DIY_EFI Digest V4 #607

[Doug Dayson]

Hi rpettibo...sorry...didn't catch your name...

I'm very interested in your Performer vs Victor Jr dyno charts...

I see the peak torque and HP improvements mentioned below...what were the
other changes in the total torque curves?

Below 4000 rpm...above 4000 rpm...below 2000...below 3000 etc...

In my experience the difference between dual planes and single planes occurs
around 4000 rpm...single better above and dual better below...

Did you notice that with your carbureted dual plane to MPI single plane conversion?

What rpm do you shift at and recover to?

TIA...Doug

 

> Date: Wed, 27 Oct 1999 17:19:30 -0700
> From: rpettibo at hpubs.com
> Subject: Re: DIY_EFI Digest V4 #606 Re: Intakes
> 
> On the issue of single vs dual plane, I converted a 383 Chevy from a
> Edelbrock Performer RPM (Dual Plane)  and Holley 750 (#3310) to an EFI
> using a Victor JR  with sequential port injectors.  Torque increased over
> 50 lb/ft and HP by 30.  Both set ups were dyno tuned.  From my experience
> the best air-flowing manifold is the one to go with for EFI applications.
> I know the runners on the Victor flow much better than the Performer on the
> flowbench.  I don't remember what the numbers were but it was significant.
> The other VERY interesting thing about this conversion was an increase in
> maifold vacuum.  With the carb I ran 12" at idle, which is about right with
> my solid roller cam (244in, 249ex @ 050 and 555 lift).  With the fuel
> injection I am at 15.8 - 16".  Anybody see this on other applications?  I
> still find it hard to believe.
> One thing is for sure injection is worth the price of admission.