Garrett GT3040.

[Guest INASNT]

didnt jms recon their rb25 was making close to 400rwkw with stock internals and td06 25g??

[R31Nismoid]

yeah... and what happened to THAT motor i wonder...

NICE results there Steve.

with a big increase in housing, there is not much more lag really for the change.

And your RB20 aint you?

or was it RB25... either way. GT3040 .82 housing.. IM EXCITED

[Guest INASNT]

GT3040 .82 housing.. IM EXCITED

im excited also, my car is at trufit getting the new intake and front section of the exhaust done!! yay i might finially get to drive it soon :headspin:

[yogi000]

Ok.....this might sound stupid (cause i am) but what effect does having a larger intake turbine compared to a larger exhaust turbine? I dunno if that really makes sense

[Roy]

Ok.....this might sound stupid (cause i am) but what effect does having a larger intake turbine compared to a larger exhaust turbine? I dunno if that really makes sense

I think you will find the compressor housing A/R is not as critical as the A/R of the exhaust housing. Its still important though as it impacts the range in which a turbo is effecient (the shape of the effeciency islands of the compressor maps).

People seem to change exhaust A/R when there are problems with compressor surge, but if the A/R of compressor covers influences the shape of compressor maps, then i imagine it can just as easily influence the surge limit

[Steve]

Its not a massive difference in where boost is made, more so in how it is made.

0.61 was like a lightswitch - just nuts, 0.87 is more progressive, but still pulls hard when it gets serious:)

And R31Nismoid, it is an RB25, RB20 - hmm, make sure you wind that redline right;)

Another thing too, bigger the exhaust housing, lower the back pressure, less detonation.

[Steve]

didnt jms recon their rb25 was making close to 400rwkw with stock internals and td06 25g??

Dont think so, it survived Danny! if you can believe it.

Danny was saying a little while back (week or so) how well it performed without anything giving up.

[Freebaggin]

Steve, great to see your turbs is reponding better now with the ECU change. Time to hit AIR :wassup: Need some decent tyres mate. Believe it or not I am runnign ZE-326 Falkens and they are pretty good on the strip!?!

I still reckon the GT3040 would be very laggy with a 0.82-0.87 turbine housing. Two things:

1. Steve is running 2.5L with VVT. Not 2.0L with no VVT.

2. Steve's GT30307S has a smaller compressor wheel.

Anyway, depends what you want I spose. I'd say you will have to rev to well over 8500rpm to get the benefit and by the the RB20 head may have run out of flow anyway.

[hungry6]

Ok to lay things to rest i had the exact turbo on my car a couple of years back(rb25 with front facing T/B), i ran it with a 0.63 ex.housing initially and founded that it was choking at top end , so i went to th 0.82 housing and the problem went away, i was running a turbonetic 42mm wastegate at the time also. the on boost different between the 2 housing is only 300 rpm and the 0.63 housing is more instant than the 0.82 but the 0.82 was a much better drive as it was more well natured and very-very thrusty when on song. Also not sure if this will mean anything, the .082 is over twice as loud as the 0.63 housing. Just food for thought.

[rob77]

Rob your TD06 has the exhaust housing meant for a 13B rotory, so do you really think if you gave a Garret 3040 (Internal or external gate) a 1.12 A/R exhaust housing that it would still spool up quicker.

If you used the recommended Trust housing on your car (12cm^2), then it would provide a lot more midrange hit.  The response you are getting could probably be matched by the bigger Trust TD06-25g (Trust recommend 10cm^2 for an RB25...remember what Freebaggin said about A/R sizes and wheel sizes )

...but this aint a thread about Trust turbos, just pointing out that a turbos characteristics can vary a lot depending on the A/R housings used.

The garrett or hks is a ball bearing turbo, so in should spool quicker than the trust sleeve bearing unit. I dont think the 16cm^2 unit is laggy, I wouldnt call full boost at 4200rpm laggy when I'm making 250+kw @ wheels. I'm sure with cams and adjustable cam gears and a better manifold (I am still runing the stock exhaust manifold) I could get it down much lower.

[Freebaggin]

Ok to lay things to rest i had the exact turbo on my car a couple of years back(rb25 with front facing T/B), i ran it with a 0.63 ex.housing initially and founded that it was choking at top end , so i went to th 0.82 housing and the problem went away, i was running a turbonetic 42mm wastegate at the time also. the on boost different between the 2 housing is only 300 rpm and the 0.63 housing is more instant than the 0.82 but the 0.82 was a much better drive as it was more well natured and very-very thrusty when on song. Also not sure if this will mean anything, the .082 is over twice as loud as the 0.63 housing. Just food for thought.

Hmmmm, interesting stuff Hungry6. I might have to eat my words a bit re RB25 at least. I see power drop off at 6300rpm odd as well, not much but enough. Might look into the 0.82 later down the track. The louder exhaust might be due to the lower exhaust back pressure. I made basically no other change on my motor except bigger turbo (up from stock) and it was louder for sure.

However for RB20, I reckon even with the 0.63, the lag might be alot.

