R32 Gtr Exhaust

[gtrboosting]

Hey guys i know this has been covered many times. I have a 3 inch cat back exhaust on my gtr. To get the most performance for the less amount of cash should i just gut the cat and get a 3.5 inch front pipe? I heard the dump pipes require removing the turbo's and i'm not really up for that at this stage. The car will only ever have about 250-270awkw. Thanks alot!

[InterCooL]

you'll most likely get flamed for suggesting to remove your cat, considering it carries something like a $10 000 fine and is bad for the environment and that a hi flow cat does not rob you of much power

as a side note, there was an article in a not so long ago hot 4's / hpi where an r32 gtr had an exhaust upgrade, from stock to a full system, with back to back dyno runs. the stock put out 0.5rwkw more than the aftermarket custom made one. i do not understand why, they were shocked and hypothesised that the stock nissan system has extremely well engineered bends and diameters. but nothing definate. food for thought

[gtrboosting]

did i say gut the cat? i'm sorry i meant go out and buy a high flow one.. stupid me

Thanks for yoru comment mate but you have done nothing but confused me! ha ha.. dont do that!

[saliya]

you'll most likely get flamed for suggesting to remove your cat, considering it carries something like a $10 000 fine and is bad for the environment and that a hi flow cat does not rob you of much power

as a side note, there was an article in a not so long ago hot 4's / hpi where an r32 gtr had an exhaust upgrade, from stock to a full system, with back to back dyno runs. the stock put out 0.5rwkw more than the aftermarket custom made one. i do not understand why, they were shocked and hypothesised that the stock nissan system has extremely well engineered bends and diameters. but nothing definate. food for thought

Hey,

Agreed - the fine isn't worth the performance (what can you buy for $10k?). A good cat's expensive, but if

250kW's being aimed for on stock turbos I'd be spending the money on a hi-flow cat so you can keep the flow

(kW) up with lower boost levels.

Incidentally, there's no way a stock GTR exhaust works better than any reasonable aftermarket system of 3" or above at 14psi on stock everything

(which is the minimum you'd be running for 250awkw on stock turbos). The more flow, the more difference between stock and a good

system. Seat-of-pants feel is a 25awkw difference at that level; haven't measured the 'before' but have driven from Queensland on a stock exhaust

and changed only the exhaust for that guesstimate.

Anyone that thinks a stock GTR exhaust works better than a 3" aftermarket one is welcome to buy my complete stock R32 v.spec exhaust

for $800 (the cost of a reasonable full 3" system )

Regards,

Saliya

[gtrboosting]

wow 800 for a full system to suit r32 gtr?? mate show me where!! The real question is since i already have a 3 inch catback will i gain a decent amount of power from adding a high flow cat and 3.5 inch front pipe. Also i wanted to know if an exhaust shop can change my dump pipes with no major dramas as i heard its a pain in the but!!

Also can you find front/dump pipes that are one piece?

http://www.nengun.com/hks/stainless-front-pipe-gtr

Does this item just bolt straight up the cat? If so i'd probably go somthing similar.

Edited August 17, 2007 by gtrboosting

[InterCooL]

Incidentally, there's no way a stock GTR exhaust works better than any reasonable aftermarket system of 3" or above at 14psi on stock everything

(which is the minimum you'd be running for 250awkw on stock turbos). The more flow, the more difference between stock and a good

system. Seat-of-pants feel is a 25awkw difference at that level; haven't measured the 'before' but have driven from Queensland on a stock exhaust

and changed only the exhaust for that guesstimate.

Anyone that thinks a stock GTR exhaust works better than a 3" aftermarket one is welcome to buy my complete stock R32 v.spec exhaust

for $800 (the cost of a reasonable full 3" system )

if i can find the article in the 1000 magazines at my brothers house (his magazine..) i will see if i can show it to u.

magazines and shops will bag the crap out of forums for having "know it alls" who dont know anything. then they write a 2-4 page article basically saying that the stock exhaust on a r32 gtr is as good as you need.

i have no opinion. IIRC it was same day, same dyno, reputable exhaust shop. ...

