R33 Rb30 Conversion

[discopotato03]

Hi Stocky, what spec of GT40 do you have ? I've been looking into various bush and BB GT40's of late . All I can remember is that your using a large 1.32 ? AR turbine housing . There's a bit of variation in GT40 turbine trims ie 73 78 and 84T . Compressors can be GT37 76mm , GT40 82mm or GT4088mm - so many variations . Pics ?

Thanks cheers Adrian .

[StockyMcStock]

yep there's HEAPS of them, lots of trim variations that's for sure.

it's a GT40 bush bearing. oil cooled only. 1.34 A/R exhaust stage - 88mm wheel i think? the compressor is an 82mm with a 0.72 A/R. the compressor stage has such a large A/R because i needed it to produce 500hp worth of airflow at a measly 7psi. the exhaust A/R is so large because the next step up, a GT42, didn't have the right compressor options that i needed to make it all work without surging.

matching everything up was a bit of a bitch - given that the turbo is only providing about half the total boost pressure you need huge flow rates but low pressure on both turbine and compressor stages - an interesting thing to pick from a bunch of flow maps that's for sure. also went for a 50mm wastegate and i'm still hoping that it will be big enough.

[discopotato03]

Hi again StockyMcStock , I looked into these GT40's a bit closer and the one I think you have is the GT4088 unit no 703457-2 / cartridge no 449739-34 . The specs say 88mm GT40 54 trim compressor in a .72 AR port shrouded cover and 77mm GT40 turbine in 84 trim . We should give you a round of applause for getting any boost before the red line with that turbine housing ! As the map shows 40lbs exhaust flow with that housing/turbine LOL .

The later C117 compressor in the GT4088R (88mm 52T) is a bit more efficient and wider across the 1.5 PR line on its map but probably costs more than double what your turbo did . No doubt the wheel will turn up later in bush bearing turbos so may be able to be fitted if needed .

Does your turbo use a T4 mounting flange or the larger T4 International which also gets called T45 flange at times .

I am looking into BB GT4082 and GT3582 custom hybrids ATM , I just have to be careful not to be too greedy with exhaust flow and lose too much shaft/compressor speed . One thing that does concern me with the GT40 turbine side is the size of the exducer outlet , I'm not sure if I can shut the noise of the exhaust up with outlets that big - only really want to run 3" pipe . I also have a bad feeling that the larger GT40/42/T51R sized BB centre section is very expensive compared to the GT35R's if US pricing is anything to go by .

Cheers and good luck with your project , Adrian .

[conan7772]

Are you planning on entering the Auto Salon this year ?

Just kidding. Nice work. Not everyone's keen on neon.

You planning on breaking the speed record in that thing ?

I think it's still 346 km/h.

[StockyMcStock]

disco: that's my compressor stage alright, but the exhaust stage is different. i'm sure it's an 88mm 1.34 A/R on the hotside. here is a link to the exact turbo:

http://www.atpturbo.com/Merchant2/merchant...tegory_Code=BCS

it does use a T4 footprint on the hotside too, yeah.

i boosted it in third yesterday once, right before the clutch started slipping. if you give it a bit of time to spool by using a higher gear, you can get quite good results out of it actually. i had 6psi by 4000rpm, then the clutch started slipping. the car is quite slow until you get to about 5psi, and then it all just suddenly hits you in the ass. 2nd gear is just scary. third feels just as fast as 2nd i guess my awesome manifold is spooling that big sucker up quick? that's the only thing i can think of

this turbo would be a good option with the smallest A/R it comes in on the exhaust side i reckon, if you were using it on its own.

[discopotato03]

Hi Stocky , this part of the Garrett catalog is the closest I could find to that GT40's turbine housing AR .

Search Turbochargers GT40 Family GT4088 703457-2 . It shows the turbine as a 77mm 84 trim in a 1.34 AR housing . I am not trying to say you are wrong it just seems to line up with that pages specs . I checked out GT42/42R's and they are shown as having 82mm diametre turbines . If you can give me the turbos ID tag numbers it would confirm the wheel sizes .

Its also curious that the pics of the turbo (yours) at the ATP site show a different style of turbine housing on the GT4088 . The outlet is V band and the profile of the inlets looks more like two capital "D" miror imaged around the divider rather than two 00 shaped T4 style inlets . I think I smell a rat here and want to know if ATP is passing T4 housings off as GT40 housings .

As for your cars boost rise , do I remember you saying it has a 50mm wastegate ? What pressure is it set to regulate at ?

Cheers Adrian .

[StockyMcStock]

you could be right there - i'm just going off what that page says down the bottom. either way, that style exhaust housing is what i have, not the V-band one that you posted. i'd love to have a look at the ID tag but it's a bit hidden on the car.

here's a quick video of what it does in 2nd gear, then third for a little bit. ignore the tacho jumping around, there's a loose wire somewhere that i haven't fixed yet.

Also starring: my feet! In a cameo appearance.

edit: it's a 50mm gate - gets to 10-11psi or so at the moment. doesn't knock even on the standard RB25DET base map which is very nice. however, the injectors reach max duty cycle at about 5500rpm or so. i guess it's making a bit over 200rwkw then?

