Gtx3076R Vrs Gt3076R.. A True Comparison.

[JustinP]

This has me a bit excited after reading so many negative comments about the new GTX version turbos. I am hoping to have my build complete in about 2 months with a GTX3071R 0.82.

[Lithium]

I have to admit that I am still a bit unconvinced that all things are equal here, not deliberately - but.

I also can't see any reason why the GTX would spool any faster, it would be absolutely awesome if it did.... but its at odds with all other results, and with the general likelyhood. Being more or less the same wouldn't surprise me so much though.

The "GT3076R" dyno plot also looks more like what you get with a faster ramp rate - but the on road difference does sound promising.

[Simon-S14]

i can assure you there's no trickery with the ramp rates. i have nothing to gain/lose by doing this comparison. i wasnt being paid to do it. and did it out of my own interest/pocket. the results are clear as day and the on road feeling confirms the difference. true test shall be tomorrow at mallala tho

[Lithium]

I imply I don't think you (or anyone) are trying to fudge the results, just look at the relative shape of the different curves - its like there is something more different than just the turbo. Curiouser and curiouser, etc.

Obviously its a no brainer thats its either a good or a great result, as basically its definite that the new turbo will make more power - if it makes it with the same spool then thats awesome.

Any chance you accidentally ended up with a GTX3071R?

[kwickr33]

+1

Both curves looks great, It makes lot more sense if the light pink line is GTX.

[Simon-S14]

I imply I don't think you (or anyone) are trying to fudge the results, just look at the relative shape of the different curves - its like there is something more different than just the turbo. Curiouser and curiouser, etc.

Obviously its a no brainer thats its either a good or a great result, as basically its definite that the new turbo will make more power - if it makes it with the same spool then thats awesome.

Any chance you accidentally ended up with a GTX3071R?

i'd be stoked if a 3071 could flow that much power at that much boost.. has anyone done any testing on one at 25+ psi?

[scotty nm35]

This Sunday. (If I can talk the tuner into it as im only running an Emanage Ultimate. lol.)

[Simon-S14]

sweet! what engine+set up?

[JustinP]

How much boost should I tune mine for when it is finished being built?

Turbo is GTX3071R 0.82 on an RB25DET Neo with a forged and balanced bottom end.

i'd be stoked if a 3071 could flow that much power at that much boost.. has anyone done any testing on one at 25+ psi?

[Rolls]

Keep screwing it in until it makes the power you want and isn't out of the efficiency zone. Check the compressor map and see work out the rough max psi you can run before it'll be out of the zone.

Edited July 1, 2011 by Rolls

[Simon-S14]

yeah thats it... keep upping it by 1 psi each run until you start not making as much power thats where you'll be nearing the end of its range

[R31Nismoid]

I imply I don't think you (or anyone) are trying to fudge the results, just look at the relative shape of the different curves - its like there is something more different than just the turbo. Curiouser and curiouser, etc.

Ye the way it comes on so hard is still making me look @ the graph over and over.

Wondering if during the swap there was perhaps a slightly split line or something causing a minor issue not neccesarily noticeable.

Simon - were the hoses etc all replaced or was it a literal 'bolt off/on'?

What about the actuator sitation - same or new?

(not having a go, just thinking outside the norm here)

And side question entirely, are the GTX housings different to the GT ones? (ive not really paid attention to that?)

Either way - more more tuning around the 4000rpm mark. Sure looks like it could bring up a massive mid-range increase which would make it MUCH more than 10% gain. Almost 20% if it keeps picking up like it was, would be very impressive

[Simon-S14]

was a true bolt on swap, boost control lines not touched. i run a tial 44mm extrernal gate. and yeah when time permits we might try putting a degree of timing in around the midrange to help it.

let me just say this tho... with a super responsive set up and such a large wack of torque in the midrange. traction is very difficult. i believe for circuit stuff you wouldnt want this type of arrangement. you'd want to opt for a larger rear and lazier ramp to prevent wheelspin.

[Decs31]

to save some confusion...

settle time of 3sec, ramp time of 7. both runs. increasing either of those times would mess with the results but they were both done the same.

simon has swapped to a 4.11 from a 4.35 diff but the dyno was set accordingly so it shouldn't mess with it at all.

i didn't touch the tune for the gtx. i can see a few spots i'd like to tweak but this was just a quick run up. I had no time to mess with it.

the one thing i did note was that i had to turn up the boost controler a touch to get the boost to the same point again.

[ido09s]

You cant really compare them without having the tune finished....

Looking at that graph the way it is i would be pretty disapointed that it fell over like it has, but its not tuned so to say that isnt very fair

[D_Stirls]

simon has swapped to a 4.11 from a 4.35 diff

wouldn't that in effect change the ramp rate as the ramp rate is measured via wheel speed and the ratio of wheel speed to engine speed is now different?

Edited July 1, 2011 by D_Stirls

[discopotato03]

Purely from what you see through the comp housing of a GTX3076R . These compressor wheels appear to be eleven bladed where the GT37 series BCI-18C wheels have twelve . As we know the GT37 ones halve six full height and six splitter blades and only the full height ones sweep over the radial slot in a port shrouded compressor housing .

One of the things you notice when looking at GT series compressors and turbines compared to T series ones is their axial length and it would be interesting to to compare this on GT and GTX compressors .

I'm a conservative in the turbo world and that makes me think that they are looking to get higher airflow rates at mid range wheel speeds but at higher pressure ratios . To me the islands on the maps are a bit narrow and thats why I think they could do with a larger compressor housing - if not a higher A/R one .

Garrett do make a 0.70 A/R T04E compressor housing but its an ungainly looking thing with the same inlet and outlet diameters as and isn't much if any more compact than the T04S housings which are more common things anyway .

In the State FP makes up "HTA" compressors for upgrades to Garrett BB turbos and I think they use a T04S housing on their HTA30R turbo .

I can only go off trends I see with other compressor wheel families in sometimes a number of different compressor housing families and I think these GTX wheels are getting to the stage of needing larger housings than the GT25BB center section can support . Also making up adapter rings to get say GT40 compressor housings on GT25BB center sections means more inventory for a very low volume , aftermarket , rage of turbochargers . This is really where the larger center section/frame Garrett BB turbos come into their own , native to larger housings both sides but they are starting to get away from being "compact" turbos . Also few are itegral wastegate and many use T4 international flanged single and twin entry turbine housings .

I work for the Intermodal Division of one of the interstate rail freight carriers .

A .

[Rolls]

wouldn't that in effect change the ramp rate as the ramp rate is measured via wheel speed and the ratio of wheel speed to engine speed is now different?

From what decs said I'm assuming the ramp rate was adjusted to compensate.

[PM-R33]

This has me a bit excited after reading so many negative comments about the new GTX version turbos.

Yeah +1

[D_Stirls]

From what decs said I'm assuming the ramp rate was adjusted to compensate.

When i read that is assumed that they made the changes to make sure that the RPM signal was correct so the graph was displayed correctly, not that they adjusted the ramp rate by 5.7% to make up for the change of ramp rate that the engine sees. But after re reading it i'm not sure?

Edited July 2, 2011 by D_Stirls