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Gtx3076R Vrs Gt3076R.. A True Comparison.

Simon-S14

By Simon-S14,
in Engines & Forced Induction

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Simon-S14 Grand Master

Simon-S14

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Hi all... i have conducted a TRUE comparison between the two turbos thanks to Sonic Performance and Garage 7. By true comparison i mean the only thing changed was the turbo. nothing else was touched. The result was suprising and disappointing both at the same time. We found that the GTX version DID spool quicker and hence started making torque and power earlier in the midrange. i now have FULL boost around the 3500 rpm mark which for a turbo like that is impressive. Its highly streetable!

The downside is that for the same boost level peak power is changed by .1 of a kw! its pretty much lineball! the two turbos match each other on the graph pretty much spot on.

runs were done with air temp probe and same correction mode and dyno that STatus uses for real world comparison.

Heres the pics.

Solid pink line is GTX, thin red line is GT.

p1020473s.jpg

p1020471v.jpg

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sneakey pete Grand Master

sneakey pete

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Question:, is running the GTX at the same boost pressure as the other turbo a true 'fair' comparison? I mean... for example if your comparing a gt2871 with a gt4088 you don't leave them at the same boost.

R31Nismoid Grand Master

R31Nismoid

Posted
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It's interesting to see it ramp hard @ 3500rpm.

And then @ 4000rpm the GTX suddenly stops making power almost as if it's hitting surge. Was that just a case of the tune?

(ie back to back test, no tune adjust?)

Also interesting that its more responsive when other results all seem to show the opposite thus far.

Simon-S14 Grand Master

Simon-S14

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Question:, is running the GTX at the same boost pressure as the other turbo a true 'fair' comparison? I mean... for example if your comparing a gt2871 with a gt4088 you don't leave them at the same boost.

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

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

Lithium: no tuning.. was just run up. Declan ran out of time on the dyno but the AFR's were the same as before so its still fine.

Simon-S14 Grand Master

Simon-S14

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  • Author
Posted

It's interesting to see it ramp hard @ 3500rpm.

And then @ 4000rpm the GTX suddenly stops making power almost as if it's hitting surge. Was that just a case of the tune?

(ie back to back test, no tune adjust?)

Also interesting that its more responsive when other results all seem to show the opposite thus far.

yeah it probably needs a degree or two added in one part of the map to bring it back inline. this could be due to different airflow charactoristics of the two turbos.

i have seen other peoples results.. but they often have changed other things in their set ups which couldn potentially cause issues. as i said mine is a back to back. use the info as you please.

Lithium Grand Master

Lithium

Posted
Posted

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...

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

If it didnt nose over hard, it would be looking to pickup a solid ~40kw @ 4500rpm.

Now that would be very interesting indeed.

Good to see a 18psi comparo too where most comparo's have been on 20-24psi for the most part.

Perhaps with more boost the differential between the two would be more noticeable.

rob82 Mentor

rob82

Posted
Posted

Its a good comparison in that most cars are probably only going to run around this level of boost but this result is exactly what I would expect - apart from earlier spool. If you had of reved it to 7500rpm you may have actually seen some results.

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.

PS what type of engine management?

tridentt150v Grand Master

tridentt150v

Posted
Posted

Been waiting for this.....the next step is to tune/map for the GTX but don't lift the boost. I reckon the ramp up will likely maintain its margin over the GT a bit better throughout the rev range . But I have a sneaking suspicion that the peak power [for 18psi] will be very similar.

But the GTX would be a lively package on the street, an extra 30rwkw at 3500!!! I'm almost tempted to sell my GT and try one [but I have other plans involving a dirty 30, so this challenge is not for me].

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