Garrett GT2860RS vs Holset HY35

[TiZiK]

Been running the Holset up to this point and haven't reached its full potential as I haven't had a chance to get it on the dyno and see how well it works (or doesn't work).

Ill be picking up a ported cylinder head with oversize valves soon and that seller also has the Garrett GT2860RS.  

I know the Garrett is good up to ~350hp and spools quick and the Holset is good for 450+.  Without a proper tune/set-up, I'm not sure how well the Holset ACTUALLY works in regards to spool/power curve etc.

You guys have any input on either of these and how they compare to each other when ran on an oil cooled?

[Arttu]

I don't have any comparison data from these two. Closest pair that I can offer is Holset HX35 and Garrett GT2871R on Busa engines. There the Garrett spooled up slightly earlier and probably made a bit more power at the same boost (~1 bar boost, 300-350hp).

So I think it's quite safe to predict that the GT2860RS will spool up earlier and be more responsive compared to the HY35. And most likely it's overrall better choice when staying under 350hp power. But it's difficult to say how big the difference will be.

[Gixer1460]

A very simplified approach would say - how many Holset turbos do you see used against Garretts at the drag strip?

[Jdeac]

On 2/22/2023 at 1:30 PM, Gixer1460 said:

A very simplified approach would say - how many Holset turbos do you see used against Garretts at the drag strip?

And the answer to this is?? Ran at a few events last year. But not so many turbo bikes. Curious

Edited February 27, 2023 by Jdeac

[TiZiK]

On 2/22/2023 at 3:00 AM, Gixer1460 said:

A very simplified approach would say - how many Holset turbos do you see used against Garretts at the drag strip?

I get what you're saying but that is probably mostly due to Garrett being such a mainstream brand name.  Holsets are mostly regarded as heavy commercial turbos and although the heavy part is correct, their wheel technology is up there with, if not better than, Garrett.  They've produced turbos for Indy cars even, but I'm not trying to discuss which is the better brand.  They're both really good at the end of the day.

I was just wondering if anyone has used either and what their results were.

Granted, the Holset in question is a larger turbo than the disco potato.  The 9cm^ turbine housing on the Holset is close to a .65 A/R and I think the Garrett is a .48 A/R.  The Holset compressor side is also massive in comparison moving appx 500 cfm.  

I started this thread as I may have the opportunity to grab a new GT2860RS but the specs I have read has it maxing out at the bottom end of my target HP with the Holset.  Just looking for some real world feedback when mounted to an oil boiler.

If anyone cares for a bit of reading on the Holsets, Stav out of the Uk is a big fan of them and has done a superb write up.  Compressor Racing, also out of the UK, sells them as well.  They currently have HYs with a 7cm^ housing for £500 and is an absolute beast of a turbo.  Super fast spool and 450+HP capability.

http://www.stavtech.co.uk/home/the-ultimate-holset-turbo-guide-probably

 

[TiZiK]

Decided to stay with the Holset. Managed to get my hands on a rare(ish) 7cm turbine housing. 

Should lower spool and keep me in the turbos efficiently zone over a wider rpm spread. 
 

Guys with 1.6L report seeing positive pressure by 2500rpm and full boost (20psi +) by 3300. 
Should work well with the 1316. 

[TiZiK]

Top picture is the 7cm housing. 
Bottom picture is the 9cm. 

7cm housing retains original turbine wheel and is a straight swap. 

Edited March 24, 2023 by TiZiK

[Jdeac]

I've been looking and keep looking. And researching turbo snails

What sort of bearings do these holesets use?? 

Found a UK supplier with he221w 7cm for around £250 isj

[TiZiK]

4 minutes ago, Jdeac said:

I've been looking and keep looking. And researching turbo snails

What sort of bearings do these holesets use?? 

Found a UK supplier with he221w 7cm for around £250 isj

Journel. But don’t be fooled. Holsets have some of the best wheel designs. They’re also one of, if not THE, largest turbo manufacturer in the world. 
 

read the link I posted above to Stavs site

[Jdeac]

I have read the link you posted. Thanks by the way.

Everytime I try to sort turbo parts for my build. It don't work. Had the warp speed manifold that @clivegtonow has. Got a second hand pete kit. But that hits the tyre on almost full compression. (Was made for a bandit i believe). Think i nead to have loopy make one or someone else. But i struggle with what turbo to use.

[Jdeac]

[TiZiK]

Ya, if you’re doing a slabby, it’s tight up front. The switch in housings has me re-doing my headers. 9cm was t3 and 7cm is t2. 
 

I had to cut the cross brace off the front of the frame 

[Jdeac]

It's not a slabby. But I'm just not sure what turbo to use with the engine spec. And every manifold I find/buy I have clearance issues. The above pic is a tdo4 something! Don't really want to cut the frame!!! Well any more 

[clivegto]

30 minutes ago, Jdeac said:

 

Found a UK supplier with he221w 7cm 

Going down this route myself I am thinking after reading bits about it.

[TiZiK]

My compressor side is pretty big and it really only fits in one spot. That’s why the cross member had to go. This is gonna be a drag bike only tho so I’m not worried. 
I’m also using a front end off an 01 R6. It has a much larger offset helping to gain a bit more clearance up front. 
 

I was weary of spending money for off the shelf headers so just made my own. Tedious, but worth it. I just tacked it up and brought it to a welder for final welding.  Guaranteed to fit this way. 
 

I know the UK has a few places to just bring your bike but no such place here in canada. Not for these old school bikes anyhow. 

[TiZiK]

Just now, clivegto said:

Going down this route myself I am thinking after reading bits about it.

Holsets are sooooo underrated. Maybe cause they were never mentioned in Fast and Furious. Lol 

 

[Jdeac]

I get what your saying. Little harder for some people though!!

[TiZiK]

Oh trust me, was not easy. And my first set left a lot to be desired but they worked and were solid. 
 

It’s really our only options. Pay someone, or tackle ourselves and learn a few things along the way. 
 

I found just jumping into it was the best way. If you try to sit and think it all out you’ll never start and will just be overwhelmed with the task at hand. 

Edited March 24, 2023 by TiZiK

[Jdeac]

11 hours ago, TiZiK said:

My compressor side is pretty big and it really only fits in one spot. That’s why the cross member had to go. This is gonna be a drag bike only tho so I’m not worried. 
I’m also using a front end off an 01 R6. It has a much larger offset helping to gain a bit more clearance up front. 
 

I was weary of spending money for off the shelf headers so just made my own. Tedious, but worth it. I just tacked it up and brought it to a welder for final welding.  Guaranteed to fit this way. 
 

I know the UK has a few places to just bring your bike but no such place here in canada. Not for these old school bikes anyhow. 

What holset is this. And what size housing?

[TiZiK]

10 hours ago, Jdeac said:

What holset is this. And what size housing?

Modified HY35. I just installed the 7cm turbine housing. Cold side is original. 
 

SPECIFICATION-

-Large alloy Holset compressor housing with 4inch ported anti-surge inlet and 2.25in v-band outlet

-500bhp capable 76mm 7 blade compressor wheel with 52mm inducer capable of 3bar boost

-Oil cooled journal bearing core with 360deg thrust bearing and heavy duty shaft

-Quick spool 7cm (~0.55 A/R) turbine housing with T28 inlet flange and 2.5inch v-band outlet flange

-12 blade high flow 65mm turbine wheel with 58mm exducer