New Garrett Gt3540 Internal Gate Is Here + Dyno Results

[Abo Bob]

I was playing around with the timing on my car at Eastern Creek on sunday and I can tell you that 5 degrees of extra timing is a shipload of extra power so I think it is certainly worthwhile dropping the boost a little and seeing how much more timing you can stuff in there.

Not only that but if you add a bunch of timing to your lower revs you should be able to get your turbo spooling a little earlier too.

Interesting article Cubes.

[discopotato03]

Yes Cubes if not too much trouble . Others here may be interested to see views of its collector if you can get some light into it . I think someone in the US recently posted pics here of an RB with that manifold and a GT30R turbo (sadly with a T31 exhaust housing) on it . Gives everyone an idea of turbo placement and how its slightly different to std .

Cheers A .

Edited October 10, 2006 by discopotato03

[chris davey]

Re ignition timing

What fuel did you use when on the dyno?

What fuel is the guy running 24deg using?

What was the knock reading on the PFC?

There are a lot of things which come into play with tuning and avoiding knock and ignition timing is a big one.

I wouldn't be too worried about another guy running more timing than you. Each engine is different and they all like slightly different things.

His car may be tuned on the edge whereas yours might be backed off a little for longevity.

I don't have an rb25 but a single turbo 1jz and I have only tuned up to 18psi but I run 17deg at peak torque to 19 at redline at that boost. 26psi has 15deg at peak torque and 17 at redline. This is using shell 100RON fuel with martini super boost.

[dangerman4]

Re ignition timing

What fuel did you use when on the dyno?

What fuel is the guy running 24deg using?

What was the knock reading on the PFC?

There are a lot of things which come into play with tuning and avoiding knock and ignition timing is a big one.

I wouldn't be too worried about another guy running more timing than you. Each engine is different and they all like slightly different things.

His car may be tuned on the edge whereas yours might be backed off a little for longevity.

I don't have an rb25 but a single turbo 1jz and I have only tuned up to 18psi but I run 17deg at peak torque to 19 at redline at that boost. 26psi has 15deg at peak torque and 17 at redline. This is using shell 100RON fuel with martini super boost.

we were both running 98 octane pump fuel

all the runs i did untill the last one knock was only reading up to 12, the last run was 32.

the car had been on the dyno for over an hour so plenty of heat soak etc.

im thinking about either changing front bars or attacking my bar with the 9 inch grinder to let more air to the intercooler. i know it will help to get the intake air as cold as possible.

i was also thinking maybe a plazmaman plenum may reduce the heat soak from going over the engine.

[Abo Bob]

I don't think going over the engine will hurt your intake temps. The air isn't there for long enough to transfer the heat.

Feel free to hack your front bar though.

32 knock is still bugger all. 12 is nothing. Push it and see.

[Cubes]

dangerman4,

The plenum and heatsoak really isn't an issue as on wot the air moves in and out of there so damn quick that it has so very very limited time to absorb heat.

You would be much much much better off spending the $$ on a nice exh. manifold.

Regarding knock.. From my experience its not really linear. You tune it and get x knock no matter how much ign you punch in (providing its not massively retarded) I find the few pfc's I've watched + mine tend to get up around 30-45ish depending on the engine and knock sensors. Following that if you dial in 1 more degree it will spike to 70+ and ping. Its not like as you approach detonation the knock levels slowly rise. Well not from my experience anyway.

[The Mafia]

Discopotatohead (and anyone else for that matter) - I need some advice.

I currently have the GT30r with the 7 blade to4s wheel, and a RB25 turbo ground out to fit. Come on 15psi at 3200rpm in second. Motor is standard. Running about 112mph

I want to go bigger (to this GT35) but I have a few questions

1. Will a ground out Rb25 ex Housing made to fit a GT30 fit the GT35?

2. Is that a bad idea? Or is it possible until I get my built RB30 or RB25 up and running?

3. I want minimal lag, would the Garrett .63 housing be a good choice?

3a. What would its top end be limited to if Running a built RB30

3b. What would the top end be limited to if running a built RB25?

4. I have a Compressor cover on the GT30 which is .7. Its got a Custom bend welded onto it. Could I just buy a GT35 with a .7 Comp cover and swap them?

If you haven't relised yet, I'm really trying to do a direct swap from GT30 to 35. I'm hoping the oil and water lines are the same size and location, and the cartridge is similar etc.

