R34/vg30 Turbo: Compressor & Turbine Wheel Changed To Metal?

[Andi]

Hey guys,

Now I've seriously been considering a turbo upgrade the past few weeks but I've run into too many choices. I was after something straight bolt-on being able to retain my current intercooler piping, dump and intake pipe. Obviously the best choice would be a highflowed turbo but when thinking about this I thought of something:

What if I just change the stock ceramic wheels to metals ones, while not honing/boring the turbo out? If I was happy with the stock turbo's responsiveness and didn't want anymore lag that would come with "hiflowing" the turbo, could I just change the weakness of the stock turbo being the ceramic turbine wheel that doesn't allow high boost?

If this is done could I theoretically run more boost now while retaining the same responsiveness of my stock turbo? Which leads me to my next question: whats the max efficiency boost range of the stock R34 VG30 turbo, and what sort of end power figure would I be looking at?

I'm really sort of after a turbo that would give the same results as a HKS GT2530, blistering mid-range punch. Would changing the wheels of my stock turbo to metal and running more boost give me this?

Any answers or feedback will be appreciated. Thanks in advance!

Andy

P.S - would anybody have any idea on how much it might cost to get something like this done?

Edited April 23, 2007 by Andi

[Andi]

So anybody any ideas on how much boost the stock turbo will be able to make if they had steel wheels? Anyone got a compressor map for the stock R34 turbo?

[Dale FZ1]

Compressor maps are something derived from testing by the development engineers. Nissan don't publish them.

My GT2871R 48T high flow runs a very mild size upgrade from stock, using R33 spec housings. I suspect maximum useful boost sustainable through the range will be around 15-16 psi. Any higher and compressor flow limitations would probably see boost dropping towards the 6000rpm mark.

There are some good combinations out there able to meet your requirements. If it were possible to simply replace the composite impellers with metal items (probably not available in exactly the same specs), then it would be an expensive exercise. You can get a performance increase with little discernable lag penalty if you do some homework.

Try looking at the stickies section, and use the search function. Plenty of experiences to draw from.

cheers

[JustinP]

Just get a GCG high flow.

[MANWHORE]

It is possible. The vl guys on calais turbo experiment a lot with different wheel sizes for highflowed turbos, unlike here where everyone just says get a gcg.

What you'd expect, is response a decent bit later since metal is heavier than ceramic. It's not worth the upgrade.

having said that dyno testing a stock turbo on 15-16 psi (was dropping off) and was tuned, yielded 225 rwkw. I would say that if the wheels were metal, and if you pumped it up to 18 psi, you'd expect 230 rwkw max probably.

not worth the upgrade. just go for a gcg