GTRS = 28R or 2860RS??

[kermac]

I fitted a GTRS around 18 months ago along with ATP manifold, 3" pipe, Unitronics, water/meth etc etc. The other day I noticed a little plate on the turbo with the serial number on it but also stamped on it was GT2560R. This is (of course) the same as a GT28R.

But I thought the GTRS was based on the higher-flowing GT28RS or "disco potato"? Do ATP base the GTRS on the 28R frame or the 28RS? Could my turbo be old stock? Is the information on the plate incorrect?

Or is this just another case of confusion with the various models in the GT28-series range?

[hercfe]

The GTRS is not a 2860. This has been covered countless times. Its a 2560. The 28 series is completely different since garrett reclassified their turbos.

ATP never released the data on the gt2x, but i'd say its a 2554. looking at the difference between the gt2x, gtrs, and 2871, it's amazing that anyone buys anything less than a 71r anymore. if i could do it again i would do a 71r. the gtrs just doesn't cut it anymore.

[AudiNFS]

The GTRS is not a 2860. This has been covered countless times. Its a 2560. The 28 series is completely different since garrett reclassified their turbos.

ATP never released the data on the gt2x, but i'd say its a 2554. looking at the difference between the gt2x, gtrs, and 2871, it's amazing that anyone buys anything less than a 71r anymore. if i could do it again i would do a 71r. the gtrs just doesn't cut it anymore.

I think the GTRS option is good for those who don't want to build their motor at all

[kermac]

The GTRS is not a 2860. This has been covered countless times. Its a 2560. The 28 series is completely different since garrett reclassified their turbos.

ATP never released the data on the gt2x, but i'd say its a 2554. looking at the difference between the gt2x, gtrs, and 2871, it's amazing that anyone buys anything less than a 71r anymore. if i could do it again i would do a 71r. the gtrs just doesn't cut it anymore.

Yeah - I did a search but didn't find this information. I have seen it said (including - I think - on the ATP website) that the GTRS is based on a full GT28RS.

When you speak of the 71r, I assume you are mean the GTRS with the 71r option as opposed to the full Garrett GT2871R? I have also read in a number of places that the GTRS 71r is too restricted both on the inlet and the outlet side, and thus offers little extra at the top end while requiring an extra 400 or so revs to spool up. While the full frame 71 offers an extra 50hp or so over the 28RS, it seems this doesn't materialise on the GTRS.

Happy to be corrected...

[kermac]

I think the GTRS option is good for those who don't want to build their motor at all

Exactly my position. After years on a K04, I would be happy (I think) if my GTRS was working up to full potential. I read on another post that a properly set-up GTRS runs a sub-4 sec 0-60 time. I took that with a pinch of salt. I thought sub-5 secs would be more realistic?

[viceprp]

4.7seconds 0-60 on a gtrs..

[flynnr]

this was probably covered, but the gtrs was apr's stage 3 kit turbo, and the stage 3+ was the gt28rs (or 2871r?)

[A4Rob]

and the stage 3+ was the gt28rs (or 2871r?)

28rs is a 2860 aka disco potato

[M-Hood]

this was probably covered, but the gtrs was apr's stage 3 kit turbo, and the stage 3+ was the gt28rs (or 2871r?)

The APR stage 3 is a GT28R, their Stage 3+ is a GT2871r.

The GTRS/GT2871 Elim kits are a custom turbo that tends to use a GT2560 CHRA with a custom wheel that is cut to fit into a GT28R 2 bolt compresssor housing. What it says on the name plate just tells you what CHRA was used. The CHRA is the center section and the exhaust wheel.

Funny thing is at the drag strip the Elim kits have gone as fast or not faster then any real GT28rs/GT2871r on a A4.

Seems every time someone reads the tag on their Elim kit they freak out. lol

[kermac]

The APR stage 3 is a GT28R, their Stage 3+ is a GT2871r.

The GTRS/GT2871 Elim kits are a custom turbo that tends to use a GT2560 CHRA with a custom wheel that is cut to fit into a GT28R 2 bolt compresssor housing. What it says on the name plate just tells you what CHRA was used. The CHRA is the center section and the exhaust wheel.

Funny thing is at the drag strip the Elim kits have gone as fast or not faster then any real GT28rs/GT2871r on a A4.

