1995 7.3 has 205/100 injectors, ts6 position, 3 inch dp, cold air and exhaust. I am in need of a turbo bad, have a 40 foot fifth wheel camper I pull and my egts are outrageous. I'm looking at a d66 or I might have a guy built me one, what are some spec numbers for a good turbo that would suit this thing good. I need like mm, cfm, and any other stuff use full. Thanks!

 

s366 with an irate T4 mount

 

First, tow tunes and an IC will help with EGT's...

Stock TP38 with a stock wheel and an A/R 1.15 turbine housing pushes only 750 cfm and 59 lbs/min... and it stats winding up above 1800. I don't know your gearing, so I don't know what you're running at cruise. That's what you are running now? The tunes are tuned down to that turbo and no IC as the lowest common denominator. I think I remebr that the stock TP-38 starts dropping out at 400hp.

A D66 or D66 clone has about the same comp mapping as a TP-38R (same comp wheel size), although the TP-38R has a smaller turbine (overall) so the trim to trim is different. The D66 with a billet wheel is around 1050 cfm and 79 lbs/min.

D66 is a bolt on swap. The power band comes in around 1800 with 1.15 A/R housing and just above 1400 rpm with a 1.0 A/R housing. <-- I think the 1.0 housing is better for towing. The rpm spins up lower providing torgue in rpm range that you need for towing. An EBPV delete exhaust housing and an EVPR delete pedestal seems to help with EGT's further and opens up exhaust a little more. The comp housing inlet is still only 3", with an outlet of just above 2"(?). Those are restricting points, then going to 3" IC tubes. I think I remember them potentially as up to 590 hp, but have only seen them tuned up to 525hp. So I would say 300hp to 525hp.

A GTP-38R is ball bearing turbo about the same flow, but spins up faster and from lower rpms, because of the BB bearing design, rather than journal bearings. The turbine exducer is smaller. The comp housing inlet can be ported to 4". You would have to change the up pipes and all to be able to mount it, as well as the pedestal.. If you were going through all that work, you would have almost the same labor to install a T4 kit.

The S366 is not a bolt on swap. It needs a T4 kit with up pipes and such just to mount. You also have to run feed and return oil to that trubo. The flow is 1108 cfm and 82 lbs/min. That doesn't sound like much above the GTP-38R but the comp mapping extends into a wider and higher hp range and it is more tuneable. The power perspective of that turbo is 330hp to 800hp. There are a lot of difference turbine and compressor housings for that turbo. Turbine housing go from .71 through 1.10 A/R. The way it flows and the way the T4 adapter kit flows to the turbine housing generates less egt's. A big part of that is that it has a 4" outlet on the turbine housing. The comp inlet is 4" with a 3" outlet.

 

What I'm looking for a I guess a should have said is like the specs of those turbos, like the intake side mm and exhaust, what size wheel or what wheel in general and what exhaust and intake housing size should be.

 

the S366 compressor Wheel: 66mm Inducer / 91.4mm Exducer w/ Extended Tip Technology. turbine wheel: 80mm Inducer / 73mm Exducer. the housing is a .91 divided

 

S366 Turbo Features:
-Twin Hydrodynamic Journal Bearings
-Twin scroll turbine housing options available
-Adjustable compressor and turbine housing orientation
Compressor Specs:
-Compressor wheel inducer dia: 66mm
-Compressor wheel inducer dia: 91.4mm
-Compressor Outlet: 3.00"
-Compressor Inlet: 4.00"
Turbine Specs:
-Turbine wheel inducer: 81mm
-Turbine wheel exducer: 73mm
-Turbine Outlet: 4.00" v-band
-Turbine housing options: T3 .70 Open, T4 .83 divided, T4 .88 open, T4 .91 Divided, T4 1.00 A/R Divided, T4 1.10 A/R Divided

What I didn't say on that, is I have to agree with Bob... That if you can afford it (turbo and mount) I think the S366'es are one of the most widely adaptable, most tunable turbos covering a very wide band of power ranges (330hp to 800hp). Other turbos have narrower power bands.

Your stock TP-38 had:
Compressor Specs:
-Compressor wheel inducer dia: 59.97mm
-Compressor wheel exducer dia: 80mm
-Compressor Outlet: 51mm
-Compressor Inlet: 3.00"
Turbine Specs:
-Turbine Wheel inducer: 76.2mm
-Turbine wheel exducer: 69.64mm
-Turbine Outlet: 3.00" v-band
-Turbine housing options: .84 A/R, 1.0 A/R, 1.15 A/R

D66 is a mod'ed TP-38, so same measurements as your stock except that the original compressor housing is ported to take a comp wheel of 66mm inducer and 88-89mm exducer. All else is the same specs. A/R of the comp housing will still "say" 1.10, but will be changed by that larger wheel.

Whatever you end up with... by tuning, I mean that optimally, you want to have you drive pressures (EBP) to driven pressures (Boost) between 1.10 to 1:12... and the rpm power band where you use it by what you are doing.

Power for towing would be lower and you lose a little top end tuning for that... That is why I whole heartedly agree with Bob on that S366 with it's wide power band. You could go bigger, but with what you have, you would lose mid-range power, chasing more top end... where you don't usually pull a trailer at top end. It's that getting to cruise speed and maintaining it.

Example: My '97, 3.50 gears, 1800 rpm at 70 mph. Stock turbo on stock tunes just starts winding up about there.