Gt3582R/gt3788R/gt4088R .

[R31Nismoid]

When talking about trim, you talk about the area of the actual wheel

Garrett have basically everything you need on their site. Some really interesting stuff even for intermediates.

http://www.turbobygarrett.com/turbobygarrett/wheel_trim

[Cowboy1600]

Turbine AR sizing appears to be what I'm talking about. I didn't think this was the same as trim, but wasn't 100% if there isn't some crossover in terminology.

[SilverECR33]

Stop it Dale, you already know the answer.

I dont give a tinkers toss if garret originally made the 37/88 for a briggs and stratton lawnmower, It owns the 35r in every department. Most importantly in longegivity,

Stop thinking man, It weakens the team.

haha thanks mate . just really for debate. yea the 35r is a fail in design. I like lawmowers

I'm still a turbo newb, so excuse my questions, if they seem a little silly.

By 78 trim do you mean the size of the exhaust housing? ie, 63 and 82 that we hear about.

So you're saying there needs to be a third option, a 78, which sits between the 63 and 82?

Not exactly, and no its not a silly question at all. You see theres alot more to it than rear A/R. rear trim size and design, comp trim size and design,number of blades size of blades and their design, bearing types etc. heaps of variables come into play and changing each component will change the characteristics of the turbos. How and When they come on boost, how responsive they are, max airflow etc. how charged the air will be at a given psi which = how hot comp temps will be, and how long the turbo can last on the edge of its effeciency.

However I was just trying to get some of the more knowledgable old skool people to jump in, and discuss other options ie.. HKS 3240 Oddball however with a T3 housing, but now that i check the thread title again.. it really should have its own thread.

[The Dan]

I'm still a turbo newb, so excuse my questions, if they seem a little silly.

By 78 trim do you mean the size of the exhaust housing? ie, 63 and 82 that we hear about.

So you're saying there needs to be a third option, a 78, which sits between the 63 and 82?

If so, like I said, I'm only a newb to the whole turbo thing so am still learning but this is something which became apparent to me very early on in the piece. It seems there is a void between the 63 and 82, at least for "our" motors. But then I suppose the 4 banger boys probably do well with the 63 and the 3L/4L boys fill an 82 or even 1.06 well. So perhaps the mid capacity motors, such as RB25/26s, are the only ones who would do well with something between a 63 and 82?

That is, of course, assuming we're talking about the same thing....

If you got something like a 0.75 A/R rear you wouldn't even notice the difference. 0.75-0.82 = f**k all difference. Too many people over think this stuff

a 3L engine is borderline 1.00 territory so a 4L is definitely 1.00 or larger.

You need to get gasses out. Forget about A/R, focus on housing flow. RB25-26 T3 housing up to 500hp, T4 for anything over that and the housing size not only marginally effects the boost response, it also effects HOW the power comes on. Smaller ratio housings come on very slowly but earlier, Large ratio housings are much snappier but later.

[The Dan]

haha thanks mate . just really for debate. yea the 35r is a fail in design. I like lawmowers

There is nothing wrong with 35R's. They have their place. And they will still beat a GT3788 in the under 500hp category. You can run a smaller housing and get away with it. Once you start wanting power though, it comes out of its element.

[stiddy]

so how does one of these fancy GTX35R's 1.06 rear compare agaisnt the the GT3788 with similar rear. Say on a RB25, 28psi and E85.

from what I read, the GTX turbos have it over the GT turbos for spool and power.

Reason I ask, is because I have a GTX35R 1.06 rear lol for my RB25.

[WARLORD]

Reason I ask, is because I have a GTX35R 1.06 rear lol for my RB25.

do you have this on the car now

[R31Nismoid]

the GTX turbos have it over the GT turbos for spool and power.

Which results have you been reading?

By and large results tend to point in the way such that GTX spool is not as good. It's also obvious you need a gut load of boost to get to the power you want as opposed to the GT series which give good results on lower numbers. Obviously the GTX will make more as you keep screwing boost in as they perform better there etc.

[jet_r31]

That is good information disco but none of it really will make any sense to the end user. They simply don't need to know that so it's not really important.

I have already spoken to this person about the various options for the power goal he has.

For a turbo to spool up the same response as a GT35R with a 0.82 rear and make the same or more power than a T04Z, I don't know why anyone would ever consider a GT35R ever again. They are also the same price

We have done nearly a dozen of these GT3788's now on all different setups inc 1JZ, RB26, 26/30, 25/30, RB25 and XR6 4.0L and they just hammer everything else out of the water.

They are a bit of a fall over in power in the top end when pushed but if you use the 0.99 housing they will go further, especially on a 3.0L bottom end like this guy has

what size exhaust housing do you generally use for Gt35 .82 response and more power?, sounds like a nice little turbo.

cheers

darren

Edited June 17, 2012 by jet_r31

[discopotato03]

Garretts "GT3582R" is a variation of what they produced for HKS in the "GT3240R" .