Thanks for this

Seems every time someone reads the tag on their Elim kit they freak out. lol

This could be because there is a lot of stuff on the web suggesting it's built out of GT28RS bits. Even the name suggests that.....

[Seerlah]

GTRS is an eliminator kit
GT28RS is a full frame GT2860RS

[M-Hood]

Thanks for this



This could be because there is a lot of stuff on the web suggesting it's built out of GT28RS bits. Even the name suggests that.....

The name just suggest that it is made using Garrett parts, the turbo is a ATP custom turbo.

They most likely use the GT2560 CHRA because it has a slightly smaller exhaust wheel then the GT2860.
GT2560 = 53mm 62 trim
GT2860 = 53.9mm 76 trim

[ZimbutheMonkey]

Turbines should be the same. The 2560 uses an 11 blade compressor whereas the GTRS elim uses the 9 blade one found in the 2860.

Here's a 2560


Here's the turbine in my GTRS elim

[M-Hood]

Then ATP is only using the CHRA to build the turbo seeing they put a different turbine/compressor wheel to make the Elim turbo.

[sean1.8t]

The APR stage 3 is a GT28R, their Stage 3+ is a GT2871r.

in their newer gen kits, yes. but in the B5(only offered to the 2001 MY) and B6 world their stage 3+ kits was centered around the 60mm GT28RS (aka 2860 aka 2860RS)

Funny thing is at the drag strip the Elim kits have gone as fast or not faster then any real GT28rs/GT2871r on a A4.

yep, as far as where it counts, on the track, and where it doesn't really count, on the dyno, all 28 series turbo's(GTRS, 71r, GT28RS, and GT2871r) on the 1.8t have proven similar results. when fully optimized, all put down a little north of 300awhp, and all run mid to high 12's at the strip.

[ZimbutheMonkey]

Then ATP is only using the CHRA to build the turbo seeing they put a different turbine/compressor wheel to make the Elim turbo.

No, as far as I know you can take a GT2860RS CHRA and slap it into a GTRS elim. Only difference should be the housings. It wouldn't surprise me if ATP was buying Garrett CHRA rebuilds through the CHRA exchange program. That may explain the GT2560 tags.

[Seerlah]

What doesn't someone call or email ATP to inquire about this information? I do that all the time on other companies when I want to know about a certain item. I will do it if no one wants to. Just post what you want to know, and I'll send them an email.

[kermac]

Thanks guys for all this useful information. It looks as if there is still a bit of uncertainty about, although I take heart from Sean's post that the results at the trap are pretty much identical no matter which configuration or trim you have.

I emailed ATP when I first discovered the marking on the ID plate on the turbo to see what was going on. I had my GTRS installed about 18 months ago, but somehow I wound up with ATP's pre-2006 model TIP with the cast alloy elbow at the bottom secured (or not secured, as the case may be) by a tiny grub screw.

I still have no satisfactory explanation from the installer, and wondered whether the turbo itself was also old stock but it appears not.

ATP btw have been good in their response to my complaint about damage to the compressor wheel and shaft bearings resulting from the failure of the TIP-turbo connection. They have cut me a reasonable deal, although they haven't yet responded to my query about the 2560R marking on the CHRA.

Seems I was worrying unnecessarily. Also seems there's no point in looking for a 2871 replacement - loses out at the bottom end and no appreciable gain at the top end.

Thanks again!

[kermac]

I found that reference on the ATP website (http://www.atpturbo.com/root/releases/release041205.htm)

A lot of the information is quite old - but the site was updated in December 2010.

Here is the text:

GTRS – Big power, small package, still stock appearing.

For those 1.8T customers that have “GT28RS” envy but simply do not want to turn their engine bay upside down to run the “disco potato”, the solution is here. The GTRS is a bolt-on solution using the ultra-efficient and much larger than stock, GT28RS ball bearing turbo popular for making 350+ HP. Tasked with the mission to make the GT28RS bolt in the stock location utilizing all stock components (ie. manifold, downpipe, inlet pipe, etc.) for a stealth appearance, ATP set out to study and test the characteristics of those components that will remain in use with the GTRS turbo once installed. Our findings, surprisingly, leave a lot to the favor of the stock exhaust manifold. Contrary to popular speculation, the stock manifold does perform quite well and when coupled with the right turbo combination, the power can exceed expectations. A lot of the deficiencies in the stock turbo system can be attributed to the low flowing design of the stock turbo and turbine housing itself! The OEM's integration of the original turbo into the 1.8T engine allowed too little flow potential in the stock turbine housing simply to promote exhaust velocity for low end flow. The result is too much backpressure and there lies the cause of the “choking” in the system, causing the lack of power in the high rev range. Confident that we have removed the “bottleneck", which at this point has been identified as the stock turbo itself, we set out to make power with the GT28RS as planned.

