Gtx3076R Vrs Gt3076R.. A True Comparison.

[ARTZ]

hey simon can you upload a bigger picture man I can barely see the little one you posted

[STATUS]

nice what was the run length in seconds they definitely look different, maybe the hold time was 4sec instead of 2... ?

tell declan to run the right correction too, its running the old stp correction. SAE is the right correction nowadays and will only knock about 10-15rwkw off that graph.

[Rolls]

Interesting, everyone seemed to think it would be laggier and other results seemed to show that it would be, this shows a huge change in spool.

What is the transient response like simon, much nicer to drive? Also what manifold are you using, and internal gate?

edit: Were the dyno run settings EXACTLY the same?

Edited June 30, 2011 by Rolls

[Simon-S14]

Yeah dyno settings are exactly the same as also. Street use shows it to be awesome. Comes on quick and fast!

[Jap_star]

Manifold is made here by AM Performance (http://www.facebook.com/mobileprotection#!/pages/AM-Performance/135203453221377) and the turbo is externally gated

good to see it made some improvement. now its up to people if its worth the extra coin

[Harey]

Very interesting results, I wonder if the 0.63 housing is limiting the GTX from doing any more up top??

[Rolls]

Do you think the manifold makes any difference to spool? If you were to use stock manifold with internal gate how do you think it would influence the result? Spool and top end that is.

Edited June 30, 2011 by Rolls

[Simon-S14]

well yes the manifold prob does make a difference to spool. but the thing is this is a back to back comparison

[Rolls]

well yes the manifold prob does make a difference to spool. but the thing is this is a back to back comparison

Oh I wasn't talking about the comparison, just generally curious how much it improves it.

[sneakey pete]

what do you want me to do? run less or more boost?

i feel same boost level should give a truer comparison yes?

If the new turbo can flow more than the old one then potentially without raising the boost and/or adjusting the tune to maximize the new found goodness then potentially not really telling of the real difference. That result suggests to me the old turbo had more on it too...

What he said, was basically what i was thinking. I understand the limitations you have with testing this, that's why i was just asking a question in general, not really stating that you should do xx and yy.

[SimonR32]

I just dont know why you guys are so dissapointed - you only need to compare the compressor maps to see that there are f**k all gains unless your running around 2bar of boost with the gtx.

Man speaks the truth!

Good to see a decent gain in response though

[Simon-S14]

yeah the main reason why i did it was to gain more response... not to gain more peak power because honestly for what i need it for (drift) anything over 300 rwkw is excessive.

the rest of the info is for you SAU'ers to debate over.

[Rolls]

You would need to run 25psi+ to really show where these turbos shine.

Kind of why I would like to see a 71 back to back or a gtx28 if they made it. Most people don't run these turbos to their max. Still I am delightfully surprised by the gain in response. Does anyone know if they make these similar wheels for GT28 style turbos ?

Edited June 30, 2011 by Rolls

[discopotato03]

I honestly cannot remember where but I thought I read about a 68 or 70mm compressor version . Possibly something on a GT28 turbine but No details come to mind .

Purely using the force here but I think it could be possible that the 76mm GTX compressor in the port shrouded T04E comp housing may possibly benefit from having all blades exposed to the radial slot , unlike a GT37 6/6 bladed wheel where only the full height blades sweep over that slot . GTX compressors appear to have all full height blades and I guess if they can run in a "partially unloaded state" it could help the turbine spin them up a little sooner .

The telling factor is the transient responses compared to a conventional GT3076R .

Looking purely at the GTX3076R comp map I get the impression that the islands are taller but possibly narrower than a std GT3076R and I have to wonder if it can gain from a slightly larger port shrouded housing .

Anyway good results particularly with no tuning , cheers A .

[Rolls]

discopotato what do you do for a job, you are a walking encyclopedia

[Lithium]

may possibly benefit from having all blades exposed to the radial slot , unlike a GT37 6/6 bladed wheel where only the full height blades sweep over that slot . GTX compressors appear to have all full height blades and I guess if they can run in a "partially unloaded state" it could help the turbine spin them up a little sooner .

Looking purely at the GTX3076R comp map I get the impression that the islands are taller but possibly narrower than a std GT3076R and I have to wonder if it can gain from a slightly larger port shrouded housing .

The taller/narrower islands would probably be a result of the increase in trim, I'd have thought? And in regards to increasing the exposure of the blades to the ports, no doubt it would increase the compressor's ability to gain outright shaft speed but unfortunately the shaft speed is just one part of a puzzle which involves getting air into the engine - anyone with a boost leak can vouch for the fact that more shaft speed doesn't (necessarily) mean better response.

I'm sure there is a fine balance, but my understanding is the main purpose of the ports would be to try and stretch the surge line and islands between for given pressure ratios to the left (funnily enough, given the whole anti-surge term) while maintaining a balance between that effect, spool and trying not to topple the choke point. Wouldn't exposing more start eliminating some of the advantage of the higher flowing 58trim wheel?

Just trying to get an idea of exactly what you're envisaging by that, or if I am on the same page.

[34GeeTeeTee]

I've been looking forward to this

The info i got from GCG initially was -

The GTX usaully flows about 10% more power than the stock GT3076R, and response time is nearly identical (it doesn't come on faster). This would be the gains that you'd see from the Billet compressor wheel. The GTX version is also more efficient at high boost pressures.

This turned me away from spending the extra money (That i don't have at the moment) on these turbo's... I will be running a pretty similar setup to your car but have a .82 rear housing, the reason i chose the bigger was that i thought it would match the engine size better, but now seeing your .63 results i am confused

[hypergear]

looks good but how ever I think those 2x runs are not based on the same dyno sittings, the GTX appears to have more ramp load then the GT run unless some thing with the car or the tune was not 100%.

By going larger sized comp wheel without any modifications to the turbine wheel or housing is not going to end up with that much better in response, its suppose to be opposite as larger blades fights against greater amount of surge per rotation. Plus it would not shift the areas of whe the car is on vacuum.

But any thing can happen with E85, does it feels that much of differences on the road?

[Simon-S14]

Same rampload. Feels crazy on the road feels like so much more midrange and Coles on earlier then before

[ARTZ]

i think the whole point was never to make a turbo that just made more power but one that was more efficient and will no doubt 'feel' better and more transient under your foot..

There will always be skeptics but at the end of the day garrett know more than anyone about this ssubject and

I never doubted them.. It would be suicidal to release a less responsive version of there best selling turbo..good on you Simon for busting the myth