Garrett Medium Frame Gtx Turbos

[hybrid_eg]

thanks! thats some major power! i guess i'm gonna try it with .63 for sure.. as response with 82 sucks.. full boost isnt there till after 4500++

[GTScotT]

The only issue is that the .63 will really limit you power wise.

For reference, a .63 on a normal 35R limits its capability to be very similar to the 3076R. It still keeps some of the lag though.

There is also the Kando Dynamic 10cm rear housing you may like to try. It is MUCH cheaper than buying a garrett and has shown to flow very well with the TD06 wheels in it (up to roughly 400rwkw is not out of the question).

I think under $200 delivered as apposed to $700?? for a garrett housing.

[Lithium]

If a .82a/r GTX3582R is going to be too laggy then I suspect a GTX3582R is the wrong turbo for you in the first place, to be honest - going .63 is probably pointless.

[discopotato03]

Well boring out turbine housings for larger turbines does increase their flow potential but given a choice a designed for the turbine housing is a better bet . There is no real T3 flanged GT35 turbine housing so what you get is a bored out GT30 one from Garrett .

If you go to turbobygarrett you can compare the exhaust flow differences between a 0.63 AR GT30 and a 0.63 AR GT35 based turbo .

I'd have to look again but I'm pretty sure Robert Young at FP uses 0.70 AR T04S compressor housings on his GT30 based HTA turbos , I think these are port shrouded too .

Yes Buschur is a bit of a whis with Evos in the US . Its a bit hard to compare a stroked 4G63 to an RB25 because the engine dynamics are so different , as are the cars themselves . The sort of power a well sorted Evo can put to the ground isn't possible with a RWD Skyline .

I don't qnow the full story yet but the version 9 Evo heads are different and its not just the MiVec variable inlet cam biz . They changed the water jackets and spark plug size so that they can raise the detonation threshold a bit and that would make a significant difference in itself . I suspect Nissan did something similar with the last version of the RB25DET in the R34s and if I wanted the best from a 25DET I would base it on a Neo head and pistons designed to work with it .

The best part of those TR30Rturbos was that 60mm NS111 turbine wheel , actually TR30Rs came with four compressor wheel options and two trim sizes for that gun turbine (73 and 76 from memory) so they are not just one turbo rehashed . Ironically many of the old T series turbines were also 76 trim and can actually work quite well for their era . I think Garretts aim with the production GT30 and GT35 turbines was to use the larger 84 trim size so they could increase their flow potentials without increasing the turbines major diameters . The ODs are approx 60 and 68mm (GT30 GT35) and while they do allow high flow it comes at a price and that is turbine response . The 60mm TR30 turbine does not flow as much as a GT30 but it is lighter and a lot more responsive in the real world . The TR30Rs aim was to make brutal torque from a lot of boost without a lot of engine revs , to do this you need a free flowing but responsive hot side so the EGT doesn't melt everything .

I think killer road car power comes from brutal mid range torque and the maximum kw output is less important .

I honestly don't know what the ultimate RB25DET turbo is but I do know that any engine thats making good torque off boost tends to hammer on boost even if it doesn't rev to the moon . If you can make boost reasonably early without choking the hot side engines tend to be torquey as was proven with the old FIA Grp A rally cars .

Its history that TR30R turbos work and not surprisingly better than std GT3071Rs do . I reckon if you could option a TR3071R or even the TR30R with the 76mm 56 trim motorsport compressor they could be pretty shit hot things .

I don't think the GTX compressor/housing pairs are fully developed yet and I think Garrett can do better than these now old GT30 and GT35 turbines .

A .

[zebra]

How do you thing a 76mm GT comp wheel would go with the older 76 trim T04 turbine wheels?

Is there much difference in blade design or is it simply the newer 84 trim wheels are going to do a better job than the old 1970's stuff?

[ARTZ]

he is running 11.1 c.r. on e85 pretty insane.. (S54 motor) but at 10psi his gtx3582r with .82 rear made some 630whp.. insane.. response is stupid to say at least.. S54 also revs to 8k just like the GTR of course downside on GTR is half liter displacement less and all that compression..

