Crappy Dyno...What could it be?
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TECH Junkie
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From: Burleson/Ftw,Texas
Crappy Dyno...What could it be? 
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
Last edited by Ravenous T\A; Oct 30, 2009 at 09:50 AM.
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
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
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TECH Junkie
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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?
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.
). 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.
Last edited by Vcious04; Oct 30, 2009 at 04:48 PM.
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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 
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Verdad Gallardo 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
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.
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?
That's alot of difference.. 370rwhp vs 450'ish with an m6. D- any #'s out of autos with that cam?
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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.