Supra Holset Dodge turbo Project revisited

[MDCmotorsports]

Well, if any of you know me from the past, you know I tried running a Dodge Ram Holset turbo on the supra without much success.

Two problems no matter how hard I tried to fix them, would not go away.

1.) Boost creep
2.) Oil consumption through the front oil seal area

The first question from most people is, WHY?

Well, lets begin here. We all know that the Ct-26 can be a mightly little turbo, but it runs out after about 300hp @ 5000 rpms. They have very short lives living at those numbers.
The dodge ram turbo runs life at 20-32 psi, constantly for hundreds of thousands if not millions of miles. The 7mgte is a 3.0 litre engine, with the Cummins engine being 5.9 (6 litres). These turbos are rugged, and ARE VERY VERY VERY PLENTIFUL!

So my original idea was to graft the Diesel Turbo onto a 7mgte with a ct-26 wastegate actuator..... and it worked! Spool characterisitics were superb! Full boost at 3k rpms, and full pulls all the way to redline. No wimpy fizzle outs at 5k like a stock CT-26.
The major problem at this point was HUGE boost creep.

So most people at this point are thinking why not an upgraded ct-26? Well most turbo rebuilding companies WILL NOT touch these turbos with the hybrid wheels attached to the compressor end. They know they are trouble monsters. Most of all, they are a BALANCING NIGHTMARE! Other than that, I have heard more "It puked and snapped the shaft" comments about upgraded ct's then I have "It works great for thousands of miles." comments.

So heres the overview of a stock Holset off a 98+ dodge ram:
Compressor minor/major: 2.077"(52.75mm)/3.0645"(77.84mm)
Turbine minor/major: 2.2825"(57.98mm)/2.5670"(65.20mm)

And heres an upgraded Ct-26 57 trim:
Compressor minor/major: 2.2690"(57.63mm)/2.989"(75.91mm)
Turbine minor/major: 2.033"(51.63mm)/2.6675"(67.76mm)

In all, a stock Dodge turbo is the same performance wise, it not bigger than you would have on an upgraded Ct-26. Not to mention the fact, the parts are cheaper to rebuild the unit, and most units can be "exchanged" at any diesel supply store for around $300-450.

BEARINGS! A stock Ct uses what we know as a 270 deg (I think???) thrust bearing. The Hy35w series off the Dodge ram trucks use standard a 360 THRUST WASHER! Most of not all your "High performance" turbos now use a 360 deg bearing. IIRC, there is not a 360 bearing available for the Ct26 turbo.

SHAFTS! The Ct shaft has been known to snap under high PSI. The CT shaft measures accordingly: .3930"(9.98mm). The Holset shafts are .4305"(10.95mm). A shaft that is a whole lot more beefy than a Ct shaft could ever dream about being.

Now for the GOOD STUFF!

The Holset company has introduced a new turbo for the 04+ rams. This is called a HE351Cw turbo. Its the same as the HY35W turbo, but has an updated 4" exhaust 360 deg rotateable exahaust elbow, and a 90 deg compressor discharge neck.

BUT wait theres MORE!
The Holset company has a bigger brother to the HE351CW, THE "HE451CW." Its measurements are as follows:
Compressor minor/major: 2.4645"(62.60mm)/3.6455"(92.59mm)
Turbine minor/major: 2.3630"(60.03mm)/2.7405"(69.61mm)

So this thing should be a monster. The exhaust housings on the HY35W turbo and the HE451CW/HE351Cw are about .68 A/Rs. Should spool just fine!

I will also be porting out the wastegate hole so that the Boost creep will not be a problem.

So most people are asking what about the oil issue?

Well it just so happens that the HY and the HE series turbos are identically put together just like a ct 26 is inside the bearing cartridge. After rebuilding my own CT 26 and having it fail, I had the turbine ASSY off the old Hoslet project checked:

-Grossly out of balance
-Too much bearing clearance

So! Theres the oil problem.

All in all, I just wanted to give you guys something to pick your minds on.
Im really thinking about putting on the HE451CW (biggin) on for the meet in Chicago.

Questions, comments, ideas, flames what ever. Post away. Maybe here in the near future, we can have a cheap way of upgrading our supras with turbos that are readily available.

(Just like Roy) Cheers! :drink1:

 

[Stanzaspeed]

that sounds like it has some good potential. could you provide more info on the custom/fab work required in grafting a ct26 wastegate to one of these. who knows, with a little R&D this may be a good upgrade over an upgraded ct26. also how did you get it to bolt to the manifold? or did you have a custom manifold fabbed up? good info none the less, keep us updated!

 

[lagged]

id only run one if it looked nice.

(i really hope people get the sarcasm there..)

 

[MDCmotorsports]

I made an adapter plate out of 1" thick steel to go from the Holset flange to the CT flange.

As for fab work for grafting on a wastegate, it takes two threaded bosses welded to the front of the compressor housing to mount the wastegate. I also cut the wastegate rod off the hoslet, and welded it onto the toyota wastegate rod so I could get the length that needed.

For IC piping, the compressor housing has a 90 deg elbow on the front, so you would have to fab up the IC piping just like some of the big HKS or Greddy turbos.

Also, these turbos come STANDARD with a anti-surge compressor housing.