Both these turbos use the same series turbine and compressor but the HKS spec one has a cropped turbine and a slightly smaller trim compressor wheel .

To me it looks like Garrett wanted something they could market without dramas with the HKS technology tie up .

The "GT3240R" , technically in todays speak a GT3582R , is in the same situation as a "GT2835R/GT3071R right down to the cropped turbines .

The trouble with the 32R and 35R is that the turbine and compressor wheels have been pinched from larger framed turbos and squeezed into smaller housings never intended to work with these wheels .

With both versions they simply machined out GT30 turbine housings and bashed the 35 turbine into them and its a compromise .

The compressor wheels are the same 82mm GT40 (BCCW18C I think) and both have T04S compressor housings on them .

From memory T04S and TB41 compressors are 76mm major diametre with the diffusers set up for 76mm wheels .

And to the center section . Garretts BB units from GT2554R to GT3582R use a centre based on a modified (for ball bearings) T25 bush bearing centre and its not exactly huge . It does Garrett credit that they can use big wheels in them without hand grenading but the GT3582R is getting close to the edge and they will bend turbine shafts if pushed hard enough . It goes without saying that they destroy themselves when they do .

The large frame BB units are based on a BB conversion of Garretts GT bush bearing centre section and are longer larger in diametre as is the turbine shaft . The T series wheel versions like T04 60-1/T04Z/T51R have the four ears machined off the back of the bearing housing to form a flange so they can clamp up to T series turbine housing with crab plates - like T series bush bearing turbos do .

These big frame units in GT format can only mount large frame GT40 type turbine housings which is why you tend to see them with large T4 International flange style twin scroll turbine housings . Some have single or twin entry "T3" mount flanges but they are hardly an ancient T3 or GT30 based housing .

Same with the compressor side . The compressor back spacing is different small to large frame and Garrett modified GT40 compressors to get them in GT3582Rs .

Housing wise big frame units tend to use GT40 comp housings and if they put modest wheels in them they just use a smaller AR like say the 0.58 one lifted of a plain bearing GT4082 . The BB GT4088R gets a (from memory) 0.72 AR compressor housing .

Garrett does do larger frame GT35 BB turbos for Hino and Isuzu and they use the larger GT40 housings both sides . I have a plain bearing one somewhere and it is more bulky than a small frame GT3582R even though its turbine is the same dimensions .

I know some here regard the GT4088R as dated and not the highest performance thing for a big framed BB unit , I think it tried to be a big frame replacement for a GT3582R but its harder to use because of it greater bulk and that TS T4 flanged turbine housing . Also its larger turbine even in 78T would take a bit more driving than a GT3582R .

The $64 question is how would it go with the 82mm 56T GT40 compressor that is an option on the GT37BB series turbos . With the right comp housing it should all screw together but I doubt anyone would ever do it .

Big frames/big turbine housings/significant lag on "smallish" petrol engines . Your calls .

[The Dan]

The $64 question is how would it go with the 82mm 56T GT40 compressor that is an option on the GT37BB series turbos . With the right comp housing it should all screw together but I doubt anyone would ever do it .

The real question is why go to all that trouble to create something that isn't a problem in the first place?

The 3788 ticks all boxes in power and response if you want something up to 600whp on a 2.5-3L engine. The response is phenomenal considering its size.

Despite all the tech data you have written above, there is maybe 1/100 people who will understand what you are talking about or even know how it effects real world results. The simple fact is - it works, and it works well. People can stay with the GT35R or use the X if they wish. We will continue to use the 3788 until something better comes along. We haven't broken one yet and we are pushing these things hard.

[The Dan]

what size exhaust housing do you generally use for Gt35 .82 response and more power?, sounds like a nice little turbo.

cheers

darren

We generally go with the 0.89 rear for anyone wanting 550-600 max. Expect to have to push it though, these things run out of puff in the top end. The larger 0.99 rear will still beat the T04Z for response and make more power but it's only the 0.89 that matches the GT35R in response.

[discopotato03]

The point of what I posted above was to point out that the GT3582Rs are a compromised bitzer , basically bigish wheels in a smallish cartridge using non family housings .

Me personally I'd be using a GT4088R on upwards of 3 litres though probably need 3.2 to 3.4 to make it truly responsive . I can't see any big frame turbo beingw what I'd call responsive on an RB25 particularly on the street .

My opinions only cheers A .

[Lithium]

Despite all the tech data you have written above, there is maybe 1/100 people who will understand what you are talking about or even know how it effects real world results. The simple fact is - it works, and it works well. People can stay with the GT35R or use the X if they wish. We will continue to use the 3788 until something better comes along. We haven't broken one yet and we are pushing these things hard.

