Highest HP From 243 Heads?
#81
11 Second Club
My guess would not be more than 10rwhp. But I could be wrong. Would have been cool to do dyno before then right after install. Just couldn't do it. From the butt dyno the engine likes them & is more happy at 7k rpm. Although my exhaust is 3" x-pipe dumped. TSP true dual. So the 1 3/4 did ok. Putting that dumped exhaust on was 20hp/20tq.
#82
When I dynoed mine, I saw the print out and it was within 1.5hp difference from the 1 3/4 to the 1 7/8.
Torque curve was the same.
Might work better with a bigger camshaft though with a bigger exhaust split.
Will see
Torque curve was the same.
Might work better with a bigger camshaft though with a bigger exhaust split.
Will see
#83
11 Second Club
Interesting. So not much power gain. If you don't mind what were the dyno numbers?
#84
TECH Senior Member
Slight gain. . I would have thought more difference in power between the header sizes
#85
With the 1 7/8 headers I was at 505 rwhp
Pretty much nothing.
As I keep mentioning though, this might be because engine is not spinning high enough.
Going for a 12 degree overlap to a 24 degree might make a difference.
#86
If I was building another na engine up to 800hp I would stick with the 1 3/4 size.
I have a feeling the bigger header might be better over 6500rpm but I will never know.
#87
10 Second Club
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My guess would not be more than 10rwhp. But I could be wrong. Would have been cool to do dyno before then right after install. Just couldn't do it. From the butt dyno the engine likes them & is more happy at 7k rpm. Although my exhaust is 3" x-pipe dumped. TSP true dual. So the 1 3/4 did ok. Putting that dumped exhaust on was 20hp/20tq.
#88
TECH Senior Member
But it's good to know there is little or no loss below 6500 with the larger header.
#89
11 Second Club
#90
10 Second Club
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Yea they're 3". Same system the bolt on ls6 made 451whp through. They're also easy to quiet down more if one wants to. Pop the tip off and you can shove a spiral in the muffler......takes like 5min if that once they're fitted.
#92
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What ET with that 137? That is badass on a ls2
#93
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10.41, with a 1.72 60’. I went through +- 15 clutches until I put in a soft lock style clutch. All the tracks that were close are closed now so I never got the chance to dial it in as a slipper. I had 60’d 1.42 on a monster stage 3, but that clutch would not work above 7500 rpm. (I shift at 8000-8100)
#94
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I struggled to get 60ft down on mine. Ended up going to bias ply. Then if the tire spins it does not just give up like radials. QTP was big over ET streets.
Any other build details you would like to share? Or maybe a build thread? Most of the 500+ Ls1 sbe builds have AM heads. And most even with AM heads get stuck around 480.
Edit - not doubting. Just impressed.
Any other build details you would like to share? Or maybe a build thread? Most of the 500+ Ls1 sbe builds have AM heads. And most even with AM heads get stuck around 480.
Edit - not doubting. Just impressed.
#95
10 Second Club
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I struggled to get 60ft down on mine. Ended up going to bias ply. Then if the tire spins it does not just give up like radials. QTP was big over ET streets.
Any other build details you would like to share? Or maybe a build thread? Most of the 500+ Ls1 sbe builds have AM heads. And most even with AM heads get stuck around 480.
Edit - not doubting. Just impressed.
Any other build details you would like to share? Or maybe a build thread? Most of the 500+ Ls1 sbe builds have AM heads. And most even with AM heads get stuck around 480.
Edit - not doubting. Just impressed.
I had had a bunch of threads back in the day, I really haven’t posted here in 5-6 years.
Its a kaltech h/c package. T4p 799’s, “with special sauce” as it was labeled. Cam was 25x/26x .680/.660 I believe. Ported supervic, Manton pushrods, 13:5-1 comp ls2, now it’s bumped to 14.2-1 ish. I built the suspension/rear end housing in my welding shop. I got tired of trying to get updated in the fastest six speed list so i gave up here, I don’t know if that ever did get updated. It’s like a ghost town here now!
#97
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Brought this thread back to life huh? Well back around when I made this thread I was wondering because based off my set up. My set up is a 346ci 90mm intake, 92mm TB, bigger size custom cam, ported/polished 243 heads, 9" rear end with 28" slicks through a m6. Did 456rwhp & 421 lbtq. But unfortunately during the dyno I was aware of a ticking noise going on that had started prior. I didn't wanna spray it to cause any more damage but soon after we took apart the engine & found out that my piston had gotten damaged & came in contact. So took apart the engine fully forged the bottom end & well see what I'm able to put down & take it to a track
#98
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