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Old 04-26-2014, 07:53 AM   #226
Vlad
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Thanks. More is coming up:
Alternator third wire connection (just got the Nissan connector and it fits)

I may bring here the info that I already posted about the JDM fuel vs USDM fuel, as it relates to how the tune of a JDM should (or not) be different to the USDM tune, because of just the fuel difference (or lack there of).
I may post the factory tune differences between JDM EJ257 and JDM EJ207 (quite different in terms of timing allowed by the factory), to show how tuning with EJ257 mindset deprives an EJ207 of its legitimate timing and output torque

I may bring here the info about dyno measured wheel torque, which is actually crank torque (there is no info put out by a dyno in output torque, or the stock WRX in the lower gears measured output would be 6-700 ft lb), to question why some tune EJ207 in some cases put out so little tuned torque.
Fictional Example: Dyno readings: 350 WHP, 280 WFTLB.
Well congrats, you reduced the engine torque output of the factory by 5 ftlb, by tuning it, although you increased the power 100 HP. It's not W ftlb, it's C ftlb.

Once, these ideas were controversial, but I think the time is now right.
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Old 04-26-2014, 08:01 AM   #227
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Post ALL the things!
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Old 04-26-2014, 05:22 PM   #228
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Quote:
Originally Posted by Vlad View Post
Thanks. More is coming up:
Alternator third wire connection (just got the Nissan connector and it fits)

I may bring here the info that I already posted about the JDM fuel vs USDM fuel, as it relates to how the tune of a JDM should (or not) be different to the USDM tune, because of just the fuel difference (or lack there of).
I may post the factory tune differences between JDM EJ257 and JDM EJ207 (quite different in terms of timing allowed by the factory), to show how tuning with EJ257 mindset deprives an EJ207 of its legitimate timing and output torque

I may bring here the info about dyno measured wheel torque, which is actually crank torque (there is no info put out by a dyno in output torque, or the stock WRX in the lower gears measured output would be 6-700 ft lb), to question why some tune EJ207 in some cases put out so little tuned torque.
Fictional Example: Dyno readings: 350 WHP, 280 WFTLB.
Well congrats, you reduced the engine torque output of the factory by 5 ftlb, by tuning it, although you increased the power 100 HP. It's not W ftlb, it's C ftlb.

Once, these ideas were controversial, but I think the time is now right.
very interesting indeed. wonder how choked back my tune is
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Old 04-27-2014, 08:26 AM   #229
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A lot of this that this that. I want facts!!
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Old 04-27-2014, 08:42 AM   #230
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Hehe.
You will have your facts.
I just finished logging the current 2 wire alternator setup. Today hopefully, I complete the 3-wire conversion and maybe a log.

I chose to use the Delta dash logger, because it has a nicer graph output. The Delta dash logs alternator duty and voltage at the battery.

I have to go back to Romraider to remember what they offer. Edit: they offer the same parameters to log.
The alternator duty spiked almost random in my log.
I think this is a case of a parameter that was defined wrong.

Anyway, the battery voltage seems to be constantly bouncing, kinda like readings from an O2 sensor, but mostly over 14 volts in my case.
Except when you floor it, at higher boost. then it drops to 13.2 volts, the spikes coincide with load.

Let's see what happens with 3 wires. Maybe nothing...

Last edited by Vlad; 04-28-2014 at 12:37 PM.
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Old 04-27-2014, 08:48 AM   #231
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Hopefully something (positive).
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Old 04-27-2014, 01:07 PM   #232
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Tried searching this thread but I'm currently over in Germany and have access to a set of 2007 Spec C cylinder heads. I either need my current EJ205 2002 WRX heads machined and serviced due to recent damage from when I cracked a piston.

Or I could just buy these Spec C EJ207 heads instead. I'm curious on if I can use them with the wiring harness and sensors from the 2002 WRX EJ205?

