Hks Front Pipes On Standard 32 Gtr Dumps

[Piggaz]

tomei's are bellmouth right?

Yup. 72 mm for the old ones and 68 for the new ones

[R31Nismoid]

tomei's are bellmouth right?

Correct!

[SiR_RB]

when i changed my stock turbos to -7's there was no way in hell i was gonna put back the stock dump pipes, while everything is out you may aswell do it

i got lucky and found some r34 gtr dump pipes, much much better design than the old 32/33 items

[R31Nismoid]

Did you measure internally the size between R33 and R34?

[J - Rad]

When I did my turbos I went out of my way to find Greddy dump/front pipe kit. Why pay $700+ for dumps then $500-$600 for a front pipe if you can pay $900 or less for one?

[Piggaz]

Would have to be big power...they are very short pipes so there is no real time for the gasses to be held back...being that they are exiting the turbine at near supersonic speed (I no make that up)

Quick edit - Also, whilst the standard dumps are quite small, they are still larger than the turbine exit, and only have 3 cylinders worth of gas flowing down each one.

So whatever size the stock dumps are, 2 1/4" or so, that is quite a large exhaust for a 1.3L motor

Fair enough. BUT why do our cars respond so well to larger front pipes, cats and catbacks?

Wouldn't it be better to have 2 3 inch dumps going into a matched twin 3 inch front pipes rather than out of turbo, into something larger then into something larger again.

Perhaps on a 430rwkw+ car this is where the bigger dumps count? As Ash said at 350 or so the dumps are not as restriction .... YET

[R31Nismoid]

I don't doubt somewhere they offer benefits. From what I've seen though around the 350-370 not so much.

I mean i wouldn't be making 370rwkw on 19psi if there was an exhaust restriction, you'd soon spot it nose over.

[zebra]

There is more length in the front pipes, and more again in the catback also the gasses lose inertial the further down the system they go, so the friction on the pipe walls start to have more of an effect.

Also as a little bit info info, The only friction in an exhaust pipe is within 3mm of the pipe walls, so effectivly the radius of the pipe - 3mm, and there is no friction on the exhaust gas outside 3mm of the wall

So thats what im getting at re: the turbine outlet compared to the dump pipe, Also works for exhaust manifolds, if you want no restriction then have your primary pipes 6mm in diamiter larger than your exhasut ports (obviously less applicable if you throw a turbo in the mix)

[harks]

i know im ressurrecting an old thread here but in relation to

i got lucky and found some r34 gtr dump pipes, much much better design than the old 32/33 items

arnt the R34 ones longer? so do they fit propeperly to the R32 Front pipe, or does it make the exhaust sit stupid low off the car?

and, does the R34 front pipe offer any gain from the 32 stock? (or would it be better going r34 dump, to aftermarket front, to aftermarket catback)

[XKLABA]

i know im ressurrecting an old thread here but in relation to

arnt the R34 ones longer? so do they fit propeperly to the R32 Front pipe, or does it make the exhaust sit stupid low off the car?

and, does the R34 front pipe offer any gain from the 32 stock? (or would it be better going r34 dump, to aftermarket front, to aftermarket catback)

No, they are all the same length

Yes, the 32 ones are just garbage, the 33 ones where a massive improvement over the 32 and the 34 are fabricated instead of cast but IMO don't offer much if any of an improvement in flow over the 33

Split V bell, if the split is designed correctly then the split are better IMO, it is just easier to get the bell mouth to work then the split

I use both of the CES racing designs, factory replacement ones on the 32 and the longer race ones on the 34, when I'd did the 34 ones that was all that changed, unfortunately it didn't go on the same dyno for retune though it did need more fuel as they made it a little lean

[harks]

ohh thanks for that mate,

only other query. does anyone know the dimensions of the stock front pipe. i got out and measured it this morning.. because i believe mines still stock.

my split pipes were 20cm circumference (63mm diameter externally) and meeting in a 24.5cm circumference (78mm diameter External) pipe. im assuming i would be able to find some gains through replacing these. Im running N1 turbos atm, and at 19psi making 248awkw, tuned for mid range and SMOOTH power curve.. but seems alot of boost for the power.

my only power mods incl.

greddy FMIC (unknown size.. looks same as stock, maybe fractionally larger)

modified actuators on the N1s

apexi 3" catback.

