to a fully programmable EFI system (that comes later).

DISCLAIMOR #1: Given the user-dependant nature of performance tuning, nothing is guaranteed. If you make tuning error (and anyone can make them!), something nasty may happen to your engine. In other words, follow my advice at your own risk and discretion. Please note that this upgrade advice does not necessarily reflect the views/opinions of Minnam Racing, or anyone else other than myself. As always, be safe. Don't drive irresponsibly on public roads. Don't drink and drive. Wear your seat belts. Two hands on the steerig wheel at all times. Wear clean underwear. Don't shout at your mother. Help grannies cross the road.

DISCLAIMOR #2: The following advice applies specifically to my Minnam Stage II turbocharged MY99 2.5RS which includes (among other things) a T3/T04E turbo, external wastegate, GReddy Type S blow off valve, free flow cat, J&S Safegaurd (Absolutely necessary for anything over 6psi of boost!) and Field/S-AFC fuel controller (also to be considered manditory). Other cars with other systems will require different approaches. All testing was done using CA92 octane gasoline. Any lower and you are asking for trouble. AND MOST IMPORTANTLY, IF AT ANY TIME, YOU HEAR DETONATION (a.k.a., knocking, pinging, rattling, etc,.), GET OFF THE THROTTLE! Detonation, not sheer power output, is the cause for almost all catastrophic engine failures. Knock is bad. BAD BAD BAD. If you develope a healthy fear of (and good ear for) knock, your engine will thank you in the long run.

DISCLAMOR #3: Before we begin this horsepower hunt, it is absolutely necessary to outfit the car will the following gauges: Exhaust gas temp (readable up to 1600F), fuel pressure (up to 90psi), boost/vacuum gauge (up to 15psi), and optional J&S dual monitor (a/f ratio and ignition retard). To make your life easier, go with an electric AutoMeter fuel pressure and EGT gauge. They are more expensive since they both require a sendor and an associated little electronic control module. However, both are very reliable, accurate, and most importantly, fast-reacting. I mounted the EGT sensor on the driver's side header (#2) just a few inches downstream of the exhaust port. At highway cruise, EGTs measure 1400 degrees. This should be a reference for all further temperature readings. In other words, if you mounted your sensor elsewhere (i.e. further downstream), your gauge will read lower under all conditions. Take this offset into consideration when looking at my temp readings.

DISCLAIMOR #4: Also, as with any turbo system, a non-restrictive exhaust is critical. Minnam Racing went to through great lengths to minimize hp-robbing and knock-inducing exhaust back-pressure by using a big turbine housing/wheel, an external wastegate, free flow cat, and fat exhaust tubing. It's completely counterproductive (and possibley unhealthy for the engine) to ruin this by using a small diameter cat-back designed for non-turbo cars (like the Stromung 2.25" cat-back I used during dyno testing). Currently, I'm using a Ralispec cat-back. It uses a wonderfully non-restrictive Apexi N1 canister with 2.5" inch stainless steel tubing throughout. It's loud and big-tipped, but it works better (for a turbo car, that is) than anything else I've tried so far.

Now that the disclaimors are out of the way, here goes...


PRELIMARY MOD #1: Blow off valve re-plumbing
--Vent blow off valve (BOV) to atmos and properly seal the discharge inlet. Don't use something filmsy to seal it off or it will eventually be sucked down by the turbo and cause a good deal of damage to the compressor wheel. This mod doesn't incease HP but it could very well prolong the life of the notoriously flimsy MY99 MAFs. Note that venting to atmos may require adjusting the BOV a little tighter so it won't leak under cruise and idle. Doing so will also insure a stable idle when cruising to a stop. Doing this, there should be no need to use the AFC's 'Decel' function. Besides, when the surge pressure is released into atmosphere, the car runs rich for a split second. This rich run condition can't hurt. In fact, it may even help and offset the temporary lean-run condition that can occur between full throttle, full boost shifts. It's also a good idea to mount a small K&N air filter on the BOV outlet since it does allow a small amount of unfiltered air to enter the system. Even more critical for those who go off roading.


