holset small h1c questions?

[90tsi6bolt]

I recently purchased a used holset small h1c that needed a rebuild. I have a couple wuestions . should I stay with the 16cm twin scroll hotside or would it better to go bep hx35? ( if it will fit in the housing)? What power goals can I see from this turbo. I don't want it to take forever to spool. my gsx is still driven regularly.

 

[bastarddsm]

i would definitely run the bolt on housing. It's the quickest spooling housing, and won't be a restriction for the small wheel.

 

[90tsi6bolt]

Also what kind of boost press can I see from this turbo any gain from a small 16g

 

[JusMX141]

Depends what you mean by "Small" H1C. There are some with smaller compressor wheels than a 20G....if that's the case, you're going to go through a lot of work getting it on the car to see a minimal gain in performance over a Small 16G.

 

[90tsi6bolt]

This one is a little bigger than a 20g wheel

 

[JusMX141]

Tells us nothing- wheel specs are needed in order to give you an idea of what it's capable of.

 

[bastarddsm]

I'd assume this woud be good to make 400whp, nearing 500 if you push it, and your tune is solid.

 

[Phantom DSM]

This one is a little bigger than a 20g wheel

Please don't say its the baby h1c 45mm
The big H1c 54 mm came with 18cm2 housing and flowed about 49 lb/min, barley putting it over a 20g in comparison.
Do you have a serial number or meaurements ?

 

[90tsi6bolt]

Nothing I can really see on the comp side there are some things on the exh side the plate was removed previously to me getting turbo

 

[Phantom DSM]

Hmm some measurements would help, or pic too.. ^^Justin is the man on this one.

 

[90tsi6bolt]

here are a couple quick pics I took of it. like I said plate was removed before I bought turbo. I believe it says 16 on both sides of the twin scroll cant really make it out tho. and pic didn't come out good.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

 

[lasthope05]

here are a couple quick pics I took of it. like I said plate was removed before I bought turbo. I believe it says 16 on both sides of the twin scroll cant really make it out tho. and pic didn't come out good.

Correct me if I'm wrong, but I don't think that's a h1c. I thought the h1c and h1e both came in vband compressor covers. Plus that compressor cover looks tiny.

 

[Breezio69]

I thought the 8 blade h1c was the larger turbo, almost same flow as the hx35. And the 7 blade is the smaller of the two, off of a non intercooled early 90's dodge.

EDITED- Belive it or not... this article was made right here on tuners, quick search would have identified it by blade count... here ya go

In 1994, there was the Wh1c which has pretty much the identical compressor as the hx35 but with a Vband compressor cover. The turbine wheel is the same. It will bolt into the BEP bolton hx35 turbine housing. It has 4 bolts at the housing instead of 6. So you will need to buy 2 more bolts and use 6 washers cut to make a flat side. Honestly, I just used bolts that were cut a little short and the bolt head was wide enough to pull the chra to the turbine housing. No sealing issues. Since the Wh1c is for all practical purposes an 8blade hx35 the spool and flow is the same too.#I have the big h1c. It comes on the INTERCOOLED 1991-1993 cummins pickups. It has the webbing for MWE but no groove cut like the hx35/wh1c has. This turbo I term the big h1c because it has a 54mm compressor inducer and same exducer than the 8blade hx35/Wh1c. The other h1c is the small h1c found on the NON-intercooled cummins pickups. This has a 50mm inducer but only 7blades and has no webbing for MWE. Less blades helps flow, but so does a larger inducer diameter. The most whp ever recorded on a gas 4cylinder with the#small h1c#was done on a KA24 nissan:#411whp. Since the big h1c has a 4mm larger inducer and the same turbine wheel as the hx35, it is safe to say that it flows enough for between 411whp and 500whp. The diesel sources state that it flows SLIGHTLY less than the early hx35. So 4lb/min less than the 8blade hx35 puts the flow of the big h1c at 48-49lb/min right where a 50-trim or 20g is. The small bep housing is all that's needed to get the most from the compressor and the spool speed is 20+psi by 3500rpms.

So to sum that up, the larger one is good for 400 hp, the smaller one... whatever you can get out of it.

 

[bastarddsm]

Big h1c is good for more than 500whp. Lil is a bolt on cover not v band good for at least 400whp.

