33dogstreet

Just got tuned on the dyno today, I have a 1998 LS1/T56 that I just put on 243s, a TSP Torquer V4, headers, and a CAI (motor is in a 68 Chevelle).

The dyno sheet said I made around 315hp/315tq, which seems pretty low to me. I know all dynos are different, but I was still pretty disappointed with the numbers considering the amount of money I put in it. Are there any common problems I should be addressing or was it just a stingy dyno?

soloman369

iTrader: (13)

Ugh that horrible no matter what dyno.... Got the sheet post a picture

33dogstreet

Here's the sheet

HCI2000SS

iTrader: (2)

That's messed up. It looks like your horsepower is peaking around 5700 as well. Should be more like 6200

Darth_V8r

iTrader: (4)

Check that cam timing. Looks advanced

33dogstreet

Check the timing as in if the dot-to-dot is off?

Darth_V8r

iTrader: (4)

Yes. As in dot to dot. It's easy to be off a tooth

soloman369

iTrader: (13)

Yeah it looks like it's peaking early, but also looks like a little bit of float what kind of springs do you have in it?

33dogstreet

I'll check that out, thanks for the tip.

PAC .660 dual springs.

thunderstruck507

iTrader: (18)

Please post your full specs to help rule things out.

What kind of air filter/ MAF/ tubing assembly?
What intake manifold? What throttle body?
What size headers? What exhaust after the headers?

Did the dyno operator do the pull in 4th gear or did he use a lower gear (common if he was concerned about the length of the driveshaft versus it's build quality)?


Hard to imagine your car making less than 370rwhp on the stingiest dyno assuming there are no mechanical issues. Should be 400+ pretty easily.

33dogstreet

The air intake is a Spectre LS swap intake (P/N 901234) with a card style MAF. Intake manifold and throttle body are stock LS1. Headers are LTs from Speed Engineering, 1 3/4" primaries. The dyno run was performed on headers only with an extension tube for the O2s. The operator performed the pull in 4th.

Here's some other info about my setup to rule anything out. The 243s have stock LS2 valves with new retainers, seats, and seals. I am running 7.400 TSP chromoly pushrods and stock lifters. The timing chain and upper sprocket are new, as is the oil pump. Stock fuel injectors and fuel rail.

Another thing a friend brought up that might affect the numbers could have been altitude. I don't believe the numbers were corrected and I am located in Colorado Springs (elevation 6035).

thunderstruck507

iTrader: (18)

That would certainly do it. The elevation equates to about a 60hp loss based on a calculator from Wallace Racing.

http://www.wallaceracing.com/braking-hp.php



That would put you back up to 375hp which is still low but not out of the ballpark. Could be stingy numbers at that point or other weather factors. Or just minor tune/combo tweaks needed to fully optimize the car.

The most major one I see being the LS1 intake which is garbage for a cammed car and is likely the primary contributor to the low HP peak. A friend of mine had a 228r cammed LS1 in his Chevelle and the switch to a LS6 intake gained him 2 tenths and 2mph in the 1/8 mile. A Fast would gain another 10+ over that.

Ricer math can add you up to over 400rwhp so I wouldn't be overly concerned but maybe someone else with more experience with high altitude can chime in and further shed some light for us before you start looking for major issues or throwing money at it.

kinglt-1

iTrader: (26)

well there lies your problem...High DA combined with the dismal LS1 intake, mediocre headers, and the rear end is probably what a 12 bolt minimum? So yea your numbers make sense.

Check your cam timing, move up to set of 1 7/8 headers, LS6 intake & ported TB minimum(Fast would be better), measure for correct push rod length instead of using the standard 7.4 and I bet you pick up 40-50hp even @ 6000+ ft.

AINT SKEERED

iTrader: (2)

what transmission is in this car? i seen you said pulls were made in 4th gear, if this is an automatic, that will also drop numbers

mOtOrHeAd MiKe

iTrader: (8)

While I agree it can happen, torque is still peaking between 4800 and 5000 rpm which is ballpark for the cam. If it was showing 4400rpm peak I'd be more suspect.

It is dying up top and falling short by about 500rpm. That is likely a hole in the tune and the intake choking it.