SS Viper

[GUMP]

Originally Posted by JP

This is how the plenum ended up looking. It works realy well above 4000rpm, but under 4000 it would have been impossible if we didnt have a fuel injected engine. To get the engine to work at low speed we had to remove 80% fuel at the rear cylinders and linear add fuel towards the front of engine (closer to trottle houses).
The guys who did the Dyno tuning in USA dind't bother to do that, so we spent two days in a chassie dyno to get the engine driveable...

I wonder if some of your tuning issues would go away if you regulated the pressure after the injectors? That way you would be guaranteed that all of the injectors are getting the same fuel pressure. It would also reduce heat soak related issues with the fuel in the rails. Or, am I missing something in this photo?

Love this project!!

[BlackMax]

JP:

I have been watching your project with great interest. My Gen II has an after market cam and I have the same fuel in-balance issue as you described with your manifold but with the stock manifold. I know you had to keep the TB's in the stock location but had you ever considered how a system might work with the TB's air dumping into the center of the manifold? I am thinking about cutting off the top of a stock manifold and building a cover that would accomplish that.
Thought I would check around before cutting metal. The Gen II manifold has the exact same air flow problems we had in the old days with the Hemi cross ram manifold.

Thanks

Jim
hartsnet@yahoo.com

[theman440]

Bitchin' Car.

[JP]

Yes, we had that design on the drawing board, and if I don't miss mind I think there have been some vintage intake manifolds/plenums with similar designs as you have in mind. We would probably have been better of with the injectors moved closer to the valve but In our case isn't the performance and driveability in low rpms a big issue, we are more interested in 4500 and up, so only by tweaking the fuel flow solved most of our problems. But for a street type of car would our manifold be a total failure...
The issue with the stock manifold can easlilly be solved with a after market ECU...no problemo :-) Just remove som fuel for the rear injectors at low and mid rpm.
What ECU are you running now?

Originally Posted by BlackMax

JP:

I have been watching your project with great interest. My Gen II has an after market cam and I have the same fuel in-balance issue as you described with your manifold but with the stock manifold. I know you had to keep the TB's in the stock location but had you ever considered how a system might work with the TB's air dumping into the center of the manifold? I am thinking about cutting off the top of a stock manifold and building a cover that would accomplish that.
Thought I would check around before cutting metal. The Gen II manifold has the exact same air flow problems we had in the old days with the Hemi cross ram manifold.

Thanks

Jim
hartsnet@yahoo.com