"More power and even sooner than expected!"

During our mechanical design stages, we focused on shaping the turbine inlet port of the GTRS’ newly cast exhaust housing to fit the stock exhaust manifold precisely. This allowed for a 1 to 1 alignment and the result was a perfectly contoured entry without any turbulence. What this means is the exhaust gas entry from manifold to turbo will now be close to perfect with negligible resistance. In addition, we found that the slight taper designed into the runners of the stock manifold promotes exhaust gas velocity even further. Further testing resulted in a much quicker GT28RS turbo on a 1.8T engine, at least by 300 rpm faster than any other off the shelf GT28RS turbo driven by an aftermarket manifold on the original T25 flanged turbine housing.

And the rest is butter! The GTRS even in the bolt-on combination has no problem extracting close to 350 Crank HP @ 22 psi of boost on the otherwise stock engine.

**********************-

Would it be fair to say they are describing a 2560R (aka GT28R) as a GT28RS?

[M-Hood]

I found that reference on the ATP website (http://www.atpturbo.com/root/releases/release041205.htm)

A lot of the information is quite old - but the site was updated in December 2010.

Here is the text:

GTRS – Big power, small package, still stock appearing.

For those 1.8T customers that have “GT28RS” envy but simply do not want to turn their engine bay upside down to run the “disco potato”, the solution is here. The GTRS is a bolt-on solution using the ultra-efficient and much larger than stock, GT28RS ball bearing turbo popular for making 350+ HP. Tasked with the mission to make the GT28RS bolt in the stock location utilizing all stock components (ie. manifold, downpipe, inlet pipe, etc.) for a stealth appearance, ATP set out to study and test the characteristics of those components that will remain in use with the GTRS turbo once installed. Our findings, surprisingly, leave a lot to the favor of the stock exhaust manifold. Contrary to popular speculation, the stock manifold does perform quite well and when coupled with the right turbo combination, the power can exceed expectations. A lot of the deficiencies in the stock turbo system can be attributed to the low flowing design of the stock turbo and turbine housing itself! The OEM's integration of the original turbo into the 1.8T engine allowed too little flow potential in the stock turbine housing simply to promote exhaust velocity for low end flow. The result is too much backpressure and there lies the cause of the “choking” in the system, causing the lack of power in the high rev range. Confident that we have removed the “bottleneck", which at this point has been identified as the stock turbo itself, we set out to make power with the GT28RS as planned.

"More power and even sooner than expected!"

During our mechanical design stages, we focused on shaping the turbine inlet port of the GTRS’ newly cast exhaust housing to fit the stock exhaust manifold precisely. This allowed for a 1 to 1 alignment and the result was a perfectly contoured entry without any turbulence. What this means is the exhaust gas entry from manifold to turbo will now be close to perfect with negligible resistance. In addition, we found that the slight taper designed into the runners of the stock manifold promotes exhaust gas velocity even further. Further testing resulted in a much quicker GT28RS turbo on a 1.8T engine, at least by 300 rpm faster than any other off the shelf GT28RS turbo driven by an aftermarket manifold on the original T25 flanged turbine housing.

And the rest is butter! The GTRS even in the bolt-on combination has no problem extracting close to 350 Crank HP @ 22 psi of boost on the otherwise stock engine.

**********************-

Would it be fair to say they are describing a 2560R (aka GT28R) as a GT28RS?

I dont see how seeing that a GT28R is not going to make as much power as a GT28RS. GT28R will make around 300chp on our cars pushing 22psi. Big difference between a GT28R and a GT28RS.

[mocomotor]

i think this will be a fast solution for what we discuss here, check it out: http://zio.in/1dy

[M-Hood]

I am going to guess you posted on the wrong thread. lol

[kermac]

I dont see how seeing that a GT28R is not going to make as much power as a GT28RS. GT28R will make around 300chp on our cars pushing 22psi. Big difference between a GT28R and a GT28RS.

