2G Holset HX35 14cm

[jmt2028]

Does anyone have any information of the flow, spoolability, and power band of a Holset HX35 turbo. I am looking to buy a HX35 for my current build (2g dsm early 7bolt) but a I am having a hard time finding a 12cm housing but I have found a 14cm housing HX35 set up for external wastegate. Turbo is 8+8 54mm inducer/83mm exducer compressor, 60mm inducer/70mm exducer turbine, 14cm housing T3 twin scroll with 3" v-band outlet with anti surge compressor inlet. My car has all supporting mods, forge internals, recently polished crank with block decked and honed. Completely upgraded valve train. DSM Link. SMIM with s90 70mm throttle body. T3 twin scroll exhaust manifold from CCDesigns. Wahlbro 255 and 950cc injectors, including methanol injection. I plan on running kelford 264/260 cams to keep the car more streetable. My goal is 500hp give or take, it wont be a constant daily driver but it will be driven often so I want it to be very streetable with quick spool up and decent power band. I am interested in peoples thoughts on the HX35 with 14cm housing for this application, any input is greatly appreciated.

 

[1990TSIAWDTALON]

In a T3 twin scroll housing, it will spool early. I can't remember when my son's 97 TSI spooled, but MUCH earlier than my HX40 in an open T3 housing. The are a pretty friendly turbo and will wake that car up! I am thinking around 3k was when it woke up. Mine is much later than that.

 

[jmt2028]

That's awesome thank you for your input! Do you recall if the turbo was a 14cm turbine housing or a 12cm? Do you know what size the compressor wheel was on it? I am having the hardest time finding the 12cm I am looking for but I found a 14cm for a good price so I am trying to figure out the top end gains from the 14 vs the 12 and if I will lose a few hundred rpms in the low end of when the spool kicks in. I think with my set up though I will be good with good spool and good power.

 

[1990TSIAWDTALON]

I can ask my son when he gets off work tonight and let you know what he had. He has an Audi RS3 now (9 second 4 door sedan)
I'll hit him up on what specs he remembers.
Marty

 

[jmt2028]

Awesome, thank you so much I appreciate that. Its amazing on how much power you can download into newer Audi's and BMW's.

 

[1990TSIAWDTALON]

He still has both of his DSM's, one JUST LIKE YOURS but in primer black and a 97 TSI that is purple. Both are pretty nice cars and I hope he keeps them since THEY are paid for and I build the motors for him, .

 

[1990TSIAWDTALON]

I got ahold of my aon and here is his reply:

"I had a VERY hard to find, oem holset 12cm^2 hotside with twin scroll t3 flange and 2.5" vband discharge.

I bought a brand new oem NOS turbocharger (wasnt a hx35) for $400, removed the hotside and put it on my hx35. Justin whitesell told me what all hotsides would interchange and even helped me find it. So may ask him too'

I hope that helps in some way. He didn't answer about the spool so I will ask him about that later, since he is still at work.

 

[jmt2028]

Yes that is helpful, thank you so much for the information. My car is a 1995 Eagle Talon Tsi early 7 bolt 4g63 and I too love it because its paid for. It ran great before I pulled the motor but I decided it was time to take it to the next level! I've slowly been piecing it together and the specific turbo I am looking for is proving to be the most difficult part to find right now so I think I might settle for the 14cm housing thats available to me. Ideally I want a 12cm T3 twin scroll with 54mm inducer/78mm exducer compressor wheel with a 2.5" vband hotside but I cant find one. I have a found a few shipping out if Poland in Europe but I am suspicious to buy versus buying from a legit dealer in the states.

 

[llxkevinxll]

Here is a post from last year I made regarding how the HX35 works in the 12cm housing paired with a TS 12cm exhaust manifold.

https://www.dsmtuners.com/threads/holset-turbos-in-2023.545377/#post-153901651

 

[jmt2028]

That is awesome, thank you very much for that info!

 

[jmt2028]

I decided to go with the Holset HX35 that was available to me. I was able to pick it up from a reputable surplus dealer for $600. I believe it is a 14cm but I have read mixed articles on the part numbers on whether it is a 14cm or a 12cm turbine housing. Holset part number is 4036370. 8 +8 blade compressor wheel with 12 blade turbine wheel. 54mm ind/83mm exd compressor, 70mm ind/60mm exd turbine. Compressor wheel part number is 3599594, turbine wheel part number is 3595832. It is non v-band compressor housing but with anti surge. I believe 3" v-band exhaust exit on the turbine housing, TD03 twin scroll. Turbine housing part number is 3536830 which cross references with part number 3537021 on turbomaster.info, all part number data came from turbomaster.info. I will run the turbo with a T3 twin scroll manifold already purchased from ccdesigns. Super excited to keep moving forward with this build. If I get 450hp with good spool out of it on 93 pump gas with methanol then I will be happy but I'm really hoping to break 500 with a good tune from Rix Racing.

 

[1990TSIAWDTALON]

You're gonna like it

 

[CrackedDSM]

Beans(either BeansTSI or BeansDSM or some variation) here on the forum had a 14CM and 16CM twinscroll HX40 setup. I know it's not an HX35 like you asked, but he recorded spectacular spool up on those housings using a quality RedJackRacing TS manifold. Such good spool up, he was able to stall up/brake boost on the STOCK 1G converter. To put it in perspective, a 20G will struggle to get up on a stock 1G converter, but his big ass HX40 with no nitrous did the job.

So on an HX35 I'd expect similar results, obviously erring on the side of faster spool. There's posts he made where he outlines spool numbers and when he sees what boost.

 

[1990TSIAWDTALON]

I wish I had a twin scroll for my auto HX40 car. They really do a good job set up like that. I have a stock Holset twin scroll housing but that SOB must weigh 40lbs. It's HEAVY and has a WG on it so not for my use. A TS T3 or T4 would help me get out of the hole so much better.

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[jmt2028]

1990 TSI, that thing looks super heavy! CrackedDSM, thank you very much for that info! I am stoked all around! I am super excited to finish my build but one pay check at a time for now . I thought about going 2.1 stroker on it using a 94mm crank with 150mm rods and stroker pistons to match but I did not have my block bored at all, just a light hone for new pistons and rings, but my stock crank is in great condition and I had it polished when I had my block hot tanked, decked, and honed so I am going to stick with the standard bore and the 2.0 set up for now. Local machine to me does great work for a great price. I also purchased Kelford 264/260 cams today because I was able to get a brand new set for $300. I think with the cam set up and the twin scroll holset set up I will have good low end through mid range power. I don't ever plan on running it out to 8000 rpms as it will be a daily driver for me and will most likely never see a track, hence why I thought about going stroker with it but at this point in time I just cant justify spending the extra money on a new stroker crankshaft. I appreciate everyone's input so far, the DSM community is awesome!