Here is my old website on the OLD OLD OLD CAR AND THE OLD OLD OLD setup....

http://www.mdcmotorsports.com/supra.htm


Here are some pics of what an turbo off a new Dodge Ram looks like.... (Can we say flow like a MOTHA! in that last pic on the right?) :icon_eek:

 

[Stanzaspeed]

oh gawd damn! :aigo:
maby you should consider making kits with the materials/instructions needed to get one of these set up in our cars... :naughty: i have to give you some major credit for making this all work in the car.

 

[IJ.]

On the oil issue: Diesel's don't ever see vacuum so have no oil control ring in the Compressor section.

 

[supra90turbo]

IJ: is there a way around this? somehow make the turbo "blind" to vacuum? or, more probable, to machine an oil control ring into the compressor?

 

[IJ.]

Kurt: Not sure I'd need to either see tech drawings of the Turbo or a real life one but I imagine it wouldn't be too hard.

 

[gixxer750]

this sounds promising

 

[IJ.]

MDC probably noticed the Oil smoke after awhile and usually the reason for this is the Air filter gets a little dirty or blocked and you get a vacuum between the Turbo and the TB so the Turbo sucks some oil.

In a Draw through System using these turbo's is a huge no no as they mount the TB/Carb on the front of the Turbo so as soon as you shut the throttle you get huge vacuum and lots of smoke! (This is all really old school stuff back from the dark ages)

 

[supraredliner]

LOL, I am glad to see someone is working on this. My buddy jerry tried this 5 months ago on his Cyborg R. Problem was his 2.0 4g63T didn't have enough strength to spool it without the help of Nitrous, so the turbo was scraped. What I have been wondering is doing for the Supra, what Mitsu guys call a Frankensien Turbo. They take a 1g housing and insert a Turbo II RX-7 twinscroll turbine and bearing assembly. It takes minor fabricating and modiffing, but that thing is mean. That's what my buddy did after the holsec plan backfired. His car spools at the slightest squeeze of the throttle, and it pulls like a comet even at top boost on the interstate.

 

[JZ_killa_t68]

Somebody correct me if I am wrong, but don't the new Holset turbos come with variable geometry turbine housings, and eliminate the need for a wastegate (I've been checking these things out, and they spool faster than a BB). www.holset.com I think it's hy45 and up models.

 

[MDCmotorsports]

On the oil issue: Diesel's don't ever see vacuum so have no oil control ring in the Compressor section.

The CT 26 doesn't either. Both only have one piston ring seal up front.

Take a look at the exploded view I have attached in a word document. THe CT is built the same way as noted in the exploded picture view.

What I don't understand is how ANY turbo doesn't leak oil with the oil wanting to travel through the clearance of the "nose" of the turbine shaft out the front of the turbo.

Also wanted to add that most big horsepower turbos on the market are "diesel" turbos. To4 etc etc etc. They are all built the same way, unless like some one stated they are "blow through", then they have a metal clad or "carbon" seal machined in the back plate.

 

[MDCmotorsports]

Somebody correct me if I am wrong, but don't the new Holset turbos come with variable geometry turbine housings, and eliminate the need for a wastegate (I've been checking these things out, and they spool faster than a BB). www.holset.com I think it's hy45 and up models.

Yes and no. The variable vein programs from Holset and Garrett are still in limited production.

The most popular Holset turbo series is the X series. HX35 and HX40.

 

[MDCmotorsports]

Also found these sites...

http://www.bullseye-power.com/product_info.php?products_id=56

http://www.dsmtuners.com/forums/showthread.php?p=1292492

http://pictures.bullseyepower.com/

 

[Shawndude]

What I don't understand is how ANY turbo doesn't leak oil with the oil wanting to travel through the clearance of the "nose" of the turbine shaft out the front of the turbo.

Pressure differential. The turbocharger manufacturers are banking on you having more air pressure in the exhaust, than oil pressure in the turbocharger. Since the turbo is really "oil drip lubricated" due to the restrictor in the oil inlet and gravity fed outfeed, this is a reasonable expectation.

 

[MDCmotorsports]

Thats what I have always been told, but it still seems like a possible crappy design.

 

[IJ.]

MDC: Thanks for the pics!

Don't Gas Turbo's use a different labyrinth seal on the compressor section?
(I'm really dredging the memory here way back to when T04's were starting to be in common use in cars here) I remember there was a seal difference in one for diesel use and 1 for gas.

You could safely use a diesel one in blowthrough as long as you kept the air filter clean but in drawthrough they sucked!

I ran old T04's on my Z in Drawthrough without issue as they were different in the front seals (I always assumed it was a ring seal that was different but as you've noted they don't have one so it must be a labyrinth)

 

[MDCmotorsports]

MDC: Thanks for the pics!

Don't Gas Turbo's use a different labyrinth seal on the compressor section?
(I'm really dredging the memory here way back to when T04's were starting to be in common use in cars here) I remember there was a seal difference in one for diesel use and 1 for gas.

You could safely use a diesel one in blowthrough as long as you kept the air filter clean but in drawthrough they sucked!

I ran old T04's on my Z in Drawthrough without issue as they were different in the front seals (I always assumed it was a ring seal that was different but as you've noted they don't have one so it must be a labyrinth)

On non-drawthrough applications, most turbos use a piston style ring seal. This is called a Dynamic seal. On drawthrough applications, the front compressor area uses a Carbon seal, or nothing more than a metal clad lip seal as found in a rear end or transmission oil seal, just smaller.

 

[MDCmotorsports]

I got this email back from www.Bullseyepower.com....

"Too much oil pressure is likely the cause. You can't exceed 55 psi on a Holset."

Thanks.
David Hall