The HOLSET Thread

I know most people don't have the time to read this thread from cover to cover but if you have the time it's well worth it

I'll let the JZ engine specialists recommend the oil feed setup, but to quickly cover off the other bits:

- You need a big oil drain that goes straight down. No AN fittings. I repeat, no AN fittings. If you can't find an off the shelf solution, get an oil drain flange and get a long piece of tubing welded on as big as you can fit and still access the oil drain bolts. Have the drain finish well clear of the manifold so you don't have to put any rubber hose close to the runners.
- Minimum 3" dump pipe off the turbo, but if you have the space (and you should being LHD) a 3.5" or 4" will see big gains in flow and boost control. Even just for the first couple of feet, but further ideally. You won't have to go far back through this thread to see what people have done as far as trimming the rear housing to fit V bands to the housing to free up the housing exit
- You'll have to consider an ECU as well, stock will throw it's toys out of the cot with the bigger injectors. I believe ECU Masters is big in Florida right now?
- Last thing is the things people tend to overlook: fresh water pump, timing belt & tensioner, oil cooler, bigger radiator, coilpacks - all things that tend to pop up when you start pushing an engine harder
I was looking for the proper oil drain setup that you suggested but can’t find anything on it, everything that I have found on the oil drain/return were all about lines and that -12an is best for the Holset HX35 but even that I am having trouble finding, everything is -10an, and I’m still unsure about the oil feed or if I need a restrictor/size if so.
 
I was looking for the proper oil drain setup that you suggested but can’t find anything on it, everything that I have found on the oil drain/return were all about lines and that -12an is best for the Holset HX35 but even that I am having trouble finding, everything is -10an, and I’m still unsure about the oil feed or if I need a restrictor/size if so.

Holset manufactures themselves recommends no smaller than a 19mm internal diameter for the oils drain. From what I could find a -10 and even -12an fittings are too small. So as previously suggested a made my own drain out of a piece of steel tube that has an ID of 20mm

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Keep the drain tube as straight and direct as possible.

With regards to my oil feed I decided to try withought a restrictor first with the intention to add one later if necessary. I would rather risk too much oil which can then be fixed later rather than not enough and risk destroying the turbo.

My cars done a load of pulls on a dyno so far but all seems ok without a restrictor using a -3 oil feed line.

All on an RB25DET by the way.
 
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Holset manufactures themselves recommends no smaller than a 19mm internal diameter for the oils drain. From what I could find a -10 and even -12an fittings are too small. So as previously suggested a made my own drain out of a piece of steel tube that has an ID of 20mm

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Keep the drain tube as straight and direct as possible.

With regards to my oil feed I decided to try withought a restrictor first with the intention to add one later if necessary. I would rather risk too much oil which can then be fixed later rather than not enough and risk destroying the turbo.

My cars done a load of pulls on a dyno so far but all seems ok without a restrictor using a -3 oil feed line.

All on an RB25DET by the way.
Awesome I will look for he proper tubing for it and weld it to the flange and make it fit nice. Thanks for the help
 
Hey guys I have another question, so I’ve been looking for an hx35 turbo everywhere and still can’t seem to find a website that sells them (that are trustworthy) even some eBay posts. And if I search for the hx35 it comes up with the hx35w, Should I go with that? any recommendations on where to get turbos?
 
Hey guys I have another question, so I’ve been looking for an hx35 turbo everywhere and still can’t seem to find a website that sells them (that are trustworthy) even some eBay posts. And if I search for the hx35 it comes up with the hx35w, Should I go with that? any recommendations on where to get turbos?

Best place hands down for Holsets in the UK is either a company called Compressor Racing (search on Facebook) or you could try Stavros on this forum. He always has a load of crazy turbos for sale and is very helpful.
 
Hey guys I have another question, so I’ve been looking for an hx35 turbo everywhere and still can’t seem to find a website that sells them (that are trustworthy) even some eBay posts. And if I search for the hx35 it comes up with the hx35w, Should I go with that? any recommendations on where to get turbos?
The "w" stands for internal wastegate so If you are going to use an external one you need to weld the internal one shut. The rear housing is a bit bigger than on non-internally gated ones, but you can cut quite alot of it incase clearance becomes an issue. I had clearance issues with my he351w and I cut quite a lot of it to make it fit my r33.

Posted pics here spring 2017 I think. Not that many pages back

For some reason it seems to be that certain UK tuners (and some Irish ones!) are extremely prejudiced against Holsets.

I'd say its a combination between them trying to push their own shit, and because of the fact that back when holset turbos started appearing on the scene, there was one dude in particular that sold A LOT of them as "12cm" turbines, but they were actually like 16-18cm. I think this is really what started the whole "holsets are laggy" sort of stigma that they receive a lot of in the UK.
This, in conjunction with the fact that most of them are bolted to cheap setups with little to no thought put into them (this is because they are a cheap turbo that anyone has access to really) just do not paint them in a good light whatsoever.

