Twin Turbos for Towing

S

Smokey Joe

TN 12 Valver
Joined
May 9, 2011
Messages
11
What is the best Twin Setup for Towing 20,000 lbs?
1998 12 Valve 4000 Gov, Timing advanced, 50HP Injectors
 
Stick a gt4294 over that hx35. Great setup, you can even go up to a 125 horse or so injector too..
 
24vriviera said:
Stick a gt4294 over that hx35. Great setup, you can even go up to a 125 horse or so injector too..
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What are the specs on this gt4294, I see it thrown around a lot but I'm not familiar with that series turbo.
 
What about HX35 over S472 with 1.10 exhaust? Is the exhaust too small on the 472? I want crisp response no lag but be able to utilize my rpm band without overspool.
 
Smokey Joe said:
What about HX35 over S472 with 1.10 exhaust? Is the exhaust too small on the 472? I want crisp response no lag but be able to utilize my rpm band without overspool.
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this is setup will work good too I have a similar set on my tow rig
 
I run a he341 over gt4294(1.28ar).... Havent really towed heavy with them. But the spool up instantly, im guessing the would make a great towing setup.

Even though im probably over fueling them with 5x14s, 181s, 22* timing, 4gsk




-ViTO-
 
I'd stay away from HX turbo's if your going from scratch, 35's are tough but a baseline S300 is a better design and a 475 is a great bottom turbo.....this will make (not support) some big HP too, don't sell it short!

Jim
 
running a HE351 over an S475/96/1.32 with a 181/210 cam, 131 DV's and stock injectors for now, spools up nice and i have to hold my foot into 5th gear for awhile before she ever gets real hot... this is with a 6" lift, 35's and 3.55 gears

I have a set of 5x.014 SAC nozzles sitting in my room... im sure they will only help these twins come to life.
 
I've had really good luck with HX35w's with modded internal waste gates over HT60's. I had 64/65/14 over a GT4294 and they made boost fast. The best set we've done was a S358 over a S478 with a 1.10 exhaust housing. That truck was pretty nasty!
 
DieselWrencher said:
I've had really good luck with HX35w's with modded internal waste gates over HT60's. I had 64/65/14 over a GT4294 and they made boost fast. The best set we've done was a S358 over a S478 with a 1.10 exhaust housing. That truck was pretty nasty!
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I was originally gonna stick my gt4294 under my 64/71/14, but i was told my 64 was too close in size to the gt42. And they wouldnt work rite together


-ViTO-
 
How far apart on sizes from the two turbos are normally the best, oviously too close to the same size you wont get the true benefit from them on low and high range, but to far apart and it wont be right either. Sorry if the way i asked the question is hard to follow. Im planning on doing twins this winter, and i can come up with a he351 easy so ide like to use that, but what about a s475/96/1.32 or a s478/92/1.1 are those turbo's to big to mate with a he351?
 
phatboy07 said:
I was originally gonna stick my gt4294 under my 64/71/14, but i was told my 64 was too close in size to the gt42. And they wouldnt work rite together


-ViTO-
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I ran a 64/71/.8 over K31(similar to 4294) for quite a while and it was an excellent towing setup. Ran cooler than my old 35/3b setup.
 
phatboy07 said:
I was originally gonna stick my gt4294 under my 64/71/14, but i was told my 64 was too close in size to the gt42. And they wouldnt work rite together


-ViTO-
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Yeah, I heard the same stuff. However, I swear that 71mm garrett works as nice as any box stock S475, but with quicker spool up.

From what I've learned from some of the biggest turbo builders, is you want your primary to be 30% bigger than your secondary.
 
chevy_man said:
How far apart on sizes from the two turbos are normally the best, oviously too close to the same size you wont get the true benefit from them on low and high range, but to far apart and it wont be right either. Sorry if the way i asked the question is hard to follow. Im planning on doing twins this winter, and i can come up with a he351 easy so ide like to use that, but what about a s475/96/1.32 or a s478/92/1.1 are those turbo's to big to mate with a he351?
Click to expand...

I'd use the s478/92/1.1. It'll light faster and flow more. We used one of these over a S358 and it runs awesome!
 
DieselWrencher said:
I'd use the s478/92/1.1. It'll light faster and flow more. We used one of these over a S358 and it runs awesome!
Click to expand...

ok, thats kind of what i was leaning toward. Ive heard spool up is basically the same as the s475 although with more flow, so it only makes since.
 
DieselWrencher said:
Yeah, I heard the same stuff. However, I swear that 71mm garrett works as nice as any box stock S475, but with quicker spool up.

From what I've learned from some of the biggest turbo builders, is you want your primary to be 30% bigger than your secondary.
Click to expand...

30% bigger in what way? Compressor? Turbine? Flow capabilities?
 
Jim Fulmer said:
I'd stay away from HX turbo's if your going from scratch, 35's are tough but a baseline S300 is a better design and a 475 is a great bottom turbo.....this will make (not support) some big HP too, don't sell it short!

Jim
Click to expand...

How would that setup work for a CR?
 
Total mass flow is determined by the primary. The secondary provides flow in the lower rpms for quick spool up and can also recompress the primary flow if sized correctly. I would size the primary according to your fuel.

Sent from my LG-P930 using Tapatalk 2
 
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