all the kits say they are going to include a 2.5in down pipe.. wouldnt a 3in. make more sense considering turbos will create more power the less restriction is on exhaust.... i would hate to have a 2.5 downpipe w/ a 3in exhaust ...

and one more thing.. CAI such as the K&N will not work w/ a turbo correct..... i need to get mine returned...even though it hasnt come yet..3 weeks later (Creative Compacts)..i think theyre on back order...

 

3 inch will be noticably louder and the difference between 2.5" and 3" will probably be insignificant considering the size of the turbo, engine, etc.

Most likely any aftermarket intake will not work with a turbo. They will probably come with their own, it should be part of the kit.

 

the 3inches are going to cause you to lose a lot of back-pressure and youll lose a significant amount of low-midrange torque and horsepower.

the amount of high end power you make with the 3inch downpipe isnt going to make up for the low-mid range power you lose.

CAI does not work with turbo.

 

2.5" is adequate for the applications. 2.5" pipe is made for cars up to 350-400hp. My dads v8 corvair pushing roughly 375hp has 2.5" exhaust. 3" would have a larger amount of turbo lag and it would be a little louder too. I don't know if it would actually hurt power but it would be stretching it to go 3". IMO

 

or any intake of that matter

 

You are wrong in everything you have said. First of all the less backpreassure you have in a turbo car, the more power you will get out of it. Turbochargers are very different from NA or supercharged applications. In fact, the turbine will give most power if there is no exhaust and downpipe on the car.

Second mistake is that CAI will work fine. The colder air you suck in the better. There is a reason you see supras racing without right headlight.

As for original question; 2.5 is plenty for the turbine sizes we are running on our scions. You need larger if you are planning to put larger turbos that would not work well for daily driving. JasonH has nailed it.

 

Correct, 100% correct.

While a CAI will function fine, the reason that a K&N or Weapon R won't work is because the intake piping will probably be in a different position with a turbo. It's not a functional problem, just a matter different measurements.

 

i know i was wrong, i just read on rippmods.com i was wrong
sorry guys.

 

i have a question, sorry if its obvious im dumb lol

Why wouldnt a aftermarket CAI work with a turbo? I am currently researching turbo and collecting parts for a turbo setup. Im planning to run around 6-8psi. My estimate for the custom turbo kit is around 1000 bucks.

 

becuase the aftermarket CAI is bound to the throttle body while as the intake piping for a turbo is bound to the TURBO

 

The reason we chose not to go with a 3" downpipe is so that you could bolt the downpipe to any catback that you may have already purchased.

As far as power; with the turbo we are running a 2.5" is more than enough flow to make power. Our stage two kit will have a 3" downpipe.

and to answer you question you will still see a power gain with a 3" catback even if the dp is still 2.5. We will offer a 3" turbo back at the time that our kits are released.

Thanks

-kenny

 

I would seriously be leary about a $1000 turbo. Unless you have all the piping tools and are building the kit yourself and purchasing the turbine

 

I was always told that the compressed air from the intercooler makes a CAI application on a TURBO car impossible. Is this tru? I know an intercooler is necessary for TURBO.

 

No this is not true a cold air intake can still be utilized on a turbo charged vehicle. All a cold air is that your induction system na/turbo/supercharged etc......is drawing a fresh air supply outside of the engine bay.

An intercooler is only to cool the charged air post turbo prior to the air is inducted into the intake manifold and used in the combustion process. A turbo can be used without a intercooler and can be very efficent at low boost levels this way.

Thanks

-zpi

 

yup that is right!