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Garrett GTX Series or precision Turbo


Jellybean

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Ber Jesus, it's all a bit of banter and anyone that knows me knows I'm just messing about, don't take offense if I called u bell pipe! All im saying is on road looking at my gauges it looks like I'm hitting full boost at about 2000 revs and spools up insanely fast as it's prob the smallest single I have ever seen!

Morning to u to Jaime ;-)

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Ber Jesus, it's all a bit of banter and anyone that knows me knows I'm just messing about, don't take offense if I called u bell pipe! All im saying is on road looking at my gauges it looks like I'm hitting full boost at about 2000 revs and spools up insanely fast as it's prob the smallest single I have ever seen!

Morning to u to Jaime ;-)

 

Your dyno graph says otherwise, Dans precision T67 makes more power and torque at 3000rpm than your garrett GT30 does. tbh i didnt think your car had ever worked right from reading your posts.

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Ber Jesus, it's all a bit of banter and anyone that knows me knows I'm just messing about, don't take offense if I called u bell pipe! All im saying is on road looking at my gauges it looks like I'm hitting full boost at about 2000 revs and spools up insanely fast as it's prob the smallest single I have ever seen!

Morning to u to Jaime ;-)

 

I don't know you though :) But I didn't really take offense, I've been called worse :)

 

There is a history of rather wild claims on here, from 300bhp NA's to 600bhp stock turbos to the mythical 2JZ returning 32mpg while being driven at 100mph. Extraordinary claims require extraordinary proof, as the saying goes ;) I've been through many a 'row' with people claiming stuff on here over the years because as soon as proof is asked for it usually gets nasty so your response wasn't a great surprise heh.

 

Anyway, as I'm at work I thought I'd look into your turbo, it's basically a Garrett GT3076R. It's pretty small so it should spin up fast, but it appears to be undersized for the 2JZ. Here is a compressor map with some stuff plotted on:

 

attachment.php?attachmentid=153134&stc=1&d=1339316446

 

You can see that 1.4bar at 2000rpm (pink dot) is waaaaay outside the surge line on the left. But, you could just about squeak in at 2600rpm (blue dot). I still don't think the turbo's boost threshold would allow for that level of boost that low down anyway, but I can't find info on that, not even on Garrett's site :(

 

The worry is the right hand side, 7000rpm at 1.4bar (red dot) is well outside the operating range of the turbo, it'd be overspeeding. 6500rpm is 52lbs/min which juuuuust gets in on the edge of the map, but it's not ideal. Perhaps the biggest exhaust AR helps there but that'd cripple the low down spool.

 

I'm all up for a techie discussion on this stuff and I'm not trying to urinate on anyone's chips - as I said I'm interested in the GTX3076R myself for a quickspool street monster, I'm just concerned about the surge and overspeed issues shown here :)

GT3076R comp map.jpg

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Hard to keep track of what the current flavour of the month is......seems like the twin scrolls and BW turbos have fallen from grace.......

 

I only look at stuff that publishes their compressor maps properly, and I've not seen any for those turbos. But then I haven't looked either :) I'm happy with my GT3582R, but this graph should show you why I'm interested in the GTX3076R:

 

attachment.php?attachmentid=153141&stc=1&d=1339318712

 

You can hit 1.4bar by 3100rpm, and if the boost threshold allowed it, 0.8bar at 2000rpm ;) So no surge worries and even with an extended rev range it'll still be on the map at 7200rpm.

 

This is what my current one looks like - you can see the technology change, the GTX allows almost 500rpm faster spool and still delivers T67 oomph:

 

attachment.php?attachmentid=153142&stc=1&d=1339318712

 

I can only achieve 1.4bar at 3500rpm in 6th gear, so it's close to surge but not a problem :) (and that's all datalogged from testing before anyone thinks I just looked at a gauge while booting it)

 

-Ian

GTX3076R-comp.jpg

GT3582R (current) comp map.jpg

Edited by Ian C (see edit history)
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The worry is the right hand side, 7000rpm at 1.4bar (red dot) is well outside the operating range of the turbo, it'd be overspeeding. 6500rpm is 52lbs/min which juuuuust gets in on the edge of the map, but it's not ideal.

 

Actually, having a closer squint at the dyno plots in the for sale thread, they both appear to stop at 6400rpm, and the power is falling off a cliff at that point. That corresponds to the turbo leaving its operating range at that point, overspeeding, and overheating the intake charge.

 

I've got 256/264 cams and run a 0.68ar housing on my GT35, and the power only starts to fall off north of 6500rpm. Wider cams and a much bigger exhaust housing AR should move the powerband upwards, but in this case it drops off beore 6000rpm so something is choking it up. I'd conclude that the GT30376 is slightly undersized for a 2JZ :shrug: But the successor, the GTX3076R, would be spot on.

