331 Dyno #'s Dead @ 5100 RPM (Long)

[fiveohpatrol]

post your air/fuel curve from either run, it really sounds like you're going lean and not making the power it should

[andy669]

The heads should not be the problem. I have seen 330rwhp with a stock cam, 306, GT40 intake, shorty headers.

Take a 3 1/2 inch floppy with you to the dyno. Have them save your files to it, then email them to me. I have WinPep and can post all the info.

Andy

[Dark_5.0]

Originally Posted by andy669

The heads should not be the problem. I have seen 330rwhp with a stock cam, 306, GT40 intake, shorty headers.

Take a 3 1/2 inch floppy with you to the dyno. Have them save your files to it, then email them to me. I have WinPep and can post all the info.

Andy

I am with this guy

[Fox-4-Cobra]

I did not clarify in my update post that the peak HP stayed put from 5100-5300 before dropping this time.

I dont know much about the computer systems and programs that work with the Dyno's. Would I have to get another run or would they have it saved from my tune so they could check it with the next upgrade? I would love to get it and e-mail it to you guys.

I figured the GT-40 Irons would hold me back some but felt the car would put out 275-295 RWHP as is. I was originally planning to use those heads until winter and then replace them for something better. If it's not the heads then I'am at a total loss for what would be holding me back.I did not expect over 300 RWHP with the GT-40 Irons with just a mill job and 3 angle on them. I have tried replacing the TB, Fuel Filter, Plug Wires and MAM and gained so little

I'll call the shop and see if I can get something worked out if they save the programs. Hate to drop another $ 100-150 on a retune without heads.

Appreciate the help guys.

[andy669]

They will have them saved and they might even be able to email them to you. The files are only 4k each. Did the dyno operator have any ideas? Where was the fuel pressure, and did the tuner note the injector duty cycle?

Andy

[Fox-4-Cobra]

[QUOTE=andy669]They will have them saved and they might even be able to email them to you. The files are only 4k each. Did the dyno operator have any ideas? Where was the fuel pressure, and did the tuner note the injector duty cycle?

I will call them Tuesday morning and ask them to e-mail them to me. The operator thought the heads and intake were killing the power potential of the shortblock. I dont think the fuel pressure was checked, I did not have a guage on it or an adjustable regulator. That is an obvious oversight on my part, probably could have picked up a few HP there. The duty cycle of the injectors was not discussed either.

I'am ignorant to what can and cant be checked via the computer during a tune/chip burn session. Hopefully I can get that e-mailed to me and forward it to you. Again maybe I was way off with expectations out of this combo (275-295 RWHP), and figured with new heads 310-330 RWHP. But I would like to maximize it for now until new heads are purchased this fall.

I have a cousin with a 94 Vette and a big mouth that keeps asking about it. Right now I'm too embarrased to let people know it's stroked to a 331.

Thanks for all of the help.

[rwhite65]

As far as the cousin goes, tell him you have some tuning issues right now. You can spank him when you get your combo dialed in....depending on his year of vette.
Ryan