Gt3782R Pm .

[discopotato03]

I normally would not reply to a PM this way but this silly site would not let me reply in the normal way . This is about a GT3782R on a 25 BTW .

To the OP , these are pretty big turbos for a 2.5L engine and its not surprising it came on boost ~ 3500 revs . If your mate was using a std cast TS manifold it was probably going to be a limiting factor even though these turbos have the TS T3 (Euro T4 actually) mounting flange .

Now these GT3782Rs were intended to be American aircraft carrier / ute "pickup" truck turbo upgrades and I think from memory they have the lower temp diesel spec turbine material too . Their Stage 1/2/3 were mainly compressor wheel options the largest (st 3) being the 88mm 52T from the GT4088R . The st 2 is same wheel as the GT3582R and stage one I think an 82mm 50 T version of st 3s wheel . Being a 7/7 bladed wheel in 82mm I'm guessing its stage 1 .

Most GT3776s and GT3576s are big frame plain bearing turbos but there are a few BB units on some Hino and Isuzu trucks . In any case you can now get them in the smaller GT25 BB cartridge size because I think the later Ford Typhoon XR6s use this one .

Ultimately most find that truck turbos are a PITA mainly because the housings aren't really suitable unless you intend to fabricate everything around the turbo or need a certain housing size not available as an aftermarket car part .

Personally I think you are better of putting something on an RB25 that boosts closer to if not a little under 3000 revs so you get some benefit from the thing more often . GT30 based ball bearing turbos seem to work pretty well though I'd avoid the GT3082R/GT3040R version unless its the HKS spec one because the Garrett marketed ones seem to be a bit lazy to come on boost .

I have no experience with Holset turbos but others here do , just remember the time/effort/money involved in fitting diesel truck turbos because it can be a painfull way to find the result is not what you expected .

Hope this helps , cheers A .

Edited January 30, 2012 by discopotato03

[urtwhistle]

Hey mate, was that target at me? Cos around Xmas time I sent you an email about a GT3782 and we sent a few emails back and forward. If not i'm curious to see whom else is playing with these turbo's. PS i was gonna fit it on a Rb30.

[Dale FZ1]

And was it just idle thought, or has the plan been progressed to something concrete?

[urtwhistle]

well I have the turbo sitting on my shelf. Its off an 8lt Scania LPG bus. But after plotting out the flows to make any sort of power it was way out of it's efficency zone due to the diesel trim. Part of me wants to rip the 82mm wheel off and put an 88mm wheel and a normal exhaust housing on it since I already have the turbo. The other half is saying buy a TD06H 25G and put the 3782 on a mates diesel Patrol or Land cruiser which it would be more suited to. So many choices, so little money.

[urtwhistle]

Hey Dale, see the attached compressor map. I must have deleted the copy where I plotted my RB30 on it. But even with a Rb20 its pretty rubbish with the trim compressor trim.

regards

Chris

[discopotato03]

To the OP , sorry but I went back and re read and I had though you had a GT3782R which is a ball bearing diesel pickup upgrade family .

If what you have is the plain bearing one then I'm not surprised it was laggy . While some used a 52 trim 82mm GT40 compressor the compressor housings weren't always port shrouded and that makes a difference .

If you had access to the big shaft GT35 turbine that would help but then the turbine housing is no good . I'm not sure what AR ratios Garret made GT40 housings that were profile machined for GT35 turbines but I think they were pretty big . I think I have a GT3576 plain bearing turbo kicking around here somewhere but from memory it has a chipped turbine and the housing is something like 1.16 AR ratio .

Honestly the BB ones are better and in time the Hino/Isuzu tax will come off them . The plus points would be a usefull TS turbine housing AR ratio and a suitably sized port shrouded compressor housing .

Possibly the cheapest ball bearing big frame turbo is a T04 60-1 or the same thing with the T04R compressor marketed as a T04Z , I think HKS marketing came up with the Z = BB in this case

A .

[urtwhistle]

Hey Ash,

I currently have fitted to my RB30 a hypergear bush bearing 3576 which is laggy for some reason unknown to me. (it's currently at a well known shop here in Perth getting a look over with a fresh set of eyes to see if I have stuffed up some where on the build). The GT3782 I'm not 100% sure if its BB or bush, thats 1 thing I have never noticed or checked. Shouldn't be too hard to figure out. Also to my knowledge it isn't a port shrouded cover. If I remember I'll measure the shaft size and figure out some more specs and see what it options there are for converting it to something more useful.

Let me know if the pics don't load and I'll reattach them again

http://www.skylinesaustralia.com/forums/index.php?app=core&module=attach&section=attach&attach_rel_module=msg&attach_id=371535

http://www.skylinesaustralia.com/forums/index.php?app=core&module=attach&section=attach&attach_rel_module=msg&attach_id=371536

http://www.skylinesaustralia.com/forums/index.php?app=core&module=attach&section=attach&attach_rel_module=msg&attach_id=371537

[robots]

Thanks for the replies.

As we all know, some of garret pump turbos are out of flow from calculations, but still making power.

Just a thought.

What do you rekon would be possible max power with GT3782 on rb25 ? And its journal bearing.

[discopotato03]

Thanks for the replies.

As we all know, some of garret pump turbos are out of flow from calculations, but still making power.

Just a thought.

What do you rekon would be possible max power with GT3782 on rb25 ? And its journal bearing.

Well that map in post 5 shows the maximim airflow (on that map anyway) as 55 pounds of air which roughly equates to 550 hp . My old rule of thumb was to subtract 10% which lands it around 495-500 . I think what cuts it a tad short for an 82mm GT40 compressor is the lowish AR of its housing and to some degree its trim size . I think I have a map somewhere of the GT4082 and its possibly similar with I think a 50T version of that wheel . Better looking map though .

Rifles through maps - no its actually a bit more at 570 odd - 10% = 513 . I'd have to look but I think they used a port shrouded compressor housing in the same ratio .

That aside as usual the hardest parts of getting any turbocharger "right" are the turbine and turbine housing . If you get these in the ballpark the compressor end is reasonably easy - provided a suitable range of wheels and housings are available .

Hopefully one day these larger frame center sections , BB ones , will be more readily available and people should be able to play around with turbines and compressors to get what they want . We wouldn't have as many issues with the smaller GT25 BB frame units if Garrett would gives us a wider selection of turbine trims (ie 78T GT30/GT35) AND a range of twin scroll twin integral gate turbine housings . If they can do it for Evo 10 GT3076Rs they can do it with twin inlet T3 flanged turbine housings as well ditto T4 flanges .

A .

[robots]

GT3782 I got was .9AR, GT3576 was .82AR all bush. And GT3782 was making full boost by 3500-3700. (1 Bar) on RB25.