genyosai

any input here would be appreciated!



This is a stock JDM GTE motor with stock side-mount IC that I installed with exception of a US harness, injectors, and US ECU (superchips modified--boost cut removed). The radiator is the stock SC radiator (new). I have no check engine light and there are no codes in the ECU.



more pics here:

http://home.sc.rr.com/ntgr/images/SC300/

anyway, this run is at a steady 17psi, no boost loss at all. I have Denso iridium plugs installed with a .026gap, so I'm sure the spark isn't blowing out. I run the same plugs and gap in my MKIV Supra and run 21psi with no spark-blow-out.

I recently installed a SAFC and straightened out the A/F ratio across the RPM range. The exception here is that now the A/F ratio is perfect except at 6,000rpm (just as in the dyno image above). A/F ratio comes back up to 12:1 at 6,500rpm now, and the power creeps back up to 300rwhp before I run out of RPM at 6,800. No matter how much I try pulling out fuel at 6,000rpm, it still drops off the chart rich.

This is where I need help. Any ideas as to what could make this thing go rich at 6,000rpm no matter what?? the only thing that has changed since this dyno run is the SAFC in which I was able to level the A/F ratio EXCEPT at 6,000 rpm, and a TRD Japan 160 degree thermostat.

The one thing I haven't replaced yet, but I'm thinking about it, is the primary o2 sensor. I hear that the GTE motor is very particular about the o2 readings. and considering that stupid me drove for about two weeks with the o2 sensor lying in the plastic under pan (and no check engine light), the o2 sensor could've gotten damaged.

William N.

iTrader: (2)

genyosai, I just wanted to tell you that both your SC300TT and your supra are beautiful...Congrats on the TT swap in the SC...

genyosai

Thanks!

VSsc400

iTrader: (1)

sick car dude. did you do getrag-6 with it too?

genyosai

Nah. I'm actually using the 1jz-gte 5-speed tranny. No custom drive shaft was needed. I had to use the clutch of a 92 Supra turbo and have my stock flywheel tapped so that the pressure plate would mount.

qtb33

I'm fairly new to the supra/SC300 programming and ECU compatibilty but there may be some issues with the US spec ECU and the japanese Injectors. I believe that US injector are bigger. Please correct me if I'm wrong/misinformed.

In a previous car i worked on. With the incorrect injectors with ECU would work and the engine would run but would "freakout" at certain RPM's. This was due to the fuel equation in the programming. The equation contained a coefficent that was directly related to injector size and the number had to be changed to increase injector flow capablities. Not even SAFC could affect this, for more than one reason, but this is part of it.

Like i said I'm new to this ECU and its capabilites so I might be talking from my butt. But this could be a possiblity and a easy fix. I would assume you'll just drop in US spec injetors or a piggy back ro standalone.

Well I hope i didn't make a fool out of myself but either way best of luck.

Oh and I like your cars too.......very jealous

VSsc400

iTrader: (1)

NICE! good work dude!

genyosai

Thanks for the input, but I'm running US 550cc MKIV injectors.

Oh... and I have another car that you won't see in the links I supplied. So, here ya go:



More here:

http://home.sc.rr.com/ntgr/images/IS300/

qtb33

Come on now, you left out pics of the 328 you have in your sig

So would i be correct assuming that the IS 300 will be getting the same treatment as the SC300?

Eitherway.

genyosai

328is is stock. Nothing much to look at... yet. looking at Eurosport vs Active Autowerke supercharger kits, M3 body panels and racing dynamics rims and suspension to begin with.

And YES... it's safe to assume that the IS will get a SIMILAR treatment. researching SRT's stage 2.5 kit right now. comes complete with preprogrammed EManage. Should be pretty much a plug-n-play 430rwhp. Not bad for starters.

5spdSC300

iTrader: (1)

the dyno does seem to be a little on the low side. i know the jdm supra and aristo motors have diffrent turbos which might be the cause for the low hp? are you running stock exhaust?

DaveH

It looks like a bunch of timing gets pulled on the top end. What fuel were you running?

genyosai

Hey.

I'm running the Greddy dual exhaust for this car.



Also, the dyno run was with 93octane fuel and 17psi?

What might cause the computer to pull so much timing in my case (running 93 octane and only 17psi)? The tech running the dyno suggested the same thing)? Sad part is that I get the same sort of power-curve when running stock boost (power dwindles down the same way). I have another ECU I could try... different programming. Think it's worth a shot? Or, is it possible that a have a lean condition on one or more of the cylinders (causing the computer to pull timing)... something the dyno (I guess) wouldn't be able to tell? If this is the case, what would be the culprit... bad injectors? I also have a different set of injectors, should I try them instead?

I'm running USDM 550cc injectors and USDM ECU (boost cut removed by Superchips). Also, the JDM turbos (when I compared to the USDM) are actually a little larger as far as the inlet is concerned. However, the turbo exhaust outlet is only 2.5 inches compared to the USDM 3 inches. Seems dumb to me.

Help with the timing theory would be appreciated.

Thanks,

Dew23

iTrader: (1)

Did you try to reset the ecu pull the efi fuse and see if this helps .

genyosai

Yep. Think maybe I could be losing fuel pressure on the top end?? It doesn't seem that way on the dyno reading (fuel curve), but maybe the ECU is detecting knock and pulling out timing before the dyno reads a lean condition.

I'm going to check my vacuum lines to the FPR when I get back home (out of town until Tuesday). The fuel filter is also the original one with 165,000 miles on it. Think I should change it ?