PRELIMINARY MOD #2: Install a modified stock airbox.
-- This is yet another MY99 MAF reliability mod. This may require a little trimming of the blue Minnam intake tube. Once trimmed properly, use a 45 deg. 3" silicon elbow from Samco to conntect the box-mounted MAF to the blue minnam inlet pipe. This effectively isolates the MAF from engine-side vibrations. The stock panel air filter is restrictive. Dump it and install a K&N replacement. Now, the car will make full power/boost. Also, get rid of the inside-the-fender resonator system. Don't need it with a turbo. It's restrictive and unnecessary. Not to mentiont that the idea of the pastic snorkus/resonator ducting BACK INTO the hot engine bay is silly, to say the least. Instead, seal off that secondary hole with tape/pastic/whatever. This basically transform the intake box into a true cold air system that is fed air from the fender. The fender is fed air from the small vent next to the passenger side fog light. I can't imagine this setup could be improved upon. It's cold air and effectively non-restrictive. The mod only costs the price of your time and a K&N panel filter. Also, I'd bet that the MAF won't fail again.


(continued next post)

--
Shiv Pathak

-----------original iclub post unedited------------

Author Topic: Making 300hp. Full disclosure (very long)
shiv
Scooby Specialist
Posts: 1234
From:SF Bay Area, CA
Registered: Dec 1999
posted January 17, 2000 06:04 PM
--------------------------------------------------------------------------------

(cont...)

Now, let's get down to business.


TO RUN 8 PSI (est. 270-280HP)===>

1) ADD HIGH FLOW FUEL PUMP
-- I installed a Mazda RX-7 twin turbo pump. Almost any high-flowing fuel pump will do. In fact, the pump flows so well that the tiny stock fuel pressure regulator proved to be a big restriction, making it impossible to get anything less than 40psi of fuel pressure. No big deal but it should be noted. This explains why the car would temporarily run rich (before the o2 feedback system would correct) during engine braking and coast down. With the pump, the ran richer and stronger at the top end. Appearantly, the stock pump was beginning to show its limitations at 8psi. How do I know? J&S monitor shows that maximum ignition retard went from 8-9 degrees to just 3-4 degrees. Less retard is more power. MY a/f ratiometer also shows that now the car can hold a nice rich mixture all the way to fuel cutoff instead of becoming ever-so-slighly lean (or actually, less rich) at max rpm. Also of interest is that peak EGTs dropped from 1650 to 1500. A nice change and no doubt a result of less ignition retard and more fuel. Double bonus. You may also want to take this opportunity to remove the tiny stock fuel pressure regulator and replace it with an aftermarket unit. I used the Weapon R regulator. It's pretty. I have it set to delivery stock pressure (43psi of fuel at atmos. pressure). Make sure to confirm fuel pressure with your autometer electic fuel gauge as I found the gauge that is mounted on Weapon R regulator to be inaccurate.

2) INSTALL APEXi ITC IGNITION CONTROLLER
-- As far as I know, this is the only unit of its type of the market. It is desinged to intercept the cam and crank signal, modify it, and effectively retard or advance (+/-15 degrees) ignition timing in 5 different rpm zones. But why do I need it if I already have a J&S Safegaurd unit? Well, theoretically, I shouldn't need it. But in application, the J&S has to be set very sensative to catch ALL the knocks. In essence can over-retards when you ask it to do too much (i.e. when you run too much boost). It's safe, but not optimal for performance. Ideally, the J&S unit should be used as a back up or fail-safe (hence, it's "Safegaurd" nomeclature). Used as a primary form of ignition retard in a higher boost system, it can get overenthusiastic. This can lead to too much retard, low power and high EGTs. Enter the ITC. To dial it in, I watched the J&S monitor and followed ignition retard activity. I noticed that retard was only necessary between 5000rpm and redline. So, I dialed back some timing in that rpm zone using the ITC. With a little trial and error, I retarded ignition by only 6 degrees in that range. The result? No J&S activity and less overall retard. A lot more power and even lower EGTs (now they rarely go over 1450 deg). Appearantly, it's more effective to prevent knock with the ITC than to react to it with the J&S. When both are used together, it's a killer package. Wonderful.

