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hi everyone , i'm buying a new turbo for my rb25 on the aim for 260 - 300rwk , i have all the supporting mods to handle this sort of power but i'm getting mixed opinions on what is best for my application . My aim is for as much torque as low as possible , budget isn't so much an issue as i'd rather save and get the right one than rush into purchase and not be happy . any help would be great . cheers

p.s yes i read the dyno thread but i'm looking for more in depth input :)

t67 10cm, without doubt. Td06l2 way too small.

Just finished a 33 4 door with 6boost manifold, blitz gate and custom T67 (t3 flange) and it made 320rwkw @ 18psi, super responsive and lots of broad torque. (im on the dyno ATM so no graphs til later)

t67 10cm, without doubt. Td06l2 way too small.

Just finished a 33 4 door with 6boost manifold, blitz gate and custom T67 (t3 flange) and it made 320rwkw @ 18psi, super responsive and lots of broad torque. (im on the dyno ATM so no graphs til later)

So he got it finished! That's mint!

t67 10cm, without doubt. Td06l2 way too small.

Just finished a 33 4 door with 6boost manifold, blitz gate and custom T67 (t3 flange) and it made 320rwkw @ 18psi, super responsive and lots of broad torque. (im on the dyno ATM so no graphs til later)

i am very keen to hear moaarrr

t67 10cm, without doubt. Td06l2 way too small.

Just finished a 33 4 door with 6boost manifold, blitz gate and custom T67 (t3 flange) and it made 320rwkw @ 18psi, super responsive and lots of broad torque. (im on the dyno ATM so no graphs til later)

oooh nice! , i know it's a big ask but is there any chance you could put up a graph to show when it comes on full boost and where it makes all its torque? :D it'd be very much appreciated

Out of interest do we mean T67 as in the Mitsubishi based Trust turbo or a Garrett thing built around the T04R/Z compressor and the T350 (AKA Stage "5") turbine ?

By the sounds of things its a Mitsy if the turbine housing size is measured in cm .

Cheers A .

Much talked about and difficult thing to make everyone happy . 260 to 300 is also a wide range with an RB25 because some turbos will just make a potential 260 with no hope of seeing 300 . This 260 and up area is getting towards the upper ranges of what a mechanically std 25 wants to flow and any non turbo breathing mods like porting and cams makes the ask easier .

Realistically you probably need to go for a ride in a few sensibly modified cars to see what a responsive 260 Kw feels like because obviously a so called responsive 300+ isn't going to feel the same . Your call but I'd be aiming for a performance result rather than a number if response is an issue - and it is .

One thing you see all the time is people fitting big turbos and being bitterly disappointed because the lack of response or turbine lag if you like kills the fun for them . If you don't have any example you like to go by I suggest you start a little conservatively with turbos because they tend to achieve good results over a wider part of the engines rev range you live in . Maybe the question people should be asking themselves with turbo sizing is when do I want the boost and torque to start and go from there .

If money isn't an issue you could start looking at HKS units like the GTRS or the GT2835 Pro S because these are responsive things in their respective power ranges even on mechanically standard engines . The compressor housings are both port shrouded (the nearest Garrett equivalents aren't) so their conservatively sized turbine housings allow for response without compressor surge . The HKS turbine housings bolt up and with the GTRS so do std or aftermarket RB25 dump pipes .

I have spoken to GCG about getting Garrett T3 flanged GT30 IW turbine housings machined to take the cropped GT30 turbine in some GT3071R/GT2835 cartridges but that's still up in the air .

Also the full turbine sized Garrett GT3071R comes with a large boss T04E compressor housing but its not port shrouded .

There is a possibility that results were not fantastic when using the Garrett GT3071R and the smallest available (0.63 A/R) turbine housing and some of this may have been because of compressor surge or being right on the edge of it .

HKS uses the exact same comp wheel as Garrett does but their custom made (hint) housing does have it .

Once you start into the GT3076R range your not going to get instant turbo response because of the size of the turbine and compressor . Using the mid or 52 trim compressor size and again the 0.63 A/R turbine housing is probably as good as one of these turbos is going to get "response wise" but I don't think that combination has been tried yet .

I don't know much about the Trust spec Mitsubishi turbos other than it sounds like they did special compressor and turbine housings for Mitsy cartridges much like HKS does with Garrett cartridges . Some people feel that Mitsy makes more responsive turbos for their size than Garrett and occasionally put it down to development gained from lots of small/medium OE turbo production ie Evos and Subarus .

Off the top of my head the only Garrett GT BB OE apps I can think of are some S15s and the XR6s .

Anyway see if you can go for a spin in a few other cars and you be the judge .

A .

This 260 and up area is getting towards the upper ranges of what a mechanically std 25 wants to flow and any non turbo breathing mods like porting and cams makes the ask easier .

The rb25 will support mid 300's unopened all day everyday, there are however a handful that fall over valve spring wise.

Also the full turbine sized Garrett GT3071R comes with a large boss T04E compressor housing but its not port shrouded .

