The reason I ask is that Steeve Wright from Gillett Diesel Service stated that there is no 50mm H1C compressor availible that has a Map Width Enhancement slot. I am on my fifth turbo combination, and still think I should be able to get better drivability than Im getting with the larger units. I have run H1C 46mm/16cm3, H1C 46mm/12cm3, H1C 54mm/12cm3, HE351CW 62mm/9cm3, and the current HY35W 54mm/9cm3, all non wastegated. The best overall was the H1C 46mm/12cm3, very quick to spool with good egt's. All the others are slow to spool, with fast rising egt's, peaking about 150-300 degrees hotter. The current HY35W seems to have late spool up, right before the 9cm3 exhaust housing chokes. If I had a way to run a very progressive and adjustable wastegate, and if the power came on sooner, the HY35W would be great, but not in its present form. I think the H1C 50mm/12cm3 non wastegated would be perfect, save for the possible surge concern. I know the 46mm will slightly surge only on quick closed throttle decel, and the H1C 54mm surges HORRIBLE past 1800rpm. And, with the units I have right now, I dont even have a good canidate set for twins, the bigger fronts are on the smaller rears, and I baerly have enough room for 1 turbo, let alone 2. Any thoughts or suggestions would be greatly appreciated. Thanks.

 

Get in touch with Swank, I know he cut an MWE slot on an H1C.

 

Wow! It seems you may be over-thinking this a bit...I'd guess a WH1C/HY35W cold side housing paired with a 12cm w/functioning wastegate would do everything you're looking for...what say you wanna, isn't that basically the setup you run? They both have the MWE slots already. I simply replaced my stock H1C(54 or 56mm, I can't remember?) with the WH1C housing, and have yet to install the 12cm exhaust, and though it seems a bit more responsive(but probably really isn't - yet), it certainly should after the 12cm is on!! Actually I'm holding out for a 14 or 16cm non-wastegate to replace the 21(here we go again...anyone for a trade of my 12cm?) as I would prefer not to modify the dp.
One thing it DID do is create a nice turbo !

 

The H1 and HY housings are not intechangeable, if they were, I would have already tried the possible combinations. I am looking to go 2 to 4mm larger in the compressor wheel and housing, and keep my exhaust housing, which is what you did. The first gen intercooled compressors were 54mm and the WH1C was 56mm, = 2mm larger. I am currently 8mm larger, which works out to be to large for good power delivery, and 16mm larger(62mm HE351CW) is totaly worthless for my current setup. Anyone have any specs on the HX30? Or think a Garrett T3 with a 46mm/.60 A/R front and around a 10cm3/.48 A/R rear will work as a first stage for twins? I will figure out how to put a hood on it after I see how well the two turbos run.

 

Any good machine shop should do it. I had a friend do mine. Just make sure they go slow. On mine when the tool just started to get through, it hit one of the webs on the other side and broke the tool tip off in the slot. Since the slot was there but not through, I finnished it with a dremmel and a 1-1/4" cut off wheel. (well, a few wheels)
The slot works real good, no surging- and the sound....