Front End Exhaust Recommendations

[LotusGTR]

So I'm looking for around the 260-280 rwkw mark from my R32 gtr. I've got some -7 turbos and want to get dumps, front pipes and a cat. The exhaust to the rear of the cat will stay as is. I don't want any dramas in fitting, so the dumps gotta fit the turbs, the front pipes got to fit the dumps and the cat the front pipes etc.

As it's not going to be a monster I'm looking for a reasonably cheap way out. JJR have suggested the Blitz front pipe and their std Catco 3" hiflow cat. We didn't discuss dumps and I'm nervous opening up this topic as there seems to be a lot of condradictory info on the merit of going after market.

Can you suggest a combo that will meet my requirements? Perhaps it's easiest just to get a system rather than shopping for individual bits?

Cheers.

[R31Nismoid]

Dumps - waste of money. Stock will do it easily. Im making that exact power now, and i won't be changing either when i chase another 40-50rwkw early next year.

The advice from JJR sounds pretty much spot on in my book.

A simple blitz front pipe, although i would put in a 3.5" hi-flow cat personally, then just attach it to the cat-back you already have.

Should bolt to the stock dumps as well.

[LotusGTR]

Ash, your advice is appreciated as always. When searching before posting I came across this, which confused me when I saw it as I'm sure you've recently advocated that stock dumps are fine (as per your very recent post in my thread). Is this is case of wisdom changing? I'm not trying to be smart (hopefully you know that), but can you reconcile for me?

http://www.skylinesaustralia.com/forums/R3...;hl=front+pipes post #3

Knowing you have an RB26 DETT in an R31, are the stock dumps you have from a 32,33 or 34 as I've read the latter 2 have a 10mm ID difference to the 32?

Thanks again.

[R31Nismoid]

R32 GTR dumps were never pushed as hard, generally accepted you change them for R34 items at least.

A certain person i know decided to give them a crack (and R33 ones a bit before that) and see how much power could be made without changing them...

380rwkw from -5's was the result with factory R32 GTR dumps, and 33 items alike. I must admit i was as surprised as the others involved when this occurred.

I actually had trust split dumps on my car, and had to pull them off due to ride height issues, just before that the R33 ones were pushed over 350rwkw so on stock dumps went.

It proves that it can be done either way, so for your aims, i see no value or point in spending money on something that will not offer any percievable gains.

So indeed, as time goes on, more testing occurs people find out new possibilities.

I have R33 items on mine i believe, i will make 330-340rwkw through them without a problem.

Currently im making 280rwkw through stock R33 dumps on around 15-16psi with GT-SS's. I have intake temp problems to sort out which is hurting the power a tad as well.

[Beer Baron]

32 and 33 dumps are the same. 34 dumps are bigger and are stainless. good budget upgrade. personally I've now used tomei dumps on about 4 GTRs of mine and loved them every time. they cost money but you do it once and they're done. for front pipes my favourite is the current biggest HKS stainless front pipes which are a true twin 70mm ID (not OD) front pipe which have the flanges welded on the inside, gives a lovely smooth entry to the pipe and come out in a single 85-90mmID (i forget exactly) pipe. they all fit together and work together nicely. once out of the turbo exhaust outlet you want to allow the gas to expand as much as possible as quick as possible so big dumps and front pipes do make sense. as to whether or not they are worth it on $ per kw basis only the user can answer that. but they definitely gave me better spool up time as well.

[LotusGTR]

Ash, thanks for that.

Richard, good to hear from you again. I'd love to splash the cash on your suggested set up but the dumps and pipes alone are $2,600 from JJR. My budget is around $1,000 for the lot so perhaps I'll consider:

R34 dumps - second hand

Catco 3 or 3.5" metal cat

Blitz front pipes

Should sneak in around my budget. I've got the crawl under the car and check out all the flanges and make sure they're 2 bolt.....

[LotusGTR]

The JJR site claims 80mm outlet and dual 70mm pipes. Are these ODs? Must be. Be a striaght bolt up to the R34 GTR dumps or even the R32 if I decide to go all tight ass on the upgrade?

[R31Nismoid]

I'd argue the increase in response based on my own testing

From changing from Trust split dumps to factory dumps, i did not see performance drop one iota. Boost still came on exactly the same.

I still have boost building from the late 2k RPM range, and by 3,300rpm the show is well and truely on with GT-SS's, same as everyone else really.

