What Exhaust Size For A Efr 800Hp Setup ?

[cobrAA]

I have 3 inch right now. However, I'm thinking I *might* be better with a 3.5 inch and would the 4 inch be over-kill ?

[scotty nm35]

Are you planning to run a screamer pipe off an external gate? Otherwise you are thinking too small.

[cobrAA]

Are you planning to run a screamer pipe off an external gate? Otherwise you are thinking too small.

re-routing in the exhaust. it would be way too lound if i go external, I'm afraid.

[Piggaz]

4 inch with quality mufflers. Done.

[cobrAA]

4 inch with quality mufflers. Done.

Just heard my friend 4 inch exhaust and it wasn't that bad.. by reading most people opinion on this website, 4 inch is way too loud, but to my surprise, it isn't THAT bad..

[Ben C34]

4 inch isn't a volume. It's a diameter.

The silencing ability is determined by the mufflers, not just the pipe size. I've heard some loud 3 inch exhausts, doesn't mean they all are.

[cobrAA]

4 inch isn't a volume. It's a diameter.

The silencing ability is determined by the mufflers, not just the pipe size. I've heard some loud 3 inch exhausts, doesn't mean they all are.

Agree, but its a lot easier to find 3 inch *quality* muffler/resonator than in 3.5 inch or 4 inch ( most are just ',race spec'' and barely do sh*t lol). Lets be honest, people who go 4 inch usually don't care too much about sound isn't ?

Edited September 27, 2014 by cobrAA

[Piggaz]

... but a 3 inch exhaust doesn't belong behind a 79 lb/minute turbo.

[cobrAA]

Yeah, I gotta admit that lol. Now, the challenge is to find a ''quiet'' 3.5 OR 4 inch exhaust. #challengeaccepted

[Piggaz]

Get one custom made. It'll hug the body better than that off the shelf junk.

[AngryRB]

What about having it 3.5/4inch all the way to the last muffler and having that smaller eg. 3inch/3.5inch? would that be effective seeing how its so far from the turbo or still restrictive?

Edited September 27, 2014 by AngryRB

[cobrAA]

What about having it 3.5/4inch all the way to the last muffler and having that smaller eg. 3inch/3.5inch? would that be effective seeing how its so far from the turbo or still restrictive?

I was actually thinking about doing a 4 inch dowpipe and using a 3.5 inch cat-back.

At the dyno, I could remove my 3.5 inch cat-back and see how much i gain. this way I would need if it's worth the price of custom.

[Piggaz]

I was actually thinking about doing a 4 inch dowpipe and using a 3.5 inch cat-back.

At the dyno, I could remove my 3.5 inch cat-back and see how much i gain. this way I would need if it's worth the price of custom.

You're going to all the effort to go to a modern single on you're setup. Give it the best chance that it can by going the biggest exhaust you can. The "small exhaust" on turbo engines has been blasted out of the water and a 3 inch on a 8374 won't do it.

4 inch with the biggest, baddest mufflers you can find. Custom made (which really won't cost you much more than a off the shelf system). Done.

[cobrAA]

You're going to all the effort to go to a modern single on you're setup. Give it the best chance that it can by going the biggest exhaust you can. The "small exhaust" on turbo engines has been blasted out of the water and a 3 inch on a 8374 won't do it.

4 inch with the biggest, baddest mufflers you can find. Custom made (which really won't cost you much more than a off the shelf system). Done.

Gotta love forum's influence !

But I have to say that Geoff when he managed to make 700whp with his efr, he had a 3.5 inch with cat. So I'm thinking 3.5 without cat shouldn't that much restrictive.. I mean.. i dont think we can really make 750whp with this turbo on a rb26.

[GTR_JOEY]

4 inch to the cat and 3.5 after at the minimum.. Otherwise full 4 like Paul has said multiple Times now

[colinhunt]

Gotta love forum's influence !

But I have to say that Geoff when he managed to make 700whp with his efr, he had a 3.5 inch with cat. So I'm thinking 3.5 without cat shouldn't that much restrictive.. I mean.. i dont think we can really make 750whp with this turbo on a rb26.

Seems like you already know best.

[cobrAA]

Seems like you already know best.

I'm not, I'm simply stating the only one 83/74 -rb26 I know of and his exhaust combinaison. Just posting another option/point of view, we are there to discuss

[Skepticism]

dyno readouts of cars with exhaust restrictions are the saddest shit ever. takes forever to spool and no power.

even if you can still hit your power goals you'd want to get the thing spooling as early as possible right?