 

[JusMX141]

Something's unusual about that turbo.

1) The compressor wheel looks much larger than any of that series of H1C I've seen with the small cover.

2) That version of H1C used on the earliest of Dodge Ram trucks should have had a 21cm2 turbine housing....yours is an 18cm2.

Not sure if it's from a completely-different application that I'm not aware of....perhaps something industrial, or it's been fondled / molested.

You must be logged in to view this image or video.

 

[90tsi6bolt]

I've searched pic on Google also and other web pages and came up same pics of the turbo with plate tho. I have to get a battery for my digital caliper to get measurements. Also I had the wheel off the turbo it did say h1c on the back of the wheelalso

 

[JusMX141]

Well there are a bunch of different H1C's which is why I was asking for wheel specs, but apparently I'm asking for too much.


The smallest of which had a 44 or 46mm inducer on a 7-blade compressor and came from non-intercooled 4BT engines and has an 18cm2 turbine housing. The next-larger had the same size cover as yours but had a 50mm 7-blade wheel and was found on non-intercooled 6BT's and has a 21cm2 housing.

Next step upward had a 50/83mm 8-blade wheel and had a much bigger diameter cover but still had a 3" inlet. Next step had a 54/83mm 8-blade wheel but jumped to a 4" inlet. Finally, the WH1C had a 56/83mm 8-blade wheel and was found only on intercooled 6BT applications...then the HX35 was born.


If I had to guess, it seems like you have the 50mm 7-blade Small H1C from a 6BT but someone installed a 4BT's 18cm2 turbine housing.

 

[90tsi6bolt]

Now there is no reason to be like that. Your not asking for to much but in my last post I stated need to get a battery for my digital caliper. But right now I'm playing with my children I will take measurements tomorrow and I post them up. Jusmx141 your the person to give me the info that's needed I'll get the measurements for you don't worry.And I'm not doubting you on how many diff size h1c's there are. Just know nothing about this turbo that's all.

 

[90tsi6bolt]

Ok took some measurements today forgot my caliper was at work its a 50mm inducer. Base of comp wheel is 70mm. Exh is 70mm at base and 60mm at tip. 3" inlet, that reduces to 50mm.

 

[bastarddsm]

I'd think on that your best bet would be to run a BEP bolt on housing, I'd wager you'll see 450whp at close to 30psi on E85 with a good setup.

 

[90tsi6bolt]

If I could find e85. Not a big e85 state. Haven't found any places that carry it out here

 

[JusMX141]

Ok took some measurements today forgot my caliper was at work its a 50mm inducer. Base of comp wheel is 70mm.

It's definitely a Small H1C from a non-intercooled 6BT....comparing these compressor specs to that to a 20G at 52.5mm/68mm, it's quite similar but has a larger turbine wheel which is beneficial for tuning purposes by reducing backpressure and lowering EGT's.

I think it's safe to say this is around a 45-46 lb/min compressor depending what boost level you plan on running.

 

[Phantom DSM]

It's definitely a Small H1C from a non-intercooled 6BT....comparing these compressor specs to that to a 20G at 52.5mm/68mm, it's quite similar but has a larger turbine wheel which is beneficial for tuning purposes by reducing backpressure and lowering EGT's.

I think it's safe to say this is around a 45-46 lb/min compressor depending what boost level you plan on running.

What about that compressor housing Justin You mentioned it looked odd, would that be the original one on small h1c's ? Its different from others i have seen.. You see more turbos than i ever will

 

[90tsi6bolt]

Ok. Boost press maybe 20-25psi if can push that much. Looking for a goal of over 350hp. If it will produce that. What could it produce in your opinion justin.?

 

[JusMX141]

What about that compressor housing Justin You mentioned it looked odd, would that be the original one on small h1c's ? Its different from others i have seen.. You see more turbos than i ever will

I wasn't talking about the compressor housing as much as the wheel....the turbine housing on this turbo wasn't the one that came on it from Holset. The compressor cover is just a standard Small H1 cover.

Ok. Boost press maybe 20-25psi if can push that much. Looking for a goal of over 350hp. If it will produce that. What could it produce in your opinion justin.?

It will produce 45-46 lb/min of airflow. Whatever your setup can do with that in order to translate it into horsepower is up to you, not the turbo.