Now that some of you believe that the cold start issues I have with the Z32 MAF + 370's + JWT Program isn't my car and is actually JWT's Cold Start Program sucking azz.....I thought I'd share my data - maybe it will help us figure out the issue with why JWT sucks so much azz.

http://www.cyberhub.net/jwt/

A32MAF_A32ECU_WARM.xls = A32 MAF, JWT ECU, 370cc Injectors - car at full temp. <Car runs fine>

Z32MAF_Z32ECU_WARM.xls = Z32 MAF, Z32 JWT ECU, 370cc Injectors - car at full temp. <Idle is somewhat jumpy, sometimes stalls when coming to a coasting stop - but otherwise runs fine.>

A32_COLDSTART.xls = A32 MAF, A32 JWT ECU, 370cc Injectors - car at cold start after sitting overnight. <Car runs fine with ever so slight hesitation at warm-up for first minute of driving>

Z32MAF_A32ECU.xls = Z32 MAF + A32 JWT ECU + 370cc's - Car runs just the same as with Z32 ECU both cold and warm.

Z32_COLDSTART.xls - Z32MAF + Z32 JWT ECU + 370cc's = This is where it REALLY runs like poo! - Vacuum drops fast, car bucks when trying to get going. Goes away after warm-up mostly.

 

what exactly am I looking at? is this datalogging? did you do this at the same times?

I'm going to make a chart and compare.

 

I did all of these in winter last year - IIRC, all were withina few days of each other - weather was approximately 35-45 degrees each day.

(had to let the car sit overnight to get true cold start readings)

Readings were done with an NProbe directly to a laptop - each reading is .25 seconds apart.

 

When i start my car after the night, it really runs like crA*...the idle is slightly loopy and it runs rough...

The issue is only during cold start up..I guess JWT doesnt have a good cold start up yet.. Its only after sitting all night, even if its warm out...after the car is started and running, it runs fine

Im going to call up JWT, and If I cant get this figured out, I may go back to the A32 setup...(injectors, MAF, and computer)

-matt

 

Yep - I'm looking into the E-Manage Ultimate - Sort of just watching for more data for the VQ30 before I make the plunge.

Ben at JWT got pretty agressive with me once I even MENTIONED cold-start program issues as a possibility....good luck!

But then again, does ANYONE have the Z32 MAF Program on a S/C running on the non-charged side? That could be the whole issue as JWT suggests.

 

it seems like timing is all over the place. when I talked with Mike yesterday, he seemed to think that it was similar with his program as well.

The problem with the data is that rpm level and tps is a little different for each file. did you rev it?

it seems to me like the 1400 rpm idle (startup) for the z32 program is high and then it completely stumbles.

It doesn't look like the a32 program is that great either.

 

Look at the RPMs vs TPS - you can see where I revved it.....you can also see where I didn't.

With the Z32, I HAD to rev it to keep it from stalling.

 

yeah, i could see it. it looks like the timing is Whacked on both programs, but especially on the z32 maf.

 

Yep - it levels off pretty well when warm however.

Comparing with a friend's stock car, it's normal for the timing to fluctuate some at idle - but what it's doing when cold with the Z32 is just ridiculous.

 

if you are planning on going eu, we should have similar set-ups. The main difference between the two is your mevi, but our lower end maps should be the same. 2.87 pulley goes on when i my injector/maf setup working properly.

 

I got some consult data yesteday and I see similar things.

My timing with the JWT ECU is all over the place at idle, more than yours. Jumps around from 5-21 degrees.

Timing with the stock ECU is dead steady at 5 degrees

Idle AFR with the JWT ECU is off the charts lean. It can't hold a stoich idle

Idle with the stock ECU is hunting right at 14.7

 

I saw your other thread.

With the A32 ECU (Stock) + Z32 MAF + 550cc Injectors you are able to boost with an 11.5 AFR??

That's just crazy. What the hell does JWT do to the ECU then if all it does is screw up cold-start and reduce timing and raise the rev limiter?

Seems like a $600 waste!

The next question is how will my 370cc Injectors react with a Z32 MAF? Once I get the LM-1 in, I'm going to find out.

Or am I misreading your other post? Have you talked to JWT yet?

 

Sorry, my internet access went down for a couple days.

My AFR was in the 10:1-10.5:1 range with the stock ECU, Z32 MAF, and 550's as well as 7% fuel taken out from 3.6K-6.6K via an SAFC. But I am actually running 580's since I am at 50psi base fuel pressure. With DeatschWerks injectors you get the flow rate at many different fuel pressure rates. My injectors flow 550 @ 43 psi.

I think my comment was that all I need to do is turn down my base fuel pressue to give me a safe 11.5:1 AFR.


