Highest HP From 243 Heads?
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You added the ONLY to this one...HAHAHAHA. Seriously though a dyno is a tuning tool and not really a measuring stick IMO. My cousin has a very tight dynojet dyno that hurts a lot of feelings but it's well maintained and calibrated often. I have had my truck on his dyno and a local Mustang and his was 32 hp lower on the same tune. We then picked up another 25hp to the tires with tuning. A 1/4 mile is a much better guide IMO.
To be honest i wouldn't take any dyno numbers with a grain of salt. A buddy of mine made 485 rwhp with PRC 5.3 heads through a stalled auto HCI LS1. Was it any faster than other HCI LS1's with a similar build that dynoed lower?? No not really. Bottom line is even if you did find one that made 500 rwhp it likely wouldn't be any faster than one that made 450 rwhp. Dynos vary too much. Take two cars with the same build, tune, etc...and they will run basically the same regardless of the dyno number
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To be honest i wouldn't take any dyno numbers with a grain of salt. A buddy of mine made 485 rwhp with PRC 5.3 heads through a stalled auto HCI LS1. Was it any faster than other HCI LS1's with a similar build that dynoed lower?? No not really. Bottom line is even if you did find one that made 500 rwhp it likely wouldn't be any faster than one that made 450 rwhp. Dynos vary too much. Take two cars with the same build, tune, etc...and they will run basically the same regardless of the dyno number
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Try this. Go to Corvette Forum. Apply the mph to weight formula in Wallace racing site to the 2 or 3 fastest ls2's in the bolt on list and average it out. You could add about 20-25 rwhp to the results for porting and whatever. There are more formulas there for smallest cross section within a ported head as well. With minimum cross section info you can calculate for maximum potential horse power at a given rpm per cid size.
Last edited by handyandy496; Mar 23, 2018 at 03:19 PM.
I think Big Hammer is pretty close with this estimate
I've read that the Wegner 799/243 Nascar spec heads with stock valve size could make high 500's rear wheel ~575-585 whp with all the supporting goodies like vacuum pump etc in the NASCAR configuration. I've not seen a dyno graph to support that however. It's been said the stock valve size was the governing factor and more hp was possible with a bigger valve and a little more port work.
I've read that the Wegner 799/243 Nascar spec heads with stock valve size could make high 500's rear wheel ~575-585 whp with all the supporting goodies like vacuum pump etc in the NASCAR configuration. I've not seen a dyno graph to support that however. It's been said the stock valve size was the governing factor and more hp was possible with a bigger valve and a little more port work.
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Allan Futral eclipsed 500rwhp a LONG time ago. The car's performance backed up the dyno numbers.
https://ls1tech.com/forums/dynamomet...fms-346-a.html
https://ls1tech.com/forums/dynamomet...fms-346-a.html
Allan Futral eclipsed 500rwhp a LONG time ago. The car's performance backed up the dyno numbers.
https://ls1tech.com/forums/dynamomet...fms-346-a.html
https://ls1tech.com/forums/dynamomet...fms-346-a.html