Apologies if some questions sound stupid.

Edited October 12, 2006 by The Mafia

[Cubes]

Mafia... I think your better off grabbing one of garretts internal gate turbine housings.

For the street I consider the GT35r .82 on an RB30 with a 5speed only 'just' bearable. That counts out the GT35r on an rb25 UNLESS its behind an auto which makes a massive difference as to the way the turbo comes on. To be honest a GT35r .82 behind an rb25 auto feels similiar to that of a GT35r on an 5speed Rb30. Its quite freaked out how the turbo loves the auto.

Behind the RB25 5speed used for the street... I would go the GT30r running the 76mm 56t comp wheel; .82 internal gate turbine housing, possible grab one of ROGUEPI on ebay (who's AMOSITE here on SAU).

He flogs the internal gate GT30r's for the low to mid 1700's. The GT35r internal gates go for high 1700's. So well priced.

GT3540r Internal

GT3040r Internal

He had the GT3076 floating around yesterday, can't find it right now.

and the port shroud adaptor he does.

Steve who used to own an r33 some years ago ran a HKS3037S which is essentially the GT30r 76mm 56t comp wheel with a nice little comp cover. RoguePI sells little insert bits that bolt in to your comp cover inlet to make it similiar to that of the HKS comp housing. Running 23psi I think it was, cams, plenum, exh. manifold he made 323rwkw. Also on a stock bottom end that had a thicker headgasket slotted in to drop the static comp.

Ran well and never let go. He ended up returning the car to stock and selling.

I'm not sure if its possible to use the same comp cover; I'm guessing yours is the 52t 82mm comp wheel? The GT3540r's run the 56t comp wheel. Disco will know.

Discopotatohead (and anyone else for that matter) - I need some advice.

I currently have the GT30r with the 7 blade to4s wheel, and a RB25 turbo ground out to fit. Come on 15psi at 3200rpm in second. Motor is standard. Running about 112mph

I want to go bigger (to this GT35) but I have a few questions

1. Will a ground out Rb25 ex Housing made to fit a GT30 fit the GT35?

2. Is that a bad idea? Or is3. I want minimal lag, would the Garrett .63 housing be a good choice? it possible until I get my built RB30 or RB25 up and running?

3a. What would its top end be limited to if Running a built RB30

3b. What would the top end be limited to if running a built RB25?

4. I have a Compressor cover on the GT30 which is .7. Its got a Custom bend welded onto it. Could I just buy a GT35 with a .7 Comp cover and swap them?

If you haven't relised yet, I'm really trying to do a direct swap from GT30 to 35. I'm hoping the oil and water lines are the same size and location, and the cartridge is similar etc.

Apologies if some questions sound stupid.

[The Mafia]

thanks cubes, thats helpful also.

I'll see what discopotatohead says about the internals of the turbo.

This sounds a little too good to be true?

Past applications and results:

We have had excellent results with these turbo's including my own 200sx making 330 rw kw on a dyno dynamic's dyno on about 26 psi. Fitting to an R33 RB25 det with RB30 bottom end (a good friend of mine owns this car), full boost is reached at 2200 rpm and 300 rw kw on only 17 psi on run in tune.

Edited October 12, 2006 by The Mafia

[Cubes]

Yer it is... GT35r .82 on the RB30's are all in around 3500rpm maybe a tad later depending on cams.

They start making boost around 2k but.

[discopotato03]

Mafia difficult to say . From other peoples experiences head work seems to do really good things to RB25's and it seems logical that what works for 2.5L would work for 3L . I would think seriously about porting particularly on the exhaust side and researching larger exhaust valves . I would not go under 9.0 CR if I could help it , these things are aimed at pulling up the bottom end pre boost so you get reasonable squirt before the turbo gets cracking . What most people want on the street is torque so breathing and being able to run advanced timimg is what it takes IMO . I hate soggy engines with huge turbos and a farts worth of static CR because the power curve is waitin waitin waitin WHAM why has my car swapped ends ?

