Bore Intake Manifold? Pros and Cons?

[Qr25vet]

i think this is a better ITB setup [sweatdrop]

10 throttles from an E60 M5....Man i love my job :P

[Qr25vet]

just like how the E39 M5's 5L V8 only produces 400BHP in factory tune...but give it to ascari...they can give you 600BHP just by altering the valve timing and ignition!! [sweatdrop]

[Qr25vet]

just like how the E39 M5's 5L V8 only produces 400BHP in factory tune...but give it to ascari...they can give you 600BHP just by altering the valve timing and ignition!! [sweatdrop]

[Normal_aspirated]

topic getting interesting..................juz lika ol' days.

[Route]

anybody knows where i can bore throttle body with butterfly plate change?

[Yuan]

There can be no one particular modifications related to air flow without changing 1 variable. A combination of compensation to eliminating air flow restrictions has to be carried out.

 

Hence explain why I brought camshaft into the picture because I am under the impression that you felt that because valve size is factory, all other components that propagate air flow is redundant.

 

I don't think you get understand factory engine set ups.

 

Factory engine set ups are never tuned for maximum volumetric efficiency. The closest ever I have come across are cars like E46 M3 CSL which runs 280 deg camshaft and Honda S2000 F20C.

 

The M3 and the S2000 are both running very high volumetric efficiency because it all becomes very obvious that after all that CAI, pod filters, 3" exhaust, advancing ignition timing till its no longer feasible, you soon come to realise the horsepower gain is minimum.

 

More drastic modifications are needed to squeeze horsepower out of them but I won't mention what and how we are able to do so for the purpose of staying on track.

 

Back on the topic of volumetric efficiency, most factory cars are mainly restricted by air flow and hence are not running optimum efficiency. This gap can be narrowed if less restriction is imposed on air flow.

 

When you remove air restrictions, you are enabling the engine(NA) to take in as much air as it wishes to.

 

In addition you need to look at various engine load relative to rpm. Just because you are running at 30% engine load with little air restrictions, it does not mean that there will be just as little restrictions at 100% engine load.

 

At higher piston speed or rpm, the amount of air flow demanded is increased. Simply changing to pod filter does not help much because at higher engine load, intake pipe diameter becomes too small to allow air flow. Restrictions are further imposed at the throttlebody size as well as intake manifold.

 

If you want to fully maximise volumetric efficiency, go ITBs.

 

As to whether boring the intake manifold would help ? The answer is no. You need to do a whole lot other things. Its just like asking whether chucking a T04Z would increase horsepower ? The answer is no as well. Without some form of ECU tuning, changes made to air flow instruments, fuel supply, there can be no horsepower gained.

 

Simply boring the intake manifold alone without looking into other aspect of is simply being tunnel visioned.

 

Bro, nice sharing.

 

I learn something new today.