Help, missing HP
Thread Starter
TECH Apprentice
Joined: Jun 2002
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From: Fayetteville, NC
Help, missing HP Anyone have any ideas why I would only dyno 369RWHP/372RWTQ, with JPR S2 Heads, TR 227/224 cam, and other mods in sig. I just am kinda disappointed. Esp. when I have friends that are dynoing like 20-40 more with similar mods, or even stock heads I thought I'd have seen 400RWHP. 
Originally Posted by purevilss
Anyone have any ideas why I would only dyno 369RWHP/372RWTQ, with JPR S2 Heads, TR 227/224 cam, and other mods in sig. I just am kinda disappointed. Esp. when I have friends that are dynoing like 20-40 more with similar mods, or even stock heads I thought I'd have seen 400RWHP.
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Thread Starter
TECH Apprentice
Joined: Jun 2002
Posts: 301
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From: Fayetteville, NC
Yeah, I got my dyno numbers from the dyno tune. I can't see my exhaut as restrictive, with PPC LT's, 3 1/2-3" Y-pipe, and a cutout. I do have the LS-1 intake still as do others I know, but have an SLP lid. This is the reason I went with a reverse split cam, 
I am adding the ASP pulley next week. A/F was around 12.8, and I peaked HP at 6400 and it began to drop off. Maybe my heads aren't as good as I expected. I heard good stuff from JPR, but I'm just not seeing it. Yeah, the track will tell. Before I installed the heads, cam and headers, I was running 13.4's here in Las Vegas on motor and 12.7's on the 100 shot. If I can't run 12.7's all motor now, this will show me somehing is just not right!
I am adding the ASP pulley next week. A/F was around 12.8, and I peaked HP at 6400 and it began to drop off. Maybe my heads aren't as good as I expected. I heard good stuff from JPR, but I'm just not seeing it. Yeah, the track will tell. Before I installed the heads, cam and headers, I was running 13.4's here in Las Vegas on motor and 12.7's on the 100 shot. If I can't run 12.7's all motor now, this will show me somehing is just not right! LS1 Tech Stories
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well you loosing a good bit of power on the dyno with three main things. decent size converter, gears and automatic tranny. id say anywhere from 15-40 hp. depends on a few things, mainly the average power loss on a 3000 converter.
hasnt anyone told you dyno numbers on a auto mean nothing once you start changing those things. they are always going to be way low. i lost like 15 hp with my 12 bolt and 4.10 but picked up almost half second with nittos
hasnt anyone told you dyno numbers on a auto mean nothing once you start changing those things. they are always going to be way low. i lost like 15 hp with my 12 bolt and 4.10 but picked up almost half second with nittos
Thread Starter
TECH Apprentice
Joined: Jun 2002
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From: Fayetteville, NC
I didn't get a print out of my dyno, 
. I have been reviewing my tune on LS-1 edit and my high octane timing is stock, but the tuner added a lot to the low. and did a lotof fuel work, which I really needed. A friend went on after i with S2 heads, a 230/232 cam, Long tubes, in an auto with a converter and gears and pulled 400 RWHP. I just cant see that much diff. Another auto frien pulled 355RWHP with an auto, converter, 3.73's, and stock heads. I must have a step child motor 
. I have been reviewing my tune on LS-1 edit and my high octane timing is stock, but the tuner added a lot to the low. and did a lotof fuel work, which I really needed. A friend went on after i with S2 heads, a 230/232 cam, Long tubes, in an auto with a converter and gears and pulled 400 RWHP. I just cant see that much diff. Another auto frien pulled 355RWHP with an auto, converter, 3.73's, and stock heads. I must have a step child motor 
TECH Junkie
Joined: Dec 2001
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From: Lakeland, FL
Even with the tuning did you plug in an autotap or scanner to see if you were getting any knock retard? Also the ls6 intake will be worth a few ponies and the asp will be some more. Also I would think that increased timing would give you even more hp so maybe they can work the tune a little more. The other thing that I would try is to call Joe and ask him what your flow #'s were.
TECH Resident
Joined: Nov 2002
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From: Orlando
I was gonna ask if you thought your cam was off a tooth, but seeing that your power is peaking at 6400, I now doubt that's the case. You never know, but it could be off. One tooth will easily suck up that much power. Just a thought.
Thread Starter
TECH Apprentice
Joined: Jun 2002
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From: Fayetteville, NC
Our altitude is 2000ft. I am 100% sure my cam is dead on. Thanks for the thoughts though. On the dyno, there was no KR during the runs, on the street I occasionally see some, but due to it being occasional I feel it to be false. I just thought for sure there would have been 25-30 more RWHP at my wheels. Oh well. What cells are mostly WOT, where I could add a degree or two and see how it does?
Launching!
Joined: Sep 2003
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What kind of dyno was it on? What tires? Rims? Those are keys in dyno numbers too, which as far as I'm concerned don't mean a thing. My 95 only put down 403 according to the dyno but I was trapping what you see in the sig at 2200' DA in a full weight car. That's a lot more than 403rwhp. 
Launching!
Joined: Sep 2003
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Oh, and don't mess with the WOT timing would be my guess. If the tuner set it up right, you'll see more harm than good out of 2 degrees more timing. 2 degrees is only like 4-5 rwhp, maybe. But knock will take away more than that.