I'm with everyone else with the rear housing on the turbo being to big. Did you build it for the street or the strip? Best suited turbo for a street driven car with a RB25DET is a GT3076r. If your going to track it a fair bit stick a .82 rear housing on that turbo to make it spool a little quicker.

Honestly in this age of enlightenment a garrett is pretty old technology. If you decide to change your turbocharger I would recommend shopping around... As per my post above technology has come a long way and you could get something a lot better. That said Chris makes the best point so far about deciding what you want and progressing from there.

Quote: Originally Posted by inferno [View Post] BT- why would you pick the .63? it would run out of puff pretty quick wouldn't it? cheers everyone for their advice! it is really helpful and definitely giving me ideas and looking forward to more comments! i'll post a picture of the dirty engine bay when i find a second. still requires a lot of painting/cleaning but will give you all an idea of where i'm heading! Cheers, Inferno well his made 320rwkws on 21psi with a manual with standard cams with standard intake standard motor on pump not e85 so u tell me ? i think a .63 or .82 are the way to go i would of gone .63 but my turbo was a .82 and already had the housing modified to suit the gate on it so i didnt worrie about it and i see full boost before 3k rpm ..

3540 .63 versus 3076 .82 make sameish power but with a completely different curve The exhaust housing is to big for a manual trans...not enough load...with a auto and converter..it would work, but still be laggy. a 3076 .82 is what you want, or if you have no money, a .63 housing on the 3540... Cams will not fix it, most grinds will make it worse, theres a WORLD of difference between a Rb25 and a R25/30 RB25's are torqueless ****boxes..give me a single cam RB30 any day of the week over one... cheers darren

jack speaks the truth. well. this thread is full of answers. but yeah. basically you change the turbo and it will completely change the characteristics of the car man. 25's have so many tried and tested solutions to make power. i'd hop aboard the precision turbo train. you should be able to flog yours and buy a journal bearing precision for minimal $, chuck in a set of squirters and re-tune. you will be amazed at the difference a correctly sized turbo makes.

thanks everyone for their advice, i really appreciate it (also thanks for not taking any shots at me for not knowing haha) i'll definitely need to have a rethink about my intentions before advancing. i think ideally i'd like a 80% road car and 20% track. i know if i change my injectors toa bigger size, it will boost my HP significantly, but won't fix my main issue unless i am on the track. i may look into a set of injectors and a .63 or .82 and go from there, where is the best place to get new rear housings on their own? i've had no luck with finding one atm. i'm really looking for 400hp with the manual, but if traction becomes a serious issue then there is not really any point in it. i'm trying to get all mods done that makes me happy so i don't have to keep going back to the pits/engineer. the car is off the road at the moment due to overheating issues (i think there is a block in my radiator...) so now is the best time to do what needs to be done. cheers again everyone for their help on this and i really hope i can get out cruising with everyone soon. ---------- Post added 27-12-12 at 16:17 ---------- terrible photo but just for an idea Some original photos have not been recovered yet.

before you do anything at all, go do a tk head check and make sure your head gasket is still intact. once you've made 100% sure your hg is ok, then start sorting ya heating issue by elimination. replace thermostat, flush radiator etc. make sure your fan is working. even though your gate is welded onto the rear housing, its not the end of the world. just buy the new rear housing and take the car to a shop that does fab work like metalcraft marine for example. they might not even need the whole car, possibly only the old housing. then once thats sorted slot in the injectors and take it to get tuned. .82 rear and a set of 720s and it will go 400+, be more responsive and should put the power down without too much wheelspin. more of a progressive power curve. .63 rear and a set of 720s and it probably wont make 400, but it will make the tyres piss when it comes on boost. it will be a bit choked and create alot of under bonnet heat tho. someone mentioned earlier how chucking a .63 on a gt35 doesnt quite match it like a 3076 or even one step smaller a 3071, and they're spot on the money mang. i personally wouldnt go a 63 on that turbo, but a responsive turbo is definately a lot of fun on the street. anywho it sucks you gotta spend a bit more, but you will enjoy the **** out of it when its all done and dusted.

thanks heaps everyone for their input, i really appreciate it. caibs - yeah i'll get the head checked, although my coolant is completely green with no sludge, i will still get it checked as it doesnt lose pressure even when turned off for a day. there is a lot of **** sitting at the bottom of my overflow tank so i am thinking maybe my thermostat has been blocked up or something. i'll check that. i think i will be going a .82 rear housing and bigger injectors and hopefully that will give me the response i am after plus the power figures. i dont want to start a new thread so i'll ask it in here also. should i put in a bigger rear sway bar? or is that gonna stiffen it up to much. i have complete SuperPro Polyurethane bushes and a 30mm front sway bar. cheers.

i reackon leave the rear sway bar as is.... I've done searching on the forums in the past and other ppl tend to agree..

**** I swear I posted yesterday. Standard size rear swaybar, never known anyone to say bigger, even those with much firmer/caged setups. not many people track their cars so maybe ask jase his opinion if you are ever in the situation where your car has a roll cage and you are redesigning suspension. As it stands, leave it standard. new bushes obviously and a bigger front one

I think the rear housing is fine.... you just need to change your diff ratio to 4.11 five0motorsport for your injectors