Garrett Medium Frame Gtx Turbos

[islade]

What wastegate would you guys recommend for a exhaust-housing mounted on a 0.6x for GTX3071? A Tial 38mm or is there a better/cheaper option?

Isaac

[bradsm87]

A Tial MV-S 38mm v-band gate should flow enough on an RB25. I'd be getting an MV-R 44mm in case u want to upgrade cams down the track where the 38mm would start to fail to control boost.

[GTScotT]

After upgrading from a broken stock turbo, to a kkr560, i've never felt decent response in my car, so that's the new priority, and i've screwed around enough now, to know that this time, i want to do things properly

I think that a GTX3071R on standard manifold with a 0.63 rear with external gate welded to turbine housing would be a good idea...

Guys, to note.. It has been shown many times that the .63 housings on these turbos (and when matched to RBs) are very hit and miss.

I have seen a few that have responded in a decent way yet most will have boost control issues OR excessive heat control issues. My own brother has an issue with a 3076 and a .63 glowing white hot at 18psi. You also seem to limit yourself to roughly 250rwkw before things go pear shaped.

These results are not to be confused with a .63 35R.... Strangely the 35R with .63 can be used to a completely different application and powerband. This is related to the trapping efficiency of the turbine wheel (open enough to allow gas to bypass the wheel when the housing maxes out).

islade, I respect the fact you state you have screwed around enough now... As such I am only willing to recomend ONE option to you, 2835. The HKS 2835 kit is tried and tested as one of the most balistic sub 300kw turbos around. Be it myself still with an RB, I would definitely be buying one of these. The kit from new would come with all fittings, you would simply need to bolt it with the other off the shelf support parts you would expect. Viva la BS fast skyline.

Let it be known, I am of the opinion the HKS housings outflow the garrett equivilants a substantial amount. HKS all the way (and kando T67 for me).

[islade]

I'm trying to do searches in the "Classifieds" section of SAU for "2835" and "gt2835" but none of the sponsors are coming up, so I can't find any prices for the kits. I'm guessing they go for around $3500 though? Wheres the best place to shop?

[GTScotT]

I'm trying to do searches in the "Classifieds" section of SAU for "2835" and "gt2835" but none of the sponsors are coming up, so I can't find any prices for the kits. I'm guessing they go for around $3500 though? Wheres the best place to shop?

www.nengun.com is your best bet.

So far we are unsure about the "KAI" kit and recommend the regular "GT2835 proS", not the one listed as "KAI".

[bigmikespec]

The 60mm turbine wheel actually helps response though because there's more blade area to catch the exhaust gas at very little weight difference.

The GTX compressor wheels are lighter but the 58 trim probably cancels that out. It's VERY unlikely that the GTX 3071's compressor wheel is heavier.

Yes the .82 GTX3071R will be laggier than the .68 GT2835. 2 very different configurations. I bet the .63 GTX3071R would spool the same as the .61 GT2835 tho.

Come on mate; you either work for Garrett or you are just making stuff up as you go along...

[bradsm87]

lol. not at all. i've only ever bought 1 turbo in my life but i do my research. i really cbf going into it but which rims are lighter? which pistons are generally lighter? forged or cast? compressor wheels are the same.

The garrett 56.5mm cropped turbine wheel in the GT2835 is based on the 60mm wheel but trimmed down, even though the centre takes up the same space.

The GTX3071R kills a HKS GT2835 in every way. If I were to put one on an RB, I'd be using a .82 turbine housing, allowing more ignition timing to be run from the reduced back pressure and letting the engine make more power at lower boost.

[bigmikespec]

The GTX3071R kills a HKS GT2835 in every way. If I were to put one on an RB, I'd be using a .82 turbine housing, allowing more ignition timing to be run from the reduced back pressure and letting the engine make more power at lower boost.

Glad you took it the right way.

Yes it might in theory

[wolverine]

Until we see some local results it remains a theory but a promising looking one.

I agree with using a 0.82 housing.

[GTScotT]

Agreed the GTX3071 looks excellent in theory, yet I believe the theory behind cropping the turbine wheel is the opposite.

I believe HKS crop the wheel to get higher shaft speed at lower exhaust gas flow. The full rear wheel would allow for more outright flow. If Brads Mate's theory is correct then we could all build HKS killing combos with 3037 proS rear housings on Garrett 3071s (or in this case GTX3071 WOO).

There is one person I know who would be able to confirm...

[bradsm87]

One combo that'd definately be an HKS killer would be the GTX3071R with a Garrett divided T3 1.06 turbine housing, twin scroll manifold and twin gates. The 1.06 divided has about the same max flow as a non-divided .82 but quicker onto boost.

[wolverine]

Do you have the flow figures for the divided and undivided housings?

[Harey]

The GTX3071R kills a HKS GT2835 in every way. If I were to put one on an RB, I'd be using a .82 turbine housing, allowing more ignition timing to be run from the reduced back pressure and letting the engine make more power at lower boost.