Interesting. M-Hood says 300 chp, Sean 1.8T says "a little north of 300 awhp". That's a huge difference

[Seerlah]

^Sean never said a GT28R will make 300whp. He stated that the GTRS, GT2871R eliminator, GT2860RS, and GT2871R can make a little north of 300whp. Which has been proven true.

[kermac]

^Sean never said a GT28R will make 300whp. He stated that the GTRS, GT2871R eliminator, GT2860RS, and GT2871R can make a little north of 300whp. Which has been proven true.

Sorry - I misread him. That's still a big difference between what a 28R will pump out and a GTRS/2860RS etc.

The issue remains that ATP claim they are making the GTRS out of the GT2860RS where in fact they are making it out of the 28R. Would it make any difference in horsepower terms - bearing in mind the major differences in configuration between the GTRS frame and the original garrett frame - if the 28RS was the basis for the GTRS?

[Seerlah]

But what parts are used from the GT2860RS and GT2560R (aka GT28R)? I think that is what makes the difference. Because the closest thing to the GT28R being made as an eliminator kit is the GT2x eliminator.

[sean1.8t]

Sorry - I misread him. That's still a big difference between what a 28R will pump out and a GTRS/2860RS etc.

The issue remains that ATP claim they are making the GTRS out of the GT2860RS where in fact they are making it out of the 28R. Would it make any difference in horsepower terms - bearing in mind the major differences in configuration between the GTRS frame and the original garrett frame - if the 28RS was the basis for the GTRS?

what does it matter what PN is stamped on your turbo? they are a reseller of said parts and can do with what they please. as long as the promised power levels and results are attained, what do you have to complain about?

and as far as the differences between 28R and 28RS power levels that me and Mike were talking about, i was talking maxed out racegas numbers and mike was talking daily driver pump gas numbers.

given all variables are the same, a 28rs on pump will do about 350chp. a 28r on pump will do about 300chp. any more questions?

[ZimbutheMonkey]

OK, so could someone please explain to me how we've come to the conclusion that ATP is calling a GT2560 a GTRS elim? I called ATP a while back and actually spoke to someone there (yeah, I know, it's a Christmas miracle). I asked what CHRA they used on the GTRS elim, he said it was exactly the same as a GT2860. While the tag may say 2560, the turbine, and power output suggest that it's a 2860 CHRA.

[Seerlah]

I am thinking they maybe use a modified GT28R exhaust housing with a GT2860RS CHRA. This would also explain why they spool faster than a t25 flanged manifold. There is the reason of the 3 bolt flange being smaller, which is also a feasable reason. But eh? I know it really should not matter if it grants what ATP advertised, but it seems people just want to get down to the root of the GT28R stamp.

[M-Hood]

Well we already know it is a 2560 CHRA, they just put other parts on it. Most likely use that 2560 because it might cost them less since Garrett most likely has way more of then sitting around. Doesn't really matter what CHRA they use, its the compressor/exhauat wheels that make a turbo what it is.

If you put a GT30r wheels on a 2560 CHRA, do you think people are going to call it a GT2560? No.

[Seerlah]

Whoops, reading compreshension was not readily available

[kermac]

what does it matter what PN is stamped on your turbo? they are a reseller of said parts and can do with what they please. as long as the promised power levels and results are attained, what do you have to complain about?

and as far as the differences between 28R and 28RS power levels that me and Mike were talking about, i was talking maxed out racegas numbers and mike was talking daily driver pump gas numbers.

given all variables are the same, a 28rs on pump will do about 350chp. a 28r on pump will do about 300chp. any more questions?

Nah - that pretty well sums it up! Thanks for your input

[kermac]

Have just received a response from ATP which answers most of my earlier questions, as follows:

*********

"The 707160-5 [my turbo's serial number] is incorrectly badged in the description.

"It's 99.9% identical to the disco in fact it has the same turbine wheel and the compressor wheel has the same trim. We used that turbo for the 2 bolt flannge type on the compressor inlet. There is no power difference between the two. You can also go on Garrett's site and review the wheel specs as well as the flow maps for both turbos and you'll find that they are twins."

*********

Thanks again to all contributors