A TP38 is a stock OBS turbo.

By a TP38R I assume you're meaning the Garrett ball bearing drop-in for the SD's right? That's a GTP38R, and as far as I know, nothing will interchange.

Dave

 

I hybrid the turbo on my old 96 using the intake housing and compressor wheel from a GTP38R. worked great, cost about $350 for new parts. thats why I'm looking for used parts for my current truck. I had no problem making 40 PSI. I was mean to that turbo and it never failed me.

STROKER

 

That's cool, what sticks were you running with it, and how did they clean up?

Dave

 

Stock as far as I know. I had a little smoke with TW's extreme but it was only a puff when I hammered it from a stop.

If I ever find some cheap parts I will do a writeup with pictures.

STROKER

 

Where did you get the parts to make that hybrid turbo?

Dave

 

A local turbo shop. The parts were not on the website, I had to call. Turbo Supply

NOTE: You will have to use a 99.5+ spider because the outlet size is bigger then our turbo.

STROKER

 

This exactly what I'm looking to do.

Got the spider part. What did you do with the intake?

Did you retain the OBS pedistal? I think the SD pedistal is taller. Any issues with retaining the fuel bowl set up?

Right now I'm running an early 99 spider and had to use the reducing silicone couplers to matte it to my intakes.

If you have any pics, they'll be great. Part numbers would be great also.

Thanks

Billy T.
gnxtc2@aol.com

 

i've posted this a few times yes it can be done and they interchange that is how a d66 is made. the parts are readily available and shouldn't cost more that 200 for the wheel and housing.

p/n wheel: 729567-0001
comp housing: 741460-0004

i have just used the wheel and had the turbo shop machine the factory comp. housing to fit the wheel so i could keep my obs spyder. so i never looked into the compressor housing and if it would bolt up to the obs turbo or if the gtp38r backing plate would have to be used with the comp. housing.

 

i have just used the wheel and had the turbo shop machine the factory comp. housing to fit the wheel so i could keep my obs spyder. so i never looked into the compressor housing and if it would bolt up to the obs turbo or if the gtp38r backing plate would have to be used with the comp. housing.

roosterdiesel This is comical.....
The OD of the sealing surface on the OBS turbo is smaller than that of the Powermax BB drop in for the SDs. The compressor housing on the BB is also "tab" type and the bolt screws in from the backing plate side into the compressor housing, on the OBS the backing plate is only 4 bolt and screws through from the housing side into the backing plate.
I've seen both the D66 and a BB and the D66 is not using a BB compressor housing, it's bolt in for the OBS guys.

Was this in response to my post? If so thats why "like i posted inthe quote" i have never looked into the GTP38R Comp housing and backing plate. Just the wheel.

 

You shouldn't have to buy a new compressor housing for a bigger wheel. Just get the stock one machined for the bigger wheel and it should keep cost lower.

 

The compressor housing on the GTP38R has a ported shroud.

Billy T.
gnxtc2@aol.com

 

This is comical.....



The OD of the sealing surface on the OBS turbo is smaller than that of the Powermax BB drop in for the SDs. The compressor housing on the BB is also "tab" type and the bolt screws in from the backing plate side into the compressor housing, on the OBS the backing plate is only 4 bolt and screws through from the housing side into the backing plate.


I've seen both the D66 and a BB and the D66 is not using a BB compressor housing, it's bolt in for the OBS guys.ointlaugh:

 

Ooops

Billy T.
gnxtc2@aol.com

 

For 73LSTROKER - Not the air filter side. What did you do with the spider? Do I retain my reducing coupler that attach to the intakes on the head?

Billy T.
gnxtc2@aol.com

 

Yes

 

Hey I just dug this thread up cause I am looking to do this to my truck. So? There would not be anything beneficial about buying the
741460-0004 housing or will it work at all? I have heard the stock housing can seperate sometimes after machining. Or would the early 99 housing be better? I know where I can get either one for a good price.
Any help would be appreciated.

 

I did not look into this fully at the time of the post due to other projects that needed to be done.

I don't think the 741460-0004 compressor cover would work. The OBS comp cover attached differently that the SD one. The comp backing plate is what's different. I briefly looked into it.

I spoke with Dave in the turbo shop at Coumbus Diesel. http://www.columbusdieselsupply.com/ They said they can machine the OBS cover for the GTP38R compressor wheel.

The prices that I was quoted:
- New comp wheel: $133.55
- Machining: $180.00
- Rebuild if needed: $269.65

I spoke with my connections at Precision Turbo to machine the cover. Precision told me that they are too busy to do one off stuff and told me to contact Tad (Elite Diesel) 719-647-0232 to have the work done. This is another option. I did not speak with Tad yet.

Billy T.
gnxtc2@aol.com

 

Thanks Billy!
That is what I thought from what I found out about doing this. I got a guy gonna do the machining for about the same price.
Actually he said 125.00 I think for machining and 100.00 for the wheel. I am gonna do the rebuild myself they are a piece of cake.
I forget what he quoted on balancing, but the whole deal for parts machining with rebuild kit included was 425.00.

 

Yea, I was going to ship off my entire turbo to Columbus Diesel so they could go through it (bought it as a core), machine it and balance the rotating assembly. What shop are you using?

I have a local machine shop that can machine the cover but I don't know the tolerances of the wheel to cover distance.

Keep me/us posted when you have it done.

Thanks

Billy T.
gnxtc2@aol.com

 

so from what i understand a d66 is a tp38 with gt38r comp wheel and thats it?

 

yea and machine the housing