Obviously there are people that know better and have got great results with them, so I prefer to try and look at the positive side of it - the less people that want to use them, the cheaper they (and their associated parts) will hopefully stay due to little demand!
I dont think its just UK. In Finland some people are really strongly against them and say all of them are laggy as Hell and dont work at all on petrol cars.

Like you said they are cheapish turbos so a lot of people just slap them on without any supporting mods or any clue on which sized turbo they should use. Often you see people looking for 300hp on 2-2,5 liter cars running stuff like hx50 with massive rear housings on Chinese crappy manifolds, leaky wastegates and stuff and then complain that all holsets are useless and laggy
 
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Awesome! Thanks guys I finally found a HX35 and can start building the 1jz single turbo swap, will be going with the 6boost twin scroll manifold, definitely going to welding a custom oil return line thanks to the help of you guys. And slowly adding other things like the siemen 650 rail injectors and other things that Benrice said earlier to make the engine run smooth. Last thing I need to get are some oil feed lines and I’m ready for the swap.
 
Hey guys last question before I get on with the 1jz single turbo install.. so after I get the manifold, all the lines needed, and the turbo. Next I need a Downpipe and dump pipe, the dump pipe will most likely need to be modified, the Downpipe will be a 3” but before I get the Downpipe how will I be sure that it will fit to the next part of exhaust (noob here learning more in depth) the frontpipe I’m assuming?
 
Hey guys last question before I get on with the 1jz single turbo install.. so after I get the manifold, all the lines needed, and the turbo. Next I need a Downpipe and dump pipe, the dump pipe will most likely need to be modified, the Downpipe will be a 3” but before I get the Downpipe how will I be sure that it will fit to the next part of exhaust (noob here learning more in depth) the frontpipe I’m assuming?
You will need a custom elbow/downpipe. If you have room go for 3,5" or even 4" downpipe. Holsets seem to like a big exhaust.
 
You will need a custom elbow/downpipe. If you have room go for 3,5" or even 4" downpipe. Holsets seem to like a big exhaust.
Okay I will look into the bigger size, so I pretty much need to make my own Downpipe? And from that saying I get a 3.5” Downpipe I’m assuming the rest of the exhaust needs to me 3.5” as well ie. frontpipe all the way to the end
 
You will need a custom elbow/downpipe. If you have room go for 3,5" or even 4" downpipe. Holsets seem to like a big exhaust.
I have a 92 Toyota Soarer and I can not find any exhaust that size for my car unless getting a full exhaust custom fitted to the soarer
 
Okay I will look into the bigger size, so I pretty much need to make my own Downpipe? And from that saying I get a 3.5” Downpipe I’m assuming the rest of the exhaust needs to me 3.5” as well ie. frontpipe all the way to the end
Most likely you'll need to make your own or get one made. Every turbo setup is a bit different due to different manifold/turbo/exhaust/preferances etc so I think it would be quite tricky to make a bolt-on downpipe for aftermarket setups.

I thinkt Ive seen sinco customs do some turbo kits that come with a downpipe but i imagine you need their manifold aswell for things to fit nicely. You could contact them though, they are super helpfull.

Afaik after downpipe the exhaust can get smaller (say from 3,5" to 3" for example). As the gasses travel further from turbo they start to cool down so they dont need as big a tube to travel freely in. Thats one theory atleast.

Its all compromises on the end. Power/spool vs money.
 
I have a 92 Toyota Soarer and I can not find any exhaust that size for my car unless getting a full exhaust custom fitted to the soarer
Took a quick search with Google (soarer exhaust) and both nengun and rhdjapan were top searches and seemed to have exhausts with 80mm diameter (seems to Be pretty common size for japanese aftermarket exhausts) etc. What size is your current exhaust?
 
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If you go back a few pages there's a few pics of what Bigdave did to my turbine housing to fit a 4" downpipe. Basically welded a 4" vband onto the back of a cut down turbine housing. Because you state it's a Soarer I'm assuming its RHD, ie exactly the same as mine - they can and will fit. Mine is a custom made 4" full system, but it DOES have ground clearance issues - this is in part due to what seems to be a slight lack of foresight from the fabricator with vband placement etc, but as for body clearance and that sort of thing it's fine.

Ideally (and what we'll be doing to mine in future) you'd have a 4" downpipe into a twin-3" system, so you still have good flow after the end of the downpipe but good ground clearance too with a tucked up twin 3" system. You could go back to a single 4" after the gearbox where ground clearance isnt as much of an issue.

As for oil feed and drain, I'm running a ported/smoothed/high-flow/whatever you want to call it oil pump, and I run a AN -4 feed line, no restrictor, and a 22mm ID fabricated steel tube oil drain, running as vertically as possible into the sump. Part of the reason for this is after speaking to a lad in Finland with a 900+ BHP HX55 Soarer with a full 2JZ engine and getting information from him as to what he has done for feeds and drains.
 