[Roy]

The garrett or hks is a ball bearing turbo, so in should spool quicker than the trust sleeve bearing unit. I dont think the 16cm^2 unit is laggy, I wouldnt call full boost at 4200rpm laggy when I'm making 250+kw @ wheels. I'm sure with cams and adjustable cam gears and a better manifold (I am still runing the stock exhaust manifold) I could get it down much lower.

I didnt actually say anywhere that your setup is laggy...just pointing out that you have changed the characteristics of the turbo by using the larger exhaust housing.

And im not convinced that BB turbos spool quicker then bush bearing turbos. On paper two otherwise identical turbos, then yes i agree, but practically the differences in A/R, wheel trims and sizes used by different manufacturers play a bigger part in the characterisitcs of a turbo. I dont think it is safe to say that one will spool quicker then another purely because it has a BB core.

[Roy]

And for an RB20 i think the 3040 with the 0.63 housing would be the go.

I wouldnt be too worried about the smaller A/R choking flow on an RB20 and hurting top end.

Id be more inclined to think that the valve size, and cams used in the RB20 may pose a flow restriction before the A/R housing at those sort of hp/cfm targets.

Go for the smaller housing and get the thing giving you as big a midrange torque hit as possible.

[rob77]

turbo matching is obviously a very difficult art. It comes down to what the owner wants, low down response matching the stock turbo's low down boost, or top end power

[RB GUN]

Hello guys,

Wat u rekon my boost kicks in with the .63 A/R housing? and wen do i have my full boost and how far should i boost it up with my stock internals? and how much power ill be looking for..

My mechanic said that after the turbo instalation he will power run it to see if i need bigger injectors or not if so ill put in the 600cc ones

anyways im dropping my car of on thursday and get it back in couple of days.. I CANT wait guys.. thenill let you know wat have i done...

Cheers

--- Babak ---

[Field]

I have a friend selling a 3037S and from what I gather, you would be able to use the stock manifold and exhaust housing for a stealth type of application.

-Remove original turbo

-Pull off the turbine housing

-send both turbo's to the turbo shop for machining (machine stock housing to fit 3037 exhuats wheel)

-Enlarge your wastegate at the same time

-bolt it all back up

-dyno and road tune

The end result should be 230 odd rwkw on about 1 bar of boost.

You could extrude hone your manifold and exhaust housing to increase flow and A/r

and add bigger injectors and pump, then run around 1.3 bar. I would be realistic to expect about 280 -300 rwkw.

Anyway he has an ad in the for sale section

[Guest INASNT]

The 3037 Pro s can be used with the stock manifold not the normal 3037.

But if u r getting such a nice turbo y not get the manifld to match it so it work properly.

[Cubes]

I'm going to be running a .69 a/r for hopefully just over 300rwkw using a 3037ProS (needs a 10mm spacer plate from the exhaust manifold).

Freebaggin,

Have you tried a stronger wastegate? I found my Blitz SBC-iD used to have trouble holding boost with much more than 3-4psi over the stock wastegates spring load, I slapped on a VG30 (6-7psi) wastegate and had boost drop to 10-11psi, on went the rb20 10psi stock waste gate and boost would drop to around 13psi. THe Blitz SBC-Id had a manual and auto mode. The manual mode was related to the maximum boost possible and the auto was simply dial in say 15psi and let the solanoid do the work. Up when boost would start to drop (5500-6000rpm) the solanoid would be totally closed in order to make 16psi.

Sydneykid went in to this a while back.

Also... I remember talking to the blokes down at JMS when they were doing Matt's old RB25 R32 up. He said the stock exhaust manifold starts to pose a big restriction upwards of 300rwkw. They would pump more boost in but it would keep dropping off.

So there's a couple different things possibly causing problems.

I spoke to Tim a while back, he said his fiddlings with exhaust a/r's has shown that a .61-.69 is fine for 300rwkw (just). He also mentioned something about a 900hp VL Turbo that was running a .82a/r. If he went to the bigger 1.01 or what ever it is the top end power would be the same as would the exhaust back pressure measured from the turbo BUT the car was much laggier. Hence slower & less responsive. Problem with steve's car is that he changed too many things at once, in turn not knowning really what caused the extra lag. My Motor was dropped in last weekend getting the goodies done to it...

[Steve]

Well, after a good hard thrash through the adeliade hills last night I have decided there is no way I will be going down in turbine AR, 0.87 is awesome, very controllable boost with the throttle. There is no way I could have driven like I did with my 0.61 housing still in place.

Stealth appearance, it would be easier to just get an adaptor for t3 to GT25 flange, mine cost around $50 to be machined up. I would really hate to start farking with the stock housing and trying to get it right for a 3037, by the time you have enlarged your wastegate and stuffed around, it would be pretty bloody expensive - then you dont have a tried and proven product, chances are you have taken a perfectly good turbo, and turned it into a surging POS. If it aint broke, dont fix it.

[hungry6]

WelL done STEVE!! So i'm not the only one who believes in the .82 ex. housing. To me it is almost perfect for the rb25. all u need now is some cams and dial her in and u be smiling until the top half of your head falls of.