Engine/Transmission (1994 - 1998) will a 16cm housing be good for me?

[Forrest Nearing]

with the wastegate line pinched on my stock HX35w12, I can swing the needle past 42psi. currently got it set at ~35psi.



I can keep EGT's in check alright, but it feels like the 12cm housing is really choking off the engine at higher RPM, and I'd like to slide the plate forward a little... basicly just looking for MORE without spending too much...



I've got a buddy who's got a 16cm wastegated housing that he'll trade me for my 12cm.



going by pastor Bob's rule of thumb that every step in turbine housing size roughly equals 2-3psi, I should still be able to make 35psi (and then some if I slide the plate!) with the 16cm.



if there are any holes in my reasoning, please poke them before I make a mistake!!



thanks in advance,



Forrest

 

[Smokin Dodge]

You should be fine with the 16 cm housing, cruising temps may be a little higher but they wont rise as fast.

 

[1dslram]

The 16cm housing is a great choice and when you need more air you can add a HX40 compressor housing and 60cm pinwheel. To keep the HX35 in one piece we need to keep max boost at 35# or less.

Bruce



R. I. P. Nowel

 

[Deezul1]

Thats a good trade, if you dont want it I have a 12cm that I will swap. It will work well for you.

 

[BushWakr - RIP]

Forrest,



I'm not sure if I was missunderstood or whatever but.....

Let me base my statement using all none gated housings to keep things on the same basis... .

All things being equal, if you are running an upper boost value of say 35psi with a 12cm, then the step up to a 16cm (two housing sizes bigger) will result in 2-3 psi LESS boost for each housing upward you go.

So the example of a 12cm compared to a 16cm would show approximately 4-6psi less total boost or roughly 29-30psi.

This is not necessarily bad, it simply means you will have cooler boost with better upper end performance such as on the highway.

Taking a quote from Joe D. the upper end performance of a 16cm housing is almost indestinguishable from an 18. 5cm but will have better spoolup. .

The bottom end spooling may suffer slightly but normally you can "tune" some of that out a bit...

Does that help??? Clear as mud



Pastor bob

 

[Forrest Nearing]

Bob, with the wastegate line pinched and no bleed (essentially disabling the wastegate), I've seen 42psi and climbing with the 12cm housing... I've got it gated to 35 right now...



I figure two housing sizes roughly equals 4-6psi... 42 - 6 = 36... and that's just with my current fueling. I'm looking to slide the plate forward some. so I figure I'll still be able to see 35+ with no problem.



I realize I really need more compressor, but I'm hoping a bigger turbine housing will allow me to cheat a little more power out of it... (or at least be able to stay in it a little longer! )



looks like I'm gonna do the trade!



Forrest

 

[Sled Puller]

Back in the day, I loved my 16 housing, with a #5, 191dvs and 370 injectors. It gave a touch of lag on the bottom end, just about enough to get the clutch hooked, and hit hard at 1800 rpm.



I think I was maxing out at about 36psi. Temps were never a problem, and you may see a slight mileage increase.



Dropping a few psi to make your engine more efficient, is definately a good thing.

 

[Smokin Dodge]

When I went from a 12cm to an 18cm housing I went from making 48-50 to 38-40 lbs of boost and egts where still way to high at wot with either but they didnt rise near as fast with the 18 and way more lag-smoke.