[InterCooL]

wow 800 for a full system to suit r32 gtr?? mate show me where!! The real question is since i already have a 3 inch catback will i gain a decent amount of power from adding a high flow cat and 3.5 inch front pipe.

there is a thread on here where someone had an r33 gtst with catback. he put on a split dump and gained a significant amount of power. many other ppl claimed the split dump gave superb top end bla bla. so the general answer will be 'yes'

however my mate (who had cat back r33) upgraded to split dump + boost and it didn't put down much on the dyno...

edit: logic will say that if you remove a restriction, such as cat / small front pipe, then you will reap a benefit. how much? back to back dyno it and put it up for everyone to see ..but no one really has the money / time to do that

Edited August 17, 2007 by InterCooL

[Adriano]

I would fit a front pipe and highflow cat, then save up and get some better turbos, or at least have steel wheels put in yours, trying to get 250rwkw out of stock 15y.o. turbos is a recipe for disaster. When you fit the turbos fit some dump pipes at the same time

[MrStabby]

My 32 GTR came with 3inch front pipe, stock cat, then 3.5in apexi system. After putting in a 3.5 inch metalcat, the seat of the pants dyno said extra ~20kw. Car went from [email protected] psi to 242@13 psi (brought to boost down for extra safety margin a long time before the cat went on)

I would fit a front pipe and highflow cat, then save up and get some better turbos, or at least have steel wheels put in yours, trying to get 250rwkw out of stock 15y.o. turbos is a recipe for disaster. When you fit the turbos fit some dump pipes at the same time

+1 for Adrianos comment - that's my plan.

[heller44]

That hpi atricle was a crock. The stock cat was on the aftermarket system as well.

[gtrboosting]

ok so what i want to know now is. If i buy a dump/front pipe in 1 like the hks one http://www.nengun.com/hks/stainless-front-pipe-gtr

Will an exhaust shop be able to fit the thing with out too many dramas? Will it cost a load in labour etc? I'm not looking to upgrade the turbo's any time soon but i dont want to buy a dump and front pipe seperatly when i can get a 2 in 1. Thanks!!!

[gtrboosting]

also in between the cat and muffler has a huge resonator/muffler thing. I know this would quiet the exhaust down but would it restrict flow at all? It's pretty massive. Thanks

[Godzilla32]

Im pretty sure anything you have to bolt directly onto the back of the turbos will require either removal of the turbos or engine and you fit it back into the car as one. You could just bolt up the first section of the dump/front pipe and fit the rest once it was back in the car.

CES make a similar combined dump/front pipe. Not sure if the akwardness of it all is worth it persoanlly. However i would be interested into hearing the outcome.

The other thing regarding that HPI article is that they are saying the CAT is the most restrictive item and if you replace that and leave the rest of the exhaust its not a bad alternative to a full system. Besides the stock gtr system is only a little smaller than a 3in system. I think from memory its 2.5in stock

Edited August 18, 2007 by Godzilla32

[gtrboosting]

ok thanks alot!!! As for a cat. Does anyone know a good value for money high flow cat going around that wont break the bank?! I see some going for around 500:S

[SLIPPERY]

i think i got my MetalCat from a group buy for around $300 delivered

[gtrboosting]

ohok last one i had was a flyn high flow.. dont think they make them anymore but that seemed to do the job well. Anyone else?

[Godzilla32]

Metal Cat seems to be the way to go for good value. They have some impressive flow figures. From memory the stock GTR car will flow 350cfm. So anything over that is an improvement.

Deren

[WRRR]

On the 32 your dump pipes are not the best for flow.

Changing to bigger front pipes and geting a decent cat in there will help things flow better but not as well as they could - depending upon your power/torque target.

You could put new front pipes in yourself fairly easily - if the studs/nuts free up (lots of CRC or similar beforehand).

If you are planning a turbo upgrade in the future make sure you buy bits that go together well later.

Have fun

[gtrboosting]

ahok looks like ill go for a metal cat then. now i just have to wait for some sort of deal to pop up