Also if I use these heads would I be able to bump up the max rpms above the 7k redline they have to around 7.5-8k redline for more power. I know I wouldn't be able to use the AVCS with the 2002 WRX ECU but I'm fine with that.
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Old 04-27-2014, 09:19 PM   #233
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Quote:
Originally Posted by Vlad View Post
Thanks. More is coming up:
Alternator third wire connection (just got the Nissan connector and it fits)

I may bring here the info that I already posted about the JDM fuel vs USDM fuel, as it relates to how the tune of a JDM should (or not) be different to the USDM tune, because of just the fuel difference (or lack there of).
I may post the factory tune differences between JDM EJ257 and JDM EJ207 (quite different in terms of timing allowed by the factory), to show how tuning with EJ257 mindset deprives an EJ207 of its legitimate timing and output torque

I may bring here the info about dyno measured wheel torque, which is actually crank torque (there is no info put out by a dyno in output torque, or the stock WRX in the lower gears measured output would be 6-700 ft lb), to question why some tune EJ207 in some cases put out so little tuned torque.
Fictional Example: Dyno readings: 350 WHP, 280 WFTLB.
Well congrats, you reduced the engine torque output of the factory by 5 ftlb, by tuning it, although you increased the power 100 HP. It's not W ftlb, it's C ftlb.

Once, these ideas were controversial, but I think the time is now right.

I thought the dyno calculation stuff was common knowledge, here is a copy/paste from AMS that explains it pretty well.

HP and TQ - How to Understand a Dyno Chart


Written by AMS Performance

Lets take a moment and explain how horse power (HP) and torque (TQ) relate to each other and hopefully help people understand what they see on a dyno chart.
Part 1: Torque

First off, lets discuss the numbers you get from a chassis dyno. The two numbers everybody wants to see are HP and TQ. I am going to discuss TQ first.

The TQ number you get from a chassis dyno is a calculation of how much TQ you would see 1 ft from the center of the crankshaft and NOT the amount of TQ you have at your wheels. A measurement is taken at the tires and calculated back to the motor. The ACTUAL TQ you have at your tires is MUCH more than what the dyno chat says.

Engine TQ is multiplied by the gearing in your transmission and then again by your rear differential gearing. Tire diameter is also a factor in how much TQ you actually transfer to the street. Friction, drag and the mass (law of inertia) of all the drive line components are the final factors in the equation.

Here is an example of how to figure the TQ at the tire of the 2025 Hyundai Make-Be-Lieve 2.0T AMS Edition. While the numbers here are made up, they are close to real world numbers for the average auto. I just made them whole numbers for simplicity.

Engine peak TQ: 300 lbs @ 5500 RPM's
Transmission ratios: 1st 4:1/2nd 3:1/3rd 2:1/4th 1:1
Rear end gear: 4.00:1
Tire diameter: 24"

For 1st gear, you take 300 (Engine TQ) times 4 (1st gear ratio) times 4 (rear end ratio) which nets you 4800. The distance from the center of the axle to the tire contacting the ground is 12" so tire diameter (in this example) has no effect on TQ at the tires. Subtract drive line losses (DLL) and what you have left is the TQ you have available at the ground. In this scenario, you have 4800 lbs of rotational force (minus DLL) pushing your car forward @ 5500 RPM's.

If you play around with this formula, you will find that the TQ at the tire changes with which gear you are in.

1st = 4800 lbs - DLL
2nd = 3600 lbs - DLL
3rd = 2400 lbs - DLL
4th = 1200 lbs - DLL

This is why you accelerate so much harder in 1st gear than you do in 4th gear.

Keep in mind that the TQ your motor makes changes throughout the RPM range. This means that the amount of force you have pushing your car forward is also changing. You will always accelerate hardest at your peak TQ in each gear and less as TQ drops away from your peak. Your acceleration curve will end up matching your TQ curve exactly.

So when looking at a dyno chart, keep in mind that the TQ curve represents exactly how your car will accelerate. A large jump in TQ at the beginning of the graph and TQ dropping rapidly as you approach red line is going to feel exactly like that on the street.
Part 2: Horsepower

After reading "part 1" I am sure you are asking yourself "why do I need to know HP?" As I explained, Your TQ curve dictates your acceleration curve, so why does HP matter?

The formula for figuring HP is TQ x RPM / 5252. So HP is a function of engine TQ and is directly related to RPM. As you can see from the formula, HP will always be lower than TQ below 5252 RPM's and above TQ at over 5252 RPM's. Here is a quick example using the formula: Our 2025 Hyundai Make-Be-Lieve 2.0T AMS Edition makes 300 lbs TQ @ 5500 RPM's. 300 x 5500 / 5252 = 314.16 HP @ 5500 RPM's.

The easiest way to explain HP is: Horse Power is a representation of what you can do with your engine's TQ using gearing. The higher the RPM you have substantial TQ, the more HP you have. Let me use an example to explain this.

