Did a baseline dyno this week. Mods are as follows:

2001 Corvette
2002 LS6 longblock
LG Longtubes, Corsa exhaust - no cats
Vararam intake
M12 transmission
3.90 R&P
Monster Level 4 clutch
Z06 wheels w/drag radials




My question(s) relate to the differing torque numbers. What could cause the 2nd run to have so much more torque than the first? I'm thinking timing must have been pulled on the first since a/f was the same, but I always thought timing affected a/f.

Even at 5200 rpms, the a/f is the same (12.2) but the torque and hp difference is over 20 each.

Also, fuel cut came on at 6400 ish. Is that suffice for an LS6? The way the power was carrying, it seems like on the track it would be best to shift at 67-6800, no?

At 5800, a/f dips rich - is that most likely the tune, or perhaps something else affecting it?

I'm not really disappointed with the results, though one would always want more, lol. I'm sure the 3.90s are taking a small bit of power, and the tune looks like it could definitely use some work.

Is it just me, or is the torque low in general for an LS6 with longtubes? I was expecting closer to 350-360ish torque.

For the next step - this is FAR from a daily driver, but I do enjoy being able to lug the motor at pretty much any rpm in 6th. Should I jump right to a cam, or would a FAST intake be worth doing at this point?

I'm so torn on the cam size as well -I went with an 847 cam in my old LT1 and LOVED it -peak power was the same as this motor, but gobs more torque. That makes me lean towards a big cam.

I know people love having power from 2000 rpms on, but my thought is if you have enough to cruise at low rpm in 6th without surge, go as big as possible for more high rpm power, right?

If you're at 2000 rpms and need more power, downshift! Wouldn't the car be faster overall having more power where you'd USE it, i.e. 4500 - 7000?

Thanks for any suggestions and comments guys. This forum really is a great place to learn!

 

some one correct me if im wrong but, i think timing gets pulled from a result of knock.. you might of had a few degrees of knock so timing was pulled. ? THats my guess.
Same goes with your a/f at the end, it does go pig rich, a tune will fix that for you!!

And im with you on the cam, i personally dont hit the pedal to the metal at 2k rpm lol 3500-7000rpm is the sweet spot if you want to go fast from a roll. go with a big cam

 

My buddy has a very similar setup. It was a 2002 Z06, LG LT's, No cats, Borla Stingers, Vararam CAI, 3.90's gears with 315DR's & tuned & it made 371rwhp. Im sure the 3:90s & fat 315's hurt the rwhp reading by 10-13rwhp would be my guess.

 

30th - did he ever take it to the track? I'm hoping to go within the next month, depending on how busy work is. It's 100+ degrees here right now, so I'm not shooting for a record or anything, but I'd like a general idea of what to expect.

 

No he didnt. All depends on the DA of the track that day and how good of a driver you are.

 

Heat was providing you a knock-rich environment and given that, I second bestlude's guess. I'd sling a set of heads on it, given how easy they are to swap on a C5. Have AI work your heads or some AFR 205s would give you all upside and no downside. Pop your FAST 102/102 on top, spend big effort on the tune and prepare to be impressed. If you can find a nice deal on some ARH 1 7/8, I'd go that route. Some would find it hard to justify since you already have them but there really is no downside. This will all put you easily into 425/400 territory on a stock cam. If you truly don't put many street miles on it, sling a healthy (not donkey dick) cam into it and you'll be 475/420+.

 

AFR 205s and 224/228 114 cam that Mamo did on his personal car would be tough to beat for what you want. He installed his on a 114ICL and it would spin to 7k with plenty of hang-on past peak yet it's small enough to drive just like stock. I'd imagine sixth gear lugging would be no issue whatsoever

 

Looks to me like something starts going just a little wrong right at 5500rpm. HP looks less linear and shortly after it drops rich.

 

thunderstruck - any thoughts as to what may possibly be the issue there?

I wasn't sure if the tune is just going rich as a protective method, or if there could be something else causing it.

bestlude - I figured it could be timing being pulled, but I would have thought if it was heat related, it would be MORE pronounced on the second run, rather than better on the second run. It made more on the 2nd pull than the first. Just seemed counter-intuitive to me.