R34 Gtt Gcg High Flow

[drgnball34]

Im in the process of getting my R34 GTT highflowed ( GCG). Since the exhaust housing is larger then the R33, I should be able to gain 30 odd extra rwkw . I have a 38mm tial wastegate laying around which i was going to use on a different setup but changed my mind. Im thinking of welding the internal shut and change to the external instead. Im assuming that this will allow for better boost control and maybe even push the turbo to around 280-290 rwkw. Could i still use the standard exhaust manifold and get it modifyied with the wastegate or get a custom one fabricated up? What cost are involed?

[R31Nismoid]

An external wastegate does not increase turbo power.

A wastegate int or ext is there to regulate boost pressure. One does not make more power than the other in a correctly working situation.

If the turbo suffers from a int gate hole that is too small, boost control problems can arise.

Seeing as though no-one to date has reported issues, there is no need.

You can convert it to external if you want, people do weird things all the time.

However, you are mistaken if you think it will make anymore power.

Its that simple. How better boost control equals more power i dont understand. 20psi is 20psi. Doesnt matter what regulates it.

IMO, why butcher what is proven to be a superb turbo?

[jazza08]

Ext gate with a screamer pipe will make more hp... however otherwise there is no point in it. A good new elc boost controller will be able to regulate ur boost settings fine, if you cant a actuator with a stronger spring then the elc boost controller onto that will do the job. I found abit more lag with the external gate so i wouldn't go down that route unless you REALLY love the noise and want around 10-15 more rwhp at most

[R31Nismoid]

Ext gate with a screamer pipe will make more hp...

prove it

[jazza08]

I made 12rwhp from it...

If only i kept the old fkn dyno sheet damn it!! I was so proud of my new one i didnt keep the rest lol

[Craved]

and nothing else was changed?

was this peak power? average power? power lower in the rev range???

just when you think of what a wastegate does.... it controls boost

so unless it wasn't doing its job in the first place and the boost was dropping, there is nothing to explain the increase

[jazza08]

To be honest... external gate brought power on later (around 300-500rpm) but controlled it MUCH better. I have 20psi from about 4500rpm to 8000rpm.

The increase was from having no restrictions in the exhaust, it went from a split 3' dump/front to a single 3' dump/front and the screamer comes off the ext wastegate, there is no mixing of the exhaust cause turbulance which is wat makes the exhaust wheel spin easier! Or so logic should go... lol

Edited August 4, 2006 by jazza08

[R31Nismoid]

I made 12rwhp from it...

If only i kept the old fkn dyno sheet damn it!! I was so proud of my new one i didnt keep the rest lol

12rwhp would suggest to me dynoing difference rather than an actual power increase.

Being you can go to the same dyno, a week apart, and the reading wont neccesarily be the same.

[R31Nismoid]

To be honest... external gate brought power on later (around 300-500rpm) but controlled it MUCH better. I have 20psi from about 4500rpm to 8000rpm.

The increase was from having no restrictions in the exhaust, it went from a split 3' dump/front to a single 3' dump/front and the screamer comes off the ext wastegate, there is no mixing of the exhaust cause turbulance which is wat makes the exhaust wheel spin easier! Or so logic should go... lol

Damn posting while im typing.

If you had a restrictive exhaust, then thats where the gain came from.

It has absolutely nothing to do with the wastegate itself.

I bet you if you changed to a 3.5-4" exhaust keeping the internally gated turbo... you would see the same increase in power... all beit a poofteenth in your case.

As for boost coming on later, thats poor wastegate spring selection. im guessing, so your getting a bit of gate creep as it cant keep the thing shut long enough

[Craved]

oh well

back to the original issue ..

280-290 kw - sell the tial gate, spend a little extra on poncams.. and have a more streetable car that would have close to your power targets.. be very hard to defect and less fabrication costs ..

fabrication costs and first defect would pay for the rest of the cams anyway

see abo bob's r34 GTT 4 door Auto for comparison ..

[jazza08]

Damn posting while im typing.

If you had a restrictive exhaust, then thats where the gain came from.

It has absolutely nothing to do with the wastegate itself.

I bet you if you changed to a 3.5-4" exhaust keeping the internally gated turbo... you would see the same increase in power... all beit a poofteenth in your case.

As for boost coming on later, thats poor wastegate spring selection. im guessing, so your getting a bit of gate creep as it cant keep the thing shut long enough

Thinkin about that.. it may not be true because i never ran 20psi when it was internally gated... full boost was more around 15psi and made that abit earlier as you'd expect. Ah well im happy with the result for now, on the issue id also say cams are a better option than spendin money on gate etc if hp/driveability is ur main goal

[R31Nismoid]

Each post you make you give more information... :sorcerer:

Next time put it all into one post next time, makes it easier to make a comment on it all rather than posting little snippets each time you reply until we get the full story a half a dozen posts later

[jazza08]

Sorry.. lol