okay guys, so first off I know this isn’t the best choice for a ls engine but I got a decent deal on it (imo). The h1c came off first gen cummins. its the predecessor of the hx35 I think it flows slightly less. but I’m curious how much more quicker this would spool if I swapped over to a 12cm non gated housing vs the 18cm? I want to say it comes on the smaller of the two h1c’s.
sorry for the double post. I do know that they are twin scroll turbos to but can be treated as regular turbos long as the manifold port matches that of the housing but obviously a twin scroll would be the best. is it possible to make 300whp at a reasonable psi with the reduced housing or is the housing still too large for it to spool up sooner then later? in the sense that I’m not even hitting full boost by 6.5k or 7000 rpms? I would like to see full boost by 5 to 6000 rpms. I don’t want something out of this world fast. I’m just looking for some direction and I feel as though this is the place to do it and yes I’ve looked through a bunch of pages of the “holset users unite” thread on HT.
I ran an 18cm baby H1C on my ls/vtec very briefly. The baby H1C only has a 50mm compressor inducer. There are an 18cm (manual truck) and a 21cm (auto truck) exhaust housing. They are both large and laggy. If you have a regular H1C with the ~54mm compressor inducer IIRC then try and find a smaller exhaust housing and it’s a decent charger extremely comparable to an hx35. If you have a baby H1C then sell it and find something better IMO. As a note the hx35 exhaust housing will fit the H1C but it’s not quite the right size. It works and is still an improvement but isn’t quite right but does sound interesting. I made that error on my 92 Cummins and it sounded like a 6.0L Powerstroke at idle.
Well I’ve been talking to theshodan over on ht and Tim’s turbos sells a 9cm housing for the h1c. He told me that if I swap housings it would be comparaple to a older Garrett t3/to4e 50 trim so that’s what I more then likely will do. I got it for a decent price and it’s brand new so I’m going to try and work with it. I know the baby h1c made 411whp on a ka24de I want to say. I’m just shooting for 300whp on a built bottom end/stock head with arps headstuds. Just want to build a somewhat reliable weekend car. But thanks man
Sounds like you’ve got it figured. That 9cm will spool good and the charger will barely be working at 300whp, good combo.
thanks boss