I just got some new coil packs on her yesterday along with an o2 sensor a few days prior. I am finally able to run 14psi without the ignition breaking up, which is a start.

I observed yesterday higher than I would like knock counts/mild detonation higher than I would like and slight occasional surging when the motor was hot and running on the interstate or during any longer pulls. I noticed today with the engine up to operating temp but still "cold" it pulled smooth as butter with very low knock counts and experienced no runability problems.

I am wondering if perhaps the intercooler is not doing it's job and when making pulls in 3rd, 4th, 5th with a hot motor that the intercooler is just not keeping up and not cooling the air like it should. I start to experience knock after about being in boost for maybe 4-5 seconds so I know the turbo is putting out some hot air. I don't see this knock say in 1st gear because I am shifting before it gets really loaded down. In addition my boost levels were smooth and steady today, while yesterday were fluctuating 2-4 psi.

Anybody have any experience with something similar and the slanty intercooler?

i notice that heat soak went way way down when i finnaly got the correct splitter

The slanty G motor IC is a POS. Even when i had a ARC TMIC i had cooling problems/ heatsoak during long pulls on 13psi, so i can only imagine how much worst the slanty IC is.

Check your spark plugs, and all that stuff again. I was having the same issue as you, with slugish performance when the car was up to operating temps, but good performance when it was cool. However after i changed my 3 bad coils i got rid of that problem. I also changed my plugs about 3000mi ago with NGK coppers and it helped out as well. When i had my ign problem it would start hesitating and acting up around 14psi, however after i got it taken care of im running 1.2 bar and have yet to feel any hesitations.
Also if you have acces to a dataloget look at your settings such as water temp vs ign, and things like that and make sure that they look good.

Also im assuming that you have a PFC, what is your knock count, inj duty cycle, maf setting? And last thing, what are you using for a boost controller the stock solenoid or a manual one?
Kirill

Thanks guys!

Kirill, do you know the number of the plug your running? I am currently running the expensive PFR7B's.

Maybe I need to at least try to find a splitter for the slanty intercooler, but I bet that is not going to be easy.

I have yet to fit the slanty splitter to the RS hood. I have been very suprised that even after a long high boost pull, the IC is stone cold to the touch. Even after sitting for a few minutes in the garage, it's still only warm. I still plan on adapting the proper splitter, but I have been a bit impressed by the stocker's performance and resistance to heatsoak...at least in my engine bay. Then again, the warmest it's been since my swap is 55 and I'm basically at sea level.

Are you guys using the stock turbo chimneys? I think the chimney and the staninless downpipe really help keep the heat away from my IC.

It's possible that your intake temp fuel/ignition corrections are out of whack.

-Rob

It probably is something with intake temp/ignition corrections but that is way out of my territory of knowledge. Unless someone wants to share....:)

I don't have my chimney fitted due to the down pipe. That is true with intercooler too, it has never really been "hot" to the touch.

You can fit the chimney with an aftermarket DP. I have a divorced DP and just cut the back portion out and use the remaining 3 bolts to attach it.

I also have the heatsoak problem on the track after a couple laps. I think a bigger radiator and a better IC would definitely help

Right. I used an air nibbler to trim my chimney a bit to fit over the aftermarket downpipe. It not a big deal and think it is highly effective piece.

air temp correction tables.... +1 for the stock ECU :D

-Rob

So who has a Z4 ecu they want to trade for a PFC + Cash? :D

Im not sure on the plug number, but all i did was go to my local napa and ask them for a 2002 WRX NGK copper plug. I think they where like 1.80 a peace, dirt cheap and work great. The only thing is they dont last long, so i would recomend replacing them every 2-3 oil changes.

As far as getting a Z4 ECU, DONT DO IT! A good friend of myne and i took our cars to the dyno, the settups where very similar, except he had a z4 ecu+turboxs Dtec, and i had a PFC. When we got there he made 200WHP and after messing around w/ the d-tec the best he could get was 224. When i got there i made 226whp w/ nothing except a map i got from my buddie. After messing around for about an hour or so i made 264 and ran out of injector. I was able to raise my boost up to 16psi i think before the inj. became an issue.
At the 1/4mi track, the best he could get was a 13.2 where as i ran a 12.8, i consider both of us to be very close in skill level. So this just tells you how much better the PFC is if you can get it to run properly.
And sense your in CO it shouldnt be hard for you to find a local PFC tuner. Also see if any of the local guys w/ swaps would let you try out there Z4 or another stock ECU to see how your car runs. I know that when i put in my stock 3b ecu(out of a GF8 WRX) im honestly loosing 40-50WHP.