Hey guys got another question before I start the build for my 1jz gte non vvti. I have the Holset hx35 and I was told a twin scroll manifold was best to use. so I plan on getting a 6boost twin scroll T3 manifold 50mm wastegate. Question is is that a good size? And do I need 2 wastegate a or just one?
 
Hey guys got another question before I start the build for my 1jz gte non vvti. I have the Holset hx35 and I was told a twin scroll manifold was best to use. so I plan on getting a 6boost twin scroll T3 manifold 50mm wastegate. Question is is that a good size? And do I need 2 wastegate a or just one?


Nice, what size is the turbine housing? Hopefully a 12cm?

Twinscroll results are best felt when the gas is kept separate until the face of the gate. Some people swear by two gates, but if you ask 6boost to make it a split-wastegate design the results will be extremely close if not the same as having two separate gates.

I don't know if it's an extra cost for 6boost to do that but I know it's standard on all sinco twinscroll manifolds unless you specify that you want 2 wastegates - Mine is a T3 Twinscroll Sinco with one 45mm wastegate tube, and the wastegate tube is divided right up until the gases meet the gate itself.

They (Sinco) posted on their facebook page a good while back about doing some testing with regards to the split single wastegate tube design, and they reported that responsiveness was greatly increased over having a single gate that wasn't kept divided internally.

Yes you can use a single 50mm gate - just make sure they keep it divided on the inside of the tube that goes from the manifold to the gate to make the best of it.
 
Nice, what size is the turbine housing? Hopefully a 12cm?

Twinscroll results are best felt when the gas is kept separate until the face of the gate. Some people swear by two gates, but if you ask 6boost to make it a split-wastegate design the results will be extremely close if not the same as having two separate gates.

I don't know if it's an extra cost for 6boost to do that but I know it's standard on all sinco twinscroll manifolds unless you specify that you want 2 wastegates - Mine is a T3 Twinscroll Sinco with one 45mm wastegate tube, and the wastegate tube is divided right up until the gases meet the gate itself.

They (Sinco) posted on their facebook page a good while back about doing some testing with regards to the split single wastegate tube design, and they reported that responsiveness was greatly increased over having a single gate that wasn't kept divided internally.

Yes you can use a single 50mm gate - just make sure they keep it divided on the inside of the tube that goes from the manifold to the gate to make the best of it.

After reading this I’m definitely going to go with sinco instead of 6boost. Because of the facts that you explained and that with 6boost being in EU it’s hard to get it delivered to me. This definitely helped a lot. Are you running any bov on your setup? I was thinking of getting a TiAL 50 Q. And yes it is a 12cm
 
After reading this I’m definitely going to go with sinco instead of 6boost. Because of the facts that you explained and that with 6boost being in EU it’s hard to get it delivered to me. This definitely helped a lot. Are you running any bov on your setup? I was thinking of getting a TiAL 50 Q. And yes it is a 12cm

6boost are an Australian company if that helps, so you dont HAVE to buy one from EU if there's anything closer to you.
Sinco are New Zealand and slightly cheaper than 6boost, or at least they were when I bought mine (for reference, a T3 Twinscroll Sinco with divided 45mm gate in Steam Tube was around the £900 mark after ALL shipping and customs were paid - the 6boost equivalent was, at the time, about £1100 or £1200 before i started asking about divided gates). I know the prices of Sinco manifolds have definitely went up a bit compared to when I bought mine, but as far as I'm aware they are still beating 6boost for price.

The reason I say its a standard thing on them is because when I asked about doing the split-gate design they did inform me that they normally carry that out on all twinscroll stuff apart from when the person asks for two gates, but it's always nice to confirm just incase practise has changed.
If you need to know anything else, the people on this thread are pretty helpful with things like that and there's a good portion of info scattered about various sites too.

I am not running a BOV as I like turbo chatter. In my experience this has never been detrimental to the reliability or performance of a turbo setup. I know of plenty of people that would agree with me and plenty that wouldn't, so it's really up to personal preference what you do.
 
I can tell you the NZD has taken a dive recently, so your US dollar will go even further!

Sucks for me, good for you
 
http://www.stavtech.co.uk/home/the-ultimate-holset-turbo-guide-probably

Stav has gone and put this on his website and I thought I would paste it in here as it is an excellent article with great info in it.

If you've got a bit of time, reading the other posts on his site and on his facebook page (it has the same name, Stav-Tech) are a good way to learn more about most of the technical queries that are asked in here. All of it is also, in my opinion, genuinely interesting stuff.

A lot of people in this thread will know who he is already, he's even posted in it a good few times himself, for those that don't, all info is on his site about him etc. I appreciate his no-bullshit, no sales approach to things, and I'm sure I'm not the only one.
 
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