Our 2025 Hyundai Make-Be-Lieve 2.0T AMS Edition makes 300 lbs peak TQ @ 5500 RPM's. The standard edition Make-Be-Lieve makes the same 300 lbs peak TQ @ 4125 RPM's but at 5500 RPM's it is making 150 lbs.

Using our gearing formula in Part 1, you will find that at 5500 RPM's, the AMS Edition is producing 4800 lbs of rotational force (314 HP) in 1st gear while the Standard Edition is producing only 2400 lbs of rotational force (157 HP). The TQ has dropped off so much that a gear change is needed to get the motor back into an effective RPM range. Switching to 2nd gear will reduce RPM's by 25% putting the Standard Edition's motor at 4125 RPM's and at its peak TQ of 300 lbs. The Standard edition is now putting out 3600 lbs of rotational force (235 HP) which is an improvement, but it is still less than the AMS Edition's 4800 lbs (314 HP).

As you can see, both cars cars are now at the same peak TQ (300 lbs), but the AMS Edition is at a higher RPM and can more effectively use gearing to increase acceleration.

Ideally, the TQ curve should be as flat as possible. This gives you the same acceleration rate at all RPM's in each gear. With a flat TQ curve, HP will continue to climb all the way to red line.


However, I will be interested to hear your take on the torque output and hope there is something more than dyno torque calculation versus actually measuring crank torque on an engine dyno. Definitely appreciate all of the work you put into figuring out these engines.
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Old 04-27-2014, 09:41 PM   #234
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This is a good article. I was going to go into less detail as I will only use this as one of the items in building "my case".

Meanwhile I got the alternator connector third wire all the way to the ECU.
It should not go through a engine harness connector, because it is part of a chassis harness. So if you put it through a engine harness connector, when someone wants to remove the engine, the alternator connector will be attached permanently to the engine AND the chassis.
So I routed this through the alternator harness and then through the IAP drivers side harness.
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Old 04-28-2014, 09:36 PM   #235
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The bottom is after connecting the third wire.
In the process of doing this I snipped my connector, then soldered the Nissan Connector.
So, long story short, the third wire did not change the battery voltage, it still is centered around 14 when cold, 13.7 when hot.

However, what I see, or I think I see, is the voltage having less of a variation, the line looks more centered on one value.

The alternator duty cycle spikes still seem random, this did not fix that. In fact probably the name of the parameter is probably defined wrong. May not even be an alternator related logging value.

So top graph is with 2 wires, bottom with 3.
Engine speed
Battery Voltage
Alternator duty
Engine Load

It seems the voltage stays within closer limits, let's see to where it goes after charging in a long drive.
In the end, the extra level of smoothness persisted. It can be seen in this log and felt as better off the line acceleration of my car. I got to commute with it only once, before it broke my 3rd gear (still have a 5 speed).
I had 340 ftlb, then did catless 3" exhaust and replaced the 16g with a 16GTX, it held up for two months and roughly 10 3rd gear pulls, then this work and bam, next day 3rd said bye.
I've read many posting that just above 350 ftlb, it will let go in gear.
So who knows, maybe this does give a minimal torque boost.
If any of you wants to do a before and after road dyno, would be interesting to see..

Last edited by Vlad; 05-08-2014 at 10:39 PM.
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Old 04-29-2014, 08:22 AM   #236
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So this morning, as I'm starting my commute, the voltage was back to centered around 14v. Then as I drove on, it dropped back to be centered around 13.7v.
So I'm going to call this "it's back to normal", it does what it always did.

But I think there's a change with the way the car starts off the line. Of course the ECU got reset, but I already drove 25 miles and restarted 3 times, so subjectively, I'm going to say that this feeling is here to stay.

I do a lot of 5 Mph driving in my daily commute, dodging NYC potholes and following all kinds of slow traffic. It's all about being smooth off the line.
So, subjectively, I think that before this, there was a partial stumble when starting, so in time I adjusted my reflexes to give it a more resolute acceleration kick and then backing off, to keep it going smooth.
Now, no matter how little gas I give it and how slowly I feed it, it doesn't seem to stumble at all.
Let's see if this holds as I drive home, as the car re-learns the long term and short term fuel trims.

Edit: I feel this extra level of smoothness is here to stay, still happening on my way home, so I will post the info right below the autowash.
It's something that anybody can put together and then.. have their own opinion about it, share it here..

