GT3782R over s400

oldsmokey

oldsmokey

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Hey guys I did a little searching, and for the most part everyone that uses Garrett BB turbos use a GT3788R as the secondary. Im looking for a max top end of around 650-700 but want the quickest spool possible. Will a GT3782R we a good turbo for this application? Maybe someday I can throw a BB primary under it but I dont want to spend the extra money now.

Thanks in advance for any help
Joel
 
I'm running the 3782 stage 2 with a 4202, both BB cartridges. It makes about 20 psi at 1600 rpm, 30psi around 1700 and 60+ not much later. Thats on a cammed 24v. I haven't driven any other twins, so I can't comment on how quick spooling they are to others. It does make that silver bullet look like a turd, though.

I don't like guessing at power numbers, but it is substantially stronger than the truck when it was at 520 with the bullet, especially in the mid range. Should be a good set for the 600hp range.
 
Old topic but..................Garrett now lists the 3782R in GTX series.
 
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I see the GTX30 and 35, didn't see listings on the 37 though. Link?
 
Sorry, I meant the GTX3582R.

It is showing more hp potential than the GT3788R?
 
^^^ as a single yes; for use in compounds without a wastegate???

Nothing wrong with using the 3782 in the top and it will be effective. Reaching 700? I don't know. It is more than just putting a big turbo on the bottom to compensate. It has to do with the backpressure created through the smaller turbine and EH that will choke the motor at higher HP. That is where the external wastegate comes in handy, but you were trying to keep cost down.

IMO, to optimize that turbo for 700rwhp, use a 44mm external gate with a plain jane s480 on the bottom. That should do it.
 
I just looked at the gtx3582. It compares favorably to a s300 of the 64mm compressor with 68mm turbine type. So yes, properly wastegated, it would do well in twins. The problem with garretts has always been a lousy wastegated EH.
 
GLHS said:
Sorry, I meant the GTX3582R.

It is showing more hp potential than the GT3788R?
Click to expand...

Remember that Garret lists the big # for the turbine side so that 68 wheel is more than likely a 59/68, so in BW terms would be like 64/59/.?? . Also if you look at the turbine flow chart it is really low designed for a small displacement engine. I found this out the hard way on a 4094 where the turbine wheel lists on their site as a 77 but when you measure it comes to a 68 in the terms we typically talk in.
 
He's right above... I continually forget this inconvenient fact... and that just further reinforces the point I made about choking the engine at high rpm/hp.
 
I am running a 62/71/14 (.80 right?) now.

How many lbs per min is mine rated?

Just looking for something that is as good or better for egt's and spools quicker than what I've got.

Maybe this is not possible?

What twins are you running again soulzoo?
 
64/480 good for 900hp fuel only and spool very well with stock cam
 
Tate said:
I'm running the 3782 stage 2 with a 4202, both BB cartridges. It makes about 20 psi at 1600 rpm, 30psi around 1700 and 60+ not much later. Thats on a cammed 24v. I haven't driven any other twins, so I can't comment on how quick spooling they are to others. It does make that silver bullet look like a turd, though.

I don't like guessing at power numbers, but it is substantially stronger than the truck when it was at 520 with the bullet, especially in the mid range. Should be a good set for the 600hp range.
Click to expand...

good god man!!! how hard are you fueling those turbos? whats the smoke like?
 
kuntryboy369 said:
good god man!!! how hard are you fueling those turbos? whats the smoke like?
Click to expand...

They were getting a fair share of fuel. 13mm and DDP comp injectors. It was overkill, those turbos were just a stand in at that point. Once my GTX shows up, this set will be on my DD 12v, so I'll have something to compare them to.
 
tex 6 said:
64/480 good for 900hp fuel only and spool very well with stock cam
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That doesn't sound like sound advice, a 62/475 is a little slow to spool and he asked for a quicker spooling setup so you recommend a larger 64/480 setup.


Everything truly is bigger in Texas!
 
Big Blue24 said:
That doesn't sound like sound advice, a 62/475 is a little slow to spool and he asked for a quicker spooling setup so you recommend a larger 64/480 setup.


Everything truly is bigger in Texas!
Click to expand...

Thats Sound advice...


I just got rid of a 1.32 Ar S480 in favor of a S476 1.1 Billet, so I could make more power before converter lock in 3rd... This is under a 62/71/14... If I am not happy with this setup, I will be going to a GT47 80mm Primary. I think BB turbo's only make your mod list look cooler. Well and also your budget for supporting mods smaller... IMO design twins around your personal needs and use, not a power level...
 
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I guess I should mention the truck is never below 4500' elevation.

It varies from 4500'-11000' weekly.

What I really probably need to do is get a ZZ head and different cam, then see how it spools and cools.
 
Big Blue24 said:
That doesn't sound like sound advice, a 62/475 is a little slow to spool and he asked for a quicker spooling setup so you recommend a larger 64/480 setup.


Everything truly is bigger in Texas!
Click to expand...

Yep go big or go home that's why I'm running 66/480
 
oldsmokey said:
Hey guys I did a little searching, and for the most part everyone that uses Garrett BB turbos use a GT3788R as the secondary. Im looking for a max top end of around 650-700 but want the quickest spool possible. Will a GT3782R we a good turbo for this application? Maybe someday I can throw a BB primary under it but I dont want to spend the extra money now.

Thanks in advance for any help
Joel
Click to expand...

What kinda fuel mods u running?? Inj pump ect
 
Tate said:
They were getting a fair share of fuel. 13mm and DDP comp injectors. It was overkill, those turbos were just a stand in at that point. Once my GTX shows up, this set will be on my DD 12v, so I'll have something to compare them to.
Click to expand...

got ya. i was wondering how you were making that much boost that fast. im trying to make the cleanest, fastest spooling 600hp i can. so 20psi at 1600rpm caught my eye.
 
GLHS said:
I guess I should mention the truck is never below 4500' elevation.

It varies from 4500'-11000' weekly.

What I really probably need to do is get a ZZ head and different cam, then see how it spools and cools.
Click to expand...

Before you go to that expense, you might want to take a drive over to Utah and go for a test ride in one of the trucks setup with WOP's triple turbo setup. That's if you want big horsepower and high altitude spool-up.

Otherwise, I think you should shoot for 650-700 HP and downsize to He351 over S475 setup. Much, much better throttle response and spool-up at altitude but still has enough airflow to make respectable power.
 
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