Kirill

So who has a Z4 ecu they want to trade for a PFC + Cash? :D

Sign me up :banana:

I have a couple people that can tune me here, and I definitely need some help before the 120+ summer temps get here.

My car ran great on Matt's Z4 ecu, however it was slow...Maybe worth the trade off at this point.

Now it even is breaking up at .75 bar again which sucks. I just don't get it, one pull is good, the next it surges/hesitates. Once my mbc gets replaced I am going to try that route again and see if it is something with the pfc and boost control. I also am going to try some stock wrx spark plugs as suggested by Kiril but I am skeptical.

I also noted today that I don't get the low end hesitation/stumble (under 2k part throttle) with the water temp 87 degrees or cooler but it does do it at anything over that. My water temp corrections for 80 degrees is set at 100/100 if that could be it.

i was thinking about the pfc .. but apexi has discontinued ALL GC8 pfcs ...
for about the same price (or less) as a pfc+datalogit you can get the new link g3 w/plugin harness

i was thinking about the pfc .. but apexi has discontinued ALL GC8 pfcs ...
for about the same price (or less) as a pfc+datalogit you can get the new link g3 w/plugin harness

Where? The quotes I got a link was over $1K. You can pick up a pfc with commander on ebay for $700.

But Datalogit is another $400 or so last time I looked.

Kevin,
If you are serious we should talk...

We are up in hydra territory now...I would rather just grab that. Many more tuners, much more support and more control.

My car is fast enough to put a grin on my face every time (when it actually pulls to redline) so I am not sure right this moment. I am considering getting rid of it though. I guess I need to try a few couple more avenues first like the mbc and spark plugs and then make a decision.

And get the intercooling sorted out. I really think it's part of the problem...

Is it that warm in CO? My iat during winter is easily half of what they were in the fall. I am not using a splitter nor do I have a heat shield over the turbo. the iat's that I last datalogged were in the neighborhood of 18-40C. outside temps where in the 30's.

The day he came by my place to get the coils it was 60 degrees F. In the summer, it rarely drops below 80 degrees F (even at night) and is often 100+

But that is really irrelevant. It's under engine temps. If you are getting heat soak because the ambient air isn't properly cooling the intercooler, your intake temps can be a couple hundred degrees...

Anyone have a splitter they can donate to the cause? I highly doubt this will fix anything. Plus it has been so damn cold outside in the past month I really don't believe it is that.

What about cooling around the cylinders though? I never see temps above 91c on the pfc and the temps usually stay at 88c. Under a 5th gear pull I did not observe any change in the water temps even when I started getting detonation.

I also still find it quite odd that the pfc can't control boost worth a ****, or I should say "I" can't control boost worth a ****. I played quite a bit with the boost the last couple days trying to get it to settle down and it is so inconsistent. About the only thing that is consistent, with it set at .95 bar with a duty cycle of 46 it peaks at .75 and holds for a split second then starts surging, or fuel cutting, but it is not supposed to fuel cut until .2 bar over target. Shortly after that peak is when it starts detonating. I also have noticed that my boost gauge reads different (higher) than the pfc. So when I have it set at .95 bar, I might actually see 14psi on my gauge, but the pfc reads a max of .74/5 which is considerably lower. It feels strong at .75bar though and I don't really need any more power than that, but it's unusable in 3-5th gear cause it surges/det's/blah blah. If you are thinking boost leak, I pressure tested the intake to 20psi with an air compressor and no leaks. And it is dead steady with the z4 and also with running with the wastegate hooked to the compressor outlet nipple. Sorry for the ramble......

My PFC does the same thing, my boost is set at .9bar but when im hitting full boost it will show 1bar +- .1 depending on how hard im driving the car. The boost gueage in my car will be at 1.2 bar when the pfc is showing 1bar. This is something that i belive is due to the subaru OEM MAP sensor. A local friend has the same issue when we log his runs.
As far as your settings, you duty cycle is a big off. At .75 bar setting my cycle is set at 36 and it hold boost nicely. At the .9 bar setting its set at 48 i belive and it overshoots my target boost, so i need to turn it down. However w/ it turned up a bit i will hit 1.2 bar from 4-5.5K and then it tapers down to 1.1 bar by redline.
I swear to you that you need to look into your ignition, i was having the SAME PROBLEMS, when cold it ran good, but after it got warmed up it ran like crap at higher boost levels, and i also had a problem w/ hesitiation down low under 3K w/ partial throttle.. But after i changed out my bad coils and put in some NGK Coppers in i now have yet to even feel one hesitation.

