Dyno results!!! but had some problems too..

1 Bad Burb · June 6, 2004

well, the moment we have all been waiting for! the results..

Keep in mind, not tuned, 8psi (vs 10psi), runnings really lean, engine not getting enough fuel, here they are...

Rear wheel hp: 329.5 @ 4800 rpm

Rear wheel tq: 381.8 @ 4200 rpm

not bad huh???

like i said the problems, it was running really lean. how the hek do i fix this??? the d**n fmu was all the way in.

also, the engine is not gettin enough fuel, how do i fix that, bigger injectors??? i'll post on these problems later, but gtg..let me know what u guys think, are these numbers accurate?

Aj

Chuckster · June 6, 2004

well, the moment we have all been waiting for! the results..
Keep in mind, not tuned, 8psi (vs 10psi), runnings really lean, engine not getting enough fuel, here they are...

Rear wheel hp: 329.5 @ 4800 rpm

Rear wheel tq: 381.8 @ 4200 rpm

not bad huh???

like i said the problems, it was running really lean. how the hek do i fix this??? the d**n fmu was all the way in.

also, the engine is not gettin enough fuel, how do i fix that, bigger injectors??? i'll post on these problems later, but gtg..let me know what u guys think, are these numbers accurate?

Aj

Bigger injectors, bigger fuel pump, LS1Edit..... Should fix all issues

derek_silverado · June 6, 2004

You are running lean because you aren't getting enough fuel. I bet you will see a good bit more power when the engine sees more fuel.

hcvone · June 6, 2004

LS1 Edit or Ed Wright at Fast Chips, what were your air/fuel numbers from the dyno?

1 Bad Burb · June 6, 2004

A/F #'s were very high!

about 18:1 @ 2800 rpm, then it wavers down to 11.5@ 5200 rpm. this run was done with the fmu turned all the way in...

i know this is not good, im going to try and find a fitting for the fuel gauge!

Aj

Butch 02 Denali · June 6, 2004

Of course once the injectors are at 100% duty cycle, no amount of tuning from anyone will help! Call Lyndon Wester at 1 888 Wester1, he can look up the injector flow rate vs your boost and tell you which injectors you need, even if you don't get a tune from him, he will still help!

Butch 02 Sierra Denali

Chuckster · June 7, 2004

Of course once the injectors are at 100% duty cycle, no amount of tuning from anyone will help! Call Lyndon Wester at 1 888 Wester1, he can look up the injector flow rate vs your boost and tell you which injectors you need, even if you don't get a tune from him, he will still help!

Butch 02 Sierra Denali

Exactly.. In fact ANY Corvette LS1 motor using a supercharger Requires bigger injectors and this Starts out as a high performance motor.

It comes as no suprise that the Truck is Starving for fuel...

1 Bad Burb · June 7, 2004

well, the guys on the other forums have told me there are no injectors i can use to upgrade on my L31...thats the biggest drawback on that motor...so im SOL!

Aj

Butch 02 Denali · June 7, 2004

AJ,

Are you using the 454 injectors?

1 Bad Burb · June 8, 2004

nope, using stock injectors.... i don't think u could put 454 injectors in a 350..right?

well, i actually found out why i was running lean... the first pulls, the fmu dial was about 1.5 turns out, then the "tuner" turned it in, think he was richening it up, when in reality, he was closing the dial, meaning leaning it out. no wonder why it was soo freakin lean!!! but wither way, im going to try and find a guy who has a wide band O2 sensor so i can get this d**n thing tuned!!!! im kinda getting tired of this now...

Aj

Chuckster · June 8, 2004

well, the guys on the other forums have told me there are no injectors i can use to upgrade on my L31...thats the biggest drawback on that motor...so im SOL!
Aj

you are right.. There is actually only one injector...

• SEQUENTIAL FUEL INJECTION (SFI) provides a high

level of performance. The centerpiece of the SFI

system is a single-disk injector that is connected to

eight individual valves with flexible lines. The central

injector controls the flow of pressurized fuel to

the valve nozzle in each intake runner. This GMpatented

system delivers significant benefits to

Suburban customers:

— Fuel delivery is precisely controlled for optimal

cylinder-to-cylinder distribution.

— Reduced thermal mass of the valves

(compared to conventional solenoid injectors)

provides quick hot-starts.

— Nozzle design and optimum location produce an

effective spray pattern that contributes to the

engine’s smooth idle.

— SFI’s modular design simplifies service; its central

injector can be replaced as a single unit.

Butch 02 Denali · June 8, 2004

DUH!!! I was thinking TBI, sorry!

I did talk to Lyndon about this and he says he has had some success tuning these CPI systems for blowers. He mentioned that one of the best things you can do is to get cool air into the intake and not hot underhood air.

Butch 02 Sierra Denali

Chuckster · June 8, 2004

well, the moment we have all been waiting for! the results..
Keep in mind, not tuned, 8psi (vs 10psi), runnings really lean, engine not getting enough fuel, here they are...

Rear wheel hp: 329.5 @ 4800 rpm

Rear wheel tq: 381.8 @ 4200 rpm

not bad huh???

like i said the problems, it was running really lean. how the hek do i fix this??? the d**n fmu was all the way in.

also, the engine is not gettin enough fuel, how do i fix that, bigger injectors??? i'll post on these problems later, but gtg..let me know what u guys think, are these numbers accurate?

Aj