370's with a Z32 MAf will be pretty lean. StephenMax tested this, correcting with an SAFC helps but you will still be lean with even 20%+ fuel added. From my testing, a z32 MAF and 550's is just about right. Then playing with fuel pressure should dial it in pretty good. Timing is the only concern then.

Even though I am having good results with the stock ECU , Z32 MAF, and 550's I really would not push my car past 9-10 psi because of the timing. The only way I have to measure detonation is with my ear and my knock reading on the SAFC. I have almost no knock with this set up, but when I do WOT pulls in 3rd and 4th gear I do get some high knock #'s like 150+ which makes me think that stock timing and 9psi is just about the limit for me.

So the advantage with the JWT ECU is that I could run 11, 12, 13 lbs of boost and be OK. But the night I drove around at 9psi I found that is about all my car is good for on street tires. I broke them loose a little in 3rd. So I don't even know if I want to run much more boost on a regualar basis. If I go to the track I will just fill up with some 108 octane and go from there.

I have driven around with the JWT ECU on the higher boost levels too, and the off throttle respones sucks compared to the stock ECU. You can really feel the power difference cruising around or getting on it at lower rpms. The driveability of the stock ECU is much better.


JWT has had my consult info for three days and I have not heard a thing from them

 

It would be a good investment to cancel the jwt and invest in a j&s instead to retard timing.

 

I am thinking just tune my car better with the stock ECU, Z32 MAF, and 550's. Take the money I spent on the JWT ECU (assuming I can get it back) get a nice wide band & a boost controller and be done with it. Like I said, 9psi was about all the power I could really hold on streets and the car pulled like a MF. I got to stop this maddness at some point....

 

Interesting. I was running on the Z32 MAF and JWT ECU with 370's with my 2.87" Pulley and I wasn't leaning out. I was 11.5 all the way to redline.

With the A32 MAF, I lean out at about 6000 up to 14:1 at redline due to the fact that it can't read above 5v. <I hit 5v at about 6k>.

 

Ok? I am confused by what your trying to say

I would hope you wouldn't go lean with the Z32 MAF, 370's, and JWT ECU tuned for that set up.

And going lean with a maxed out A32 MAF is what I would expect.

But you asked how a stock ECU, 370's, and Z32 MAF would work out right? Per my expierence, Baggs, and StephenMax it would be lean.

StephenMax did the stock ECU, 370's, and Z32 MAF. Don't remeber what boost but it was over 10 psi. Ran lean even with adding alot of fuel with the SAFC.

Baggs did the stock ECU, 400's and Z32 MAF (IIRC). Went lean after 4K (IIRC) and used an FMU to compensate.

For me the stock ECU, 550's and Z32 MAf works pretty good. Not lean up top, I just need to lower my fuel pressue to bring up the AFR's a bit.

 

Ah - I got confused. I thought you meant leaning out due to injectors being 370cc, not the ECU being stock.

 

Hmmm...many months later....I put in the stock ECU today just to test and play around.

With the 370's, stock ECU, and Z32 MAF I was at 11:1 A/F at 6200RPM under WOT on the LM-1 Wideband.....
I was at 9.5:1 at idle however (40PSI of FP)

Stupid question that I am sure I know the answer to - but if you add an FPR it adjusts your FP across the band, not just at idle, correct?

So if I get the A/F to stoich (14.7:1) at idle by lowering the FP, I will likely be lean under boost - right?

 

Hey are you boosting cause i worked with jim him self for like 3 months on that program with the same stuff and i got the program right i am at 11.5:1 under boost and whyle crusing i am 14.7:1 let me know if i could help ya at all..

 

An AFPR will have a rise rate of 1:1 unlike an FMU that has a rise rate of 4:1 or 8:1. That being said, it wont effect the upper rpm a/f because the boost pressure doesnt have any negative effect on it. Thats what my understanding of it

-matt

 

SouthFlMaxTech - Yes - boosting 14PSI on the Stillen S/C - But what I am talking about later in this thread (the last few posts) is the stock ECU, not the JWT ECU. The JWT works fine now (see the sticky thread in this forum to see how I fixed the problem with cold start and the Z32 MAF), but JWT ECU's retard timing too much. I'd rather not use the JWT anymore if I can boost safely without it. With the stock ECU, the car feels quite a bit more powerful than with the JWT.

Matty - that sounds about right - thanks for the answer.

After driving around some more and letting the Stock ECU learn, the car is idling at 14.7:1 and at 6000+ RPM at about 12.1:1.
Perfect! - no need for an AFPR anyway! - OR the JWT ECU!

Although I'll probably install it just because I already have one and it will go well with the EManage Ultimate when I get one.