LT1, Crossfire, etc.., Intake runner lengths

[Tom Sharpe]

ECMnut at aol.com wrote:

> >   I have been under the impression that long intake runners are for
> >  low-end torque, and short runners are for high RPMs.  What type of project
> >  are you considering?  Maybe then we could get some folks to analysie it in
> >  greater detail.
>
> Yep, I was of the same understanding, just looking for RPM ranges.
>  I bumped into an old racer buddy the other day and stopped
> by his garage.  He's got a '68 Camaro drag car, 355 chev, .
> .700 lift roller cam, 850 holley carb,  13:1 comp, powerglide trans...
>   He says there is no way a GM ECM system will replace his
> Holley & dual point dissy and still  turn 9.90s...
>
> I told him to build a low comp shortblock and
> put some turbos on it with a milder cam, and the EFI will knock
> his socks off..   Their are 3.8 liter Buicks that weigh 1,000
> pounds more than his car, that earn quicker timeslips.
> He likes loud cars and hates my turbo talk..
> Gets upset when I call him a caveman..
> He is still considering a naturally aspirated EFI setup..
> His roller cam doesn't pull much vac at idle which has me a
> little hesitant to try a MAP system.  Another concern is that
> his engine regularly sees 8500 RPM.  I don't think that the
> GM ECM can do that.  Not sure though..
> Thanks,
> Mike V

  The Edelbrock will but you need larger injectors for > 450 HP. And it uses MAP
technology. Just keep retarding the spark at idle and load up the mixture until
it settles down. I ran a mild roller until one lifter destroyed the cam. It would
idle at 1100 as smooth as silk.

TRegards  Tom