N/A Exhaust size questions:

[jihwaan]

Getting a new custom made exhaust on the N/A next week and was wondering what you guys think is the best size.

I have done a search and done some reading and the general consensus seems to be 2.5 inch.. anyone here got a 2.5 inch with a double decat on their NA? does it sound ok?

I dont want a stupid loud go nowhere exhaust - just something with a nice note.. coz u cant hear the standard exhaust for peanuts even when its up in the revs ..

 

Also is the first decat worth doing (the cat near the manifold I mean) when i get the exhaust done? I will be having the second one done anyway so I figure I should have the first one taken care of as well...

 

Can I ditch the 2 resonators and just have one muffler with 2.5 inch pipe and decat, or will that be too loud?

[Homer]

Is the twin decat worth doing? - no IMO, it might release a couple of bhp at the top end but it's hardly worth the cost and hassle. It won't make any difference if you have a 2.5in decat or 3in

 

The noise level all depends on your cat back, some are quiet, some are extremely loud. The NA's are noiser than the TT's with the same exhaust, but quieter than a single on a tubular manifold.

 

Do you intend to track it?

[jihwaan]

Thanks for the reply Homer, no track for this car, would like to squeeze a couple extra HP out of her tho', god knows she is lacking..

I just figured if the guys were making the exhaust up it wouldnt be that much more to get the second decat done near the manifold...the whole exhaust and muffler setup is only costing me $400 bucks (about $200 GBP) so I figure another 100 dollars (50 odd GBP) I might as well get the second cat taken out but if its not worth it I wont bother..

Does anyone know if you can just bash the mesh out (I know we used to do this on the r32 nissans we had years ago).

Reason I ask is I really want the low burble and popping when coming down the gears under engine braking (bit chav I know but I like the sound), which from experience with other cars I got from pulling the cats and only having one muffler...

 

Can anyone tell me if I can get an NA to sound like this?

thanks guys!

[Ian Hayward]

Yes you can get the NA to sound like this.

My supra was originally an NA and I had a custom exhaust made for it: 3" straight through with a HKS hi-power back box.

It sounded good low end and you defo get the burble and popping that you want.

The only problem is it is VERY loud. It was so loud infact that I had it taken off and the original exhaust put back on until I had the engine transplant.

I now run a Blitz Nurspec R-X full exhaust on my big single. This sound so much better but you do not get the popping.

 

I would defo advise not goin bigger than 2.5" or you may find it embarrassing to drive

Hope this helps.

 

Ian

[SpeedyAndy]

With takings the First cat out and second ( by the manifold and further down the exhaust ) yes it does drop your BHP but increases on your torque which i found. But you don't get any lag though with putting your foot down and changing gears with both de-cats. and yes they are very noise and you can pop flames when changing gears with popping aswell.

 

But if your after pushing a few more BHP ( good luck as there's not alot you can really do ) but keep the first cat in the exhaust. you will still get the popping and the exhuast is still noise but not allowed but all depends on what back box you have and how big your exhaust is.

 

Hope this helps.

[supra_aero]

Yes you can get the NA to sound like this.

My supra was originally an NA and I had a custom exhaust made for it: 3" straight through with a HKS hi-power back box.

It sounded good low end and you defo get the burble and popping that you want.

The only problem is it is VERY loud. It was so loud infact that I had it taken off and the original exhaust put back on until I had the engine transplant.

I now run a Blitz Nurspec R-X full exhaust on my big single. This sound so much better but you do not get the popping.

 

I would defo advise not goin bigger than 2.5" or you may find it embarrassing to drive

Hope this helps.

 

Ian

 

 

Never realised you could get the NA to pop. My car is ridiculously loud and thats with the cats still in so can't imagine it without.

[Dann]

I have both cats removed and stainless 2.5" front section then a middle section taking it from 2.5" to 3" for hks hi power silent back section. It sounds sweet loud but sweet and I do give flames on high rev gear change.