Gt3540

[Lepperfish]

HEy guys, just rang cgc and got quoted $3855.00 for garrett 3540 turbo with manifold to suit (rb25) and tial 38mm Gate.

Anyone know off anyone using this setup on an rb25 ?

Any constructive commment appreciated, thanks guys. :uh-huh:

[DoughBoy]

That's a pretty good deal since they list the 35R at nearly $3,000, the manifolds at $2200, and the wastegate at $600.

Would suit a drag car/larger capacity motor at that size too.

[Al]

Is the 38mm gate too small? What's on the std turbo?

[Lepperfish]

I dont think the wastegate is too small, why would they sell it with the turbo and manifold ? Im not sure of the size of the internal gate.

[Steve]

Is that with a manifold adaptor or manifold, or a second hand kit?

Price the parts individually. The turbo is around 3K, the wastegate only 600? (seems pretty cheap) therefore they would have to be giving you a manifold worth 2.2K for 200?. If they did this every day, they wouldnt be in business very long.

Not knocking what you are saying Lepperfish, so please dont take offence - you did ask what people think:) I think someone has been miss quoting things to you, or you have the absolute deal of the century.

[DoughBoy]

They've got that wastegate on special! Sounds about right if they are knocking up a plate to adapt the turbo onto the standard manifold with that small wastegate.

[Lepperfish]

Will an adapter plate be sweet ? And what size wastegate would you reccommend then ? If you say the 38mm is too small.

If the adapter plate to fit the gt3540 turbo to the standard manifold was a feasible option, then why would anyone pay $2200 for the aftermarket manifold ?

[Steve]

adaptor plate works, manifold (if made properly) works better.

If GCG offer any guarantees about the wastegate then go for it. I am fitting a 40mm gate with HKS 3037 turbo, I think it should be ok, time will tell.

Size of the gate isnt everything, it depends to some degree on the size of the turbine AR and how the wastegate is plumbed in relation to the exhaust gas flow as well. If they sell the gate matched to the turbo and manifold/adaptor - if it dont work, take it back. $600 for a new gate is pretty bloody cheap.

[Guest INASNT]

How are you planing to adapt the ext wastegate to the stock manifold??

[raist60]

GT35 Housings dont need adapter plates its a t3 flange. All they need is a spacer coz comp hits manifold

[JNR24]

Sounds like a good deal to me:

this is what i worked out.

GT3540s are not around 3K

in fact you can buy them retail for around the LOW 2K ($2225) mark (this is RRP):

http://www.rpmperformancecentre.com.au/Turbos.htm

g

Now if its a custom manifold your looking at (at a minimum) $1K. dont spend over $1400 on this.

And wastgate your looking at around $600

so i assume this is not fitted (otherwise its EXTREAMLY cheap):

Turbo:2225

Pipes: 1000

Wasgt:600

------------------

$3825 (pretty close to the money)

cheers,

trev

[EVOIV]

Steve: If you are interested in wastegate sizes, the external wastegate that I got with my 3037S kit has a 50mm outlet. It's the racing wastegate with stainless steel flange. Not the top of the range HKS GT wastegate (that has a 60mm outlet), one below that. Which wastegate are you getting?

[EVOIV]

The size of the wastegate isn't everything, but it is still important to use a correctly matched wastegate for the sized turbo. I think a 38mm wastegate for such a large turbo as the GT3540 is too small. They really should supply a 50mm wastegate at least. The wastegate should match the flow of the turbo. So I guess a larger turbo would require a larger wastegate for better boost control.

[Guest RedLineGTR]

interesting..

[raist60]

Think about the physics dude. It has nothing to do with turbo size its to do with engine flow. I am also fairly confident GCG know their shit, so why is everyone questioning them?

[EVOIV]

Originally posted by raist60

Think about the physics dude. It has nothing to do with turbo size its to do with engine flow. I am also fairly confident GCG know their shit, so why is everyone questioning them?

Can't larger turbos flow more air because of the larger size of the turbo? I'm pretty sure of that. Think of it this way, a small hose flowing air through it with a small valve to bleed off excess air. If you have a much larger hose flowing air through it with the same sized valve then there is obviously going to be more pressure built up at the small valve and hence restrict flow of the air. Using a larger sized valve for the larger hose will let more air flow out at a lower pressure which will not restrict air flow as much. Now in my analogy, replace hose with turbo and valve with wastegate.

I agree that GCG know their stuff, as they seem a reputable company...but what about HKS? I am pretty sure they know a thing or two about turbo systems too

[Steve]

Originally posted by EVOIV

Steve: If you are interested in wastegate sizes, the external wastegate that I got with my 3037S kit has a 50mm outlet. It's the racing wastegate with stainless steel flange. Not the top of the range HKS GT wastegate (that has a 60mm outlet), one below that. Which wastegate are you getting?

What size is the actual vavle? I believe that this is the normal way to express the size of a wastegate. Mine is a 40mm HKS Standard gate. It may be a bit small, but I thought I would give it a bash and upgrade if boost creep happens.

Bigger compressors do flow more, but the gasses have to leave through the turbine, which also needs to be taken into consideration when sizing wastegates.

for example, if you put a turbo on a car, and the turbine was so big that it only build 1.2 bar of boost, and you wanted to run only 1 bar of boost, you wouldnt need a wastegate at all. Silly example I know, but it is purely for demonstration:D

[EVOIV]

I have a 50mm HKS external wastegate. If you go to the HKS USA website, it's called the "Racing Wastegate S/S". The wastegates come with different springs, and mine was the 1.3bar one I think. It was too strong for my application, so a local mechanic put in a different spring (I think) so that the wastegate opens at a lower boost level.

Just found out that there's a new GTII Wastegate, looks very nice!!!

[Guest INASNT]

Originally posted by JNR24

Sounds like a good deal to me:

this is what i worked out.

GT3540s are not around 3K

in fact you can buy them retail for around the LOW 2K ($2225) mark (this is RRP):

http://www.rpmperformancecentre.com.au/Turbos.htm

g

Now if its a custom manifold your looking at (at a minimum) $1K. dont spend over $1400 on this.

And wastgate your looking at around $600

so i assume this is not fitted (otherwise its EXTREAMLY cheap):

Turbo:2225

Pipes: 1000

Wasgt:600

------------------

$3825  (pretty close to the money)

cheers,

trev

u recon u can get the manifold made in steam pipes for around $1400?? if so give me some names in melbourne that can do it.

[JNR24]

Sub zero performance (there in quensland & web-sites down??) they have custom tuned port pipes, for rb25 for $1400 dude. You might have to pay they a bit extra for a adapter plate if you need one made. i think they bolt up to t3 flange & its a high mount setup.

If the pipes i make end up looking really nice, i might make a few sets for people for say $1000. Il post pics when i have finished them in a week or so and il see what you guys think.

Cheers,

Trev