Anyone running a HX25?

[Kyle325i]

I've got the chance to pick a Holset HX25 with 11cm exhaust housing very cheap, anyone running one?

I'm not after massive numbers but a very responsive and drivable car. Its for a M50B25tu.

Thanks,

Kyle

[Butters Stoch]

Probably a nice choice for a 2.5 .

[Kyle325i]

Why do you think that?

[Butters Stoch]

Why do you think that?

i dont. its too small

[Kyle325i]

Too small in the fact it will run out at higher rpm?

I have been told it the equivalent of a gt28.

[rowleym]

Too small in the fact it will run out at higher rpm?

I have been told it the equivalent of a gt28.

I personally like laggier turbos than that with street cars, but I bet it's not a terrible match at all. Anything larger than a 2.5 and I would probably say no. You have just about the right size exhaust housing as well.

Go for it. Too small? Slap on an hx35 in a heartbeat for like 200$

[Kyle325i]

I personally like laggier turbos than that with street cars, but I bet it's not a terrible match at all. Anything larger than a 2.5 and I would probably say no. You have just about the right size exhaust housing as well.

Go for it. Too small? Slap on an hx35 in a heartbeat for like 200$

Thanks for the reply. That was my thinking as well to be honest. However holsets aren't quite as easy to get hold of over here as they are in the states. Although why couldn't I machine the housing to take say a hx35 compressor wheel in the future if I wanted?

And what do you think I will be able to achieve with this turbo?

[5mall5nail5]

And what do you think I will be able to achieve with this turbo?

Fame. Success. Liberation of your people. That sort of thing.

[Kyle325i]

Fame. Success. Liberation of your people. That sort of thing.

Thank god, I thought I would just get some hp and tq out it.

[Butters Stoch]

Liberation of your people. .

That's racist. But correct.

[Aquaticbob]

Fame. Success. Liberation of your people. That sort of thing.

These are the top components to look for when searching for a turbo. Bigger is better as well.

I would say get what you can get and upgrade to another turbo later. Might as well get in the door for relatively cheap if you can

[rossjsy]

I can put you in touch with the chap I bought my hx40 off, he had 4 of them so might have some left. But if you are looking at hx25's it's probably a bit large for you

[Butters Stoch]

Isn't the hx25 < T3? Like a T25 or something? So changing from it to a hx35 would mean changing manifolds? Not sure tho.

[Kyle325i]

I can put you in touch with the chap I bought my hx40 off, he had 4 of them so might have some left. But if you are looking at hx25's it's probably a bit large for you

I was put off by hx40 just because I want to get full boost as early as possible, but without sacrificing much up the top end, But please pm his details.

Isn't the hx25 < T3? Like a T25 or something? So changing from it to a hx35 would mean changing manifolds? Not sure tho.

It does use a t3 flange however this doesn't put me of, I have access to a engineering workshop so I'm sure I'll be able to sort something out, but it is a good point.

[E36 HateR]

How much power do you want to make?

[rowleym]

Stay t3, get a decent twin scroll manifold, and then upgrade later.

I don't really understand people with such small turbos. I understand the response thing, but I feel transient response is the most important for actual performance.

It's no like our motors are low compression 1.8L or something. There is plenty of grunt for driving around, and then top end of a turbo above 3500 Rpms is the greatest.

But then again I'm pretty weird so you never know.

Is this a street car by the way? Fuel being used?

[Kyle325i]

I'll be happy with 300whp but with great response... I know this is a relatively small turbo, but later when no doubt I want more what will stop me making this a hybrid turbo, as in hx35 compressor wheel in the original hx25 housing? Already stated that I have access to full CNC workshop, where matching the original compressor housing to a larger wheel would be very easy...

- - - Updated - - -

Forgot to say yes this is a street car and fuel is 95 to 98 Ron over her in the uk, plan to use 95 Ron petrol...

[rowleym]

I'll be happy with 300whp but with great response... I know this is a relatively small turbo, but later when no doubt I want more what will stop me making this a hybrid turbo, as in hx35 compressor wheel in the original hx25 housing? Already stated that I have access to full CNC workshop, where matching the original compressor housing to a larger wheel would be very easy...

- - - Updated - - -

Forgot to say yes this is a street car and fuel is 95 to 98 Ron over her in the uk, plan to use 95 Ron petrol...

You sure you want response like that in a street car?

Anayways. For any fun you are going to have to lower the compression or run water injection.

Id personally lower the compression via milling the pistons if you have access to that machine shop

But otherwise you can use one of those MLS gaskets and such.

I bet you could easily machine that housing.
I drilled/tapped my hx40 exhaust housing very easily in my mill. I would assume cutting a new radius with a ball ender

[rowleym]

I think those pictures are the right ones..

[bmw328m52]

From alot of the builds I've read, you'll always want more power. Machine that turbo or get a bigger one

[Kyle325i]

You sure you want response like that in a street car?

Anayways. For any fun you are going to have to lower the compression or run water injection.

Id personally lower the compression via milling the pistons if you have access to that machine shop

But otherwise you can use one of those MLS gaskets and such.

I bet you could easily machine that housing.
I drilled/tapped my hx40 exhaust housing very easily in my mill. I would assume cutting a new radius with a ball ender

I plan on lowering the compression, I did originally plan on lowering it by using a mls gasket or look into a decompression plate(coper spacer) with cut ring gasket.

However it's funny you should say about lowering the compression by machining the pistons, I was going to do this but searched all over to try and find some information on this and if there was enough material on the piston to safely remove with out sacrificing the pistons strength but couldn't find any. Have you seen this done? Got any information on it? Could you use a standard head gasket if this was done? Or would it be best to use a mls or cut ring gasket?

Machining the housing is the easy part, working out the clearances from compressor wheel to housing could be tricky as it's not easy to get in there when it's together. Yes you could mill the profile using a ball nose cutter but it would be far easier to set the housing up in a face plate on a lathe and turn the profile.

[rossjsy]

I can put you in touch if you still fancy but no point going for a hx40 if you are only after 300hp.

I would be tempted to stick an s50b32 in with those power goals. 321hp, stock reliability and far better tractability/drivability than a home brew turbo conversion