There is a possibility that results were not fantastic when using the Garrett GT3071R and the smallest available (0.63 A/R) turbine housing and some of this may have been because of compressor surge or being right on the edge of it .

HKS uses the exact same comp wheel as Garrett does but their custom made (hint) housing does have it .

Port shrouded 3071's are available through ATP turbo's ...just click on the option when ordering.....might be a cheaper option than the HKS variant.

Much talked about and difficult thing to make everyone happy . 260 to 300 is also a wide range with an RB25 because some turbos will just make a potential 260 with no hope of seeing 300 . This 260 and up area is getting towards the upper ranges of what a mechanically std 25 wants to flow and any non turbo breathing mods like porting and cams makes the ask easier .

Realistically you probably need to go for a ride in a few sensibly modified cars to see what a responsive 260 Kw feels like because obviously a so called responsive 300+ isn't going to feel the same . Your call but I'd be aiming for a performance result rather than a number if response is an issue - and it is .

One thing you see all the time is people fitting big turbos and being bitterly disappointed because the lack of response or turbine lag if you like kills the fun for them . If you don't have any example you like to go by I suggest you start a little conservatively with turbos because they tend to achieve good results over a wider part of the engines rev range you live in . Maybe the question people should be asking themselves with turbo sizing is when do I want the boost and torque to start and go from there .

If money isn't an issue you could start looking at HKS units like the GTRS or the GT2835 Pro S because these are responsive things in their respective power ranges even on mechanically standard engines . The compressor housings are both port shrouded (the nearest Garrett equivalents aren't) so their conservatively sized turbine housings allow for response without compressor surge . The HKS turbine housings bolt up and with the GTRS so do std or aftermarket RB25 dump pipes .

I have spoken to GCG about getting Garrett T3 flanged GT30 IW turbine housings machined to take the cropped GT30 turbine in some GT3071R/GT2835 cartridges but that's still up in the air .

Also the full turbine sized Garrett GT3071R comes with a large boss T04E compressor housing but its not port shrouded .

There is a possibility that results were not fantastic when using the Garrett GT3071R and the smallest available (0.63 A/R) turbine housing and some of this may have been because of compressor surge or being right on the edge of it .

HKS uses the exact same comp wheel as Garrett does but their custom made (hint) housing does have it .

Once you start into the GT3076R range your not going to get instant turbo response because of the size of the turbine and compressor . Using the mid or 52 trim compressor size and again the 0.63 A/R turbine housing is probably as good as one of these turbos is going to get "response wise" but I don't think that combination has been tried yet .

I don't know much about the Trust spec Mitsubishi turbos other than it sounds like they did special compressor and turbine housings for Mitsy cartridges much like HKS does with Garrett cartridges . Some people feel that Mitsy makes more responsive turbos for their size than Garrett and occasionally put it down to development gained from lots of small/medium OE turbo production ie Evos and Subarus .

Off the top of my head the only Garrett GT BB OE apps I can think of are some S15s and the XR6s .

Anyway see if you can go for a spin in a few other cars and you be the judge .

A .

yeah that's pretty much what i was asking (which turbo has the best torque spread etc ) the overall power output i couldn't give a stuff about. small issue with living in tassie is not many people have this sort of power and the ones that do have de-rego'd their car or live too far away etc . i get what you mean about being conservative with turbo choice which is why the td06-l2 was one of my options , i've heard people have made good numbers on the dyno with these ( sr20 mainly , haven't seen any rb series actually tuned with one) , but at the same time i remember a couple years ago asking trent about t67 for drift and vaguely he was telling me they wree almost too torquey having ~200rwk by 4krpm? on an un-opened rb25 . getting along to the 3071/6 and the 3037 , so many people have these and are claiming they are the perfect combo for rb25 with good all round power/response?. I'll be using an external gate btw , from what i've seen they seem to be more reliable/more effective at controlling boost :(

The rb25 will support mid 300's unopened all day everyday, there are however a handful that fall over valve spring wise.

:merli:

imho if money isn't an issue go a twin scroll 3076 with external gate and 6boost manifold

that or what trent said :P

money isn't an issue , i'd rather save for that extra 6 months to get the right thing first time round :D and i'm thinking of using a hks cast manifold? they seem good from what i've heard?

beau: who has the rb24 with a 3071 strapped on it?

thanks everyone for your replies i am noting it all down :)

I'd be a bit careful with turbo choice in tassie. It is not a flat state, and it also has more wet days than other area's. I think you would be happier with a turbo that doesn't come on too hard down low. I had a hiflow that made 250rwkw, but came on hard too low down and too often. In the wet and with a brass clutch, I had real trouble controlling it. Even simple things like taking off from a slightly uphill set of lights was wheel spin every time, no choice and no option. I went for another setup when I got booked for it, it was cheaper to do this than get fined all the time. Now my power is much smoother/progressive and much much more controllable. I have a GT3076 WG with the HKS cast manifold like you mentioned, and very happy with the set up.

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