ArmoE55

I understand that having less back pressure can reduce boost - but by how much are we talking? Wouldn't it almost negligible? I have been reading some threads on the board.

For instance, Long tubes on an otherwise stock exhaust, with either 172mm or 180mm pulley and a custom tune...would your boost actually decrease to less than stock boost ?


Increasing the pulley size along with long tubes can't make your lose boost...am I understanding this correctly?

Someone please school me before I decide what pulley I want to get!

Currently have EC long tubes on order!




Thanks in advance..

AMG_RL

long tubes are way more efficient than the stock headers and as such, require less boost to make more power. basically the best of both world because you're getting more ummph for less strain on the engine. and it's not a HUGE amount of boost drop so you should not worry.

ArmoE55

Thank you for the post. I had been leaning towards a 168, only because I'm trying to break any boost records here, but wanted to be sure I was understanding the theory in general with long tubes.



Others can please chime in with their experience as well ...

shardul

iTrader: (1)

.5 to 1 psi roughly will be the boost drop

ArmoE55

Thanks.

Does anybody know if the 172mm pulley has fitment issues?

PACougar

The thing you need to remember when talking about boost is boost=restriction. Less boost has nothing to do with less power. If you put a bigger pulley on and lower the restriction enough you could have less boost then stock, but tons more power. In fact that'll give you a cooler more efficient engine.

Jakpro1

Thanks for that above. So true. On you tube their is a rare before and right after dyno of long tubers. Just installed and strapped down.....35 wheel gain

ArmoE55

Good info.

So when installing long tubes, would it be wise to go with a 168 or 172 pulley? I am thinking a 180 is too large and would far too much heat? I live in a state that has hot summers, but cool springs/falls and very cold winters.

Iisn't the power difference between a 172 and 180 relatively small for the amount of heat production difference?

It sounds like 168/172 is the way to go with long tubes. 180 sounds too big and you need many more cooling mods than just a HE and upgraded pump.

Correct me if I'm wrong ...

PACougar

I totally agree you'd want cooling upgrades if you go for a 180, but I'd suggest them to anyone. A cooler intake system is going to make for a happier engine no matter what size pulley you go with. I'm sure you'd be happy with a 168/172, either way the power will be ridiculous!