Of course i'll have to push more boost to get to 500whp which is fine but mainly curious if I can achieve 500whp on that .63.. looking at his set up once that S54 motor is built this season it should make 750whp like nothing! (keep in mind motor is bone stock, never been opened)

so debate remains, do i buy that .82 housing or stick to .63 (looking at his and mine specs) no way I can achieve the same results, hence the reason i'm leaning towards smaller housing..

I think something that seems to me is often forgotten, while a smaller rear housing will help to acheive some extra ( minimal) response..

it will also help to contribute to high EGTs..so while it may be ok for a quick lap or 1/4 mile, wont it start getting to hot after prolonged high rpm in tur robbing you of power...completely self defeating its purpose in the long run..

Even on GCG website it states as a basic rule of thumb

2L use .63

2.5 usse .82

3L + can use 1.06

makes sense that there is no use having extra flow if you cant disperse it quickly enough

[Lithium]

I'd have to look again but I'm pretty sure Robert Young at FP uses 0.70 AR T04S compressor housings on his GT30 based HTA turbos , I think these are port shrouded too .

Yep, I already confirmed that

Its a bit hard to compare a stroked 4G63 to an RB25 because the engine dynamics are so different , as are the cars themselves

There was a testimony which I quoted from someone who put a GT3076HTA onto his RB25 - the evo is a different air pump but the relative performance results are going to give a reasonable indication of what to expect. The turbo is not that wildly different from ones which are known quantities on RBs already, it just takes good and makes it better.

[hybrid_eg]

Tks to all for their feedback, its greatly appreciated!

Where can i obtain this Kando Dynamics 10cm rear housing?

Just out of curiosity, what turbo would you guys suggest to make 550whp but have a potential of 600whp+ on an R33 RB26 with best response? haha, if there is such a thing! I'm sure you have to give up something, either power or lag..

Tks gents!

The only issue is that the .63 will really limit you power wise.

For reference, a .63 on a normal 35R limits its capability to be very similar to the 3076R. It still keeps some of the lag though.

There is also the Kando Dynamic 10cm rear housing you may like to try. It is MUCH cheaper than buying a garrett and has shown to flow very well with the TD06 wheels in it (up to roughly 400rwkw is not out of the question).

I think under $200 delivered as apposed to $700?? for a garrett housing.

[Lithium]

Will you be using normal petrol or E85?

[hybrid_eg]

Normal fuel, however at race track likely race gas.. so i'll tune the car for both.

[black bnr32]

he is running 11.1 c.r. on e85 pretty insane.. (S54 motor) but at 10psi his gtx3582r with .82 rear made some 630whp.. insane.. response is stupid to say at least.. S54 also revs to 8k just like the GTR of course downside on GTR is half liter displacement less and all that compression..

Of course i'll have to push more boost to get to 500whp which is fine but mainly curious if I can achieve 500whp on that .63.. looking at his set up once that S54 motor is built this season it should make 750whp like nothing! (keep in mind motor is bone stock, never been opened)

so debate remains, do i buy that .82 housing or stick to .63 (looking at his and mine specs) no way I can achieve the same results, hence the reason i'm leaning towards smaller housing..

Get your friend to post on bimmerforums. i'd love to see his set up.

[discopotato03]

How do you thing a 76mm GT comp wheel would go with the older 76 trim T04 turbine wheels?

Is there much difference in blade design or is it simply the newer 84 trim wheels are going to do a better job than the old 1970's stuff?

No I reckon if I wanted to use a 76 or "P" trim T04 turbine I'd use a 60-1 compressor . Garrett actually seel a ball bearing T4 60-1 turbo , it looks just like their T04Z externally but with that 60-1 compressor in it . I think better to use like technologies where possible .

From memory T04 turbines are 74.4mm OD and not exactly light weight things . To me it looks like the GT35 68mm OD turbine was intended to be a more modern replacement turbine for the T04 but being smaller in diameter I reckon the trim needs to be larger to compensate .

