[David85]

Hi all, first post.

I have what I believe to be a T04B turbocharger on my 1986 6.9L diesel (ATS 088 kit). The kit seems to be tuned to max out at only 7-8 psi to prevent head gasket failure. Its not wastegated, so I'm pretty much stuck with what boost numbers I have and am not really happy with it. I have since overhauled the engine and upgraded it to accommodate more boost (ARP head studs and slightly dropped compression ratio).

Heres what its making right now:

1500 = 2 psi
2000 = 5 psi
2500 = 7-8 psi

And that usually comes with too much smoke for my taste (staying at 2000 RPM and below 5 psi is the cleanest). I can get more boost at higher RPMs if I turn up the fuel screw, but that makes WAAAAAY too much smoke and causes EGTs to rise almost as fast as the boost. Its just not pushing enough air through the engine, especially after 5 psi.

Heres my question, can I swap the compressor wheel and compressor housing to a larger one to get more boost across the range. I'm really looking for some boost below 2000 RPM since I re-geared the truck to cruise at 1600 RPM @ 70 MPH. If that means 20 psi at higher RPMs, that would still be acceptable, but any higher and it might be too much. Swapping to a smaller turbine isn't really an option because ATS used a proprietary turbine housing that accommodates the inlet pipe and downpipe and I would rather not have to modify the rest of the kit.

I know nest to nothing about turbocharger theory, so sorry if this sounds off the wall.

Thanks for any advice,
David.

[David85]

Hmm, 12 views and no replies, I guess what I'm asking is what is available for swapping compressors? Does turbonetics sell just compressor wheels and housings or do I have to get a whole turbocharger?

[Robert]

Turbonetics does sell just wheels and housings but in order to properlly upgrade the unit you need to have it sent somewhere to be assembled and balanced with the proper seals and balance numbers. That being said I'm concerned that the boost pressure is so low. Most diesel units run upwards of 20-40 PSI typically. 8 PSI seems very low for a diesel truck.

[David85]

Thanks for the reply, Robert.

This engine was not a factory equipped turbodiesel, and can normally only take 7 psi contunious and 10-15 peak before the stock head bolts stretch and cause a gasket leak. This is the pre-powerstroke diesel, so the boost pressure is normal. Even with shaved pistons and ARP head studs I still don't want to go past 20 psi (by much )

Later wastegated turbo kits (like what was used in the 1993-1994 none powerstroke turbo 7.3L) were set to only 7.5 psi at the factory. The CR is in the 22:1 range instead if 18 for the later powerstrokes so you can't really squish much more air in without causing problems.

My understanding of turbo assemblies is that the turbine and compressor wheels are ballanced seperate from one another, so I thought ballancing would not be a problem. Am I wrong on this?

So what compressor housings and wheels will bolt on to what I have now? I'm still not sure if this is a viable option, but this question has been bugging me for a long time now (interchangeability)

[Robert]

Originally Posted by David85

Thanks for the reply, Robert.

This engine was not a factory equipped turbodiesel, and can normally only take 7 psi contunious and 10-15 peak before the stock head bolts stretch and cause a gasket leak. This is the pre-powerstroke diesel, so the boost pressure is normal. Even with shaved pistons and ARP head studs I still don't want to go past 20 psi (by much )

Later wastegated turbo kits (like what was used in the 1993-1994 none powerstroke turbo 7.3L) were set to only 7.5 psi at the factory. The CR is in the 22:1 range instead if 18 for the later powerstrokes so you can't really squish much more air in without causing problems.

My understanding of turbo assemblies is that the turbine and compressor wheels are ballanced seperate from one another, so I thought ballancing would not be a problem. Am I wrong on this?

So what compressor housings and wheels will bolt on to what I have now? I'm still not sure if this is a viable option, but this question has been bugging me for a long time now (interchangeability)

Any quality turbocharger is going to have the compressor wheel balance by itself, the turbine wheel balanced by itself, and thenassembled and the entire assembly balanced yet again. Depending on what trim, compressor cover, and backplate assembly you have there are several T04B compressor wheel options but all of them would require sending the unit in to get it assembled and balanced properlly.

[David85]

I'm still trying to figure out what will bolt on to the T04B center section. Am I strictly limited to the T4 family or are there other options to choose from?

If I have to send the turbo away to be ballanced than I guess I will have to deal with that, but I want to figure out what my options are first.

Thanks

[Robert]

Originally Posted by David85

I'm still trying to figure out what will bolt on to the T04B center section. Am I strictly limited to the T4 family or are there other options to choose from?

If I have to send the turbo away to be ballanced than I guess I will have to deal with that, but I want to figure out what my options are first.

Thanks

The T04B center section would give you options like the Super H, V1/V2, 60-1, etc. Its just a matter of inspecting your back plate and compressor housing to see what fits.

[David85]

Originally Posted by Robert

The T04B center section would give you options like the Super H, V1/V2, 60-1, etc. Its just a matter of inspecting your back plate and compressor housing to see what fits.

OK, so if I understand correctly, the shaft should match.

For the backing plate, I'll need the 4 bolt pattern on the compressor side of the center section, right? Is there anything else I should check if I were to order one?

These are the 60 series turbos that are shown on the turbonetics website:
http://www.turboneticsinc.com/produc...category_id=89

Are these compressors the largest that can be fitted to a T4 center section, or are some of the larger ones compatible as well? (only found a "super T" series on the website)

[Robert]

Originally Posted by David85

OK, so if I understand correctly, the shaft should match.

For the backing plate, I'll need the 4 bolt pattern on the compressor side of the center section, right? Is there anything else I should check if I were to order one?

These are the 60 series turbos that are shown on the turbonetics website:
http://www.turboneticsinc.com/produc...category_id=89

Are these compressors the largest that can be fitted to a T4 center section, or are some of the larger ones compatible as well? (only found a "super T" series on the website)

A T4 center section could technically take any of the T04 compressor wheels and the 60-1 and 62-1 but it all depends on the backplate and comrpessor housing. The 62-1 is the largest compressor wheel I know of that will fit on a T04B frame.

[David85]

My plan was to replace the compressor housing, compressor wheel, and backing plate. I just wasn't sure if the larger components would bolt onto the T4 center section and shaft.

Thanks for your help, Robert. Time to look at some turbo maps (now that I know what will fit).