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I been tuning a built RB25DET at a country next door, Engine is of stock configuration with built internals with a big turbo charger. Bigger then T04Z and smaller then 42r...

We need to rev this thing to 8500rpm to get things happening.....

I have advised the obvious, Balancer, Oil Pump.... But we need to come up with a decent head build.

Head porting is a issue. No one here will be able to port a head and get good proven results unless its a big F off fluke, and we are not going to take these chances. Because lets face it.. Around these parts of the world... To get a spare RB25 head? it will have to be imported from Japan and the cost of that would be of 5 heads back in Australia IF we are lucky.

We want a decent head build combo that will give us revs, does not matter if we have to go solids ors 280 cams. Customer wants a fast RB25 and he knows he needs to spend some coin to get it.

SO... What do we need to do to a RB25DET head to spin it to 8200 - 8500 rpm.

Please, No amature comments, if you have not done this before and have no experience then do not post crap in this thread. *nice tone of voice*

Yes... I have searched.

Cheers

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I rev'd the stock head to 8500rpm, and now that it's ported, bigger cams and Tomei valve springs we go to 9000rpm. Had this with a TO4Z running 600rwhp. Still using stock hydraulic lifters, had considered the swap to solids, but was alot of extra $$$.

hks 256/264 h/d valve springs revs 8500 rpm all day and ive done 30,000 km on it with 100 passes at the drags its a good combo.

jim at crd tuned the car he wanted to go past the 8500 rpm cos it was still was making power but i dint want to.

Edited by WARLORD

Decent cam profile and springs is the key and it will be fine, i prefer to use lighter retainers but they are $850 for a kit which includes titanium retainers and springs. Lifters obviously need to be healthy to start with.

I have a 25 head here atm which has been CNC ported and has camtech 272's and the HD springs and Ti retainer kit 9k rev limit, its a relatively new combo so i will let you know how it holds up..

on a side not how is Georgia treating you? i havent had much of a chance to chat with the shop being so busy... i apologise.

yeah good mate! :)

Do you think 264 with 9.3 mm lift and some spings should do the job nicely? what kind of oil pump do you suggest

It is a GT37 turbo, and it suffers from compressor surge a fair bit.

Decent cam profile and springs is the key and it will be fine, i prefer to use lighter retainers but they are $850 for a kit which includes titanium retainers and springs. Lifters obviously need to be healthy to start with.

I have a 25 head here atm which has been CNC ported and has camtech 272's and the HD springs and Ti retainer kit 9k rev limit, its a relatively new combo so i will let you know how it holds up..

on a side not how is Georgia treating you? i havent had much of a chance to chat with the shop being so busy... i apologise.

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