hey guys im getting new housings for my twins.
this is my setup hx35/40 hybrid over a garret ht3b

this is what i wanted to do. 18cm top 22cm bottom. but hammer wont get back to me on the 22cm housing he has for sale. so i guess i have to throw that out.


so now what i can get is . 18cm top, 26cm bottom.
the 26 cm is called the "quick spooling housing"
but im afraid that if i go bigger on my big turbo.
the 18cm will be to slow spooling on my hybrid.
but i can find a 16 anywhere for sale
not to metion for a good price.
what do you all think

 

use the 26 on the bottom, if you don't wanna fool with a external wastegate use a 16cm on the 35/40. If you can use a ex gate try and find a 14 or the 12cm housing. quick spooling and use the gate to get it out of the way

 

ok ill get the 26cm on the bottom. so do you think i should just keep my 12cm housing and put on the external gate?

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also to add, the reason im changing the housing on the 35/40 is for drive pressure.
i want to save my headgasket. and to keep my egts from going through the roof like they already are. im gunna run with a 38mm external gate. so im gunna keep my 12cm housing. unless i can find a 14cm non gated for a decent price. anyone got one? thanks

 

if you are running enough fuel for compound turbos i think a 14cm non gated would still be to small.

 

I think you should keep you 12cm housing mod the internal wastegate and run your 38 mm external wastegate as well. If you don't like it you can always change housings later down the road.

 

i would run the 26 over a 14cm housing gated would be good but not necessary, your gonna get driver pressure spikes no matter what, but it should not be that high with that setup, its tried and true. You will just wanna mod the gated housing to improve flow, these old school twins are just that old school and are good for towing and making a moderate but solid 500hp, just dont expect alot more than that without getting what you dont want. You might wanna try and get an s400 on the bottom that will help for sure, if you are after more power and lower egt's and not a towing friendly setup.

 

ok, what do i need to do to the 12cm housing

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i think i want to keep my 12 and mod it, i can tune the wastegate so it keep enough pressure in the manifold to keep that hybrid spoolin, but not alot to have the egts high, and then all that will go to the big charger to keep that going.

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i also want to include that my goal is not a super high hp truck. id rather have my setup be a more daily driver/towing friendly one. than a super high horsepower. i know im getting the 26cm for the botttom. all im trying ti figure out is the best way to get the drive pressure out of my manifold away from my hybrid to lower egts. i think the external gate dumping into the hotpipe will do the trick.

 

Drill out the divider so all 6 cylinders are vented. You can also take the cover off the wastegate and unhook it. Flip up the valves and drill out the holes so the flapper just covers them. This will vent more air through the gate.

 

you gotta make the hole in the wastegate just a bit smaller than the flapper so it will flow the maximum it can, having a divorced gate that dumps directly into the hotpipe will help and keep the flow from being disrupted. The 26 will help alot especially if you are running a 32 on it now.

DD

 

yeah the 32s slow. and it still whitles accelerating. i cant wait for the 26!!
garrets are by far the loudest turbos imo. look at the 38r ball bearing. its an upgrade for the 7.3l powerstroke. they sound awesome.
so i should bore out the wastegate in the housing so its just barly small than the flapper? and cut out the divider in the turbo and the exhaust manifold? or just the turbo?
thanks