Sarge1124

Just curious what size turbo is on the 03's and what kind of hp can they handle. Mike

doug

to the best of my knowledge, it is an HY 35 with a 10 cm housing, wastegated to 28 psi, and handles up to something just under 400 HP. I think some of the guys running the bullydog box are running the stock turbo but I dont' remember where they are HP wise -- 400+ I think, to the ground.

I'd like to see some discussion on turbo upgrades. some guys are playing with twins I know. that should be cool. wonder if the stock turbo is good for one of the twins?

WTTD

The turbo is an HY35, it should have a 9cm exhaust housing (I'll see if it's stamped 9 or 10 this evening). The 03 we are testing with is 6-speed 4x4 4dr dually w/ 5" straight exhaust and Scotty Air III, it will see 1350-1400deg. pre turbo w/ just a BullyDog adjustable box. This truck is getting a turbo next week, I am going to have to get some machine work done and buy some extra pieces to get it plumbed in. This turbo is an HX35/40 Hybrid w/ modified 14cm exhaust housing. We will see how it works, there are not many turbos on the market for the 03's. I hope to have a towing turbo upgrade avaliable real soon. There is not much room under the stock exhaust manifold and above the frame, kind of a tight fit. These hybrids should be good for up to 450-500HP, time will tell.
www.westtexasturbodiesel.com

Push Rod

The stocker turbo (HY35/10) isn't much good past an Edge EZ in its 80 HP setting. On an HO engine, that puts you about 330 HP or so. The Bully and Quad boxes make some of their power with timing, so we've found the temps stay under control a little longer, say to around 350 HP. After this point, you are gradually getting out of the range that the charger can handle.

Rod

doug

A towing turbo would be great. One important consideration here is the exhaust brake -- a turbo mounted exhaust brake won't bolt up to an after market turbo because the latter is going to have a 4" or bigger mounting flange and intended for 4" downpipe or larger. Would you agree? So the bolt-on solution from the likes of pac brake won't work if you do a turbo upgrade.

This means you have to use an in-line brake, and pac brake (as well as others) makes em. This is especially good for guys who tow AND want to get some mileage out of the stock turbo AND who want to be compatible with the future if you do a turbo upgrade. The only downside to the in-line e-brake is that it is more susceptable to road dirt. might be an issue for 4x4 offroad driving I don't know... comments anyone?

I'd like to hear from the heavy towers in this group to see what your EGTs run and what air upgrades you have. At first thought, I'd expect a pressure/timing box like the current bullydog to run a bit hotter than a pulse-width/timing box like Edge, TST, and the new bullydog, but thats just conjecture and we currently have no data on the emerging pulse width boxes.

What I'm searching for is how far the stock turbo will take you and what the weak spots REALLY are. That is, if one were to install only ONE upgrade at a time, I want to know what the optimum order would be, and submit the following just to get people talking:

1. EGT/boost gauges. I hear that the stock truck runs pretty hot when towing so you dare not do anything without gauages. I ran my 02 (empty only) with an EZ box and no gauges but that was a dice roll. What I'm hearing is don't even think about doing that with a 3rd gen because the EZ is pressure only (no timing)

2. fueling box. I put this at number 2 to allow for the owner to evaluate their own driving conditions and the resultant EGTs to see if any air upgrades are necessary. some of the new boxes emerging now combine EGT and boost gauges and this combination might be acceptable to some. Of course, if the stock truck pushes the EGT limits, then that needs to be corrected before adding more fuel.

3. cold air intake. I put this as the first air upgrade in part because it is the least expensive. I'm hearing that the stock airbox is still a wimp. If you upgrade to scotty III then you will likely run cooler which will help the towing situation. Theres a very strong argument to put this before #2 because the stock truck, when pulling hard, would benefit from the EGT reduction.

4. exhaust. stock system is 3.5" turbo to muff, and 4" muff back. I'm hearing that the front part of the system is the restriction, including the muffler, and that guys are getting 100 degrees or so from a DPP or similar full replacemernt system.

5. turbo. Apparently, the pressure only fueling boxes (granted that the pulse width boxes are not tested yet) are still too hot even for 4" exhaust and a new cold air intake? If thats the case then the turbo would be next.

6. 2-piece or 3-piece RV manifold? (not sure which it is...). ATS manifold?

WTTD

DOUG,
What is in the works is an exhaust housing that will allow you to use the turbo mount exhaust brake. I don't know if we can make it work right now. The inline brakes are excellent, they have less restriction when open than the turbo mount and they work every bit as good. A friend of mine has a 4" inline on his 96 dually, with over 200,000mi on it. Other than rewiring it once the brake has worked great, and this is a ranch truck.

On the 03 truck described before, the EZ runs up to 1200deg, but we did not tow any really heavy loads with the EZ before switching to the BullyDog. The BullyDog fuels later in the power band by the way. The EZ is max for a stock turbo if you want to tow and expect a long turbo life. I do notice that when towing heavy (20,000lb load) the EGT's will stay lower if you can keep boost at or around 30psi. It will hit 40psi, but EGTs are up there too. The stock turbo is just out of it's map with the higher hp boxes and it is not performing well. ATS has a manifold for this truck, I do not have one yet and have not put my hands on one. I
don't know what effect the intake and exhaust had on the dually, we installed everything at once. On other trucks that I have installed the EZ and guauges on the EGT's are easily kept under 1250, as long as the air intake is replaced. That factory airbox is a POS.

Charles C. Stan

I have an in line brake it goes thru a self test every time I start the engine. It's fun to watch the startled looks from some of the service people I have the early holset wastegated turbo origonal equipment. Would that mean I could bolt in a later hy35 directly and would it be an improvement for my 27 foot fith wheel towing machine.