Changing Exhaust Housing

[R32SOM]

Hey guys. Umm im not sure how to put this cos i dont know too much about it so i thought id just throw it out there.. I have a t3/t4 (to4e) and its spooling a little too late (5k+) so yeah, i got the car tuned at uas and they suggested changing the exhaust housing on the turbo to allow it to spool a little earlier (4k would be appropriate). Has anyone had experience in this area and would anyone be able to suggest which type of housing would suit my application?? thanks guys.

[Cubes]

RB20DET? RB25DET?

Give a complete run down on the current specs.. Everything.

[R32SOM]

RB20DET? RB25DET?

<{POST_SNAPBACK}>

complete rundown

RB20 det

polished

balanced

strengthened valve springs

had the head machined

copper head gaskets

billett adj cam gears

front mount

pod filter

forged pistons

o-ringed

wallbro 500hp intank pump

GTR injectors

wolf 3D v4 ecu

top mount manifold

catch can

to4e turbo

external wastegate 38mm

turbosmart series2 bov

custom dump

3in exhaust from turbo

i think thats everything

[R32SOM]

*bump

[Cubes]

Turbo specs.

Turbine a/r?

[JH32]

yeah turbo specs would help a lot !

[StockyMcStock]

first of all, try a good boost controller (even a pneumatic pressure-relief valve would do) to eliminate all wastegate creep. if you still find the lag too bad, go a size down on the exhaust housing. perhaps even two sizes down.

[Cubes]

From what I've seen, going from a .82 to a .63 or there abouts generally drops spool time by approx 500rpm.

[R31Nismoid]

500rpm @ the most.

i'd be looking at a new turbo

[R32SOM]

yeah, i understand its not in the league of 'todays' turbos as in response, power pp,lag, but i got it for relatively cheap, and after spending a fair bit on the car i know im kinda bottlenecking it with this turbo..but guys, as we all should know, sometimes our hands are tied and have to make do with what we have..and by any means, bringing on boost 500rms faster is nothing to gawk at. Im just trying to make the most of what i have, thats all, thanks for the response.

[Cubes]

My point was I highly doubt you are running a .82 at the moment.

More likely around the .63 or smaller.

That doesn't leave any room for spool improvement.

So what turbine a/r are you running?

[The Mafia]

here's my educated guess -

Its an RB20 coming on boost at about 5000rpm. Thats gotta be a .86 exhaust housing. Plus the fact the its a dirty old t04e turbo, which will be a roller bearing.

He needs a nice little HKS2530 or something arouind that size, or even a hiflo job of a T3 or t28.

But overall, he needs a turbo with a .63 or smaller exhaust housing and it needs to be a ball bearing turbo.

Now, if you have the money, I'd look at what they have said, a Boost controller with a pneumatic spring or an electronic one to prevent wastegate creep, but I'd also look at either cams or a exhaust cam gear to bring it on earlier again.

[Cubes]

My guess it isn't.

Clint32 ran a TO4E with a .6 comp cover, 54mm comp wheel, .6 turbine housing and 58mm turbine wheel on his 100,000km' RB20DET.

That didn't get going until 5k.

I've just had a quick look and it made 234rwkw on 16-17psi.

[R31Nismoid]

t04e aint a roller bearing

[Roy]

here's my educated guess -

Its an RB20 coming on boost at about 5000rpm. Thats gotta be a .86 exhaust housing. Plus the fact the its a dirty old t04e turbo, which will be a roller bearing.

He needs a nice little HKS2530 or something arouind that size, or even a hiflo job of a T3 or t28.

But overall, he needs a turbo with a .63 or smaller exhaust housing and it needs to be a ball bearing turbo.

Now, if you have the money, I'd look at what they have said, a Boost controller with a pneumatic spring or an electronic one to prevent wastegate creep, but I'd also look at either cams or a exhaust cam gear to bring it on earlier again.

<{POST_SNAPBACK}>

I dont think its that easy. I jumped down an A/R housing size and was surprised i didnt gain more response, sure it got better but he physical difference was huge and the difference in response was about 500-600rpm. The thing could have a huge turbine on it, could be back cut etc, in which case the A/R housing will not do a whole lot.

I could put a 0.48 housing on a T78 and the thing still isnt going to be responsive (not to mention surge)

As for needing to be ball bearing, again i dont agree it needs to be. If i was buying a turbo i would try to make sure it was ball bearing, better durability and improved performance. But ball bearing dont mean squat if the wheels and housings on the turbo aint right. Try my so called truck/plain bearing turbo having the same response as RB20s with 2530/2535s, there is much more to the equation then just the fact that something is plain bearing vs ball bearing etc.

Also i found that housings can get expensive...id live with it for as long as you have to until you can afford a new Garret, they can be had for around $1800, sell the T04E for upwards of $500, rather then spending money on a compromised turbo setup.

LOL..so far two of the better turbo setups on Rb20s on SAU have been plain bearing old school turbos, just well matched