This is under med-high load in 4th as its easily reproducable up a hill etc. 1st/2nd i can't test as it just turns tyres

So from what i've seen - i can say there is no benefit for larger than factory dumps with those sized turbos in terms of response, midrange or peak power.

Note: i am running larger front pipes (custom, as usual for the HR31) to a full 3.5" exhaust.

[LotusGTR]

Stolen ffrom an old for sales thread. These are apparently R34 GTR dumps. They don't look SS to me or are they just looking that way after a life time of effing hot gasses flowing through them? Perhaps not R34s at all?

[femno]

YES those are 34 dumps.

Also another way of telling is the provision for the temp sensor in the rear dump pipe.

My car made 278 with hi-flow turbos with the standard 32 dumps, having said that I dont think you would need much more than that for your setup.

The 33 units are a fair bit nicer than the 32s, in terms of smooth curves inside, and the 34s even better again.

So all in all 32 units would do the job but if you want to spend money then get 33 or 34 units.

[Moodles2]

What would be needed to fit R34 dumps on a R32?

I'm guessing the temp sensor will need a bolt to block it off, will the R32 GTR O2 sensors fit straight in or will they need an adapter (and what sized adapter) ?

[Blitz]

What would be needed to fit R34 dumps on a R32?

I'm guessing the temp sensor will need a bolt to block it off, will the R32 GTR O2 sensors fit straight in or will they need an adapter (and what sized adapter) ?

I am almost certain you will need an adapter to fit BNR32 02 sensors into BNR34 dumps, not sure on the size though.

Cheers.

[LotusGTR]

Guys, the cost and hassle of fitting new dumps sounds like a pain, especially with O2 sensors not matching etc. I'm more than sure from the feedback that the power figures I'm after will be done on the stock dumps (heck my other car runs 300RWKW and it has stock dumps) but it's a matter of how it feels. Quicker spool up and throttle resonse make the same power feel much nicer so I'm consdering things from this point of view too.

Any thoughts on that?

[Buraz]

I'm running 287rwkw on standard 32 dumps with steel wheeled turbos and a Trust pe2 exhaust and Attain front pipes, on 17 psi. Last time I had a chat with my workshop they said that 33 and 34 dumps flow similar power, both are better and flow more than 32 dumps.

[R31Nismoid]

Guys, the cost and hassle of fitting new dumps sounds like a pain, especially with O2 sensors not matching etc. I'm more than sure from the feedback that the power figures I'm after will be done on the stock dumps (heck my other car runs 300RWKW and it has stock dumps) but it's a matter of how it feels. Quicker spool up and throttle resonse make the same power feel much nicer so I'm consdering things from this point of view too.

Any thoughts on that?

Thoughts?

I've tested it before/after with stock vs the trust split dumps as i said earlier... no difference on the street, which is where it matters

If you can wait probably 2-3 weeks you can drive mine and tell me if you think spool will get any quicker/more responsive.

Although you bend it, you won't be in the good books with a certain panel beater

[Blitz]

Thoughts?

I've tested it before/after with stock vs the trust split dumps as i said earlier... no difference on the street, which is where it matters

If you can wait probably 2-3 weeks you can drive mine and tell me if you think spool will get any quicker/more responsive.

Although you bend it, you won't be in the good books with a certain panel beater

Do you really think he want's to be seen in public driving an R31?

[LotusGTR]

Do you really think he want's to be seen in public driving an R31?

I have a balaclava

[R31Nismoid]

Do you really think he want's to be seen in public driving an R31?

It'll be clean...

Fastest 31 you'll ever go in

[N1GTR]

....probably the only 31 he'll ever go in

[Beer Baron]

The JJR site claims 80mm outlet and dual 70mm pipes. Are these ODs? Must be. Be a striaght bolt up to the R34 GTR dumps or even the R32 if I decide to go all tight ass on the upgrade?

yeah almost certainly OD. most jap front pipes quote OD sadly. measure the ID and be prepared to be disappointed. but they'll be fine for what you want. and they will all bolt to factory or aftermarket dumps. they are all designed to be direct fit and all have the same flanges and the same bolt spacing it's just how much of that flange is used up by pipe. have a look at stock front pipes and you'll see how much room there is between the pipes and the flange bolts. the aftermarket pipes use the same size flange just stuff a bigger pipe into it.