Well I finally got the beast on the dyno in preparation for a re-flash. Went to Powertrain Dynamics in Huntington Beach. Steve is great, very knowledgable, and most importantly, knows what the hell he's doin'

My mods are in the sig.
I have the 3 files



I'm pretty happy with the hp and tq at this point. As you can see the A/F is sucking down low and only approaches optimal? near redline. Steve has dyno'd several Z's and thinks that most flow mods on the Z only shift this profile and not really deform the curve. For the A/F it seems a re-flash that can hold between 12.8 and 13.2 would be ideal with my current mods. After my re-flash I plan to go back to Steve and re-test the A/F.

I think I will stop the flow mods here for now. Cams would be nice but I think I want to get some more miles on before I go all out with internals/vtc and such. Plus, that damn 3.9 final drive set has me droolin, I need some 18" CE28Ns. Crap, it just keeps going lol

I want to make a thorough search of the available ECU re-flash vendors. I'm really leaning toward TS, local and I've heard good things. I really wanted a JWT re-flash if available. However, I called and was told not to expect anything until well into 05' Any suggestions are welcome.

edit: oh yeah, the date is off for some reason. All other info is correct.

 

wow, nice dyno, love the torque curve, much nicer and flatter than stock, buddy


I like that AF of yours, does what it should!

and I think technosquare will add lots of power at your level of modification!

 

Nice!!

 

very nice power, I love it. You prolly will not gain anything with a ecu upgrade, but I am curious to see if you do.

 

Interesting how every run made the same power?? I have never seen that before.

 

That IS interesting..Very nice #'s.

 

Nice.

 

Actually, each run was different in power.

 

Wow. Excellent power and a great torque curve. I'm guessing that the A/F was made with a wideband sensor (or similar) rather than the tailpipe sniffer. The A/F is not all that bad, and you might not make much, if any more power with the ECU reflash, but I've been wrong before.

 

All 3 runs were performed within 90 secs of each other. No mods were swapped/added, just 3 runs. If the values were markedly different, I would not trust the dyno. The conditions should be nearly identical over 3 runs completed in less than 90 secs.

You are correct about using a wideband O2 sniffer but the location IS at the tailpipe. Steve told me of a person who thought an O2 bung after the cats was the ONLY way to measure AFRs. So this guy always welded in O2 bung just for dyno tuning. After over 100 comparisons of AFR at the O2 bung and the tailpipe, everyone involved agreed that the readings were essentially the same at both locations. Gases other than O2 are being measured and that no real difference was observed at either detector location. This guy then stopped welding in O2 bungs on everyhing.

I'm not sure about making more power with the re-flash. A few more hp and tq may be had with it. I'm doing this more to put the car back to close to stock AFR. Running at an AF of 15 in the lower part of the rpm curve is a little scarey. Even out to 5k the AFR is still over 14! I'd like to get to 12.8 to 13.2 for the entire curve. Emissions might be better at close to stock values. I'm hoping to test the beast at a smog station. A friend of a friend works there and might be able to run the car without reporting it, just to see if it passes or not. Very interested in this, but it might be a while until this happens. Of course, I will post if this actually does happen.

I'm still a little clueless about what the BEST AFR is over the entire rpm range. A little lean is better for hp but it can also damage the engine if too lean. Anybody have solid numbers on their re-flash and how the AFR changed? I seem unable to find all the dyno slips that were posted here. Where did they all go?

 

But it's acutual horse power. If you put in SAE corrected it will be lower. Most dyno numbers are SAE.

 

yes, sae correction would show lower power because the effects of the ambient temperature and pressure are removed from the readings. By using the dyno correction factor, power and torque readings can be directly compared to the readings taken on some other day, or even taken at some other altitude. If your looking to see what an individual mod gives you sae is the way to go. But if your looking to get your peak power on that given day actual power is the way to go.

 

How would you calculate hp numbers from that dyno? I mean, a number to compare it to the stock 287?

 

assuming 15% drivetrain loss, the formula would be
X-.15X = 267 (267 being the amount of whp he has)

solve for x and that would mean he has 314 hp at the crank.

 

damn nice numbers....

 

My SAE corrected numbers were 263 hp and 243 tq with 0 smoothing.

Still pretty fair

 

How did your baseline look?

 

That's amazing for just the plenum and headers. I got 255 peak hp with my old engine at that location when I had: JWT Popcharger, LBMS testpipes w/resonators, Borla Exhaust, JWT Flywheel.

255.5 Hp 243.2 Tq

Either those headers gave you some great gains or you must have started out with a freakishly strong car from the onset. How much were your headers and the installation cost?

 

he had more than just headers and plenum. he also has stillen exhaust, kinetix hf cats, and jwt pop charger.

still seems like nice gains though.

 

Your car should pass BETTER than stock, leaner means less hydrocarbons will be in the exhaust.