Exhaust Suggestions - R33 Gtr

[rehab2010]

Guys,

This is what I'm currently planning to get for my 33 gtr - any suggestions and advice, if something with this setup is NQR, I would appreciate.

• xforce front pipes - 2.5" into a 3.5", stainless
• 3.5" xforce cat, stainless
• 3.5" cat back with the middle muffler, mild steel
• xforce muffler 3.5" into twin 3" outlets, stainless

Got a fairly reasonable quote so am considering getting it, middle section is mild steel mostly to save some $$$.

[Single]

have you done you dump pipes?

what kind of flow does the xforce cat flow? 200cfm, 400cfm or more?

try get the front pipes in mild steel, no need to be fancy under there

[TiTAN]

if the cats not 100cpi (or 100cpsi) ask for one that is as it will give better flow.

[rehab2010]

Cool, d'oh, should have checked the flow rate, yep.

[rehab2010]

have you done you dump pipes?

what kind of flow does the xforce cat flow? 200cfm, 400cfm or more?

try get the front pipes in mild steel, no need to be fancy under there

Ho, have not done the dumps yet. Was just thinking of leaving them stock. Good idea/bad idea?

Those front pipes are off the shelf in stainless, made by xforce, otherwise I'd get them in mild steel too. This exhaust place was saying that they can make them out of mild steel, but I was just worried about them getting the lengths correct. Should I worry about it or not?

[smithy85]

I threw a 3.5" Xforce cat in my R32 GTR along with Trust front pipes 70mm into 80mm, and straight away made a big difference to the mid range even with the standard turbos that were on at the time. I got the cat from Just Jap and they say they flow at 880cfm. Not sure how that converts into cells per square inch (CSPI) though. Is there a conversion?

Don't bother with the dumps until the time comes to swap out the turbos, bit of waste of time and effort - alot of effort, considering the end result is of no big gain.

Edited October 18, 2011 by smithy85

[Harey]

Make sure the cat is 100 cell. If the xforce one is not, get a venom 100 cell cat.

[rehab2010]

Make sure the cat is 100 cell. If the xforce one is not, get a venom 100 cell cat.

Thanks for all the advice fellas, I'll check before I do anything.

[Count Grantleyish]

How modified is your GTR?

Don't bother doing dump pipes, stock are fine (I made 302rwkw with stockers).

If you want to do dumps, do it when turbos are out, just to make install easier.

[rehab2010]

How modified is your GTR?

Don't bother doing dump pipes, stock are fine (I made 302rwkw with stockers).

If you want to do dumps, do it when turbos are out, just to make install easier.

Its not modified at all, stock as except for K&N airfilter element - and yes I'm thinking if I ever get some -7's then I'd do the dumps, until then stockies remain.

[smithy85]

Its not modified at all, stock as except for K&N airfilter element - and yes I'm thinking if I ever get some -7's then I'd do the dumps, until then stockies remain.

good idea, theres alot of other things to do first that will give better and easier gains.

[Count Grantleyish]

^^^ +1

[rehab2010]

good idea, theres alot of other things to do first that will give better and easier gains.

Right now I'm thinking fitting that exhaust, then boost the stock turbos a bit more than the current 11psi, but not crazy high to see them break apart - I'm thinking 15psi.

Then get the adjustable cams and get the ignition timing adjusted on the dyno. Since I already have K&N I think this should make my baby breathe much easier and go much better.

I know its power will not be anywhere near most other GT-R's on this forum but I'm hoping for a 180-200kW at the wheels - if I'm lucky

[smithy85]

Mine made 233kw at the wheels running 14.5psi through the std R32 turbos on a powerfc plus cam gears, so you should be able to get up pretty close to that, pending on the tuner and engine condition

[silva33]

If you are only getting -7's why not stick with a 3inch? It will flow enough for the -7's and at the same time you could build a nice quiet exhaust which is a lot easier to do than in 3.5 inch.

[Count Grantleyish]

Quiet exhaust is overrated...

Get power fc while you're at it.

14psi, exhaust, cam gears, good filter and PFC tune = 240-250kw at rears.

[rehab2010]

If you are only getting -7's why not stick with a 3inch? It will flow enough for the -7's and at the same time you could build a nice quiet exhaust which is a lot easier to do than in 3.5 inch.

I'm not really planning to get -7's in the next 12-18months.

Reason why I'm going 3.5" is since xforce kit is 3.5" front pipe.

Do you think that even with the suitable mid-muffler and large twin outlet rear muffler this exhaust will be much louder than the 3"?

[smithy85]

Two decent mufflers in any system, even 3.5", is usually enough to maintain a respectable noise level.

Start removing mufflers on the other hand and the real RB noise starts to show , which is the route I took:

- I went from a 3" mandrel bent system that had a small hotdog plus a rear cannon and changed it to a Veilside 3.5" JASMA which actually made it quieter (EPA tested at 91db) because of the two monster mufflers it had. Then I got sick of the over-muffled noise and got rid of the centre muffler and that has given a nice balance of relative quietness during cruising plus a good "bark" when its punching holes in the horizon!

[Ruff Ryda]

Would have gone Blitz all the way from the front pipe to the tip but Xforce isn't a bad Aussie product.

Changing the front pipe on a tuned SR makes a difference apparently but not sure on an RB. Xforce do make a metallic 100 cell cat in a 3" setup, don't know about 3.5" though.

Either way, you enjoy your setup mate. If noise is a concern either throw in on nice big muffler box and / or an Apexi ECV 95mm. If you're game try one of those velocity pipes that have a smaller diameter but flow better with pressure.

Edited October 21, 2011 by Ruff Ryda