Makes sense, and the amount of good results I've seen and experienced from GT3582Rs seem at odds to how compromised DP suggest they are - theory/whatever aside I reckon they work really well for what they are, and there still isn't that much out that offers a better compromise.... especially cost effectively.

In regards to pushing the GT3788Rs, do you have any results (graphs/whatever) which you can share, I think the topic has come up before but I don't remember actually seeing anything. I've been fascinated by them for some time, and know you've sung their praises before. Comparison with GT35R/T04Z would be awesome but well aware that its probably an unrealistic ask

Someone I know may end up trying a Precision PT6466 on an RB26, that might be an interesting unit that might lurk in that range.

[stiddy]

No its not on the car yet. But from reading on here and other online forums, the GTX35R will spool faster and produce more power than its brother GT35.. now reading that, you would think a GTX35R would spool faster than the 3788?

I would of liked a slightly bigger turbo, but was convinced otherwise because saying that even a GT35/GTX35 will be really laggy on a 25. Too late now I spose. Unless I sell it and go for a borgwarner or something. Am chasing between 450-500rwkw. Been told by just about all performance shops that the GTX I have at the moment will shit it in.. Guess we'll see on tuning day..

[The Dan]

The point of what I posted above was to point out that the GT3582Rs are a compromised bitzer , basically bigish wheels in a smallish cartridge using non family housings .

Me personally I'd be using a GT4088R on upwards of 3 litres though probably need 3.2 to 3.4 to make it truly responsive . I can't see any big frame turbo beingw what I'd call responsive on an RB25 particularly on the street .

My opinions only cheers A .

1bar @ 3500-3700rpm on a 3L an 3900-4000rpm on a 2.5 is what I refer to as responsive

Makes sense, and the amount of good results I've seen and experienced from GT3582Rs seem at odds to how compromised DP suggest they are - theory/whatever aside I reckon they work really well for what they are, and there still isn't that much out that offers a better compromise.... especially cost effectively.

In regards to pushing the GT3788Rs, do you have any results (graphs/whatever) which you can share, I think the topic has come up before but I don't remember actually seeing anything. I've been fascinated by them for some time, and know you've sung their praises before. Comparison with GT35R/T04Z would be awesome but well aware that its probably an unrealistic ask

Someone I know may end up trying a Precision PT6466 on an RB26, that might be an interesting unit that might lurk in that range.

From what I've seen of the Precision stuff, they are very good.

And yeah I should be able to dig up comparo on Z and 35R vs 3788. I just gotta hit up Sean from EFI for the printouts

No its not on the car yet. But from reading on here and other online forums, the GTX35R will spool faster and produce more power than its brother GT35.. now reading that, you would think a GTX35R would spool faster than the 3788?

I would of liked a slightly bigger turbo, but was convinced otherwise because saying that even a GT35/GTX35 will be really laggy on a 25. Too late now I spose. Unless I sell it and go for a borgwarner or something. Am chasing between 450-500rwkw. Been told by just about all performance shops that the GTX I have at the moment will shit it in.. Guess we'll see on tuning day..

Your GTX 'should' spool faster than the GT. They are also supposed to produce more flow. I'm yet to analyse the real world results though. And yes you will shit in 450rwkw....not sure about shitting in 500 though. It's generally always a push to get a 35R to 500rwkw. They can do it, it's still a push though

[tricstar]

660rwhp from 35R on a 2.5L ?? really, I've just had a quick look in the dyno thread and didn't see any above 450rwhp ?? do you mean 450-500rwHP?

also interested in the comparo's between TO4Z vs GT3788, I have TO4Z on 2.8L @ 600rwhp, would love earlier spool, at same or more power !!

Edited June 18, 2012 by tricstar

[The Dan]

660rwhp from 35R on a 2.5L ?? really, I've just had a quick look in the dyno thread and didn't see any above 450rwhp ?? do you mean 450-500rwHP?

also interested in the comparo's between TO4Z vs GT3788, I have TO4Z on 2.8L @ 600rwhp, would love earlier spool, at same or more power !!

Haha yeah I just realised I said KW instead of HP. 500kw is virtually impossible for a 35R. 450kw is even a stretch for a GTX

[SimonR32]

660rwhp from 35R on a 2.5L ?? really, I've just had a quick look in the dyno thread and didn't see any above 450rwhp ?? do you mean 450-500rwHP?

also interested in the comparo's between TO4Z vs GT3788, I have TO4Z on 2.8L @ 600rwhp, would love earlier spool, at same or more power !!

Take your homo spec plumb back gate off and you will make more power and response

[tricstar]

Take your homo spec plumb back gate off and you will make more power and response

haha ( homo spec ) unlike yours, mine does get driven on the street quite abit.. so not a fan of the screamer, had never even considered going that root