Ok, we have a lot of variety of exhaust housings for out little HX35's and
WH1C's. There is the 12cm wastegated, 12cm non gated, 14cm non gated, 14cm gated, 16cm non gated, 18.5cm non gated, and 21cm non gated. I have ran the stock 12cm wategated housing, and the 16cm non wastegated. I noticed a little faster spool with the 12cm, but not much, and the power is a little more linear. Honestly, I like how the power comes on with the 16cm better. It is a little laggier, but it comes on hard when it spools. Its just not as linear feeling. Im curious. I know that a smaller housing is going to be better for spoolup no matter the conditions. What im curious about, is what is better for the most power? I know that most say the 14cm wastegated is the best all around housing, but would a 16 or 18.5, be best for all around power and EGT's if you can live with the spoolup? With the wastegate you are bypassing some of the exhaust gasses around the exhaust wheel, where with a bigger housing you are using all of it, but your boost will be a little lower anyways because you arent spinning the shaft as fast. The only alternative to lowering the boost is either with a wastegate of some kind, or going with a bigger housing. I wonder if an 18.5cm housing would be better than a 14cm wastegated for say 400hp? I know the 18.5cm will spool slower, but I feel like it will be plenty driveable. I am making about 38psi with my 16cm housing right now, and my EGT's pretty much stay in check pretty well. Im pretty happy with the 16cm housing so far. So, im probably going to be throwing some New Era 370's in my truck pretty soon, and I have an 18.5cm housing sitting in the shop. Would I be better to switch to it to control boost, or run my old 12cm and wastegate it at 36psi or so? What is going to be best for EGT control and power. Just got to thinking, and figured id throw this stuff out there.

Eric

 

Hey, I am fairly sure Wannadiesel said that the 14cm w/g was a waste of money for his 1st gen as that housing is fairly expensive and wasn't worth the gain/to cost. As far as the other ones, I think you have them down pretty good as there uses.

 

I'm looking into the same , I've got the WH1C , I do not know what got my truck to the HP & TQ ratings that are in my sig. bought off a used car lot that had it listed here , the only thing that I could see that wasn't stock is a K&N stock box filter , smoke screw all the way , it should have more HP & TQ , but the TQ conv. would come out the last 2 dyno's , then I put in the stuff in the sig. .
I am planning on about 350-400 HP depending on how some more mods blend , one of witch is , a change in the turbo or parts , elbow to get a true 4" [ but that brings some ideas about , will that reduce the gas's turning the ex. turbine ] .
With whats in your sig. and post I would wander if an after market turbo would be the next mod , especially with the 370s , you did not mention where you were going HP wise , I would expect more HP & TQ than whats in you sig. than you are at now .

 

I ran an 18.5cm on a 97' 5spd. truck with a #10 plate & it was plenty driveable, & cooled very well loaded on the interstate, the pyro seemed to spike a bit higher going through the gears vs. the 12cm just from the lag, but that won't be an issue with your auto, after I got the turbo spooled with a load & got in high gear it done really surprisingly well as far as cooling, you may wanna give it a try???? couldn't hurt since you already have one laying around, let us know if you try it!! Dusty

 

Yeah, those numbers are with stock injectors and delivery valves. Im guessing im at 330hp/750tq or so now with the stock injectors and delivery valves from a 96 truck.

On the housings. I also dont see how a 14cm wastegated housing could possibly be worth the money. I think ill see what the 16 is like when I put the injectors in, and then I may try the 18.5cm housing. Yes, most people tell me I should just go ahead, and get a bigger turbo, but I have other plans. I want to pull in the stock turbo classes, so i plan to hybrid my turbo, run a helix 2 or piers custom grind cam, port my head,advance the timing some more, and get an HTT manifold. Thats the plan for now at least, and it will still be about as cheap as a SPS62 or something similar, and if I want to put a bigger turbo on it then, then it will really flow the air . I may end up with a bigger turbo, but it depends on what my temps are looking like after I do the 370's and a hybrid turbo probably. They are hard to get hot right now.

Soo, anyone tried a 14cm wastegated?

Eric

 

Hmmm, I'm not at all versed on the new-eras, but my weenie lil' 1st gen will blow a hole in my 40psi boost gauge with the 18.5 on so my guess is that you will not be able to control boost with the new sticks. Mid to high 30's is already pushing the MAP of the 35. Here's what I did to my 12 to keep from overcoming the 'gate:


compared to the 18.5:


I also enlarged the wastegate hole to nearly the diameter of the flapper. I can give her heck at 1600 rpms in 5th and boost jumps to 30 and sits there

Bottom line IMO: If you can control boost with a larger, non gated housing, run it, especially with an auto. But, with the fuel you're planning, I think you're going to need some sort of 'gate...