The 421 is alive!!!
Thread Starter
Race Director
Joined: May 2003
Posts: 10,749
Likes: 41
The ls7s with those giant 11 degree heads make crazy RWHP. I am going to the dyno tomorrow and there will be two built zo6's there, both making over 550 rwhp. Those motors make insane amounts of power..... The things we have to do to a gen1 motor to be able to keep up is crazy..... I have a lot of money in my 406, put 1/2 that money in a LS7 and "Its to the moon Alice". It's those 11 degree heads...
And yeah I wont be making anywhere close to 550 rwhp n/a.
Le Mans Master
Joined: Dec 2002
Posts: 5,270
Likes: 3
From: Seattle Area WA
The ls7s with those giant 11 degree heads make crazy RWHP. I am going to the dyno tomorrow and there will be two built zo6's there, both making over 550 rwhp. Those motors make insane amounts of power..... The things we have to do to a gen1 motor to be able to keep up is crazy..... I have a lot of money in my 406, put 1/2 that money in a LS7 and "Its to the moon Alice". It's those 11 degree heads...
P.S. Wait until they release the direct injection version of those heads...
I'm just joking with Rick because way back, he said he had a friend with a stock C6 Z06 and he wanted to run with him.
Pro
Joined: Mar 2000
Posts: 658
Likes: 7
From: Perth Amboy New Jersey
The ls7s with those giant 11 degree heads make crazy RWHP. I am going to the dyno tomorrow and there will be two built zo6's there, both making over 550 rwhp. Those motors make insane amounts of power..... The things we have to do to a gen1 motor to be able to keep up is crazy..... I have a lot of money in my 406, put 1/2 that money in a LS7 and "Its to the moon Alice". It's those 11 degree heads...
Racer
Joined: Sep 2007
Posts: 493
Likes: 0
From: Eden Utah
406 ci - cam 238, 242, lsa 110 lift of 558 --afr heads, 195 l98s--acell ecm gen7, headers (1 5/8) miniram with a 58 throttle body 10 to 1 compression ratio. 700 r trans. 370 rwhp 370 torque. I ran with the converter locked and unlocked, no difference... Wanted 400, got 370..God I hate dynos.
Last edited by T. Wayne Nelson; Apr 9, 2011 at 06:32 PM.
Le Mans Master
Joined: Dec 2002
Posts: 5,270
Likes: 3
From: Seattle Area WA
Thats why you need to find a better dyno...
Seriously though, I bet you'd pick up some good power with some 1 3/4" headers or larger (as long as you don't have a tiny exhaust down stream). I made some nice gains on my 383 and that was with a SuperRam and LPE cam.
Racer
Joined: Sep 2007
Posts: 493
Likes: 0
From: Eden Utah
My exhaust is too small, but I have exhausted all of my money. It will cost me a couple grand to go to larger headers and 2 3/4 inch pipes. I am running 2 1/4 inch pipes with a crossover and no cats, which was on the 350. When I made the move to the 400 I spent all of my money on other stuff. I often wonder how many more horses I would end up with.
Thread Starter
Race Director
Joined: May 2003
Posts: 10,749
Likes: 41
406 ci - cam 238, 242, lsa 110 lift of 558 --afr heads, 195 l98s--acell ecm gen7, headers (1 5/8) miniram with a 58 throttle body 10 to 1 compression ratio. 700 r trans. 370 rwhp 370 torque. I ran with the converter locked and unlocked, no difference... Wanted 400, got 370..God I hate dynos.
Thread Starter
Race Director
Joined: May 2003
Posts: 10,749
Likes: 41
My exhaust is too small, but I have exhausted all of my money. It will cost me a couple grand to go to larger headers and 2 3/4 inch pipes. I am running 2 1/4 inch pipes with a crossover and no cats, which was on the 350. When I made the move to the 400 I spent all of my money on other stuff. I often wonder how many more horses I would end up with.
Yes that does seem small Wayner. I am thinking a gain of 20rwhp wouldnt be out of the question with 1 3/4, and 2 3/4 or 3 inch true duals. I am no exhaust expert, but 20 rwhp seems realistic and maybe more.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
Another in agreement. On my 406 with essentially the same cam with more lift, I went from 1 3/4 Hookers to the ARH 1 3/4 stepped to 1 7/8 headers and picked up one and a half tenths. The car traps 127 which is more than my C6Z which was dynoed at 487 rwhp and traps 125.
Le Mans Master
Joined: Dec 2002
Posts: 5,270
Likes: 3
From: Seattle Area WA
My exhaust is too small, but I have exhausted all of my money. It will cost me a couple grand to go to larger headers and 2 3/4 inch pipes. I am running 2 1/4 inch pipes with a crossover and no cats, which was on the 350. When I made the move to the 400 I spent all of my money on other stuff. I often wonder how many more horses I would end up with.