 

Just wish I had the £1500 to buy one :D

Edited by Ian C
more typey typing (see edit history)
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Some great info there Ian, my housing and cams must play a key role to the way it drives then, I have no issues with surge on my set up on the road, I would love to take u out in it to show u what it's like in a road test.

And thx again Jaime for your great input, my cars never been right for a few reasons mainly the faulty aem fic with an intermitant fault, not the cars set up!

I'm having the new fcon fitted next week by Ryan so everything will be sorted ;-)

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And thx again Jaime for your great input, my cars never been right for a few reasons mainly the faulty aem fic with an intermitant fault, not the cars set up!

 

Im just a bit lost, you are saying how great it is (maybe because you are trying to sell it ;) ) yet your dyno graph and reading your posts say otherwise, i cant see how it can be so good with a broken gearbox and a faulty ecu/mapping.

 

Id have never have posted if it was not for the fact i read you telling Ian to "shove his 2pence up his arse" ;)

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I only look at stuff that publishes their compressor maps properly, and I've not seen any for those turbos. But then I haven't looked either :) I'm happy with my GT3582R, but this graph should show you why I'm interested in the GTX3076R:

 

Great info.

 

Have no personal expertise in this area and simply going by heresay.

 

If these other turbos and setups are as good as they say they are then surely they would publish all the relevant information to silence the critics.

 

I am extremely happy with my T61DBB, personally wouldnt want the setup to spool any quicker.

 

To the OP - suggest you try out different setups and see which one works best for your needs. Everyone's "opinions" and "expectations" of a street setup with quick spool are different.

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Im just a bit lost, you are saying how great it is (maybe because you are trying to sell it ;) ) yet your dyno graph and reading your posts say otherwise, i cant see how it can be so good with a broken gearbox and a faulty ecu/mapping.

 

Id have never have posted if it was not for the fact i read you telling Ian to "shove his 2pence up his arse" ;)

 

I'm not sure why, I'm just trying to say that my set up on the road for a fast street car is great, despite what figures and assumptions dictate to me.

I'm honest and have a build thread about my car and everything that it's been through I have nothing to hide Jamie?

The aem fic fault is/was intermittent so I had some great fun when it was ok, the box gave up after about 1000 miles due to having only half the oil in it needed, but thats all arrelavent to this post!

If u bothered to read my posts and the for sale thread it states I'm spending another 3k on new ecu, gearbox and new uk spek breaks all round?

These were problems but nothing to do with the set up when it was all rock and roll, I'm not sure why u get involved sometimes, everyone gets so involved with figures when it's only really down to how the car drives!

I know my car is a great street car and everyone that's been in it cant believe the acceleration, surely that's all that matters mate ;-)

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The aem fic fault is/was intermittent so I had some great fun when it was ok, the box gave up after about 1000 miles due to having only half the oil in it needed, but thats all arrelavent to this post!

 

If u bothered to read my posts

 

http://www.mkivsupra.net/vbb/showthread.php?244827-I-think-I-m-just-going-to-sell-the-supra-now-(

 

In this thread you say it died after 600 miles because of the power you are running, you need to make your mind up, Please dont take offence if i take anything you say with a pinch of salt :)

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Totally true mate, but wasn't aware of the issues at the time with the gearbox not having enough fluid in.

This only came to light recently, I assumed it was the power at the time.

But it seems what ever I say now is irrelevant, as your on a personal vendettas to just slate my car :-(

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Actually, having a closer squint at the dyno plots in the for sale thread, they both appear to stop at 6400rpm, and the power is falling off a cliff at that point. That corresponds to the turbo leaving its operating range at that point, overspeeding, and overheating the intake charge.

 

I've got 256/264 cams and run a 0.68ar housing on my GT35, and the power only starts to fall off north of 6500rpm. Wider cams and a much bigger exhaust housing AR should move the powerband upwards, but in this case it drops off beore 6000rpm so something is choking it up. I'd conclude that the GT30376 is slightly undersized for a 2JZ :shrug: But the successor, the GTX3076R, would be spot on.

 

Just wish I had the £1500 to buy one :D

 

From the relatively minimal information I've seen, both objective (compressor maps) and subjective (dyno plots and feedback from, mostly, US Supras), suggests the GTX series retain the low-range but have extended the usable pressure margins. Not sure, for myself, whether that would justify the expense.

 

Edit: But on reflection, the improvement in upper range of modern turbos (plus improvements in ECU technology) means that you can undersize and run higher boost to achieve the same power that only bigger compressor turbos were able previously. For example, the test Supra in SP's manifold testing (3.4 high-comp HKS motor, flowed head) made almost 1000hp on a 67mm turbo!!

