How to Increase Air Intake?
 

I'm new to the Porsche Brand, but itching to try my next mod.

My first mod consisted of a "simple to install" bolt-on plenum that replaces the original stock plenum by Peak Aire Performance, which has yielded 36 to 37 MPG highway driving ( see pic ) & 20 to 23 MPG city.

Not sure if these MPG ratings are good or bad, however the original sticker price label when the car was sold read - 20 City 29 Highway - Comments Welcomed!

Question:

Has anyone successfully increased the size of the stock TB & Intake Plenum from 68mm to 74mm?

I would like to combine the increased performance from the first mod with a larger plenum & TB from a different Porsche model.

Does anyone have the recipe for this "DIY" cocktail? :cheers:

Seems to me you would get more responses in another section of the forum. Racing boxsters is more often than not done in the context of spec series which does not allow modifications to the air intake, engine or headers.
Just my 2 cents.

Before you go off spending a lot of money on modifications that may deliver only questionable results, do you homework thoroughly and be prepared to conduct the mods scientifically (e.g.: before and after dyno pulls at a reputable testing facility).

A lot of the aftermarket intake (and exhaust) mods for these cars actually add very little, if any, gains; and even then the gains are often if an RPM range where the engine spends very little of its existence. Quite often, many of these mods do something far worse: They cost a lot of money and actually reduce power and torque, and can defeat the car’s drivability at the same time.

Bigger is not always better; only when it is definitively and positively proven to increase power output in a usable RPM range, without making driving the car a pain.

TY on the advice!

Can you comment on my MPG ratings?

Since the plenum upgrade, the Porsche on board computer indicates substantial increase in HWY driving 37 MPG (results of 3 months of monitoring).

Please comment.... thanks!

Onboard computer is often misleading and inaccurate regarding mpg. To check your results, log your mileage, log gals used, divide miles/gal.

Mods to improve gas mileage? What is this nonsense? Sounds like you bought the wrong car.

S & B,

My quest for more HP & Torque is the same as most if not all Porsche enthusiast.

However, I was just sharing the pleasantly discovered bi-product of the intake upgrade with others within the Boxster community.

Trust me... where I live 91 Octane fuel averages over $4.65 per gallon (soon to be $5.00) so any inefficiency in fuel economy is an added plus in my book.

Thank you for thoughts & comments!

An interesting data point:
The fastest Boxsters in SoCal running stock displacement, are also running a stock intake. This is not intuitive but it is true. Food for thought. ;)

Watch them go at Auto Club Speedway in Fontana next month during the Festival of Speed.

Topless,

Thanks for all your support & insight.

See you at the Festival of Speed event!