I know how you feel about wanting to sell your car, i was about to light it on fire becoue that hesitation was getting so bad. But after i got my ign. problems sorted out it runs like a charm....it runs so good that im racing a 911 turbo, and a ferrari 430 maranelo this weekend.( street racing is bad, but beating 150K sprots cars in a wagon is not:devil: )

It's good to hear your pfc runs similar. I tried lower duty cycles but the boost would fluctuate badly. Higher duty cycles cause it to simply shoot right by target.

This weekend I will put in some standard heat range copper plugs and see what happens.

I really don't want to sell the car as I have so much work into it, plus it means a lot to me. If I absolutely have to I can go back to a z4 ecu and call it good, but that is the last resort.

Good luck with the exotics! I love rolling starts in the Camaro next to Vipers and bikes.....:)

But after i changed out my bad coils and put in some NGK Coppers in i now have yet to even feel one hesitation.

What gap are you running? This seems to make a huge difference on the ej20g. I would run coppers but still go with the 7's instead of the stock heat range.

I have myne set at .o25, but im going to widen my gap to .o28 when i put in some new plugs in about a month or so.
And the stock heat range is 6, so i just stick to that. I had some 7 heat range in my car, and it didnt like it so i just went back to the stock 6 and it seems to run better then the 7's did.

Thats funny, I tried running 6's and the car ran crappy, so I went back to the 7s. 0.025" seems to work the best for me. At 0.028 I get the face to the windshield loss in power at 4-5K rpm

I picked up some bkr6es for an 02 wrx this morning. Gonna give them a shot. tomorrow night. I will try gapping at .025 as well. My current plugs are .028.

What is your knock count?

Depends entirely on the day. 1-2nd gear, usually I see less than 25 and no spikes. 5th gear I have seen spikes as high as 70 (random) and can gaurantee some high knock counts in the 40-50's if I keep it floored in 5th, but I don't. Usually it starts hesitating before it even gets into knock territory in 3rd or 4th gears.

I had some knock as high as 60 when i went WOT. I went into my PFC w/ the comander and increased my inj. from 88%-89% and it lowered my knock, the highest i have seen after that was 30.
See if this helps, go into the Settings, and then scroll down like 4 options down untill you get onto the injectors, and put them up 1%, and see if that helps.

I will give that a try, but I still need to get my boost levels under control.

I played with the boost again tonight on the way home from school and made some discoveries. With it set at .90, .95, 1.0 etc the boost fluctuates so much that maybe part of my hesitation is fuel cut. I have adjusted the duty cycles all over and no matter what it will not hold target boost.

The thing that does not add up is the peak boost that I read off the pfc is only .75 bar, with it set at .95 I should not be seeing fuel cut if that is what the pfc is reading as boost level. The only thing I can think of is that some how it magically can read intake pressure which would be infact fluctuating over .95 and then triggering fuel cut.

I started backing the boost off and now I am at .80 with a duty of 36 provides the most stable boost, but it still fluctuates give or take a few psi. Another strange thing is that it will hit target boost and stay there for a good solid second, then it starts fluctuating/pulsing. I really want to get my mbc back and try it with that.

Do you have the pfc boost controler or a mbc? The reason I ask is that the pfc does not control boost unless you have the boost controler for it and that is a whole separate thing that costs about $300 more. Changing the boost steeing in the commander or via fc edit/datalogit will do nothing without the pfc boost controler. I was cheap and went mbc because I could get a greddy quicker and cheaper than the pfc add on. I have read other posts where people think they can just change the setting not realizing that it doesn't really do anything if the pfc boost controler is not present.

Snowman - just curious, are you running stock injectors?

I was under the understanding that it will control boost up to 1.0 bar, after 1.0 bar it sets a cel unless you have the boost controller kit. I do have a mbc but it is currently on a friends swap and I am waiting to get it back.

