HP limits of 2G intake manifold

[ceedawg]

Hmmm very good information. I always wondered about this since i'm on a stock 1g intake manifold with a my old 2g Tb.

The 1g inrake is much better than a 2g intake. No comparison.

 

[Imback]

The 1g inrake is much better than a 2g intake. No comparison.

Explain. Runner? Total volume?

 

[BigBeans]

With a HX35 turbo i'd do the "race".

Big turbo cars have enough low end power loss, and you won't see a whole lot of benefit from the drag over the race until you get into really big turbos.

If you're going to run a 65+lb turbo and rev over 8K, the drag would probably be the better choice.

I run the race w/ big cams that have been neutered a bit with reduced overlap and a 52lb turbo, and my peak power comes at 7300, i shift at 7700. For a street car that works just fine.

 

[Imback]

What power are you making and where at in band?

 

[BigBeans]

What power are you making and where at in band?

Approx 430-440whp on 93 octane with 52lbs/min flow. Full boost (30) around 4400, very flat TQ curve that peaks at 6K and slightly tapers after that. Peak hp is 7300 slowly dropping off because the turbo is out of steam. Boost starts dropping off from 30psi at 7,000 and tapers to 26psi by 7750, which is my shift point.

I could pick up a bit more in the top end if i put some overlap back into the cams, but the driveability gets considerably worse and i'm more than pleased with the top end and overall curve.