Edited March 25, 2006 by StockyMcStock

[Cubes]

What load point is it dropping to?

Thats more of an indication as to what power its making.

I can hear the car but no video, what codec was it encoded in?

[StockyMcStock]

i don't know actually - how do you do a map trace and get the controller to leave the peak values there? i can only get it to give me instantaneous readings at the moment. is there a trick?

p.s. you need new codecs

p.p.s. it's an XVID codec apparently

p.p.p.s. go here and download it

Edited March 25, 2006 by StockyMcStock

[Cubes]

Yep codecs installed all sorted.

Looks as if it pulls pretty hard from 4000rpm in second, thats impressive.

Not to mention the sound.. Awesome, if only you could wind it out.

The load points... You work your way to the map trace and if my memory serves me right you hit the right arrow. That will then highlight and leave hightlighted every load point touched.

200rwkw is around load point 15 at 5000rpm.

175rwkw is around load point 15-16 at 4000rpm.

[StockyMcStock]

would that be using a Q45 AFM as i am?

that brief blurt of sound on full boost is the gate opening - in 2nd gear it gets from 80-120km/h in what feels like much less than one second.

[Cubes]

Its all the same providing you select the corresponding afm from the airflow menu.

What determines the load points is the airflow reference table.

That is seperate from the airflow curve (which is what you select when you go in to the airflow menu)

So... If you run out of load points you will have to have a datalogit hooked up and possibly drop an rb26 or custom airflow reference in there.

UNLESS you tune the last load point for peak power which really is not too good for transition power as when it intially hits load point 20 it will be running rich and not optimal timing, until the airflow gets up to where the vales entered are optimal. If that makes sense.

BUT it may flick past that point so quickly it doesn't really affect it.

On that note Bl4ck32 was maxing out the rb20det airflow reference as a result hitting load point 20, he made 200.4rwkw, dropped the rb25 airflow reference in to it and made 218rwkw at load point 16 I believe it was.

Also... Load point 20 at 2000rpm isn't say 200rwkw, it may only be 130rwkw, where as at 5000rpm it will be 200rwkw.

So if your running that nice little supercharger thats making a heap of low down power you will be maxing out the airflow reference much earlier.

This is why the Rb30DET's when running the rb20det airflow reference table can only make 200rwkw before hitting load point 20. On the rb20det however they easily push 230rwkw or so.

Hope that made sense. Can't be buggered reading it to make sure it does. lol

[BU5TER]

RB30 Power hahaha

[Cubes]

Looks like it got away from you a little there Bu5ter.. lol..

Awesome...

Whats the rev limit at?

[conan7772]

would that be using a Q45 AFM as i am?

that brief blurt of sound on full boost is the gate opening - in 2nd gear it gets from 80-120km/h in what feels like much less than one second.

I hope you got good brakes man

[ISL33P]

nice vid's stocky and buster. have to love the sound of the ext gate.

where did the 8300rpm rev limit post go ?

[mr_rbman]

where's the video of buster's car gone?

[R31 POWER]

Dont flame me but i've searched and cant find it.Ok i got the R32 rb25de head and i'm thinking i'll wack in the valve springs from my spare R32 rb20det motor.Will they fit? and should i keep the 25de cams in there or put in the 20det ones?

Jase

[momo]

Ok, just reade the first 40 odd pages of this thread and the last 6. Have done some searches and read the guide and would like to ask some questions, Please!. I want to do this for a gts4 r32. as I understand it i can use the gts4 sump with a adapter plate, where do i get it?

this is a budget conversion so,

I think most important is the loom question, keeping the rb20 loom and an ecu that can comunicate with the attesa are my two biggest concerns. I think you cant plug a rb25det computer into the loom because of the comunication to the atessa system. So, could you plug a gtr pfc into the loom (cheaper than a gts4 one) using bigger injectors i thought maybe this would be a better starting point than the rb20 pfc (if the plugs are the same?), OR how about the rb20 ecu and a e-manage, (I can get the full e-manage kit at a bargain price). I understand that if you try to use the rb20 injectors in the r33 head they wont fit but, If you get the r33 injectors and fuel rail will the r32 loom plug into them?

If anyone can clarify this for me i would really apreciate it

cheers

[Cubes]

Dropping it in to a GTS4.

You are better off grabbing a complete Rb26 and inlet manifold/plenum.

If you do decide to go the rb25 head route then you WILL require an aftermarket plenum due to bonnet clearances and the inability to easily lower the motor. All of which increases cost to the same level of the rb26 head and inlet/plenum. So go the rb26 head.

So drop a rb26 head on the rb30 block and run a rb20 powerfc.

There is no need to start fiddling with looms unless you go the r33 head.

To be honest.. The r33 in your circumstance is a pain in the arse. The Rb26 route is so much easier.

R31 Power, Unsure if the RB20DET valve springs are any different to the R32 Rb25DE, the reason I say this is the RB20DET runs smaller valves. Generally speaking smaller valves run light springs. Grab a set of GTR springs, second hand they go from $100 up to ~$200 for low km R33/34 items.