Exhuast question?

GTI-R34

New Member
Hello guys i have a question

wich exhuast is best for bhp gain, performance gain?i did search the forum and found out almost every one is using mongoose , but does it really give a bhp gain?what about the fujitsubo and the other ones

which exhuast can give you more gain ?

thanks in advanced

Myron
 

Braveheart

New Member
I can't comment on different off the shelf exhausts as I've only had exsperience with one.
As you have spotted, the goose is the most commonly used exhaust.
It's strong and with the cat removed not too restrictive. It's quite loud though. You should see at least 8-10bhp increase and maybe a further 3bhp with a good induction setup.
If noise and cost is not an issue then a 3" custom made downpipe and exhaust would be the way to go. For max gains you should match the exhaust system with a 3" custom manifold.
 

youngsyp

Active Member
GTI-R34 said:
Hello guys i have a question

wich exhuast is best for bhp gain, performance gain?i did search the forum and found out almost every one is using mongoose , but does it really give a bhp gain?what about the fujitsubo and the other ones

which exhuast can give you more gain ?

thanks in advanced

Myron
I have a custom 3" elbow and downpipe that tapers down to 2.5" as it goes to the decat pipe. The idea behind this, is to keep gas velocity up. It has a small straight through 2.5" silencer where the cat pipe was and a fairly small 2.5" rear silencer.
With that, a blitz filter and boost at 1.1bar, mine made 318bhp (249 at the wheels) and 293 lb's/ft of torque (around 230 at the wheels).

So, I'd say it works quite well.

What you're trying to do is get the gas out as quickly as possible and if you do that correctly, it will pull the new cylinder charge into the cylinder, as it exits the exhaust valves.
To help this, you need to have a large enough pipe, with as few a bends as possible. And if you have bends, these should be as mild as possible. Lagging the exhaust will help maintain gas speed too.

I think the minimum you should go for is a system similar to mine, with the most important part, being the 3" elbow and downpipe. It's not just the bore of the elbow thats important. The stock elbow has a lot of obstructions inside and, isn't smooth. A fabricated stainless elbow will be smooth and have no obstructions.

If I had the choice again, I'd go for a full 3" system, from turbo back.
 

Keira

New Member
Braveheart said:
you should match the exhaust system with a 3" custom manifold.
3" manifold :lol:

i think you might just have a little bit oif trouble getting 3" bends to fit in the space between the head and radiator tbh :lol:
 
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