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honestly i dunno but to get around 250 and more out of a standard rb25 on anything less then 17 psi, to me sounds a big challenge, and not to mention the end result will not be reliable.

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I remember freebaggin made some where up around 270-280rwkw on 17psi with his hybrid turbo using a vlt turbine housing.

The turbo specs were selected by Tim Possingham, it was an expensive bugger though, just under 3k. I suspect the comp and or turbine housings had a little bit of power porting.

The HKS int. gate housings are around $800.

Edited by Cubes

With a .63 rear housing and a GT30 comp WITHOUT zaust cam you wont get near 250rwkw under 17psi IMO. With a zaust cam gear set to 3deg advance and a HPInABox GT30 with .63 zaust housing I am hoping to get close to 260rwkw at ~20psi but not over 20psi... I think (hope) that the .63 zaust housing is good enough swollow enough to avoid serging...

With a .63 rear housing and a GT30 comp WITHOUT zaust cam you wont get near 250rwkw under 17psi IMO. With a zaust cam gear set to 3deg advance and a HPInABox GT30 with .63 zaust housing I am hoping to get close to 260rwkw at ~20psi but not over 20psi... I think (hope) that the .63 zaust housing is good enough swollow enough to avoid serging...

No work done. However I think when considdering engine life you should be right at 20 psi as long as your knock is under control. Keep in mind that this is NO race car and will only see 20psi for short periods of time. Lets face it, how many roads are there in the ACT that will allow an rb25det with 260wrkw to be going full blat for any period of time :P I think there is some risk of doing a head gasket but thats no biggy, I will get a fater one when that happens to lowwer the compression and all will be sweet.

Trust me its easier to act ignorent rather than worry about it mate :)

Edited by GunMetalR33

Yea, rb25's a good engines and I have been told a a few people that the head gaskets should last on 20psi. I think its not GOOD for your engine & an engine with less power and boost will last longer...

Things to worrie about are:

ring lands (monitor knock & A/F ratio's and all should be fine)

head gasket (no more than 20 psi / adj cam gear at 3' adv helps this)

rods (dont rev rb25's over 7000 consitantly)

Before going big boost/power get a new timming belt and water pump...

I would like to get a zaust cam to lower the boost...

rant rant rant :P

yeh i agree, coz mines pushing out about 17psi and i have been scared off by a few people telling me it wont last long.... i guess its all about how heavy ur foot is.

dude,

please correct me if i am wrong, are you running an internally gated A/R .82 housing on your turbo?

if so, what brand?

Yea, rb25's a good engines and I have been told a a few people that the head gaskets should last on 20psi. I think its not GOOD for your engine & an engine with less power and boost will last longer...

Things to worrie about are:

ring lands (monitor knock & A/F ratio's and all should be fine)

head gasket (no more than 20 psi / adj cam gear at 3' adv helps this)

rods (dont rev rb25's over 7000 consitantly)

Before going big boost/power get a new timming belt and water pump...

I would like to get a zaust cam to lower the boost...

rant rant rant :P

same me i wanna get a set of zaust cams, help boost up a little better too....

dude,

is that a genuine Garrett GT exhaust housing?

all genuine mate, only thing that aint is the dump obviously. if ur after a turbo like mine give me a pm and i can organise u someone to give u a quote, i got mine pretty cheap..

honestly i dunno but to get around 250 and more out of a standard rb25 on anything less then 17 psi, to me sounds a big challenge, and not to mention the end result will not be reliable.

Its not challenge, ive done it, as have a few others also before me :)

get a new tuner

its just that im wondering how much psi a standard engine can take and for how long?

Its not just a simple question of PSI.

Do a search and a lot of reading. There are many many things that contribute to a motor shitting itself, not just psi.

mass iv, can you confirm at what rpm you are hitting full boost and if and when your tyres start to lose traction?

You mentioned earlier that the tuner said he was losing traction in 4th (or was it 3rd) to which other including myself thought too hard to beleive.

As I mentioned previously, I'm running just over 240rwkw with full boost of 16psi at around 3500rpm and there's no way in hell my car comes close to losing traction in 3rd with newish tyres on it.

In fact, it will hardly even lose it in second, if at all.

For the record, I'm running 225 Dunlop SP3000's on the stock rims.

Maybe the stocko 16inch rims give better straight line traction?

Maybe my car is actually running 200rwkw? (no way :))

As for you guys running GT30's, being a 550-600hp unit I'd say that 250rwkw is still quite a fair whack under the efficiency range of the turbo. I have a 460hp unit on mine pulling similar power with similar boost and still haven't hit the turbos limit. Need injectors :)

Perhaps we're seeing a limit with the stock cam setup because I was actually expecting more from this turbo (GT30) considering you guys have injectors giving you enough fuel for far more than 250rwkw.

ok id like to clear up a few things, my car is at full boost by 4000rpm, which is around 17psi. secondly it spins crazy in second and does a little into 3rd, i dunno if the dyno reading is incorrect but it deffinately feels as though my car has a little more then 240rwkw... not to mention i have smoked a few big powered cars..

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