I currently have a superram and will be adding a turbo setup. My question is does it really matter what the intake design you use so long it is not a bottle neck? So hypothetically if the runner diameter was the same between a TPI, Superram, miniram when using forced induction does it really matter which one you use? Or does their flow characteristics still apply with forced induction (ie Superram=midrange vs. miniram=high RPM)?

Yes it still matters. Its not only the intake though, its also the heads and cam. I'm boosting a stock L98 TPI motor and there is a noticable drop in acceleration at 4800rpm when going WOT. The boost dosnt drop or anything, it will maintain 6psi from 3000rpm all the way up to 5500rpm, but the combo is no longer in the powerband past 4800rpm so its not making more power. This is not entirely the TPI intake's fault, its also the stock heads and cam. A roots supercharger would be a better match to a stock TPI motor in my opinion. I guess the genreal idea is that everything should be matched. So to maximize the potential of forced induction setup that makes power at the higher rpm's, you'd probably want a intake/heads/cam combo that is geared towards high end power.

Sorry you didn't answer my question.

Take heads & cam out of the equation and hypothetically if the intake port diameter is the same does intake design really matter once you add forced induction?

I guess the real question is does runner length make a difference when using forced induction?

Thanks

yws it does. i know people that are superchargered and they just changened the lower intake manifold and lost boost do to better flow. do you want torque, horsepower, or both?

to cut the **** out of the way and get to the point, i would go with a tpi, long runners for great low end TQ, the higher you rev the more boost you will have and it will MAKE the tpi heads flow a hell of a lot more for great top end

Where do you want your powerband should be the question.

LTR will put it down low
SR middle
MR etc up top.

What do you want TRQ, HP or both.

You should be just fine with a superram. If your worried about it have it ported.

Looking for middle so I may just stick with the SR.

you can only "make" something flow so well.
and from what I understand higherboost means more restriction creating heat in the intake system.

why not just put something in there that is more efficient through a wider range then what the TPI system is?

Everything else being the same, the longer the runner the less the flow, just like you won’t have as much pressure at the end of a 100’ hose as you will at the end of a 50’ hose.

Since you chose designs that “everything else isn’t the same” it’s even a more difficult comparison, runner/port shape, taper, length, engine powerband… all effect flow.

Boost does change the equation some since tuning effects… will not have as big an effect on power band as where you actually have boost.

Lastly, it’s already been mentioned, but the major restriction with a stock TPI is the heads, not the TPI.

Took the flowmaster off and turned the wick up to 22 lbs and made 572 RWHP at 5,000. And 662 ftlbs of torque at 4,300.


Peak HP @ 5k with a factory stock LTR intake... wow

Still a torque monster...

so yes the intake makes a difference although i would say less so then an na setup but still a major diff

FYI i got this from Bigl350's post