Garrett Medium Frame Gtx Turbos

[whatsisname]

ETS R35 GT-R twin GTX3584RS 1.21 ex housing kit just made 1649whp on E85

https://www.facebook.com/ExtremeTurbo/

[whatsisname]

ETS hold the R35 drag ET world record (7.09 @ 209). Hopefully the GTX3584RS car runs some numbers at the drag strip to back up the dyno figure

[Lithium]

Its not ETS' car, its a TopSpeed car running an ETS Kit.  The same guys have posted >1500whp for twin Gen1 GTX3582Rs with .82 hotsides on E85 and over 2000whp for PTE6870s so the dyno isn't a heart breaker but the 3584s are obviously more potent than the old 3582s.

The amount extra in that case is not at all proportional to the extra flow gains they've claimed but obviously could be more to the story.   It's not far off what I suspected could prove to be the case with the new turbos though, still suspect there is a chance the compressor match won't prove great to smaller motors which need lots of boost to justify them 

[whatsisname]

I was basically pointing out the set-up is a ETS twin GTX3584RS 1.21 kit, not that it's their car. Lost in translation.

They used a Dynojet, which do tend to read higher than the popular Mustang dyno.

The GTX3584RS 1.21 kit made just shy of 120whp more than the Gen 1 GTX3582 .82

A twin PTE6870 set-up probably should produce over 2000whp considering the Gen 2 is rated to 1100hp.

Interesting to note one opinion on the forum thread basically claiming the hot side isn't the issue but the compressor is the issue!

[whatsisname]

I've also read recently the Ken Block Hoonicorn 1400hp figure is produced at 21psi and is 'very conservative'.

[Lithium]

10 hours ago, whatsisname said:

I was basically pointing out the set-up is a ETS twin GTX3584RS 1.21 kit, not that it's their car. Lost in translation.

They used a Dynojet, which do tend to read higher than the popular Mustang dyno.

The GTX3584RS 1.21 kit made just shy of 120whp more than the Gen 1 GTX3582 .82

A twin PTE6870 set-up probably should produce over 2000whp considering the Gen 2 is rated to 1100hp.

Interesting to note one opinion on the forum thread basically claiming the hot side isn't the issue but the compressor is the issue!

Ahh sweet, my bad.  Had a big weekend and rolled in to look at car stuff while I turned brain off to get ready to sleep - maybe turned it off a little too much

Yeah, don't get me wrong - it's not like it does nothing better than the old GTX3582R at all, I'm just suspicious of the huge power claims relative to the old GTX... and also of the match of turbine vs compressor.  Those results go nowhere to suggest to me the GTX3584RS is wonderful.  I'll keep an open mind, but so far no real world results involving those turbos have surprised me.

In regards to the hot side not being the issue, this again highlights and possibly backs up the concern I've had the whole time is not that there is a single issue... but that the combination of compressor vs turbine makes for a bad combination.   I'd be completely unsurprised if the compressor was the limitation in that case, at the boost levels "smaller" motors (in the VR case, ~2litre per turbo) need to run to make big power the 3584 has peaked and it's choke flow is falling back to the range that anecdotal evidence suggests is no better than other common turbos with smaller compressors are achieving comfortably.  

The compressor DOES flow very well at lower pressure ratios, but that is where I have concerns the turbine side may not flow well enough to justify that - the exhaust backpressure MAY climb too much to allow that flow at low boost levels, bearing in mind VE can plummet when exhaust pressure starts exceeding boost pressure.  If you have 45psi exhaust pressure and are running 35psi to make the power you're making, that's not so bad.   If you are running 23psi (in the meat of the 84mm compressor's efficiency) and have 45psi of exhaust pressure - the odds are the engine's VE is going to be atrocious and the end result wouldn't be flattering... assuming the plug wasn't pulled before that point.

 

10 hours ago, whatsisname said:

I've also read recently the Ken Block Hoonicorn 1400hp figure is produced at 21psi and is 'very conservative'.

That 1400hp is on an engine dyno, running methanol on a high compression motor.  I don't rate that as very impressive for a pair of turbos rated at "1000hp" each - "very conservative" means little in this situation, I'd hope that would go without saying.   1400hp @ crank on a high compression methanol engine with a pair of GT3582Rs should be doable with some headroom, let alone Gen1 GTX3582Rs, LET ALONE something with a hp rating 33% higher than a GTX3582R.

Edited January 15, 2017 by Lithium

[whatsisname]

TopSpeed's R35 produced that 1649whp figure on 43psi - the maximum boost they could get out of them.

