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Discussion Starter #1
so now I finally have a chance to post my dyno results, but I am not too thrilled with my numbers... here's the story. tell me what you guys think... the day i went, my car was running great. boosting to 21-22psi all morning on the way to run it. when i got it on the dyno i ran the car in 4th gear, and it boosted to 20 psi, then immediately backed down to 16psi and held there. i ran it four times and every time it would not boost over 16psi. it seemed that the ECU backed the boost down and would not come back up... then after the dyno i floored it on the highway and at first it went to 16 psi and held, so i backed off then floored it again and it adjusted and went right back up to 21psi and held like normal.... so now here are the results for the dyno:

252 whp
289 wtq
A/F was really lean at 15:1 on the first run (which is why I think the ECU cut boost back, and probably backed off timing etc), then it settled down to 12.8:1 on the other runs

so i don't know if my dyno results are accurate. i know the car was not making full boost since i felt the ECU cut the boost down when i floored it, and the A/F's were not as good as I thought they would be. any comments/suggestions?...

also here is a picture. i will try to post a video later

 

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Who's your tuner?

My car did 235whp and 240 wtq at the same place, and I'm a stock aero. Obviously those numbers are low. A/F's 15 is really low, probably got some knock going on which freaked the ECU out. However, 12.8:1 is lean IMO, I think 12:1 is where you really want to be.
 

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Discussion Starter #3
I have a stage 3 Nordic ECU from GenuineSaab... I hope those numbers are low. I had a camaro before I got my saab, and the camaro dyno'd at 300whp and my damn saab pulls just as hard as the camaro did on the street. I just don't understand why the ECU freaked out on the dyno. On the street the car screams. it holds 20-22psi all day.

here is a list of the mods:
- K&N, open air
- genuine saab big intake pipe
- 2.5 inch aluminum pipe to front mount intercooler mounted in bumper opening, and 2.5 inch out of IC to plastic pipe going to the throttle body
- 3.5 bar fpr
- full 3 inch exhaust, race cat, one dinky 3 inch muffler
 

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Hey D-,


Maybe heat sink on the IC??? I don't see any fan and it was warm that day...

When it knoced back to 16 did it seem like it could have gone higher and that it was locking out more boost like a T7 safety thing???


Besides 280 BHP-10% is 252WHP 280 is all you can really get with Stage III

J
 

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Raven18940 said:
Who's your tuner?

My car did 235whp and 240 wtq at the same place, and I'm a stock aero. Obviously those numbers are low. A/F's 15 is really low, probably got some knock going on which freaked the ECU out. However, 12.8:1 is lean IMO, I think 12:1 is where you really want to be.
Your car's a freak... you can't be the one throwing down numbers you make everyone else look smaller than you....
 

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Discussion Starter #7
I don't know guys... as far as cooling goes i had a big fan in there aimed at the grill/IC. and the 4th run made the most power. it seemed like something happened on the first run that made the ECU freak out and run low boost and it never recovered until I got the car back on the street.... and yea J, it def seemed like a safety thing. on the first pull the car shot up to 20psi or so then fell right down to 16psi and every run after that the ECU would not let it go higher... but man, i know the car has more in it than 280 at the crank. it pulls really hard on the street.

so now i think i might talk to Nick, see what he says, and plan another dyno day. anyone from the philly/PA area up for a dyno day??
 

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Raven, are you sure it's measuring wheel horsepower? A lot of places will do something called a "coast down" or something like that, it tries to measure the amount of drag in the drive system and uses that to guess the power at the crank. Not very accurate, but they do it nonetheless. Those power figures you have are pretty much stock power figures for our year Aeros, and even with overboost you shouldn't be hitting those at the wheels if you on a stock tune.

As for the boost issue:

It does seem like a T7 safety issue from the description. Could your fuel filter be getting clogged? I'd run a fuel pressure test to see if you're within limits. The T7 system is programmed to stay de-tuned for 4 or 5 cycles of the same situation before it will program back to make sure it doesn't happen again. Preventative thing. You'd think these cars, as complicated as they are, would have a fuel pressure sensor that would throw a CEL, but it doesn't seem they do. Instead the ECU watches the A/F ratio and just automatically backs off without a CEL.
 

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Discussion Starter #9
Sector, thats a good point about the fuel filter. I just put a new filter in about 10k miles ago BUT i am running my original fuel pump with 101,000 on it. maybe it is starting to give up and i am not getting full pressure all the time??
 

