Need help with homegrown turbo

Jonny Hotnuts

I have built a hedder and have the turbo mounted but I have a few questions before I continue.

Using a Garrett M24

1. is it ok that the oil dump line out of the unit is not pointing 100% down (mine is at about 45 deg. down)

2. Can I use an adjustable boost regulator (like)

from the vacume line out of the TB's to the wastegate diapharam on that is stock on the turbo?

3. The m24 has water lines in and there a known method to get coolant to the unit....a kit maybe?

4. Where do I get the oil cooler relocator kit and the hoses to run the oil lines to the turbo?


Jonny Hotnuts

BTW this was early stages of the headder build, now everything is cleaned up and ready to be coated.

On this pic you can see the wastegate diaphram and the oil dump line out of the front.

Thanks for any help!!!!

I will be putting together a build spec sheet and how too post (including dyno sheet before and after and a cost summary for anyone else that wants to try this)



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I would think you would want the oil drain going straight down to avoid drainage problems. Using a regulator is usually done when putting boost to the top side of an external or dual port wastegate. How many ports does your wastegate have? I would assume 1 looking at it. If so you can use a small bleed off valve to bleed signal line pressure going to the gate to raise boost.

I make very inexpensive gear based boost controllers ( if you are interested or can help get you parts (tell you where to get them) much cheaper than $80 for regulator by itelf, like 1/4 of that.

Greg Smith

Jonny Hotnuts

Thanks GS, I will get ahold of you when I get further down the road.

Any ideas about the oil cooler? Is it common to use the oil cooler lines to run into the turbo and remove the oil cooler all together? I would think that with the added oil heat the turbo would make it would make more sense to have an OC.


1. point it down IMHO. no drainage issues that way, like smitha said.

2. yes, BUT, dont use the vac lines from the TB. that will make it overspool. put it on the up-pipe or something. see, if the signal line is on vac lines, then when you let off, the gate will close and then you run into the chance of it overspooling. the wastegate signal line should be pre-TB's. plus, you want to have a large signal line, mines about 1/8 ID, and NOTHING to share this signal. mine is a line that will come straight off the up-pipe, through the boost controller, and then striaght to the gate.

3. you really shouldnt need the water coolant lines. mine has them, but i didnt use them. they are mostly for engine bays where they wont get any cooling without having water go through them, but on a bike, you have lots of air flowing over them.


Yep point it down, just loosen the housings and rotate the sections to the positions required.
Can't see your turbo height in relation to oil level, if its not hi enough to drain now is the time to change it.
Switch activated solenoid and bleed valve for a simple boost control ,Smithabusa's would be ideal.
bike cooling system has trouble coping with the extra load of the turbo water cooling , just leave it open.


Donating Member
Boy you working hard Chris.Your dad called and told me about it but didn't know you were this far along,winter's here and i'll help ya when ya ready to get this done..ya got tha #...

Jonny Hotnuts

Sweet! I did not want to f- with tapping a line somewhere for the water.

I have the turbo mounted above the oil level.

-So where does the oil come from?

Do I cut the oil cooler lines (on the metal section of the line) and flair the ends and attach flair fittings to them and into the turbo oil lines? mentioned "loosen the housing and rotate the body"

On my turbo I have about 5-1/2'' nuts around the inside of the exhaust side....and it looks like I can loosen these and rotate the body but on the compressor side all I can see is a large snap ring connecting the compressor housing to a plate.....

If I was to rotate the exhaust side it would change the angle of the compressor output and would need to move it as well.

Is this done by pulling the snap ring and rotating the compressor too?

Thanks for all your help and advice

And thanks Dan for your continued help.



Yep loosen the snapring, if it doesn't rotate take the comp cover off and see if it has an indexing pin, if it has just remove it.

Oil from the oil cooler is unfiltered, i prefer to block those (and remove the allen key restrictor from behind the oil filter)
Either a Tee from the oil pressure switch or direct from a gallery plug , i use a gallery plug and bolt from the 01+ timing chain tensioner , and fit it to the gallery near the ait filter

Jonny Hotnuts

I removed the bolts from the inside of the ehaust side and the "segmented ring" but the thing is so tight it wont move....and I dont want to pound it because I am worried it will break the housing.

Should I heat it up with my torch to loosen it up?


Yes !
You may have to remove the housing and clean the surfaces to get it to rotate, just make sure it comes off without grabbing the exhaust wheel , I rock the inlet with my finger as i'm removing the exhaust so i can feel of the exhaust housing is leaning on the wheel .
Learnt the hard way after chipping a ceramic wheel once


like OZ said, make sure NOT to touch the housing to the turbine blades. comp and turb blades are really sensitive. a somewhat minor scratch on a blade could result in catastrophic failure. so yeah, take your time on the removal if it is stiff.

Jonny Hotnuts

Thanks for the advice.....a bit of heat from the torch and it came free.

I did not remove the housing.....just removed the gate arm and rotated it so the oil drain was down.

This is the a pic of the same type of turbo I have:

It has an internal gate......

Can it be modded to run an external gate or should I just keep it and use it as it is?

Jonny Hotnuts

I know this is going to sound crazy but I can not understand why you should spend 450+ on a plenum.

It looks to me like you could take a stock airbox and cut it in half just behind the filter opening and benind the flapper. Then seal the hole with sheet metal and install a 2.5 inch pipe flange to mount the up tube.

Any thoughts on this.....has it been done?

also.....why use metal for the up tube......what is wrong with PVC? Most cars I have see dont use metal tubes for their high pressure side, they are plastic.
It is not hard to use a heat gun to warm the plastic and bend it for smooth curves and there is a ton of joint fittings that you could piece a pipe together......ture that it would have some internal seams but I really dont think that it would have too much of an issue on the performance.

Any thoughts or using a modded stock air box or using a plastic up pipe?



Compression of air creates heat, heat and plastic don't work well together.also some of the angles are hard to get in plastic , metal is easier to shape

Airboxes are not designed to have pressure.and the throttle bodies boots won't seal pressure
Even a simple large bore steel tube with correct sized outlets will work fine, like Reaper 0995 has done.
my first was a 2.5"exhaust tube split and 2" flat welded in to make an oval , feeding in from the centre front.



3inch pipe worked for me, but i think i will make one from sheetmetal next time....i spent a long time trying the get the coontours right for welding...


Jonny Hotnuts

thanks oz and reaper, that would of been a waste of time.

I think I will do sheet metal as well.
I am now outfitting my tig to weld stainless (I have a ton of stainless sheet)

I just picked up my drain fitting and oil drain hose.....its a parker fitting with aeroquip cost for the set was about 11$



one more thing...i dont think i have ever seen and/or heard of plastic piping in a boosted car before... any vehicles in particular you are thinking about or pics? i mean despite the couplers being rubber or silicone, i think the rest of the systems are virtually metal, with maybe an acception if there is such a thing as a MAF that is plastic...though i do not know of any in particular.

Jonny Hotnuts

For some reason I have in my head that big rig systems used plasitc......I looked at a few at the Freightliner plant today and they were all metal.

Still not sure that Schedule 80 PVC would not is rated at 280+ psi at150 deg

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