Dump pipe upgrade? R33

[benl1981]

My new skyline has a 3.5" cat back exhaust. I'm looking to make a 3 - 3.5" Dump and front pipe.

What power gain can I expect from this one mod. WOuld it give me 10kw you think, make boost lower in the rev range?

What is standard dump and front... 2 - 1/4 inch or 2.5 inch?

The car has a pod filter (not enclosed) and a standard intercooler.

Sorry if it's been covered before.

I was going to make up the pipe myself. Is the standard dump pipe mild steel,, i.e could you reuse the flanges...

Thanks

[2BNVS]

i gained 10rwkw from fitting a 3" dump and hi flow cat on my car,

mid range was improved heaps and spooled up quicker, before u get it dyno'd get a cai box around ur pod too, that gave me 6rwkw from a kit i bought from UAS...

ben...

[benl1981]

Thanks Ben - Handy to know!

I'm intersted getting the boost on earlier for sure. Feels a little laggy at present.

Point taken about the POD

I think the standard dump pipe is cast iron so I don't think I'll be able to modify my old one.

Does anyone know a good exhaust shops that would make up flanges cheap? In Sydney? How much approx for a flange (mild steel)? I gues the one to turbo one and the one to the cat will have to be unique. The 2 in the middle that join the 2 pipes can be whatever they have. Is 3" big enough, 3.5" overkill? I'm not planning on doing heaps of mods. 170rwkw will be plenty.

[bigcarl]

i got another 17rwkws with ces racing split dump pipe, 3 inch cat at the same boost.

[benl1981]

i got another 17rwkws with ces racing split dump pipe, 3 inch cat at the same boost.

Impressive!!

Is there any reason not to make the front/dump one piece? You should still be able to get it off easily enough right?

I might save on 2 flanges.

Shouldn't be hard to make. Get some bends, cut to required angle (say $30), some straight section ($50), 2 flanges cut ($60)

SHould be about $150 all up. About half what they cost to buy.

[rs73]

If you haven't got an aftermarket front pipe, then just go for one piece front/dump pipe.

In my case I feel pity to ditch the good front pipe just for the sake of getting the dump pipe, so might have to consider just the split dump pipe section. I can sell the front pipe if I replace it with something like CES, but I just feel a bit pity as I paid for it (didn't came with the car).

[benl1981]

Yeah you might be abble to source a dump at a good price hopefully

Is 3" worth the effort - going from 2.5" (stock). I guess It must be.

Currently got 3.5" from cat back, but restrictions in cat probably make any bigger than 3" dump not really worthwhile?

If you haven't got an aftermarket front pipe, then just go for one piece front/dump pipe.

In my case I feel pity to ditch the good front pipe just for the sake of getting the dump pipe, so might have to consider just the split dump pipe section. I can sell the front pipe if I replace it with something like CES, but I just feel a bit pity as I paid for it (didn't came with the car).

[rs73]

Is 3" worth the effort - going from 2.5" (stock).  I guess It must be.

Any increase in diameter would help, even if ur cat has certain restriction. But at least if urs is a hi-flow cat then shouldn't be a problem for general street use/occasional track or drag days.

The idea is to reduce turbulence behind the wastegate so turbo can spool up easier and thus bringing the pwr curve up quicker...

[nismo33]

i was wondering is split dump pipe any better ?

i'm on the verge of purchasing either HKS split dump pipe..and then a front pipe.

or get a 3' custom dump and front pipe in one for half the price of the HKS.

which one would you guys recommend ?

[knore]

Proper split dump pipe like the ces one is the best you can get pretty much

You get more power than standard 3" dump pipe, because the CES/split one has a seperate pipe for the turbo wastegate, creating less restriction, turbulence and therefor better flow