made a few dyno pulls

[JDSfastGN]

Well this past weekend I got to make a few dyno pulls. The dyno shop was local and I got to make some free passes that I had won in a car show raffle last year. Anyways the dyno is a superflow dyno. He said its usually pretty low compared to dynojets etc... I don't think there was quite enough load as the runs were so short that my WB02 correction in the chip never really got to hone in on my set number of 11.1 so my WB readings were down near 10.6-7. I also only saw 22-23.5 psi and had 2-3* of knock at the initial hit on most runs. Does it seem normal for my power to drop off so dramatically past 5000 rpm? I thought my 204/214 would make peak around 5300 or so.
best
rwhp 427.5
rwtrq 458.3
dynojet corrected
rwhp 452.1
rwtq 484.6

and with dynojet correction overlayed

 

[wbrophy]

Looks like it tops out at 4900, I would say a larger cam would be nice but if the car shifts gears around 5000 or "sooo" than your getting the most out of what you got IMHO.
Maybe a little tighter converter may help too?

 

[JDSfastGN]

Looks like it tops out at 4900, I would say a larger cam would be nice but if the car shifts gears around 5000 or "sooo" than your getting the most out of what you got IMHO.
Maybe a little tighter converter may help too?

Yeah It definitely drops off. I just put in a PTC NL 9.5. It stalls right at 3000 rom and is pretty efficient. It shows anywhere from 5-7% efficiency on the dyno runs.

 

[wbrophy]

That 5/7% in the real world is good info! I have read that the % may improve with more rpm's? Was it the 2800 rated converter?

 

[JDSfastGN]

That 5/7% in the real world is good info! I have read that the % may improve with more rpm's? Was it the 2800 rated converter?

No he speced it as a 3000 stall. Its right at 3000 on the t-brake at 0/0 boost/vacuum. Its a pretty efficient converter. My old Pro torque unlocked was in the 13-15% range.

 

[d0n_3d]

Those numbers sound about right for that turbo. The 61 is most efficient at about 22-23 psi of boost. PTE rated the 61 at about 600-630 horse flywheel so if you figure a 25% drivetrain loss (on the high side of course), from 600 hp it is 450 rwhp. I have seen that turbo and the Garrett equivelent GT35R make 500-550 to the tires on way more efficient motors than what the Buick V6 does. Gotta remember, a 4 valve per cylinder 4 cylinder motor is way more efficient than a 2 valve 80's technology V6 Buick

 

[jerrad]

Do you think you might be getting valve float?

 

[JDSfastGN]

Thanks guys. I would have liked to see another 30 hp or so but through an unlocked converter and the timing that was lost do to a bit of knock Im not gonna complain. Jerrad I don't think it was valve float, the car freely revved to 5900. I was curious though and took a valve cover off that night and checked all my drivers side springs. They all still had a seat pressure of 100 #s.

 

[jhanson1750]

Thats some good power! Hows things been going? Iv'e got to pull the intake on mine as I think i've got a leak on the lower to head. Give me a call sometime. Jon 281-802-2565

 

[JDSfastGN]

Thats some good power! Hows things been going? Iv'e got to pull the intake on mine as I think i've got a leak on the lower to head. Give me a call sometime. Jon 281-802-2565

Hey man i didn't know if u got it back together ever. Good to hear its running at least. Ill give ya a call.

 

[Red C5]

Nice numbers.