I think 20rwhp or more with a whole exhaust would be pretty easy actually. IIRC I picked up around 3/4 of that with a swap from 1 5/8" to 1 3/4" and 3" y-pipe over a 2.5" setup. This setup made nearly as much as open headers did!
383vett, I want those stepped ARHs bad. $$$ is going gears and race gear for now. Someday, I already have a 3" system waiting in the wings for them... (Shoot Wayne, we should talk, if I get ARHs I'll have spare 1 3/4" headers and my setup coming off... for a heck of a lot less than a couple grand too!
)
Last edited by USAsOnlyWay; Apr 9, 2011 at 11:17 PM.
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
Well, I think you did it the right way. Build a solid motor and if you can't afford to pick up the exhaust then, you can always go bigger later. At least this way you know you have more power in the "bank."
I think 20rwhp or more with a whole exhaust would be pretty easy actually. IIRC I picked up around 3/4 of that with a swap from 1 5/8" to 1 3/4" and 3" y-pipe over a 2.5" setup. This setup made nearly as much as open headers did!
383vett, I want those stepped ARHs bad. $$$ is going gears and race gear for now. Someday, I already have a 3" system waiting in the wings for them... (Shoot Wayne, we should talk, if I get ARHs I'll have spare 1 3/4" headers and my setup coming off... for a heck of a lot less than a couple grand too! )
I think 20rwhp or more with a whole exhaust would be pretty easy actually. IIRC I picked up around 3/4 of that with a swap from 1 5/8" to 1 3/4" and 3" y-pipe over a 2.5" setup. This setup made nearly as much as open headers did!
383vett, I want those stepped ARHs bad. $$$ is going gears and race gear for now. Someday, I already have a 3" system waiting in the wings for them... (Shoot Wayne, we should talk, if I get ARHs I'll have spare 1 3/4" headers and my setup coming off... for a heck of a lot less than a couple grand too!
)
Racer
Joined: Sep 2007
Posts: 493
Likes: 0
From: Eden Utah
Well, I think you did it the right way. Build a solid motor and if you can't afford to pick up the exhaust then, you can always go bigger later. At least this way you know you have more power in the "bank."
I think 20rwhp or more with a whole exhaust would be pretty easy actually. IIRC I picked up around 3/4 of that with a swap from 1 5/8" to 1 3/4" and 3" y-pipe over a 2.5" setup. This setup made nearly as much as open headers did!
383vett, I want those stepped ARHs bad. $$$ is going gears and race gear for now. Someday, I already have a 3" system waiting in the wings for them... (Shoot Wayne, we should talk, if I get ARHs I'll have spare 1 3/4" headers and my setup coming off... for a heck of a lot less than a couple grand too! )
I think 20rwhp or more with a whole exhaust would be pretty easy actually. IIRC I picked up around 3/4 of that with a swap from 1 5/8" to 1 3/4" and 3" y-pipe over a 2.5" setup. This setup made nearly as much as open headers did!
383vett, I want those stepped ARHs bad. $$$ is going gears and race gear for now. Someday, I already have a 3" system waiting in the wings for them... (Shoot Wayne, we should talk, if I get ARHs I'll have spare 1 3/4" headers and my setup coming off... for a heck of a lot less than a couple grand too!
)
Racer
Joined: Sep 2007
Posts: 493
Likes: 0
From: Eden Utah
Went to RMR yesterday for T&T. This strip is at 4500 ft and driving here is like driving against a brick wall. On street tires I ran a 12.8, at 109 miles per hour, with a 60' time if 1.8. That would be an 11.8 at sea level. Car ran really good and once I get a set of MT dot's I should run 12.5 all day long. If you guys are right about the headers then possibly faster. Really happy with the car and the tune.
Racer
Joined: Oct 2007
Posts: 478
Likes: 1
"This strip is at 4500 ft and driving here is like driving against a brick wall"
Your right. That density altitude is a killer. I don't think enough people take that in consideration when comparing times and mph across the country.
Your right. That density altitude is a killer. I don't think enough people take that in consideration when comparing times and mph across the country.
Melting Slicks
Joined: Mar 2002
Posts: 3,108
Likes: 126
From: S.L.C. UT
The 4500 ft Wayne was talking about is our actual altitude. The DA is usually 6000-9000 ft. Hey Wayne, did they have problems with water coming up thru the track like they usually do this time of year?
Racer
Joined: Sep 2007
Posts: 493
Likes: 0
From: Eden Utah
Not that I could tell.
By the way after all was said and done, smaller cam, etc. The 195 (l98) heads gave me 50 more horses than the edelbrocks, not talk, have dyno runs for both..