Crappy Dyno...What could it be?

[Ravenous T\A]

here are my mods and cam specs

99' Ls1 w/ARP Rod Bolts, Ported LS6 Oil pump, LH8 Hummer Oil Pan, BRP Engine Mounts
Stg 2ish early model (243)Z06 heads, Patriot Gold springs w/Titanium Retainers, Ferrea Race Valves, Factory Rocker Arms, Comp Lifters, TSP Pushrods (flow 314cfm@.600)
Victor Jr Carb Intake w/Edelbrock 750cfm Carb, Summit High Performance Electric Fuel pump & Regulator, 16gal Fuel Cell in Trunk, Jegs Billet Fuel Filters, Steel Braided Fuel Lines
Futral Custom Cam 236/240 112+4 (.641/.612 lift)
Vette Assc. Only using AC and Alt
4000 Nitrous Stall/ TH350
3.73 gearing

timing was set at 30 degrees, we tried 32 & 33 and lost power, also tried 28 intialy and it did 326rwhp. Low number is 1st dyno with timing set at 33 degrees

HEAD Flow Numbers
0.200 148 114
0.300 206 153
0.400 255 178
0.500 295 202
0.600 314 212
0.700 319 218

[XtraCajunSS]

Check for vacuum at WOT. What headers are you running? What rear end and tire combo are you running? The 750 carb may be a tad small for your combo...

Shane

[Ravenous T\A]

Dynatech Stepped LS1 stepped race headers.
3" Summit Exhaust w/ Hooker Aerochamber Mufflers

Factory 10 bolt w/3.73 running ROH wheels 275/40/17's

[XtraCajunSS]

Nothing wrong with the exhaust although I hope you are running an X-Pipe with that combo. I've seen 30 RWHP gains going from no crossover to an X.

I still think the carb may be a bit small on your combo. After that, it comes down to how good the heads really are. Flow numbers are not everything and I've seen more than one set of LS6 heads destroyed by a porter who isn't familliar with LSx style heads.

Shane

[Ravenous T\A]

yea thats what im kinda worried about, Had a local porter off this website who seemed to know what he was doing but now im kinda unsure. I was thinking it was either the cam or the heads or someone suggested a loose converter. The guy at the dyno shop said to me that its my TH350 eating to much HP going to the rear but that just doesnt sound right to me?

[Ravenous T\A]

oh yea no X-pipe yet, so should I step up to a 850 holley/BG?

[Vcious04]

Man, ditch that carb. Get a wideband (must for fine tuning), either a proform 750 or holley 750 DP, bring it over to my house and I will tune it for free (I also accept donations ). I bet I can get 380-390 @ wheels on that combo atleast.

A 750 is PLENTY of carb for that motor. Even without a wideband I can still tune it with a few jet changes and the old spark plug method. 72's in front, 76's in the rear it's what my guess is.

Are you running the 6010 box?

My old carbed LS1 Coupe only put down 396rwhp through a TH350, 4.10 gears and still managed 6.72 @ 102 all motor. Give me a shout, I'll be glad to help.

[Ravenous T\A]

thanks man, yea wideband is on my list, im running the 6010 box, I just thought a Heads and cam combo would put more power down, hell my 98 Ls1 with stock heads did 398, of course that was a M6, but a Heads & Cam combo should IMHO made atleast that! Seems i can never break 400rwhp without sparying it

[Vcious04]

Originally Posted by Ravenous T\A

thanks man, yea wideband is on my list, im running the 6010 box, I just thought a Heads and cam combo would put more power down, hell my 98 Ls1 with stock heads did 398, of course that was a M6, but a Heads & Cam combo should IMHO made atleast that! Seems i can never break 400rwhp without sparying it

Nice! Yeah, mine ran best at 26 deg timing. Don't worry about, after you ditch that edelbrock carb, you will be ok.

Tuning a carb setup makes a HUGE difference. When I first got it going, I ran 7.32 @ 97mph. After I tuned it and changed a few things I busted off the 6.72 and it was consistant.

[Ravenous T\A]

well I guess I need to make that my next purchase then, I like this new Holley Avenger carbs, they come in pretty colors

[InsomZ]

What kind of power should it put down with this setup? I know with a c5 z06 it would be around 450rwhp or so.

[Ravenous T\A]

well im thinking of swapping to some stock LS6/6.0 heads & swapping to a holley 750DP

[Tuner@Straightline]

The TH350 with that high of a stall will definitely show a lot less horsepower than a manual transmission.

[edcmat-l1]

Originally Posted by Tuner@Straightline

The TH350 with that high of a stall will definitely show a lot less horsepower than a manual transmission.

Agreed.

+1 for ditching the Edelbrock Carb and going with a Holley.

[Ravenous T\A]

yea but do u think it would kill it that much? Plus my TQ is crap too (but it does pull like a mutha)

[InsomZ]

The heads would be alot of work I'd just do the intake swap and vacuum test. Save some wrenching.

That's alot of difference.. 370rwhp vs 450'ish with an m6. D- any #'s out of autos with that cam?

[Ravenous T\A]

cam is custom ground

[Ravenous T\A]

heads are not hard at all, alot easier in this car then it would have been in my TA

[Tuner@Straightline]

Originally Posted by Ravenous T\A

yea but do u think it would kill it that much? Plus my TQ is crap too (but it does pull like a mutha)

We've had a 408sbf that did 647bhp on the engine dyno, and then 35xish rwhp on our Mustang dyno with a 4500rpm stall C4 trans. We also had a 440cui LSx motor with ETP Canted Valve heads make 928bhp on the engine dyno, and only make 650rwhp on our Mustang dyno with a 6000rpm stall and a powerglide. Not being able to lock up the converter absorbs a lot of power from getting to the rear wheels. It doesn't mean the engine isn't making power, just it's not getting to the wheels in the same way.

[Ravenous T\A]

how could I fix that?