700hp With A 408 Possible?
#1
TECH Regular
Thread Starter
Join Date: Dec 2012
Location: San Diego
Posts: 414
Likes: 0
Received 0 Likes
on
0 Posts
700hp With A 408 Possible?
Ok so i am wanting to know what the limits of a 408 are NA on pump gas. Also what top end could do it. I was thinking something along the lines of small bore LS7 heads and a spec'd cam with matching intake but i just dont lnow. Im trying to get 600rwhp NA. Now i saw one of Tony Mamo's 383 put down 525rwhp NA. Now my thoughts are if one can squeeze 500 hp NA out of a 383 couldnt one get 600 out of a 408? Whats Techs opinion on this?
#3
TECH Regular
Thread Starter
Join Date: Dec 2012
Location: San Diego
Posts: 414
Likes: 0
Received 0 Likes
on
0 Posts
I havent really thought about e85. I was think more along the lines of 91 octane. I know the highest u can go with that is 12.0:1. If my math is correct i would need 690hp at the crank to get 600rwhp with a 15% parasitic drive train loss.
#9
TECH Senior Member
#10
Staging Lane
iTrader: (1)
Join Date: Apr 2007
Location: Wyoming
Posts: 58
Likes: 0
Received 0 Likes
on
0 Posts
i got 724HP 602 ft. lb torque out of 425 cu. in. LS2 block. Eagle rotator. LS3 heads ported by bowers out of Ft. Collins. Holley tall efi intake, 92mm intake. I think we used 45# injectors. 91 Octane at 3800 ft. elevation. Gibbs oil. lots of dyno time. Lots of ZOTARS $$$$$$ The holley tall efi intake is a tight SOB in a fourth gen.
#12
TECH Regular
Thread Starter
Join Date: Dec 2012
Location: San Diego
Posts: 414
Likes: 0
Received 0 Likes
on
0 Posts
I appreciate everyones advice. Now my 408 is a fully forged short block with arp 2000 fasteners used. The short block was built by Thompson Motorsports. As it is right now it has a 11.2:1 compression ratio with LSA heads so id imagine i could bump compression quite a bit with a smaller chamber.
Now i have looked into Forced Induction and it would cost about 7300 for the procharger, injectors, fuel pump, intercooler ect. My issue with FI is my compression ratio is a bit high, id run out of octane on 91, and i could only run about 10 lbs boost before i exceeded the rating on my short block. I would imagine 7300 would get me pretty close to my NA power desire. And if i wanted to run a power adder i could run direct port and spray my way to my goals for about 3300.
How does one determine a max rpm for a engine if u take the valve train out of the equation?
Now i have looked into Forced Induction and it would cost about 7300 for the procharger, injectors, fuel pump, intercooler ect. My issue with FI is my compression ratio is a bit high, id run out of octane on 91, and i could only run about 10 lbs boost before i exceeded the rating on my short block. I would imagine 7300 would get me pretty close to my NA power desire. And if i wanted to run a power adder i could run direct port and spray my way to my goals for about 3300.
How does one determine a max rpm for a engine if u take the valve train out of the equation?
#15
11 Second Club
iTrader: (9)
I appreciate everyones advice. Now my 408 is a fully forged short block with arp 2000 fasteners used. The short block was built by Thompson Motorsports. As it is right now it has a 11.2:1 compression ratio with LSA heads so id imagine i could bump compression quite a bit with a smaller chamber.
Now i have looked into Forced Induction and it would cost about 7300 for the procharger, injectors, fuel pump, intercooler ect. My issue with FI is my compression ratio is a bit high, id run out of octane on 91, and i could only run about 10 lbs boost before i exceeded the rating on my short block. I would imagine 7300 would get me pretty close to my NA power desire. And if i wanted to run a power adder i could run direct port and spray my way to my goals for about 3300.
How does one determine a max rpm for a engine if u take the valve train out of the equation?
Now i have looked into Forced Induction and it would cost about 7300 for the procharger, injectors, fuel pump, intercooler ect. My issue with FI is my compression ratio is a bit high, id run out of octane on 91, and i could only run about 10 lbs boost before i exceeded the rating on my short block. I would imagine 7300 would get me pretty close to my NA power desire. And if i wanted to run a power adder i could run direct port and spray my way to my goals for about 3300.
How does one determine a max rpm for a engine if u take the valve train out of the equation?
#16
TECH Regular
Thread Starter
Join Date: Dec 2012
Location: San Diego
Posts: 414
Likes: 0
Received 0 Likes
on
0 Posts
Where would one find ETP LS7 heads cause i keep hearing about them but i can never find a website for them.
#18
Mustang dynos can be calibrated to read within a certain percent of a dyno jet, and usually are. Still impressive.
#19
TECH Regular
Thread Starter
Join Date: Dec 2012
Location: San Diego
Posts: 414
Likes: 0
Received 0 Likes
on
0 Posts
#20
TECH Addict
iTrader: (83)
Making that kind of power is going to require about $6500 in heads and intake. Solid roller. so another $1200 in cam and lifters. 8000 rpm Nothing gets cheap about it. Trust me I am looking at $5000 out of pocket to sell my stuff and put a set of full tilt mast heads that will make 760-770
Tim
Tim