Hold up mate, show me one dyno with a GTX3071 being more impressive than a HKS2835? Oh wait thats right we havent seen what they can do yet. Its all good to be positive but I think its WAY to early to make outlandish statements like that.

All we know so far is the HKS GT2835 beats a GT3071 in every way.

[GTScotT]

All we know so far is the HKS GT2835 beats a GT3071 in every way.

While I would love to agree with you (for once), the GT3071R in a gated .82 has been known to produce peak figures on par with the 2835.

From what I have seen the crop in rear wheel results in a much harder hitting boost threshold, I would say that is the lower RPM shaft speeds more than anything. But by results they DO seem to make similar figures.. A proper garrett .82 will do the 290kw mark.

[Harey]

While I would love to agree with you (for once), the GT3071R in a gated .82 has been known to produce peak figures on par with the 2835.

From what I have seen the crop in rear wheel results in a much harder hitting boost threshold, I would say that is the lower RPM shaft speeds more than anything. But by results they DO seem to make similar figures.. A proper garrett .82 will do the 290kw mark.

Trust me it hurts me too to be remotely on the same side as you.

I thought you were the response fan boy? Great the 3071 with 0.82 housing can make the same peak figures as a GT2835 with a 0.68 exhaust housing. The 0.68 exhaust housing outperforms the 0.82 in the response and mid range department, and if they have the same peak then I know which one I would prefer.

[JonnoHR31]

There are a few different internal gate exhaust housings i've found online at places like ATP, is this housing the best one to get?

yes thats a genuine garrett IW housing. places like gcg and mtq can get them aswell, see what price they can do and shop around a bit. i've got one sitting here aswell you could buy if your keen

[GTScotT]

Trust me it hurts me too to be remotely on the same side as you.

I thought you were the response fan boy? Great the 3071 with 0.82 housing can make the same peak figures as a GT2835 with a 0.68 exhaust housing. The 0.68 exhaust housing outperforms the 0.82 in the response and mid range department, and if they have the same peak then I know which one I would prefer.

Yes I do believe grass is green. I would also go the more responsive option of the two. No I am seldon found to be of 'fanboy' material.

By no means does the housing AR indicate which of the two would be more "responsive". My comment was based on peak output ONLY. You said it outperforms in all ways, I just wanted to clarify that the .82 garrett will match in peak power (some people may not be able to justify the additional outlay for the HKS item).

I think if you reference the member "Usmair" for their results using the .82IW, you will see the response is also good, just not quite 2835 range. That thread was quite well documented from memory, tuned by unigroup so results were genuine.

[Harey]

Yes I do believe grass is green. I would also go the more responsive option of the two. No I am seldon found to be of 'fanboy' material.

By no means does the housing AR indicate which of the two would be more "responsive". My comment was based on peak output ONLY. You said it outperforms in all ways, I just wanted to clarify that the .82 garrett will match in peak power (some people may not be able to justify the additional outlay for the HKS item).

I think if you reference the member "Usmair" for their results using the .82IW, you will see the response is also good, just not quite 2835 range. That thread was quite well documented from memory, tuned by unigroup so results were genuine.

Yes I do remember the results of 'Usmair' and they were very impressive, still not quite the response and mid range of a 2835 but very good nonetheless. However, for every Usmair result I have seen, I have also seen 3-4 poor results, where they make less peak power than a 2835 as well as less mid range and response.

Yes I agree not everyone can afford/justfiy the expense of a 2835 (me included) but I think its hard to find a superior overall turbo for a sub 300rwkw stock rb25.

[bradsm87]

Hold up mate, show me one dyno with a GTX3071 being more impressive than a HKS2835? Oh wait thats right we havent seen what they can do yet. Its all good to be positive but I think its WAY to early to make outlandish statements like that.

All we know so far is the HKS GT2835 beats a GT3071 in every way.

The GT2835 practically IS a GT3071R. The GTX3071R is a newer, better version. The GTX3071R also comes with an 0.6 A/R compressor housing too which improves efficiency across the range. Bloody HKS fanboys

Next thing U'll be telling me that the GT-SS will outperform the Garrett -9.

Edited December 13, 2010 by bradsm87

[bradsm87]

Trust me it hurts me too to be remotely on the same side as you.

I thought you were the response fan boy? Great the 3071 with 0.82 housing can make the same peak figures as a GT2835 with a 0.68 exhaust housing. The 0.68 exhaust housing outperforms the 0.82 in the response and mid range department, and if they have the same peak then I know which one I would prefer.

Smaller A/R turbine housing doesn't necessarily mean less lag. Some (sometimes all) of the spool incease from quicker pressure build-up is lost in the fact the engine has to work harder agains the higher backpressure.

There is no denying whatsoever that the old GT3071R MUST AND DOES make more power than a GT2835. The only thing that's debatable is the lag difference. There is no way the smaller turbine wheel AND smaller housing makes more top end.