I don't believe Garrett's 1000hp rating for one second, not unless they've somehow managed to squeeze 11hp per lbs/min of compressor flow and the RS turbine wheel is a truly magical bit of kit. The TopSpeed R35 dyno result is further proof. Even with the big 1.21 exhaust housings, maximum boost (well beyond peak efficiency) they 'only' managed 1649whp and roughly 120whp more than a previous set-up running turbochargers rated at 75lbs/min / ~750hp. I think high 800-900hp is a more realistic rating for the GTX3584RS

I have little doubt they can get more power out of Hoonicorn if they wind the boost up beyond 21psi. If we are to believe the compressor map they produce their best at about 24psi. 

My intention is to run as high as 35psi (3.38 PR) in the mid-range and then drop to 30-32psi (3.0-3.2) up top. Based on the compressor map it 'should' still produce approximately 86-87lbs/min at 3-3.2 PR. More than enough to eclipse the best my HTA GT3586R could provide. I accept the inevitable drop in spool, which should be 500-1000rpm.  

The GTX3584RS has a 67mm/84mm compressor wheel vs. 62/86 of the 3586. 0.72 vs 0.70 comp cover. Exactly the same size turbine wheel but improved aero aimed at increased flow and increased horsepower. 1.01 v-band vs 0.85 T3. My GTX3584RS 1.01 should arrive from Sydney this week. It will be very interesting to see the two graphs overlaid. Hopefully I won't have to wait long to find out.  

         

   

[Lithium]

9 minutes ago, whatsisname said:

I think high 800-900hp is a more realistic rating for the GTX3584RS

My intention is to run as high as 35psi (3.38 PR) in the mid-range and then drop to 30-32psi (3.0-3.2) up top. Based on the compressor map it 'should' still produce approximately 86-87lbs/min at 3-3.2 PR. More than enough to eclipse the best my HTA GT3586R could provide. I accept the inevitable drop in spool, which should be 500-1000rpm.  

The GTX3584RS has a 67mm/84mm compressor wheel vs. 62/86 of the 3586. 0.72 vs 0.70 comp cover. Exactly the same size turbine wheel but improved aero aimed at increased flow and increased horsepower. 1.01 v-band vs 0.85 T3. My GTX3584RS 1.01 should arrive from Sydney this week. It will be very interesting to see the two graphs overlaid. Hopefully I won't have to wait long to find out.             

OK, it actually sounds like your expectations from the turbo aren't wildly different to mine when all is said and done... which in my eyes means it's basically walking into the territory the PTE6466 owns and I'm not sure it brings enough artillery to offer any serious threat to it in that area.  

Am very intrigued to see how this turbo goes, it is definitely the most interesting thing Garrett have done in ages and it'd be quite cool if it works really well.  I have no doubt that tuning it to that boost map will result in a wicked power delivery, but will be particularly interesting to see how the turbine keeps up at that 3-3.2PR across the compressor area.  I expect it'll do well regardless, but if the hot side can support that flow without pressure spiralling out of control then it could be a very very good result!

Hope you've got some stiff WG springs/4 port boost control solenoid

[Lithium]

Hmm.  I decided to actually do some maths and now have half a mind that I may have had a bit too much of knee-jerk reaction to the concept of the small turbine wheel, breaking down a bunch of what I can imagine against what you are doing - your setup could possibly be one of the best possible setups to justify one of those turbos, right down to the hotside you've chosen.

Actually think you could end up with a very good result, not sure what you aim to rev to but I still do expect exhaust manifold pressure to force things to tip over above 7000rpm but not before achieving some pretty decent numbers.  Am definitely very curious now I've actually given it a closer look.

Edited January 16, 2017 by Lithium

[whatsisname]

 

 

 There is one area that springs to mind when comparing the relatively merits of the GTX3584RS vs. PTE6466, likelihood of oil smoke from a brand new unit or after a short amount of mileage ha-ha.

But in all seriousness, I am really looking forward to putting the theory aside and seeing exactly how it performs in my specific application.

I can’t remember if I’ve got a 17 or 21psi spring set-up in my TS Pro-gate 48 WG. I need to put some effort into my boost control set-up.

I must say mate, it’s been a very different experience to my last turbo purchase. Last time I had solid feedback right from the beginning from both jet_R31 (Darren) and yourself – and others. The FP HTA GT3586R had runs on the board and was a known quantity. The GTX3584RS is uncharted territory and for whatever reason (stubbornness ha-ha) I’ve forged ahead despite wise words of advice from the exact same people I listened to last time… people that know what they’re talking about. One thing is for sure, I know significantly more about turbochargers than I did 4 years ago.

I rev the motor to a maximum of 7600rpm.   

 

[Lithium]

29 minutes ago, whatsisname said:

  There is one area that springs to mind when comparing the relatively merits of the GTX3584RS vs. PTE6466, likelihood of oil smoke from a brand new unit or after a short amount of mileage ha-ha.

