TiZiK

How much you think forks actually bend? Serious question. I use old fork tubes as breaker bars and they are tough as nails. I'm running a Holset HY35 on a slabby and also had to remove the crossbrace and shave down the other mount on the left side for proper clearence. I have a good 1.5inches between the turbo and tire but this fork flex claim is always looming in the back of my head so I'm really curious about how much flex there actually is?

I have APE 85mm Gorilla block. Wasn't aware they made an 86mm. Liners got to be getting pretty thin I would think at 86mm.

I contemplated this option as well. The one on the left side would be ideal for turbo feed if pressure/flow is adequate and has no affect on main gallery pressure.

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

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.

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

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.

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

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

I was gonna say that with all the advancements in tuning, and the accessibility of it all, tuning properly would be the best way for heat management internally.

Top picture is the 7cm housing. Bottom picture is the 9cm. 7cm housing retains original turbine wheel and is a straight swap.

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.

Good to know. So no risk of the seat moving? I guess having my welder do a small pass to close them up wouldn’t hurt? it’s a good chunk of change the guy is asking but it really is needed with my build. 85mm block and stock valves would be the limiting factor I’d think. appreciate the input

Need some feedback from the hive. Looking to buy a cylinder head that’s outfitted with oversized valves and bronze seats with some porting. One cylinder has some cracks around the sparkplug hole. Is this easily repairable? One crack is pretty much right to the seat. Will the seat have to be removed to weld it? What would be involved with a repair like this? I really want this head for my turbo slabby but am hesitant due to the cracks.

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

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?

Cheers fellas. I will be going over the bike to be sure all is up to snuff. I do have a lockup and will add a bit more weight for day of plus bring some extras with me. Tuner did say he is familiar with Tunerstudio and I will be there for the entire session as well. Arttu - I will be looking for the dyno guy to take the lead on this. He has experience with turbo bikes. I would love some input from someone like yourself in how you approach. What to focus on first and maybe some tips/tricks for getting the best power out of these oil cooled engines. I am running an 85mm block (1316cc) will all supporting mods (HD head and main studs, Carrillo rods, forged MTC pistons etc) and a Holset HY35 turbo.

I have some dyno time booked in the near future. What are some things I should do to prep for the day of? My set up is a 1316cc Turbo gsxr1100 with an efi coversion using a Microsquirt. I have boost control set up via solenoid and also a methanol injection system from Snow Performance which uses its own controller and a 2 stage MTC lock up clutch. Currently, I have a basic base tune. I have never been to a dyno tuning session before so want to show up prepared with expectations of what changes I may have to make on the day of so I can best utilize my time while there. Any input appreciated

This is exactly why. Temps at the track 20+ degrees Celsius, upwards of 30 in the middle of summer. Tuning over the winter where the fresh air intake at the shop is -10 or colder isn't gonna do me any good come summer. Now, if I was going for the ultimate high HP number, then ya lol

The guys who have chimed in are far more knowledgeable than me on the topic so I won't even try to get as deep as them. With that said, a cheap and good turbo option is a Holset HY35. It uses a 9cm^2 turbine housing (smaller than the 12cm^2 on the HX35) but uses a compressor side very very close in size to the HX35. I'm using one on my 86 1100 but I've gone 9mm overbore so its 1316cc now. Will be on the dyno in the spring as its too cold right now for accurate tuning. I picked mine up for $50 Canadian and a rebuild kit cost me $80. They were found on early 2000's Dodge ram pick up trucks with a Cummins 5.9L diesel and more specifically, the automatic trans versions. The manual trans got the HX. Great turbo if you can find them as they were designed to be overworked and underpaid. Compressor racing in the UK sell Holsets in hard to find sizes and are a big fan of them along with Stav from Stavtech.

Before fitting a scavenger pump, I had this issue. Turbo was a tad too low and oil was seeping past the seal filling the compressor housing. Once running it basically pumped it all the way to the plenum. Cleaned it all out, fitted the scavenge pump and alls been good since.

I forget now. Will need to get in there to add more soon tho

Stock clutch with MTC lock up. Getting there man. Had to get over the fear of launching this thing first. Haha

Big bore efi turbo slabby