Cubes

Roy, I'm a little scared of the 1.06 rear. All though the smallish comp cover should reduce spool time. Bullet, This Vg30 GCG highflow jobbie, say you accelerate from 2000rpm in second gear with a flat foot, what rpm does it kick? I'm assuming at that point it makes 19psi correct?

All I want is a nice efficient .8# turbine a/r internal gate turbo that makes close to 280rwkw without spending a fortune on a hks item.

Simply slapping more cubes under the same head (valve & cam size etc) will cause the motor to rev less. It will make its peak power earlier and drop power earlier resulting in the feeling of it doesn't want to rev out as much. The RB25 head has bigger ports and valves, this will result in a motor that wants to rev harder than your 2.4ltr under a rb20det head that has 5mm per inlet valve less diamater. Over both valves thats a 10mm diamater difference. No wonder the rb20det valves look like little baby toy valves next to the rb25 head. For drift that often see's over rev's I would seriously look at getting yourself a R32 RB25DE block, GTR pistons (possibly forged), rods and crank, adapt the piston oil squirters if you are going to use stock pistons. It will be a much much better drift motor vs the rb23/rb24det. It will rev harder, spool earlier and make more average and peak power. Not to mention it will be much more reliable as you wont need massive cams and huge rev's to make the power.

As the Horsepowerinabox turbo uses the .7 comp cover this combined with the VG30DET exhaust a/r would most probably make more power than the GCG item that runs the stock .4 (I think it is) RB25 comp cover. Inabox, Would you be willing to offer such an item IF the vg30det exhaust housing was supplied?

I would probably keep the transfluid running in to the radiator then in to the external trans cooler then back to the gearbox. Setup that way would no doubt help absorb peak hour traffic trans fluid temps when there is no air passing through the external trans cooler.

You would have to price up a GTS4 RB20DET as the 4wd blocks are different. No doubt the GTS4 Rb20DET's are more expensive than the average rwd rb20det as they are not common.

This is from Garrett's web site. http://www.turbobygarrett.com/turbobygarre...R_700382_20.htm http://www.turbobygarrett.com/turbobygarre...1R_743347_2.htm

Let us know how they sound on a cold start after ~1000km's. At first mine were perfectly quiet, after ~1000km's they began slapping slightly on a cold start first thing in the morning, I thought it was a noisy cam or something, its only ever so slight. EDIT: I used Wiseco pistons, I can't remember the clearance set but it was the larger side that was recommended for 24+psi or race. Silly doing that now but all appears to be well, there isn't any more slap than there was at 1000km's, its now done ~16,000km's.

I think its definitely an RB25DET issue. I have no external head drain in to the sump. The only oil drain I have are the 2 internal ones that run in the block as standard. With the sump off you can see the oil drain copper looking pipes on the edge of the block where the sump bolts are between cyl 1 & 2 and cyl 4 & 5. I'm not talking external, internal galleys that drain the oil from the head. As I said previously our engine builder checked it out and said there is going to be zero oil drainage problems. I'm unsure if he fiddled to ensure so or not as I did mention to him how the GTR's throw the oil in to the head at high rpm.

RB30-Power. This oil drain in the block.. I have 2 little copper looking tubes that drain off in to the sump. I have an 88 VL Commodore Wagon block. Bl4ck32 has just had his tuned up recently, no problems with blowing oil smoke from his. He recently made 218rwkw from a small rb20det t3/4 on 16psi. Definitely sounds as if its an R33 RB25DET head thing.

4k launching isn't so bad. The stock turbo on my rb20det used to require a 4k launch to get off the line without boggin down.

My apologies Morrie, From my understanding when you machine a housing no matter what to some extent the nozzels are butchered anyway. Offer an option for the VG30DET housing and no doubt it will be a stormer, the turbo will then live up to its 500hp rating, well close to anyway.

Your now dipping to load point 17 Bl4ck32... Next turbo upgrade you might want to look at running the GTR load points.

What boost? 19degree's sounds a little high for the 9:1 RB25DET. The stock base map pretty much always makes the rb25det ping, generally timing is pulled out. I'm running 16degree's any more and it will start to ping. Bl4ck32 has a highflowed turbo that free's up the exhaust and is able to run a maximum of 18degree's up top with around 17degree's everywhere else from memory. Its too hard. Get it on the dyno for a cheap power run to see whats going on.

Carl, Loose the attitude. I simply stated it 'may' have trouble pulling more than 250rwkw. The point I was making is GCG is reputable, they make reliable turbos and most know it. I haven't seen results from Horsepowerinabox, I am unsure where they get their turbo's done, when asked if the 500hp internal gate turbo is the same as the gcg item, they stated "its from the same place gcg get their turbo's from" EDIT: It looks as if GCG does indeed machine up the turbine housings for them.

I would be interestered to see exactly why these turbo's have lost their exh. wheel at such low boost levels. From what I have gathered its not the overspeeding that seperates the ceramic bond from the shaft but rather heat. EGT (Exhaust gas temps) increase ten fold when a car is run lean, is detonating or has retarded ignition timing. Obviously hammering the car around a race track also builds up massive temps, but on the street there is no reason why you shouldn't be able to run decent boost through it providing the tune is all good.

Paul roughly what ign. timing are you running at wot through the load points?

I think its every ones initial thought to have a low and high power type setup.

Unless you flick it over 4000rpm with WOT you won't be sucking much juice. If anything, less boost makes the exhaust louder as the wastegate has to open further to bypass more exhaust. They are not like a big cubed V8, they need rev's and a bit of throttle to kick you in the arse.

Thats what you say now... Once you get the car and drive it a little you will realise there is no need for a high low setup.

I have noticed inconsistency's with garrett's web site.

I downloaded NewsLeecher, lots of features *passwd protection* appears to work well. I went for the Limited 10gb account for now. I think I also read some where that the limited accounts allow logins from multiple IP's. Unlimited don't. Its setup this way to prevent abuse obviously. I'll have to give it a try. If so I should be able to pull down at roughly 300kb/s. Need adsl2.

alllriiiight.. I'm signed up. Care to recommend any newsreaders?

There's always adaptor plates, the exhaust a/r is a little big for the 2.5ltr though.

The cost of doing the GTST or GTR up equals its self out with the purchase of 2 turbo's vs one. Both will need injectors, fuel pumps, ecu. The GTST will need a headgasket to drop the comp. It now comes down to traction, which the GTR has lots of. GTS4 and build up a RB25DE or simply drop in a RB26DETT is a cheaper option from an initial outlay point of view. People state yer by the time you spend this much you could have got this.. Its not always the way it works, having the money or finance upfront is not always a possibility, isn't this why we build up cars to make them faster? The amount of money I've spent on mine I could have easily bought a 32 GTR. Point is I couldn't afford it outright being a full time uni student so I settled on a 32 GTST.