408 to big for vr4?

[94gt-sn2000]

i'm getting a 408 built for my 94 gt but i wanted to push about 10-12lb boost to it, i've seen people making 14psi to their mostly stock 302 but haven't really see anyone with a vr4 on a 408, also this is a 500hp on motor 408 what percent hp increase would i see, i just wanted to see where i'm at because i don't want to put much more money into the vr4 if i cant get enough out of it, thanks for any info.

[speedytang]

You need a Novi2000. You will need to pulley the supercharger way down to get 12psi out of a Novi2000 on a built 408. Your out of the realm for the VR4.

[blownzoom440]

useualy evey 2lbs of boost is 1 point in compression.that will help you figure the hp.

[94gt-sn2000]

thanks speedy, kinda not what i wanted to hear but oh well, do you think i could get 8lbs out of the vr4?

[speedytang]

You could get 8psi but it would need to be racing only because of the RPMs you would be spinning the Supercharger even with a cooler would kill the unit.

[Orion_134]

I thought the 2000 flows just as much as the VR-4, 1600 cfms... I was thinking of going this route as well. Speedy?
Jesse

[speedytang]

We are not talking flow now, we are talking Cubic Inches and you need boost. You will need to pulley the units to get 8psi and with the VR4 you will be over the Safe Max. rpm when you need to fill the cylinders on that size of a engine.

[94gt-sn2000]

well my motor is going in my car some time next week and i'm gunna try the vr4 after i break it in for a couple weeks, i'm going to try it with the stock crank pully and a 3.75 blower pully since i already have it, i just need a powerpipe for it now, anyone have any ideas who makes a powerpipe for the 94-95 body style? i'm getting it dyno tuned when i put the sc on so i'll keep ya posted hopefully somewhere in the 550's+ rwhp. but if the vr4 doesn't make 6-7psi (since i won't see 8psi) i'm going to go with the novi2000.


Speedy (or any one who would know), i always see you guys taking about changing the inch pounds on your s/c and how it can effect how much boost you can get. I know how to measure it but thats it, and before i dyno it i want to get it right because i don't know if the tunners are going to let me take my s/c off to adjust it. Kraig at p.w did the vr4 upgrade so i figured it was good but i wanna be sure. (i have to get a small torque wrench so i can check it, but where should it be?) Thanks

[speedytang]

If you told him it was street driven he probably set it at 45 in/lbs. I have mine at 52 in/lbs I think... I always play with different settings in the winter and I don't have my setting sheet on this computer.