But in all seriousness, I am really looking forward to putting the theory aside and seeing exactly how it performs in my specific application.

I can’t remember if I’ve got a 17 or 21psi spring set-up in my TS Pro-gate 48 WG. I need to put some effort into my boost control set-up.

I must say mate, it’s been a very different experience to my last turbo purchase. Last time I had solid feedback right from the beginning from both jet_R31 (Darren) and yourself – and others. The FP HTA GT3586R had runs on the board and was a known quantity. The GTX3584RS is uncharted territory and for whatever reason (stubbornness ha-ha) I’ve forged ahead despite wise words of advice from the exact same people I listened to last time… people that know what they’re talking about. One thing is for sure, I know significantly more about turbochargers than I did 4 years ago.

I rev the motor to a maximum of 7600rpm.   

 

For sure, I haven't actually encountered anyone directly who have had issues but I know at least there was a random (easy to fix, but unacceptable from something that price tbf) manufacturing issue that at least a bunch of 6766s had.  There are EFR and FP turbos which do well in the same range, but if no one tried the new interesting things we'd not learn as much!  And on that note, one of the best parts of someone trying something out is it is a good way of testing how close the theory is matching reality and adjusting to suit one way or another.  Sometimes it can mean (if results are less than expected) hinting at if something needs sorting, and sometimes it can mean the theory needs tweaking

Cool, the max revs shouldn't be too much over where I suspect it might start getting "chokey" if I have any idea of what I'm playing with - to be fair I just skimmed over the math, but yeah.  So it should be going on pretty soon after it arrives?  Post pics, too - they look like the new wheels and housings are quite handsome for an air pump

[whatsisname]

I am aware of reports of a number of Precision units (across a range of models) suffering oil smoke issues. jet_R31 (Daz) mentioned a few earlier in this thread, including at least one that happened to a mate of his after very little use - might have been right from start.  I also found a surprising number of owners reporting the same issues via online sources. Daz said they appear to be more susceptible to oil filtration problems. It isn’t so much an issue with the components but rather the QC during assembly. Of course it’s nothing that can’t be rectified with a strip and rebuild locally.  However I feel a little uneasy paying upwards of $3.2k for a new unit (more than I paid for my 3584RS) and then spending more once it arrives to ensure it doesn’t end up doubling as an oil smoke generator… ha-ha.

I certainly considered both the EFR 8374 and 9180. Cost and size limitations (without paying for a new manifold to relocate the turbo) came into play. And last but not least, and I know it’s going to sound absolutely ridiculous, a small percentage of my decision came down to aesthetics – they’re not particularly handsome. I like shiny looking ‘stuff’ – see engine bay photo. Anything brand new and current generation technology from FP means going to their XR range and I’d prefer to wait until they’ve got the bugs ironed out of their new billet core before committing funds.

In a perfect world the new turbo would arrive and all hands on deck to get it fitted and up and running. Back to reality, it will probably take a few weeks at least. I’m getting the comp housing polished and turbine housing ceramic coated so that will probably take a week or so.

I promise to provide plenty of photos in all its glory.   

[Lithium]

16 hours ago, whatsisname said:

I certainly considered both the EFR 8374 and 9180. Cost and size limitations (without paying for a new manifold to relocate the turbo) came into play. And last but not least, and I know it’s going to sound absolutely ridiculous, a small percentage of my decision came down to aesthetics – they’re not particularly handsome. I like shiny looking ‘stuff’ – see engine bay photo. Anything brand new and current generation technology from FP means going to their XR range and I’d prefer to wait until they’ve got the bugs ironed out of their new billet core before committing funds.

In a perfect world the new turbo would arrive and all hands on deck to get it fitted and up and running. Back to reality, it will probably take a few weeks at least. I’m getting the comp housing polished and turbine housing ceramic coated so that will probably take a week or so.

I promise to provide plenty of photos in all its glory.   

Awesome, look forward to it!  Most of that logic I can understand, shame the "facelift" EFR range aren't out yet - the new Borg Warner EFR housings without the internal BOV etc on them look awesome, probably some of the "prettiest" housings out... basically like the SX-E range.

The XR range is very frustrating, they COULD be really good things but I too have very little faith at the minute.

As a side note, AMS have announced they are going to do extensive testing of much of the Garrett range on a stout EVO 8 test car they've got - by the sounds of it across the range, including different housings.  I'm going to hazard a guess and say that it'll be from the GTX3071R up to the GTX3584RS seeing as the footprints will be the same or similar.   They reckon they will provide a lot of data on the whole thing, that will be VERY interesting. 

 

[whatsisname]

Well there you go, I had no idea Borg Warner were in the process of updating compressor housings throughout their EFR range... aesthetic 'issue' sorted.

I'm sure the XR range will improve to the point they become a viable option.