So why do I need the J&S? For added safety, that's way! If you are using an ITC, all that is needed for some engine damage to occur is an unexpected flurry of knocks/pings. This can be caused by fuel slosh, hot weather, a bad tank of gas, heat soak, etc,. In other words, unless you are always playing around with the ITC, constantly compensating for conditions beyond my control, you're in trouble. Of course, you can set it so conservatively, that knock is unlikey. But this sacrifices power. So instead, I let the J&S take care of these unexpected situations. In fact, I have tuned the system so I that I just *barely* see a little bit of J&S activity (by looking at the monitor). This assures me that the J&S is set sensative enough to take car of any knocks-- even the minor ones that usually go unnoticed by the ear. My healthy fear of detonation could explain why the car's cylinder compression is just as good as stock. But still, I know ***** happens so I will try not to get cocky. Really.


TO RUN 8 TO 10 PSI (est. 280-300HP)===>

1) INSTALL AUXILLARY RISING RATE FUEL PRESSURE REGULATOR
-- Now that I have both passive AND reactive ignition controls, half the battle is won. What still remains before I can run higher boost safely are the proper fuel controls. I need more fuel. Plain and simple. With fuel (and timing controls) I could raise boost levels without running lean, knocking, and blowing the engine. And now that the car has a real fuel pump capable of some serious flow, I can go to work. Since I'm using stock injectors (which max out at 8psi), I need to use some type of boost-referenced 5:1 rising rate fuel pressure regulator. Now, there is a problem with using these contraptions on a car that already seems to do quite well when it comes to compensating for boost (up to a point). Namely, at there will be a rich spot during transition or at least until 02 feedback dials back fuel-- and that's only if it stays closed loop. Either way, this is not good for driveability or power. Why increase fuel pressure under any amount of boost when the stock EFI system works just fine up to 8psi? Forget it.

Another possibility would be to use a less aggressive 2:1 fuel pressure regulator like the one Adam is using. It's conservative enough that it won't throw the stock EFI system into a rich-running fit at moderate boost levels. However, I think it's too conservative. 2:1 means that for every pound of extra manifold pressure (boost), fuel pressure is increased by 2psi. At 8psi, max fuel pressure is 43 (stock@0psi of boost)+(2*8)=59psi. That's only 8psi more than what the stock 1:1 fpr would provide. This is a negligable increase of actual fuel injector flow. Even if the unit offers adjustable offset/preload (y-intercept for those who think in algebra), the slope-- 2:1, rise over run -- is fixed and your still left with the problem of not getting enough fuel under boost levels greater than 8psi. Need something else. Something that will provide a healthy 5:1 fuel rise while not making the car run rich at low boost. So, in other words, we need a fuel pressure regulator that starts "kicking in" when the car starts to run lean (at 7-8psi).

Hmmm... the only unit I know of that does this is offered by Bell Engineering (San Antonio, TX). They make a number of FPRs-- all designed to work differently. The one that I'm using on my car has no spring pre-load and is designed for modified OEM turbo cars. Suprisingly, it's not a big seller because not many people know about it. I should have kept it to myself But the unit works wonderfully because it is designed to become active only at 8psi and above. Below that boost threshold, it is just sitting pretty, letting the very effective S-AFC do all the fuel-related work. In other words, it doesn't screw anything up. This is good. But as soon as the injectors begin to max out at 8psi, it "jumps in" and raises fuel pressure agressively (5:1). To make things easier to visualize, here's a little chart of turbo boost and its associated fuel pressure.

Boost(psi) Fuel Pressure (psi)
0 43
2 45
4 47
6 49
8 60 <--injectors are maxed out and S-AFC becomes useless]
10 70
12* 80 <--RX-7 fuel pump is maxed out]

*too much boost

2) RE-GAP SPARK PLUGS
Even if you are using a colder spark plug, it may be a good idea to gap them smaller than stock at this stage. My RS came with plugs gapped at 0.042". I reduced them to 0.035". This improved power by eliminating the subtle misfire I would notice at high rpm during full boost runs. However, the elimination of misfire also made the car run marginally leaner which I took care of with AFC/FPR tuning. As with any modification, care should be taken to make sure the car still runs safely. At the end, peak EGTs should still be in the 1400-1450F range with ITC retarding 5-7 degrees between 5000rpm and redline.


