1990 Exhaust Housing?

[BILTIT]

With a standard trans i think its been found anything over a 14 housing is too big.

[Hansen01]

hmm ok thanks, may have to try that also if i ever come accross one

[delinquent]

It may be personal opinion, but I have never found a 18.5 laggy, or even a 21cm to be laggy. Every truck I have put a smaller housing on has seemed to choke bad on the top end, and imo it ain't worth it. I'd take a 18.5 or 21 over a 12 anyday.

[thrashingcows]

It may be personal opinion, but I have never found a 18.5 laggy, or even a 21cm to be laggy. Every truck I have put a smaller housing on has seemed to choke bad on the top end, and imo it ain't worth it. I'd take a 18.5 or 21 over a 12 anyday.

Yeah I wonder about the top end as well with a switch to the HX35 with the 12cm housing. Guess I'll see if I like it or not once I swap. Guess there is always a 14cm or 16cm housing you could try as well.

Where these manual or auto?

[delinquent]

Both, I have. Its really appearant (sp?) on the autos imo

[Douglas]

hey-Hey!!!,
I have a 24V's HX35 on my 1990 with a 16cm housing. Lag is not bad at all. Now I would make a distinction between time it takes to build boost and the rpm at which it will make boost. Both are lower than with the OE housing( on a late 1990 it happened to be a 21 ). Time to make available boost at what ever rpm it happens to be at is pretty darn small. The 16 builds more boost lower( or at least if feels like that based on the pull/acceleration ) than the 21's for sure.

I put a spigot on the HX35 and made a 3" cross over pipe.
cheers,
Douglas

[Hansen01]

anyone got any opinions going from a 12 to say a 14 or a 16? or which one would be better for egts and spoolup

[Tacoclaw]

Honestly, unless you're towing at 2500rpm or higher, I just don't see the 12cm being a problem. It will spool fast and keep EGTs down while getting things moving, especially with a stick, and it can't be that much of a restriction up top. My cousin has a 24v, I know apples to oranges but he tows with no EGT problems whatsoever. All that truck has is a stock HX35 and one of those edge things and I've never seen it go above 1050*, even on the high setting.

If you don't have an intercooler, no amount of turbo band-aiding is going to lower your EGTs. Opening your turbine housing might let your engine breathe up top, but it's going to have a negative effect throughout the whole other RPM range. You could try to open up your wastegate hole some, but even then it's still a bandaid for a work truck.

What kind of boost numbers are you seeing with your H1C and the 12cm housing?

*editing post* Reread the entire thread again.

[Hansen01]

i have and have had the hx-35 with the 12cm on for a while, i recently got the intercooler in it, and could still hit 1400 degrees by the time i hit 80mph without a trailer, now with a trailer if i want to get up to speed in a resonable time even with the power screw backed out almost 2 turns it still hits 1400 degrees like cake, (24000lbs all together)
now i also got the head gone threw about a month ago, and he said it should lower my egts a little bit also, but havnt had a chance to really get on it as i just got my head tightened down good(head studs)
also 35lbs of boost with pump almost at runaway about 30lbs where it sets now
nv5600 with 4:11 gears

[Hansen01]

also thanks for all the suggestions and ideas guys

[Tacoclaw]

I was going to edit my post, but I'll let it stand as a monument to stupidity.

It's been so long that I can't remember how my H1C ran before. I had an 18cm housing, but I also had an auto with a stock converter back then. I've got a stick and twins now so it's a little different.

I'm gonna go back through my old posts and see if I can find anything that is a decent comparison to my H1C with the 18cm and the S300 with a 12cm housing.


The S300 has a larger compressor, but a smaller exhaust housing. You would think it would choke off worse...

Also, is your truck making that boost with the wastegate hooked up?

[Hansen01]

my waste gate has a bracket on it so it stays shut, was making 40 affor i put the intercooler in it, (jus to say that my waste gate is not opening and keeping me from having more air)

[Tacoclaw]

Wellll, letting it function again would help out on top end. Tighten it up so it doesn't even crack until 30psi, and give that a shot. I wouldn't let it open much earlier, or it's not going to be any better than a bigger housing. It will relieve drive pressure up top when it's functioning.

Also, found this from a while ago:

Mine is a 62/65/12, and if I had to guess I'd say it spools a tiny bit slower than the stock H1C did. If it actually does, it's not by much, but I haven't had the baby on there for a good while now so I can't really remember how it spooled.

I've got a 'Rag to put in so hopefully the 12cm housing starts to show it's worth. With the auto, I can just peg out my 1500* pyro in a good top end run.

I forgot about the baby the second I put that S300 on there. FWIW, my gauge only read to 1300*.


You can try out the bigger housings, but I don't think you're going to find the results you're looking for with them. On the plus side, they are a pretty easy swap.

[Hansen01]

so put the wastegate on, how does that help when it starts to release pressure?? i believe you, jus dont quite understand that lol
so you have an s300 and noticed a good drop? ive been thinking about that option, just dont have 6,7 hundred bucks to spend on another turbo,lol
there for a while i thought i had something wrong with the whole truck, but have checked everything and am back to turbos

[Hansen01]

maybe an he351? anyone here have experiences with that turbo?