From what I see GT35 turbines are not prolific things in truck turbos and they often use twin entry T4 flanged GT40 turbine housings with them . The biggest issue for the small frame (GT25 BB center section) GT3582R turbos is that there is no propper GT35 turbine housing made for them .

A .

[zebra]

Yeah fair enough makes sense

[GravyGarage]

Good mate has ordered gtx3076, 6 boobs, 44mm turbosmart gate for his built 26.

If its too small will be upgrading to the 35 and the 76 will be going on my built 25.

Hopefully start seeing results early next year.

Will be posting results!

[black bnr32]

http://forums.bimmerforums.com/forum/attachment.php?attachmentid=396476&d=1324166607

this is a 35r vs a gtx35r on a 3.2L bmw. t3 .82 rear

note the difference in boost, which is about 2psi

[black bnr32]

also interesting is the slightly better spool with the gtx

[DVS JEZ]

Makes approx. 50 hp more over most area's. Not too bad at all

[R31Nismoid]

EVO's are a classic example, 1.6BAR standard,

No they do not!

~18psi factory EVO 7/8/9, tapers off to around 12-14psi in the upper RPM once 18psi has been hit.

Hence the best mod to an EVO is a tune and get boost holding 18psi to redline for huge increases out of the box.

[hypergear]

The best part of those TR30Rturbos was that 60mm NS111 turbine wheel , actually TR30Rs came with four compressor wheel options and two trim sizes for that gun turbine (73 and 76 from memory) so they are not just one turbo rehashed . Ironically many of the old T series turbines were also 76 trim and can actually work quite well for their era . I think Garretts aim with the production GT30 and GT35 turbines was to use the larger 84 trim size so they could increase their flow potentials without increasing the turbines major diameters . The ODs are approx 60 and 68mm (GT30 GT35) and while they do allow high flow it comes at a price and that is turbine response . The 60mm TR30 turbine does not flow as much as a GT30 but it is lighter and a lot more responsive in the real world . The TR30Rs aim was to make brutal torque from a lot of boost without a lot of engine revs , to do this you need a free flowing but responsive hot side so the EGT doesn't melt everything .

I think killer road car power comes from brutal mid range torque and the maximum kw output is less important .

I honestly don't know what the ultimate RB25DET turbo is but I do know that any engine thats making good torque off boost tends to hammer on boost even if it doesn't rev to the moon . If you can make boost reasonably early without choking the hot side engines tend to be torquey as was proven with the old FIA Grp A rally cars .

Its history that TR30R turbos work and not surprisingly better than std GT3071Rs do . I reckon if you could option a TR3071R or even the TR30R with the 76mm 56 trim motorsport compressor they could be pretty shit hot things .

I don't think the GTX compressor/housing pairs are fully developed yet and I think Garrett can do better than these now old GT30 and GT35 turbines .

A .

TR30 turbos where designed for a 13:1 high comp race engines running race fuel. With the billet material running smaller hub and bigger blades as comp wheel, it can produce more flow with 1/3 of the original weight.

It has one less fin to the GT30 turbine, with bigger blade gaps it will flow more, produce more torque more top end and lower EGT.

How ever there are less materials on the actual wheel for combusted air spinning turbine shaft with. Putting that on a 9.0 : 1 comp ratio on pump 98 out of a 2.5L engine. In my opinion assume the only change made is the turbine wheel, it might not be a better performer then the GT30 turbine.

I'm pretty keen to see results of it running on a RB25det skyline.

[copycutter]

So has anyone definitively worked out for RB engines what the consensus for the GTX 3071/3076 is?

From the results I've seen in links on this thread to other forums, some seem to think the GTX has less response because it's one comp size up compared to its GT counterpart but better flow at big boost, judging by the compressor maps. But there was also some results that seem to show that when back to back comparison was done on the dyno, it seemed the same but with better response than the equivalent GT series.

Does anyone know which it is when we're talking 20th century RB engines and not ridiculous boost levels (<25psi)?

Edited December 19, 2011 by copycutter