Vipec ECU and electronic boost solenoid

my last (stolen) GTR had the above + cam gears, and cutsom dumps/front pipe to 3.5" decat. and it was 298 awkw on 21psi (2 psi more)

Edited February 1, 2014 by harks

[XKLABA]

Yeah that's not right, I have 293rwkw @ 19psi on stock turbos, you should have more then me on same boost not 50kw less

[harks]

what supporting mods are you running, and on -7 turbos

[XKLABA]

Stock R32 GTR ceramics, I have

Apexi Z32 pod filter kit with Z32 AFMs

UAS cold air feed

Adjustable cam gears

CES racing pump pipes and front pipe

MetalCat cat convertor, has since been changed for HKS cat convertor

HKS Superdragger cat back

Greddy oil cooler, no filter relocator

Exedy twin plate

HKS EVC 4

Apexi Power FC

[harks]

nice, you would have a hella responsive build using the stockies.

so really the 3 big differences are:

You have cam gears

your using z32's

and you have custom front/dumps

(although im not suing a standalone EVC, using it via the ECU i dont think that should matter?)

for 50wkw... hrmmm....

[XKLABA]

Any thing over 2800rpm is instant boost and it is a very angry car

The cam gears made a big difference both in response and top end

The Z32s are the best option when using the Power FC

Not custom, I have these ones

http://www.cesracing.com.au/products_2.htm

The two at the bottom right, I have the silver ones on the 32 and the black ones on the 34, what have you got ?

The EVC just means I can easily change boost level with the touch of a button, the type of controller I have means the wastegate doesn't creep open till the car gets very close to the preset boost level

Setup and tune have alot to do with, my car was initially tuned by a very well known tuning company in sydney and it was rubbish drove like shit and I only picked up 0.1 seconds on the quarter, changed there bodgy Z32 adapters to the apexi ones and took it to Insight, drove better then it did when factory and picked up another 0.5 second one the quarter going from 11.8 to 11.36

[Piggaz]

Any thing over 2800rpm is instant boost and it is a very angry car

The cam gears made a big difference both in response and top end

The Z32s are the best option when using the Power FC

Not custom, I have these ones

http://www.cesracing.com.au/products_2.htm

The two at the bottom right, I have the silver ones on the 32 and the black ones on the 34, what have you got ?

The EVC just means I can easily change boost level with the touch of a button, the type of controller I have means the wastegate doesn't creep open till the car gets very close to the preset boost level

Setup and tune have alot to do with, my car was initially tuned by a very well known tuning company in sydney and it was rubbish drove like shit and I only picked up 0.1 seconds on the quarter, changed there bodgy Z32 adapters to the apexi ones and took it to Insight, drove better then it did when factory and picked up another 0.5 second one the quarter going from 11.8 to 11.36

Have been in the car. You would not expect this off a standard car. I would rather this tha some of the bigger power cars that I've driven due to the area under the curve, let alone boost recovery.

[harks]

yeah still running stock dumps/front pipe.. which for the 32 is pretty sub optimal. someones selling a set of the standard CES pipes (not the racing ones) for a good rate, im juist weighing up weather i pick them up (At a good bargain) or get a 3.5" front pipe and cat-back.. cause turbo';s will need to come out for installation.

i was origionally going to get cam gears, but my tuners like.. nah why would you do that? thasts a waste of time.. takes a long time to tune, not worth it unless using cams.. i thought that odd. awell.

[harks]

addition to my last.. how much would i expect a workshop to charge to pull the turbos off and install the dumps/front? im thinking 2-3 hours labour so maybe 300-400? or am i way off?

and what about cam gears? 1

[r32-25t]

Time for a new tuner if he can't see the benefit of cam gears