aroundhere

Maybe you guys can help me. How much boost should I be able to produce reliably day in day out with a stock hx-35(enlarged wastegate hole and divider drilled) and a bht3b? 35 does have its own waste tube going into hot pipe. I know, I need a bigger turbine housing . Maybe a 14cm wastegated?

I had it set up running 45psi and every thing worked great for about 20k miles. I was on my way to town and blew around some slow traffic. When I stopped at a stop light and took off, I heard a loud scream. Drove it a couple of days before I could take a look at it. I could tell it was the bht3b due to the delayed spool up scream. Got it apart and found the impeller had been rubbing the compressor housing and was chewed up on one side. Bearings gave up I guess. It did send some small pieces threw the 35 but just pinged up the impellor a small amount. I guess my engine ate it from there.

I got a new cartridge and cleaned up the compressor housing and now she's back going. I'm worried about pushing it too hard now. I didn't think 45lbs would overspeed anything, but I've been wrong lots of times before. Just ask my wife .

Running a tst(4-3)w/edge ez(2). Exhaust temp 1250 to 1300 in manifold. Truck is a welding rig weighing in at 12050lbs.

O'K, it didn't really grenade.
Thanks for any help.

04 3500 reg. 4x4, 6 speed, con ofe, ats manifold, tst, ez, uni air filter, 5" exhaust, 180 thermostat, airdog, airbags

ataboy9026

Make sure you have a large enough oil supply and return line from that turbo. And let it cool down before shutting down, if you don't have a guage then wait 2 minutes after stopping in everyday normal style. Longer if you have been "spooled up" to pass some Fords < oops I mean traffic >

BlueDually

If thats a home made set, it might be a good idea to run a boost guage after the bht3b, before the hx, to see what its making for boost.

45lbs is not to much if the are gated properly,

aroundhere

Ataboy- I'm a big stickler for cool down and I'm using 1/4" steel braided for oil supply and 3/4" for drain. I wondered abouy oil supply also. 1/4 big enough? It is the crimped style that I had made at McCartys. I'll check it out.

Blue dually-I did have guage at one time installed and it produced around 18-24psi the best I can remember. I've changed things up a little (turbine housing size) so I'll recheck pressure when I get a chance. Hx-35 wastegate opens at stock pressure, its unmodified.

Thanks again

BlueDually

24 psi is what a ht3b on a N14 would make normaly, so that should not be the problem,

what size is the supply line on that turbo from factory?

1300 degrees seems high for a moderatly fueled truck, How big is the exhaust housing on the 3b?

ataboy9026

I would inquire about the line size on a big rig with that turbo, it may need a larger line due to the larger shaft and larger "surface area" that the oil needs to cool. But I would assume 1/4" is okay if the return is not restricted in any of the fittings leading to your 3/4" return line. Maybe hook up an oil temp guage in that return line somewhere and check the temp coming out of that turbo and then also hook it up to your smaller turbo and compare. If the temps reach over 230 or so you may want to run a synthetic oil as conventional breaks down at those high temps.

abc4yew

45 psi measured where.....I have three boost gauges and on hard accelerations you can get 70psi drive pressure for a moment and only 45psi on the intake. If you have a boost on the intake horn and exhaust manifold plus one between the two turbos like on the boost port on the big turbo housing then you can see what is really going on. Small compressor wheel on 35 creates a restriction for the 3B which causes the Turbine side to see 75psi and the compressor side air braking......somethings gotta give. ks

aroundhere

Bluedually-I'll check out our Kenworth when it gets back in the yard to look at oil line size. It has a N14 in it with a HT3B. One of my pyro's reads around 1300 and the TsT usually reads 50 to 100 degrees cooler. One reads 1-3 other 4-6. I swaped them and they still read same, same one read hotter. I was running a divided 23cm now it has a 26cm with open flute.

Ataboy- I said 1/4 but the line itself maybe 3/8 and the fittings 1/4. It's been awhile back and my memorys not so good. I might get a chance to look tomarrow when I get off work. I'm driving a different pickup this week. I don't think return is restricted but I'll look at that also.

ABC-45psi measured at intake horn. Can I use a copper coil with guage on the end connected to manifold to measure drive pressure? Something to just check it not permanet.What's a good ratio? I would think 1:1 would be nearly impossible. I'm probably way off.

I appreciate the help guys!!! I don't want this to happen again. My engine may not fair so well next time.

lmills

usually copper going to the fitting in the exhaust manifold. I have a section that is coiled up to dissapate heat that then changes over to poly tube. The poly runs into the gauge.

And yes if you have a ratio of 1:1 that is optimum!