What GTX turbo for race gas M8

[Vertical-Extreme]

I am thinking about swapping my GT2871 for a GTX, but I can't decide what turbo would be a better fit. The 2863 or the 2867. I know Neil and the boost-it crew are running the smaller 2863 but they only seem to run up to 10lbs of boost on the pro. Has anyone tried the bigger 2867 from 11 to 14 on a cat? According to the map the 67 should spool faster than 71 but flow like a 30 series. But maybe the 63 is a better fit. I'm confused. Lol.


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[RACINSTATION]

2867. I am pretty sure this is what Neil is running. This spools fast and pulls hard. Same power with less boost than the 2871.

 

[Vertical-Extreme]

2867. I am pretty sure this is what Neil is running. This spools fast and pulls hard. Same power with less boost than the 2871.

Thanks ! Have you tried the 67 on a cat yet to compare to a 71 ? Seams like a good upgrade but spendy.


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[Mseven]

Not going to flow like a 30. Unless something has changed, the turbine side stays the same. I doubt you will see much of a gain from your 2871, but if you swap it make sure you do it after some rides. So you can report back gains or losses.

 

[av8er]

The 2871 ran better than the 2876

2871 is tight as in very good!

 

[Vertical-Extreme]

2871 is tight

Tight as in good, or tight as in does not flow very well ? Lol


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[Whimp]

ill have my new 2867 on the snow this weekend on my 2010 m8... I know guys like them on the Polaris so Im hoping to see an improvement on the cat as well.... I ll let ya know if there is a difference between the 2871 and 2867 on the Cat after the ride... Keep fingers crossed.....

 

[dvst8r]

To the OP, what trim is your 2871?

It either may be a decent upgrade, or it may a lot of money spent for almost no upgrade.

 

[turbo800]

I mapped out both the 2863 and the 2867. The HP goal and elevation seemed to fit the 2863 better for me, so that's what I bought. I'm hoping for spool of a 2860, with the top end of a 71/76. The 63 was sitting nicely on the center island for 220HP (10K) with plenty of room to spare. The 67 was out 3 rings toward the surge line side. If your running more than 12 lbs boost, it might be the better of the two...

I've heard of guys running both on 800's though...

 

[Boyko]

If you run a water to air intercooler the air demand goes up a lot

 

[Vertical-Extreme]

Running closed loop water to air. And my current turbo is a 2871-2. The reason for the upgrade would not be for a ton more hp, but I think better spool time and a smoother power curve is attainable. And a side effect of more power at the same boost level is cool too.


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[rusty rider]

If you run a water to air intercooler the air demand goes up a lot

Boyko, why do you see it needing more air? Is it just a overall cooler charge temp? So in turn denser air, needing more of it then? As result more fuel needed then more hp's in the end?

 

[dvst8r]

While there is a slight compressor advantage in air flow going from a 52 trim gt2871r to a 55 trim gtx2867r, the turbine wheel is exactly the same, and the turbine housing is even interchangeable. At best you will pick up a touch at peak efficiency (3%) so even if you are currently making 300hp, now at the same boost level you will make 309hp...

With the same turbine wheel and housing boost response is going to be very similar as the turbine is the much heavier of the two wheels, and obviously drives the compressor.

Unless you have $1300 burning a hole in your pocket and you really just want that quieter sound of the 10 blade GTX wheel, I personally don't think the $ to performance ratio is there.

Depending on what turbine housing you're currently running on the gt2871r, I think the GTX3071r would be a much better bang for the buck.

 

[Boyko]

Boyko, why do you see it needing more air? Is it just a overall cooler charge temp? So in turn denser air, needing more of it then? As result more fuel needed then more hp's in the end?

Simply put hot air occupies more space than cool air. A turbos compressor map is a measurement of heated air, if you cool the air down the cfms are going to drop.

This is a cool online program for mapping a efr turbo, it illustrates this point and also how a smaller turbo suffers at higher altitudes, it is set up for 4-strokes though.

http://www.turbodriven.com/performa...wts=430&pt6_wd=62&pt6_wd2=74&pt6_wrsin=92044&

 

[turbo800]

Depending on what turbine housing you're currently running on the gt2871r, I think the GTX3071r would be a much better bang for the buck.

Looks like Garrett is building a GTX3067R (55 trim) also...

 

[everytime5.9]

When using the graphs and plots double the CC's to give a better picture for 2 stroke application.

The GTX is and upgrade just like the tial housing is an upgrade. The better the system the better the results. The HTA wheels have been around before the GTX and testing has been done to show that they do offer more performance. As in the 2868 HTA killed the 2871. Push is now using the HTA 2873.

 

[CO 2.0]

Is push using the ported shroud compressor housing on the HTA turbos like the GTX turbos have now? I know you can buy them separately through ATPturbo

 

[Vertical-Extreme]

When using the graphs and plots double the CC's to give a better picture for 2 stroke application.

The GTX is and upgrade just like the tial housing is an upgrade. The better the system the better the results. The HTA wheels have been around before the GTX and testing has been done to show that they do offer more performance. As in the 2868 HTA killed the 2871. Push is now using the HTA 2873.

looking at the HTA 2868 is really what got me interested in the billet wheel turbos. From what I could see the 2867 and 2868 are basically the same turbo. but I would feel more comfortable getting the compressor side from garret ( just in case parts were ever needed.)

 

[everytime5.9]

Is push using the ported shroud compressor housing on the HTA turbos like the GTX turbos have now? I know you can buy them separately through ATPturbo

The housing is modified but I don't know to what extent...

 

[everytime5.9]

looking at the HTA 2868 is really what got me interested in the billet wheel turbos. From what I could see the 2867 and 2868 are basically the same turbo. but I would feel more comfortable getting the compressor side from garret ( just in case parts were ever needed.)

Yes the GTX is their way of competing with the HTA versions. The GTX just has longer lungs compared to the Gt. For example the 2860 on the Yamahaulers would max out at 16-18. A comparable 2863 can handle much higher pressure ratios and can flow "almost" as much as a 71 on the top end, yet keep the 60 response. While it gains efficiency and you would get a slight bump in HP per pound of boost the main benefit in this scenario would be the ability to get rid of the choke point in the turbo sizing and keep turning it up.
2863 has the response of the 60 with "similar" flow to the 2871.
2867 has better response than the 2871 but more flow.

And then there is the other side of the debate of the much larger sizing "76" being able to breath better than the others on the bottom end leading to better spool... For my next project I would choose the 2867. I think the 2871 is the best all round setup for boondocking and general climbing. And if the 2867 is slightly better than that sounds like fun

*A proper water to air setup would add more power and consistency than swapping the turbo and running the exact same psi. Keep in mind Neil's GTX2863 Water/Air Pro at 8psi being the one to beat... The 2860 wouldn't have the lungs to deliver the air on the top end with the water to air setup, it would be working too hard... GTX can bridge that gap.