The GT3582R is not a bad thing though its getting a bit big for a stockish RB25 . While the 25's std cast manifold may not be a huge exhaust flow limiter for upwards of 280 + Kw it does force the gasses through a number of tight bends which is hardly ideal . A straighter shot from the ports to the turbo is preferable and my choice (play it again sam) would be the HKS cast low mount manifold . Everything you can do to reduce flow restriction means more thermal gas expansion velocity energy with which to drive the turbos turbine . I believe this manifold is an oldie but a goodie if you're sticking with the RB25 head and intend to use a T3 flanged turbo .

If you were undecided if the 3L conversion was going ahead the GT35R is probably a bit much for a daily driver . One thing I've never seen on a GT35R is a port shrouded compressor cover . HKS do this to a lot of their turbos and I'm beginning to think it may have some response benefits . As far as the .63AR ratio exhaust housing goes I would not use it . The extra restriction it causes kills the fun once the turbo gets going . The centre section of the GT35R is the same dimensions as every GT BB down to the GT25 series .

I think you first need to decide which bottom end to go with and use bits to suit its capacity . I'd leave the turbo selection till last .

[dangerman4]

Hi everyone..

as disco has allready mentioned a couple of times i wouldnt bother with the .63 a/r exhaust housing on a gt35 comp cover.. it will surge like a bitch...

My old gt3071r-sp will be for sale shortly with custom dump and intake, i sent it back to gcg for a clean and tidy up so i can sell it and be assured it would do the job for a fellow SAU member.

My cars going in tommorrow to MV automatics for a new upgraded shift kit install.

3rd gear solenoid has been giving me grief.

easy fix.

Hey cubes last time you were in the muppet bus it was only on around 240kws, if your not to busy over the weekend give me a ring and i will show you its potential after a tune.

i quess i need someone to hold the video!!!

[Cubes]

lol.. No problems Darren.

Will give you a buzz.

[tridentt150v]

Dangerman....just as an aside, what power did you make out of your old turbo set up?

Just looking at bang for bucks.

[dangerman4]

Dangerman....just as an aside, what power did you make out of your old turbo set up?

Just looking at bang for bucks.

ive seen 273kws at the wheels, without much fine tuneing on the dyno.

also with Auto,standard head and cams and standard plenum.

with a few more goodys and on a manual it should get up to 290 / 300kws

[Busky2k]

I took a good look at the dual outlet flange available for the new GT wastegated housings. While it looks like a very nice idea... does anyone think the flow from the wastegate would be pretty damn turbulent?

Have a look at this. You can see as the wastegate flapper opens up, the gas is going to spew sideways and create some serious turbulence as it tries to exit the relatively small 2" exit on the flange. Moreover due to the way the flapper opens into the exit, its half blocking the exit too.

This is a reference picture to illustrate how much area the small 2" discharge hole is covering.

What do you guys think? Maybe an open ended dump is better?

Edited October 15, 2006 by Busky2k

[dangerman4]

I took a good look at the dual outlet flange available for the new GT wastegated housings. While it looks like a very nice idea... does anyone think the flow from the wastegate would be pretty damn turbulent?

Have a look at this. You can see as the wastegate flapper opens up, the gas is going to spew sideways and create some serious turbulence as it tries to exit the relatively small 2" exit on the flange. Moreover due to the way the flapper opens into the exit, its half blocking the exit too.

This is a reference picture to illustrate how much area the small 2" discharge hole is covering.

What do you guys think? Maybe an open ended dump is better?

thats why you dont bother spending shit loads of money on the dump flange that they are using and just buy a flange from horsepowerinabox or similar. with my dump i have fully tig welded the 2 inch and the 3 inch to the flange then ground out all around the wasegate so it flows in nice and smooth, not just thru the 2 inch hole. it seems to work really well and i dont have any boost issues at all. i will try and find a pic

[dangerman4]

now imagine the 2 triangles on either side between the 2 inch and the 3 inch were filled up with weld, then attacked with a die grinder and opened up to the same size as the exhaust housing.. problem fixed....

flows fine..

[Busky2k]

Nice info dangerman4. I agree that the result you speak of would be much better than the small 2" opening that ATP is offering. You don't happen to have a pic of the final result do you???

[dangerman4]

Nice info dangerman4. I agree that the result you speak of would be much better than the small 2" opening that ATP is offering. You don't happen to have a pic of the final result do you???

sorry fella i was very happy with the fit and the eagerness to try something that hadnt been done before (and the beer) sort of took over. and i got a little side tracked. before i thought about taking a pic it was all in and running.