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OK here it is the final product/s

RB25 BB turbo

Vg30 exhuast housing

T04B vtrim Compressor

Standard ceramic turbine wheel

Turbine snout enlarged to 52.2mm

result 15psi by 4100rpm

spool starts @2000rpm goes nuts @ 3600(hello tyre fry)

Result 266rwkw @ 17psi

Or Less power Quicker response

Same specs as above with

groove in inlet (same as standard rb25 inlet)(reduces compressor efficiency)

Turbine Snout 51mm

15psi by 3800rpm

spool @ 1800rpm no sledge hammer effect like above just smooth till 3800rpm

result 245rwkw @ 10-15psi will not make more power with boost increase

# Please note these specs bring the turbo right next to the surge limit. If surge occurs it can be supassed with a Greddy E01 or dual stage rpm activated boost control, adjustable cam gear etc. I had absolutely no surge with both these specs. Every car is different however.

*The most fun I had with this turbo was with the turbine snout @ 51mm(no groove) which put it right into the surge zone. I had dual stage boost control which went from 11 to 15psi @ 4000rpm and eliminated my surge problem. Was absolutely awesome fun getting wheel spin in 4th on acceleration......on 18" 275 tyres ->not very drivable in the hills with the sledge hammer boost build. Each to there own

* This turbo will not boost more than 16-17psi due to the turbine trim. It reaches max flow around that level anyway so extra boost would have no advantage.

For those in the know a Turbonetics Super Vtrim compressor will proide 400rpm earlier boost response...Untested by myself.

Happy Boostin

hmmm i was reading about that variable housing in 21 century performance, it sounds good in theory. but to tel you the truth i have never seen on or herd of one being used on a car? it sounds amazing.

BOOSTED: what computer are you running. i have a VG30 turb on my car now and i am going to modify it very simialr to what you have done to get about a 240rwc. because i am using the VG housing with a bigger A/R, will there be a need for the groove to reduce surge?? and am i able to contor the sure as i am running a MOTEC M4?

alot of queations i know, sorry :D . thanks, jonathan

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