Edited by sdistc (see edit history)
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It's just harmless banter mate....but you started getting personal by involving my car and the fact it's for sale and there's nothing but problems with it, might well of just said don't buy this it's a bag of shite!

Im doing the right thing spending loads of money to sort them out so it will be running perfectly ready for sale.

That's enough banter for me for one day ;-)

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The thread is making me chuckle!

Just out of interest, what will a stock 2 stage turbo build boost at on the first turbo at 2k? I didn't see much before 2.2k..

 

Anyway, the amount of pressure built is not the be all and end all, it's also the gas it can flow.. so a tiny turbo may spool to pressure fast, but that's not to say that a larger turbo will be producing significantly less hp at a lower pressure.. Certainly in big gears..

so aside 1st, 2nd gear pickup, once you are in 3rd and above I have always found a lot more pull than stock and small turbos on the 35's (61's) +

 

When I left the forum a few years ago I expected to come back and read threads about variable vane turbos.. I heard porsche were running one in their production 911's some time ago, and thought it was only a matter of time before the holy grail technology filtered down. I've had a diesel one off my van and enjoyed poking around it, simple and effective, just wondered if anyone had played with them, or why aftermarket people have not copied..

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To the OP - suggest you try out different setups and see which one works best for your needs. Everyone's "opinions" and "expectations" of a street setup with quick spool are different.

 

Spot on advice.

 

OP if you get down to suprapod, I'm sure there will be a range of setups that you could maybe blag a passenger ride in, to see what setup suits you best.

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From the relatively minimal information I've seen, both objective (compressor maps) and subjective (dyno plots and feedback from, mostly, US Supras), suggests the GTX series retain the low-range but have extended the usable pressure margins. Not sure, for myself, whether that would justify the expense.

 

Edit: But on reflection, the improvement in upper range of modern turbos (plus improvements in ECU technology) means that you can undersize and run higher boost to achieve the same power that only bigger compressor turbos were able previously. For example, the test Supra in SP's manifold testing (3.4 high-comp HKS motor, flowed head) made almost 1000hp on a 67mm turbo!!

 

It's crazy how turbo technology is developing now. Over the past 2 years it's changed so much! A 67mm getting that power and spool would be the perfect street turbo IMO....

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It's crazy how turbo technology is developing now. Over the past 2 years it's changed so much! A 67mm getting that power and spool would be the perfect street turbo IMO....

 

Agreed. I'd like to have my cake and eat it too, which is why I think the 67mm is pretty much the ideal for a standard stroke 2JZ.

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The thread is making me chuckle!

Just out of interest, what will a stock 2 stage turbo build boost at on the first turbo at 2k? I didn't see much before 2.2k..

 

I checked, it'll get to about 0.8 bar by 2500rpm :sly: It's a tiddler of a turbo as well, spins up almost instantly. That's the boost threshold issue coming to the fore rather than turbo lag, there just isn't enough gas flow to spin it below that rpm.

 

Anyway, the amount of pressure built is not the be all and end all, it's also the gas it can flow.. so a tiny turbo may spool to pressure fast, but that's not to say that a larger turbo will be producing significantly less hp at a lower pressure.. Certainly in big gears..

so aside 1st, 2nd gear pickup, once you are in 3rd and above I have always found a lot more pull than stock and small turbos on the 35's (61's) +

 

Plus a smaller turbo, while it may spin up fast, will choke at higher RPMs where it just can't flow enough air to feed the engine. Boost drops off or it overheats the air and spins too fast, losing power and shortening component life.

 

When I left the forum a few years ago I expected to come back and read threads about variable vane turbos.. I heard porsche were running one in their production 911's some time ago, and thought it was only a matter of time before the holy grail technology filtered down. I've had a diesel one off my van and enjoyed poking around it, simple and effective, just wondered if anyone had played with them, or why aftermarket people have not copied..

 

I think it's something to do with the heat range they work at. Diesel is much colder exhaust so VATN turbos can be made with inexpensive materials. Petrol engine VATNs still need inconel and all that jazz to work without melting or exploding, no problem on a flagship Porsche but a bit of an issue for us mugs on a budget :) Maybe with the current trend of downsizing engines and putting on small turbos we'll see more development towards the petrol VATN.

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Hi Ian. We almost have the same turbo and cams. I have a bigger ar tho. Nice to know :) I love how it drives.

 

Could you do a sticky on how to read/work out those compressor maps? Iv always been confused.

I understand with your notations but don't see how they relate to the numbers on the axis :s

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