Yes I noticed their intro video the other day. Full credit to AMS, it's not often someone tests a full range of turbochargers using the same baseline/test vehicle. I'm looking forward to seeing the results as they roll them out.   

Just rewinding back to our earlier discussion over the Topspeed ETS kitted R35, I thought I'd found a dyno comparison with a twin PTE6466 equipped R35 run on the same dyno. Alas it was English Racing's Dynojet. Still found it interesting to note the 6466 0.82 car produced 1572whp and 1179wtq at 44.6psi  vs. GTX3584RS 1.21 1649whp and 1150wtq at 43psi

Further to the above, Micheal from ETS has stated twin 6466 running on pump fuel on their dyno equals 1100whp at 25-26psi... vs. GTX3584RS 1140ish at 27psi (HTA3586 1000whp at 25psi) Obviously there are numerous variables at play when trying to compare the two set-ups... but interesting data none the less.   

Should have my hands on my new 'toy' later today or tomorrow.   

      

 

          

[Lithium]

That thing is a pretty top spec build, 4.4litres with all the fruit, to be fair!  The thing here is 43psi is ALL in here, they completely maxed the turbos out to achieve this.

And on the same dyno, unfortunately obscured curve but Gen1 GTX3582Rs on a 4.1 with 40psi:

Worth noting that an R35 has gone >2000whp on the same dyno with Precision PT6870s

Edited January 17, 2017 by Lithium

[whatsisname]

There is no doubt they've used a solid base to trial the twin 84RS kit.

It seems almost impossible to make a hard and fast direct comparison... so many variables in play.  Look at the peak torque difference between the two examples. The 4.1L engine makes more than 40wtq more than the 4.4L despite giving up 300cc, 3psi, smaller housings, and a smaller and earlier generation specification turbocharger from the same manufacturer. Unless the extra 5% ethanol content is a total game changer  (4.1L E90 vs. 4.4L E85) the torque figures seem arse about!   

Perhaps the modifications listed against each car is the key to the surprising peak torque difference -  assuming the lists cover all the significant changes.  The 4.1L car has a 4" exhaust and ETS intercooler vs. ??? of the 4.4L car.             

   

[whatsisname]

A pair of PT6870s is 2200hp (engine) territory.     

[Lithium]

Indeed, and a GTX3584RS is rated at 1000hp.  Going by the all in result for the twin 1000hp, 2200 Garrett hp = just over 1800whp on that dyno

[whatsisname]

It's all in the wording, '...1000hp capable'. They haven't stated it will produce 1000hp, just that it's capable of 1000hp... on the right dyno with enough capacity, rpm, nitrous etc... ha-ha

[Lithium]

1 hour ago, whatsisname said:

It's all in the wording, '...1000hp capable'. They haven't stated it will produce 1000hp, just that it's capable of 1000hp... on the right dyno with enough capacity, rpm, nitrous etc... ha-ha

Haha yeah absolutely.  I guess I should elaborate on where I am coming from, and I guess it's all extrapolation but historically the Garrett hp claims were a realistic indication of that turbo could do on a typical pump gas setup - so they basically used "hp @ crank = lb/min x 10".   A GTX3582R became around 750hp being a 75lb/min turbo, the old school GT3582R was good for around 650hp with its mid 60lb/min compressor, 520hp for the GT3076R etc etc.

That kind of ended up being something of a rule of thumb and quite a few people treat Precision and FP turbos the opposite way, if you are wanting an estimate of their peak flow then you go "lb/min = hp / 10" - so the PT6262 is a 73lb/min turbo, the PT6466 is a 90lb/min turbo and the PT6870 is capable of over 100lb/min.

For my thumb-sucks I found that 10hp per lb/min was probably conservative and realistically it was probably closer to 10.5 for GOOD (ie, BP98) pump gas on a good setup, or 12hp per lb/min for E85.  These are all pretty loose, obviously compressor maps don't have a flat choke line across all pressure ratios and even then atmospheric conditions, tuning, transmissions, dynos etc all are variables so I just use it to gauge things.

If you treated the Dynojet as reading 78% of the engine power, or a "22% loss" for 4WD (yeah I know it's not that simple, but bear with me) - then use my calcs to estimate the lb/min per turbo required to make those power levels, you get:

Garrett GTX3584RS x2 = ((1649hp / 2turbos) / 12hp.lbmin) / 78% = 88lb/min

Precision PT6870 x2 = (2029hp / 2turbos) /12hp.lbmin) / 78% = 108lb/min

All pretty airy-fairy, but it usually seems to be in the right territory.  Fwiw I use ~70% for Dyno Dynamics, so I'd be not hugely surprised if I saw them do something in the range of about 550awkw and 677awkw, but I'd never say "This is what they'd make".