400 HP for a 1985 corvette?

[FourAndAHalf]

Didn't buy it but its a really long story... It has been through the family since it was brand new first it started with my uncle, then to my grandpa, then my cousin, and then back to my grandpa, and it was a gift from him to me... it has a lot of miles on it and its kind of beat up because he let a few of his salesman drive it and they tore it up because it wasnt their car and they didnt care... but now i have it and im trying to fix it up...

 

[mynewc5]

Well, that's honorable and completely understandable.. Good luck, you're headed in the right direction...

Doug

 

[FourAndAHalf]

Thank You

 

[johnny]

400 hp under the hood?

hey fourandahalf,

I have a 86 vette, i have done a lot of mods to my L98 engine. I also have installed a zf6 gearbox. The biggest improvement was the LPE SuperRam and baseplate, this will give you a highend engine....I loved it.

I have now around 340/350 hp .......my vette runs 172 mph in 5th.......awsome fast!!

Are you sure...about 400 hp on the rearwheels??

 

[90 RACER]

Getting the 400HP you want is not that hard but it is not cheap.
My 90 puts out 402HP from 4500 to 5500 RPM and peaks at 500
ft.lbs of torque at 4000 RPM at the crank using a 15% correction factor from the rear wheel dyno. You can use a stock block if you want. I went for forged pistons and rods and a .030 over block giving me 355 c.i. The key is Air Flow Research 190cc port heads with 2.05 intakes and 1.60 exhaust valves. I run a Lingenfelter 74211 cam and box intake manifold with a BBK 52mm throttle body. and 24#/hr injectors. I use TPIS 1-5/8 long tube headers running through straight pipes to the back of ther car. I have no smog equipment and no idlers. I had a custom water pump pulley made by Street and Performance mated to a custom Jones CW rotation Corvette pump. I run an ACCEL distributor and an MSD6 box. This engine is in my race car and I kept it mild for reliability.
My next engine will be a 650HP killer. Good Luck

Larry
San Jose

 

[Edmond]

Getting the 400HP you want is not that hard but it is not cheap.
My 90 puts out 402HP from 4500 to 5500 RPM and peaks at 500
ft.lbs of torque at 4000 RPM at the crank using a 15% correction factor from the rear wheel dyno. You can use a stock block if you want. I went for forged pistons and rods and a .030 over block giving me 355 c.i. The key is Air Flow Research 190cc port heads with 2.05 intakes and 1.60 exhaust valves. I run a Lingenfelter 74211 cam and box intake manifold with a BBK 52mm throttle body. and 24#/hr injectors. I use TPIS 1-5/8 long tube headers running through straight pipes to the back of ther car. I have no smog equipment and no idlers. I had a custom water pump pulley made by Street and Performance mated to a custom Jones CW rotation Corvette pump. I run an ACCEL distributor and an MSD6 box. This engine is in my race car and I kept it mild for reliability.
My next engine will be a 650HP killer. Good Luck

Larry
San Jose

Hi Larry,

That's one sweet powerhouse you've got there! I do hope to build an L98 up like that. I'm just curious why you didn't change the crank as well since you already did the pistons. Are you doing the crank next so it'll be a full 383?

 

[90 RACER]

Edmound,

I stayed with the stock crank because I never rev the engine above 5700 RPM. I'm way past the peak volumetric efficiency point over 5000 RPM. Its a mid range torque monster
not a max HP engine. You only need a forged crank if you plan to rev 6000 rpm and over on a steady basis. Your 383 comment hit
a sore spot. I had built a killer 383 using all the parts I have on the 355. Unfortunately I built it when I had my 86 automatic.
It had a pre 86 forged 383 crank and automatic transmission flex plate. There is no way to mate a pre 86 crank to a ZF6 so I wound up selling the short block.

Larry

 

[FourAndAHalf]

thanks guys im gonna consider all this info

 

[oldace84]

If you have the $$$$$$$$$$$$$$$$$$, you can do anything....belive me you can if you have the bucks...
tony

 

[LD85]

I am about to wind up my 406 build, with new alum-heads, cam , 400 block and crank, headers, intake, throttle body, full roller, machining, etc. figure on $6k, with you doing the engine pull and install.

Desktop Dyno estimates 478HP / 502 TQ on a mildly built 406 engine topping out at @ 5750 to 6000RPM.:s :cool

 

[Edmond]

I am about to wind up my 406 build, with new alum-heads, cam , 400 block and crank, headers, intake, throttle body, full roller, machining, etc. figure on $6k, with you doing the engine pull and install.

Desktop Dyno estimates 478HP / 502 TQ on a mildly built 406 engine topping out at @ 5750 to 6000RPM.:s :cool

That's a lot of performance for $6,000!

I'd like something like that one day, but not as extreme. I'm more of a fan of torque rather than horsepower. I'm more into the street light to street light driving thing.

 

[-=Jeff=-]

Unfortunately I built it when I had my 86 automatic.
It had a pre 86 forged 383 crank and automatic transmission flex plate. There is no way to mate a pre 86 crank to a ZF6 so I wound up selling the short block.

Larry,

Not to hit that sore spot again, but I know that Centerforca and fidanza make flywheels that work with the 2 pc rear main.

Reason I know is I have a 400 SBC that I was going to build and checked into different flywheels, both the companies I mentioned sell something that would work and mate to my ZF6.

 

[LD85]

I'd like something like that one day, but not as extreme. I'm more of a fan of torque rather than horsepower. I'm more into the street light to street light driving thing. [/B]

Edmond, on one cam I ram the desk top dyno for the torque came out at 570TQ/525HP, so I dialed it back to make it a mild mannered 406.