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i think the gtx would really benefit from more boost in that example, they're compressor map does suggest the biggest difference is at high boost levels

Problem is the turbine and exhaust housing are likely to be choking the compressors true potential - basically its a GT35 flowing compressor being turned (and choked) by a GT30 turbine.

E85 and/or larger ex housing would be the answer IMO.

Now I wonder what the GTX35 would be like in my turbo falcon with 1.06 ex hsg.:mellow:

Edited by juggernaut1

which comes back to the possibility of a gtx3576 being a good thing if you can afford to make one.

How?? The turbo builds boost slower than one with the 82mm GT series compressor.

gtx3076r with the skyline .73 AR exhaust housing (avoturbo.com) might be very interesting.....

currently using this housing with gt3076r bb core, lag in awd auto stagea until just over 2000rpm then it takes off! easy 250awkw with 450cc S15 injectors

better than stock automatic torque converter would change this again tho....

throw in 550cc injectors and the gtx3076r turbo and there's an easy 300awkw on pump gas with remap

Getting that setup installed at Avo on my 33gtst in next couple weeks :)

Okay... I'm chasing around 300kw... no more since it's a standard rb25... a 3076 would EASILY get that but it would be capable of more and will have more lag than a 3071... so I'm going with the 3071.

But I'm torn between housing types... .62 or .82...

Also to add: I'm running vapor gas injection so I get around 20kw more than petrol.

With .82 I'll have more power but more lag, however would that power be too much more for my engine to progressively handle? Would it exceed 300?

With .62 can I expect 280-300kw? If that's the case then It would be fast spool and thus best choice for a standard rb25?

Since it's going to be larger than the gt version, wouldn't a .62 mean more heat and thus mean less boost to avoid issues?

i think the gtx would really benefit from more boost in that example, they're compressor map does suggest the biggest difference is at high boost levels

If someone wants to buy the front/cartridge of my GT35 ill get a GTX35 to test :)

Okay... I'm chasing around 300kw... no more since it's a standard rb25... a 3076 would EASILY get that but it would be capable of more and will have more lag than a 3071... so I'm going with the 3071.

But I'm torn between housing types... .62 or .82...

Also to add: I'm running vapor gas injection so I get around 20kw more than petrol.

With .82 I'll have more power but more lag, however would that power be too much more for my engine to progressively handle? Would it exceed 300?

With .62 can I expect 280-300kw? If that's the case then It would be fast spool and thus best choice for a standard rb25?

Since it's going to be larger than the gt version, wouldn't a .62 mean more heat and thus mean less boost to avoid issues?

Where do you want the efficiency to lie? I prefer midrange so a smaller housing suits me, those chasing top end will go for the .82 or 1ar housings.

As you have a cold gas cooling the charge you may not notice a bit of extra heat...

With .62 can I expect 280-300kw? If that's the case then It would be fast spool and thus best choice for a standard rb25?

Since it's going to be larger than the gt version, wouldn't a .62 mean more heat and thus mean less boost to avoid issues?

If you want to lean on it more the smaller rear housing should make up to 300kw on decent boost.

Personally I think you should always go the smallest housing/turbo that will make your power goals and be close to maxing it out, you'll get slightly more intake heat but response is key for a street car.

Okay... I'm chasing around 300kw... no more since it's a standard rb25... a 3076 would EASILY get that but it would be capable of more and will have more lag than a 3071... so I'm going with the 3071.

But I'm torn between housing types... .62 or .82...

Also to add: I'm running vapor gas injection so I get around 20kw more than petrol.

With .82 I'll have more power but more lag, however would that power be too much more for my engine to progressively handle? Would it exceed 300?

With .62 can I expect 280-300kw? If that's the case then It would be fast spool and thus best choice for a standard rb25?

Since it's going to be larger than the gt version, wouldn't a .62 mean more heat and thus mean less boost to avoid issues?

Do not go with the .63, I have the 3071 with .82 and trust me, there IS no lag. If you go with the smaller housing it will simply come on boost too early and wheel spin. Most of the guys with 3076 & .82 are very happy with the way they perform as far as response is concerned. So why go with an exhaust housing that will choke the power and cause turbine and therefore exhaust heat. The result from this is detonation so you will have to remove timing which will reduce power anyway. The 3071 is the best compromise for no lag/good power. Personally, go with the 3076/.82 and know there is some headroom for more power but if boost is kept low so will inlet temperatures.

I think cams will be needed to hit 300rwks with a 3071/.82 regardless of the latest technology.

Edited by skylinecouple

Hm so far from people I know and I net hunting it appears .82 is the go. 3076 I would rather avoid since a gt makes 280kw on rb25, you'd assume the gtx would be near 300, meaning 320 kw for me since I'm on gas. the gt 3071 can't take more than 260 so assume the gtx version might push 280 which means 300 for my gas. so 3071 is the choice but housing is still the issue. .82 looks like the option that has the least hesitation and in reality it's a few nanoseconds of time I best not need to worry about.

I think I've made my choice, 3071 with .82

thanks guys! love these forums! like consulting with one massive car nerd :)

Do not go with the .63, I have the 3071 with .82 and trust me, there IS no lag. If you go with the smaller housing it will simply come on boost too early and wheel spin. Most of the guys with 3076 & .82 are very happy with the way they perform as far as response is concerned. So why go with an exhaust housing that will choke the power and cause turbine and therefore exhaust heat. The result from this is detonation so you will have to remove timing which will reduce power anyway. The 3071 is the best compromise for no lag/good power. Personally, go with the 3076/.82 and know there is some headroom for more power but if boost is kept low so will inlet temperatures.

I think cams will be needed to hit 300rwks with a 3071/.82 regardless of the latest technology.

So wouldn't something like a gtx3076.73 be ideal?

Thoughts anyone?

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