Last edited by Vlad; 04-29-2014 at 09:25 PM.
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Old 05-02-2014, 02:32 PM   #237
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I think I'm going to do this alternator trick, I happen to have a 04 USDM STI donor harness with the 3-pin alternator connector and wiring so this will be simple.
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Old 05-05-2014, 09:09 AM   #238
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I think you may like the result. let me know if you have questions.
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Old 05-06-2014, 04:59 PM   #239
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Good stuff.
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Old 05-08-2014, 06:28 PM   #240
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Quote:
Originally Posted by Vlad View Post
I think you may like the result. let me know if you have questions.
So vlad in a nutshell your seeing a smoother running car at low speed and Idle with the 3wire mod
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Old 05-08-2014, 10:11 PM   #241
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Yep, feels like you just put in new spark plugs and coil packs.

This just takes the already smooth twinscroll EJ207, to a higher level. And possibly caused the extra torque "straw that broke the back" of my 5 speed...

Last edited by Vlad; 05-08-2014 at 10:28 PM.
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Old 05-17-2014, 01:26 AM   #242
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Quote:
Originally Posted by Vlad View Post
Yep, feels like you just put in new spark plugs and coil packs.

This just takes the already smooth twinscroll EJ207, to a higher level. And possibly caused the extra torque "straw that broke the back" of my 5 speed...
Vlad, when you getting a 6 speed ??
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Old 05-17-2014, 08:11 AM   #243
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I am working on this. I haven't bought anything yet.
I am looking into a package deal with a JDM unit or maybe an '06 USDM.
Did you do your own 6 speed swap?
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Old 05-17-2014, 10:51 AM   #244
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Quote:
Originally Posted by Vlad View Post
I am working on this. I haven't bought anything yet.
I am looking into a package deal with a JDM unit or maybe an '06 USDM.
Did you do your own 6 speed swap?
The JDM 6mt transmission is nice, but I always find myself wishing for a taller 5th and 6th on the highway. The close ratio gears are definitely worth it if you plan on taking your car to a road coarse, but can be a little much for a daily. Just my 2 cents.
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Old 05-17-2014, 12:04 PM   #245
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Quote:
Originally Posted by 207STi View Post

The JDM 6mt transmission is nice, but I always find myself wishing for a taller 5th and 6th on the highway. The close ratio gears are definitely worth it if you plan on taking your car to a road coarse, but can be a little much for a daily. Just my 2 cents.

I agree. I wish for usdm gears on almost a daily basis
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Old 05-17-2014, 01:55 PM   #246
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Vlad, made the jdm alternator connection to the ecu today started it up and checked the alt duty cycle on the logger. It went to 18% at start up then dropped to 0%. When I turn on the a/c it jumps to 35% and tapers down to zero as the battery voltage stabilizes. So it seems it's working.
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Old 05-17-2014, 02:57 PM   #247
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Cool.
Try to also log the voltage at the battery.
Thanks for the transmission comments guys.
Is the 6 speed swap a 3 or 2 guys type work, on tall jack stands, with transmission pump jack ?
If anybody in Long Island wants to meet so I can experience cruising in 6 th on the JDM 6 speed, I would appreciate.

Keep the alternator conection comments coming.
Also someone get started on the intercooler autowash too.
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Old 05-17-2014, 03:38 PM   #248
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Quote:
Originally Posted by Vlad View Post
Cool.
Try to also log the voltage at the battery.
Thanks for the transmission comments guys.
Is the 6 speed swap a 3 or 2 guys type work, on tall jack stands, with transmission pump jack ?
If anybody in Long Island wants to meet so I can experience cruising in 6 th on the JDM 6 speed, I would appreciate.

Keep the alternator conection comments coming.
Also someone get started on the intercooler autowash too.
my friend did his 6 speed on jackstands in his garage with just his wife helping him, so if you got 2-3 people its more than doable.

i'm gonna start tackling the ic autowash mod, I already have all the parts, just need to go over your wiring diagrams again and make sure i'm pulling the right tgv pins from the ecu plugs

Last edited by murrdogg24; 05-17-2014 at 04:35 PM.
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Old 05-17-2014, 04:15 PM   #249
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Before 3pin alt mod:

After:


YMMV
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Old 05-18-2014, 03:32 AM   #250
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That is a pretty substantial power and torque increase. Unbelievable almost !
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