My friend in Japan has been tuning with them for years and told me that the boost controler does not work unless you buy the pfc controler as an add on. I have no way to confirm it but no reason to doubt it either. It may control the boost as you said but if you are having issues with it you may want to just stop messing with it and go with the mbc just to be sure.

I just use the mbc and I'm done with it. The pfc controller would be nice and easy with the datalogit though since its all one system.

Interesting info........

95sti, the PFC will work with the stock boost controller. Im doing it, and it works pritty good. Probaby not as good as a apexi unit, but i can controll boost up to 1.3bar due to the diff. in the PFC and the acual boost reading. When im hitting 1.2 bar the PFC is only seeing 1bar, and by messing around with the duty cyle of the solenoid i can run a good amount of boost w/o having to spend stupid amount of money. Right now i have the PFC boost set at .9bar w/ 48 duty cycle. My boost will go up to 1 bar on the PFC and 1.2 on my guage. By raising the duty cycle you can get a good amount of boost out of it. I will spike up to 1.2bar from 4-5.5K and then after that it tapers off to 1.1 bar by redline, which is exactly what i want :). It honestly took me about 2 hrs to get all that figgured out that there are ways to go about using the stock solenoid w/ the PFC.

As far as the Inj. go, im running usdm STi inj w/ 2.5 rs fuel rails. With the stock 440's i would hit 100% duty cycle at 15psi, now im only hitting 85-87% running 17psi :)

95sti, the PFC will work with the stock boost controller. Im doing it, and it works pritty good. Probaby not as good as a apexi unit, but i can controll boost up to 1.3bar due to the diff. in the PFC and the acual boost reading. When im hitting 1.2 bar the PFC is only seeing 1bar, and by messing around with the duty cyle of the solenoid i can run a good amount of boost w/o having to spend stupid amount of money. Right now i have the PFC boost set at .9bar w/ 48 duty cycle. My boost will go up to 1 bar on the PFC and 1.2 on my guage. By raising the duty cycle you can get a good amount of boost out of it. I will spike up to 1.2bar from 4-5.5K and then after that it tapers off to 1.1 bar by redline, which is exactly what i want :). It honestly took me about 2 hrs to get all that figgured out that there are ways to go about using the stock solenoid w/ the PFC.

As far as the Inj. go, im running usdm STi inj w/ 2.5 rs fuel rails. With the stock 440's i would hit 100% duty cycle at 15psi, now im only hitting 85-87% running 17psi :)


That's cool that you got it to work. I may have to try that on my next one in a few years.

Good idea switching the injectors, maxing out is bad. I was wondering if they were stock because you mentioned them set at 88-89 and getting pretty good knock -above 50. I keep mine (850cc) at 38% and the knock never goes higher than 50 now even at boost but usually stays around 30 or so.

~Sorry for getting a little off topic here~

I have an idea that I am going to steel from another board member:
http://forums.nasioc.com/forums/showthread.php?t=602674

This way I can have the pfc set to 1.0 bar so no fuel cut, then I can also turn up the duty cycle and have the incredible spool I was getting with it set high but still be able to limit the overall boost at 14 and not have any fluctuations by using the mbc as a cap.

I realize that post above the guy is using a Utek and gm solenoid, but i think the overall outcome will be the same.

Any input?

******Update*****

Good night of working on the car!

First off the above boost control method that I posted the link to does not work.

Second, the Apexi pfc boost control feature sucks imo.

Third, my Perrin mbc works great and holds a perfect 14psi, no more fluctuations of any type or boost creep!

Also got the new copper standard wrx bkr6es spark plugs in gapped at .025. The car now has an intermittent miss at idle. However the good news is that no more hesitation and no more low rpm stumble! I can actually ease my clutch out now at low rpm instead of having to dump the gas to get it to move.

Driving impressions tonight were good. At 14psi I was getting detonation so I ramped up the fuel map using the overall correction feature and knock went down considerably like snowman said. So I did the map tracer and pretty much had to max out the fueling in cells 9,14 through 15,14. I am able to redline in 13rd which would have never been able to happen before. The knock counts are staying below 30 as well and the car feels pretty good.

I do want to make mention that I do believe the slanty intercooler is a pos. If I do a 1-4 gear pull, each gear I can watch the knock counts get higher and higher leading me to believe that intake air temps are sky rocketing. (don't have proof). If I just do a rolling start in 3rd for example it stays nice and low.

Just need to figure out the miss and I will be good to go!

Thanks again for all the help!