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spoolin'Aero said:
Sector, thats a good point about the fuel filter. I just put a new filter in about 10k miles ago BUT i am running my original fuel pump with 101,000 on it. maybe it is starting to give up and i am not getting full pressure all the time??
That is definately a possibility, they have gone out at a lot lower mileage than that before. A fuel pressure test could give ya the answer! :cool:
 

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Interesting. I get a weird safety thing form time to time, don't really know what causes it yet, made lots o changes ( cheaper and easier than teh fuel pump- although that is one I did not think of so it might be next) but it seems like the car is afraid of the boost and shuts it to 7 PSI


Does not sound like the boost spike that I and STX see his posts- have had ( I think new boost pressure sensors helped me) The spike also seems to happen more on cars that have had the turbo uprated ( lpt to Bigger)

I will be up for adyno say the car is running good again :)
 

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Hey Spoolin',

I've been meaning to put down some dyno run's since my BSR tune this summer but never had the chance. I'm in the Burlington, South Jersey area, about 20mins from Philly. If you set this up, definately count me in :D
 

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Jssaab said:
Your car's a freak... you can't be the one throwing down numbers you make everyone else look smaller than you....
It's not my fault my car is so awesome. :lol: I think my car represents the peak of aero adaptation and overboost, but this is reason I haven't tuned my car yet, it runs really well.
SectorNine50 said:
Raven, are you sure it's measuring wheel horsepower? A lot of places will do something called a "coast down" or something like that, it tries to measure the amount of drag in the drive system and uses that to guess the power at the crank. Not very accurate, but they do it nonetheless. Those power figures you have are pretty much stock power figures for our year Aeros, and even with overboost you shouldn't be hitting those at the wheels if you on a stock tune.
It was done on the exact same dyno as spoolin aero, I doubt they would give me different numbers.

As for problem:
The fuel pressure could be the problem, the ecu might have been trying to richen the fuel mixture and there wasn't anymore fuel. Result, "holy crap! close the throttle, pull boost and ignition timing, protect the pistons!" I'd get a wideband installed and check your A/F ratios, 12.8:1 doesn't sound right to me, too lean.

As for your numbers, don't fret, you dynoed in 4th, that's an overdrive gear. ;)
 

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Raven18940 said:
As for problem:
The fuel pressure could be the problem, the ecu might have been trying to richen the fuel mixture and there wasn't anymore fuel. Result, "holy crap! close the throttle, pull boost and ignition timing, protect the pistons!" I'd get a wideband installed and check your A/F ratios, 12.8:1 doesn't sound right to me, too lean.

;)
My wideband is on its way, along with the 4 sensor computer I just haven't decided what other sensors to get. ( unless I replace my Boost guage that is)
 

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Raven18940 said:
It was done on the exact same dyno as spoolin aero, I doubt they would give me different numbers.
Hope that didn't offend you at all, wasn't my goal.

I was just saying that maybe they did a coast down for you, and didn't for spoolin Aero, but who knows, since you say you drive you car to the rev limiter every day all day maybe the car has tuned it's self! :eek:
 

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I thought we were supposed to dyno in 4th?? As that is the gear with the closest to a 1:1 ratio without going over. Wouldn't running in 3rd give you different results?

edit: nevermind, i was wrong. 4th is .89:1 and 3rd is 1.18:1 so 3rd would be the proper gear to dyno in. That could definitely make your results a bit lower.
 

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Discussion Starter #17
wow, i didn't know that 4th was overdriven... probably shoulda run my car in 3rd gear!... anyway guys, i am going to get my car squared away and plan a new dyno day.

Jynxxed, saw you are interested
J - possibly?
anyone else around the Philly/NJ/DE area??
 

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They correct for this at the computer. Or at least they should have, I guess they could have not looked up the numbers and just guessed that your 4th was 1:1.
 

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gabis said:
I thought we were supposed to dyno in 4th?? As that is the gear with the closest to a 1:1 ratio without going over. Wouldn't running in 3rd give you different results?

edit: nevermind, i was wrong. 4th is .89:1 and 3rd is 1.18:1 so 3rd would be the proper gear to dyno in. That could definitely make your results a bit lower.
Do you have a list of the other ratios and the final drive for the 2000 Aero Manual?
 

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JsnAero said:
Do you have a list of the other ratios and the final drive for the 2000 Aero Manual?
3.38:1 first gear ratio
1.76:1 second gear ratio
1.18:1 third gear ratio
0.89:1 fourth gear ratio
0.66:1 fifth gear ratio
3.17:1 reverse gear ratio
4.05:1 final drive ratio
 
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