TO RUN OVER 10 PSI (est 300+HP)===>

-- Don't do it. You will need a programmable EFI system to do this safely. While running 10+psi on the stock-ecu'd system is possible, it's bad bad bad. I've done it briefly and I'm ashamed. I did not inhale. Even though the car didn't ping or exhibit any obvious sings of running lean, there are several reasons why these boost/power levels are dangerous. First of all, almost every Japanese fuel pump is unable to reliably support the fuel pressure necessary (80+psi) to run high levels of boost with stock fuel injectors. Second, fuel injectors loose some mechanical efficiency when forced to operate at such unusually high pressures. Third, the "LEGO method" of EFI modifications that we have been following (stock ECU with lots of add-on fuel regulators and electronic gizmos) has its limitations when it comes to tunability, built-in safety margin, and response time. So basically, I feel that running over 10psi will require FULL and COMPLETE programmable control of ignition and fuel maps-- That only comes with the use of a programmable ecu (Haltec, TEC-II, MoTeC, etc,.) While the J&S Safegaurd is a wonderful safety device and has saved my a$$ more than once, even it has its limitations. Keep in mind that sh&t can happen quickly when you are right at the hairy edge between safety and complete engine failure.


IN SUMMARY===>

When in doubt, be conservative. Conservatism is the difference between a good tuner and a bad one. It's easy to make a car fast. It takes a lot more skill to make it driveable and reliable as well. Personally, a powerful car is only fun to drive when you aren't constantly worrying about detonation, overheating, lean-run, misfire, etc,. Be picky. Don't get accustomed to bad tuning. The ending to that story is always unhappy (and expensive). Also, when upgrading your car, take your time and do one upgrade at a time. Doing more than that will make the tuning and troubleshoorting process much more difficult. Also, going from 165hp to 300hp in just one week may not be a great idea if you are unfamiliar with peformance tuning and the associated inevitable glitches that comes along with it. Please note that this post does not go into the in-depth tuning issues. That's impossible given the fact that every car is different. Instead, it just offers a broad perspective, requiring that you apply your own discretion and knowledge every step of the way.

Lastly, don't get swayed by the claims of others (including myself, of course!). That is, if someone is claiming, say 500+hp streetable hp on a small displacment engine running pump gas, so what? Chances are, they are either grossly optimistic or budding supertuner destined for international fame. The nice advantage that come with learning about the tuning process is being able to seperate the fact from the fiction.

And remember, 300hp is plenty. And if done correctly, it's safe as well. Keep in mind that our cars are very unique. It's EXTREMELY rare that one can add a turbo to a non-turbo, high-compression car, nearly double engine ouput with simple bolt-ons, still run pump gas, sacrifice no driveability, and still (presumably) provide years of reliable trouble-free service. Feel lucky.

--
Shiv Pathak

Thanks Larry, very much appreciated. :)

That SDSEFI system you were talking about sounds like a lifesaver, unfortunately I think by the time I get to that level, I'll be going straight to larger injectors and a programmable ECU. :-/

I realize there are variances in what Shiv has stated, as he is testing on a MY99, and as we all know the MY00's are much different beasts - more advanced timing, different injectors, more compression, can't really use the S-AFC on it, etc.

I'll read through that all when I get to work tomaro, I'm sure I'll pick some things up again from Shiv's article.

PS again:

The prototype timing controller I am using does not throw any CE lights, other than that I can't tell you more or I'd have to kill you ;)

Larry

Can you tell me if you'd be willing to trade for a 2-week-used ITC? :) (one can hope, can't he? :) )

Ummmm... Lemme think.

...No...

Originally posted by ImprezaRS dot com

With this new setup, EGT's dropped to 1,400 at 6,300 rpm in 5th gear, and the Rich/Lean meter was where it always likes to be.

www.ImprezaRS.com [/B]

LOL, what is that, like 140mph? :D :lol:
[Edit] Lol, I think those dudes at the Academy are going to pick you up on radar one of these times and scramble some planes. :D :lol: [End Edit]

LOL, I think it's closer to 145mph.

Lol, and he's paying attention to EGT's while pretty much gear limiting the car. Bond, James Bond. I need to get a ride in that car sometime. :D

-Brian

I'll give you a ride anytime you wanna visit :D

I just have to get the wings installed first. I saw a set in spy kids that I am partial to, but they don't come in white...

Larry