wastegates / blow-off-valves

[jesusgatos]

I know there's a 5-ton turbo that has an internal wastegate, but I've got a fresh D-series turbo that Ken ported for me and I just bought a fresh LDS engine (still in the crate), but that has a D-series turbo on it too. So let's talk about external wastegates and blow-off-valves. Anybody added one to their turbo multifuel deuce? What kind of wastegate/BOV would be best-suited to this application?

 

[gimpyrobb]

Well, I only use a pyro, so I don't know what max boost is normal for an ldt/lds. I would think you could get a saftey blow off valve plumbed in pretty easy. Are you worried the D turbo will blow out the head gaskets? Did Ken say that should be a concern?

 

[jesusgatos]

No, I haven't talked to Ken about this yet. I was going to send him a PM, but figured that others might be interested in hearing more about this too. I'm not really concerned about anything, as much as I'm interested in making the most of what we've got to work with. I'm not trying to make the MOST power, or build the FASTEST deuce. I'm building a big, heavy motorhome, and will be towing a big, heavy trailer. But better is better, right?

 

[scooter01922]

Personally and this is just IMO a wastegate/blowoff valve is just one more thing to malfunction. It works well as is so i see no reason to monkey with it.

 

[tm america]

hmm not sure youll need a waste gate .what rpm are you planning on running it up to. i have mine turned up pretty far and am running about 27 psi on my ldt-1d i would bet that if you put the same turbo i have on a lds that is running higher rpm lets say 2900 you will be in the area of 30- 32psi boost.and with the lower compression of the lds you should be fine

 

[gimpyrobb]

I think you should try to find the 5ton adapter so you can put the starter on the drivers side and then find a 5ton turbo with the wastegate. I have heard they make boost quicker and hold it for a while to move the heavier trucks better.

 

[tm america]

that would probably be best .i'm not sure how much you'll gain from porting a d turbo or if it will keep up with the fuel curve on a lds

 

[jesusgatos]

Hmmm, maybe it's my misunderstanding. Is the only function of a BOV / wastegate to regulate the ultimate boost-pressure? I thought it helped to make the engine a little bit more free-revving, but my knowledge of turbo systems is pretty limited...

Any of the turbo experts care to weigh-in on this? Ken?

 

[Josh]

What did that LDS set you back if you dont mind me asking?

 

[tm america]

a waste gate is there only to limit max boost .the reason the waste gate turbo it better is because it flows more on the compressor side and the exhuast side . so it can make more boost at lower speeds without overfueling. it can take more fuel . the c and d turbos are pretty restrictive and cause overfueling due to restricting the air and exhaust . this is how you can get more boost at lower rpms with the waste gate turbo without melting the engine with high egts.but the engine can still only take so much stress this is where the waste gate comes in

 

[tm america]

i'm not sure how much a ported d turbo will flow.i guess youll have to stick it on there and keep us informed of the outcome .but the lds has lower compression ,more rings on the pistons and one more oil cooler tube to the bottom of each piston so it should be able to take a little more air -fuel than a ldt ,i still dont think you will need a waste gate with that turbo as the rpm range is not that much higher then the ldt

 

[stumps]

i'm not sure how much a ported d turbo will flow.i guess youll have to stick it on there and keep us informed of the outcome .but the lds has lower compression ,more rings on the pistons and one more oil cooler tube to the bottom of each piston so it should be able to take a little more air -fuel than a ldt ,i still dont think you will need a waste gate with that turbo as the rpm range is not that much higher then the ldt

The bottom ring on the LDS piston puzzles the heck out of me! It is beneath the oil ring, which has slots that go into the inside of the piston (if it is like any other oil ring groove I have seen), so it will do nothing for compression. What is it for?

-Chuck

 

[tm america]

i would think it to be another oil ring the more oil you can keep on the piston the cooler it will be .rather than just keep enough oil on the piston to lube the cylinder walls i think they wanted to keep enough oil on there to help disapait some of the heat.

 

[Beerslayer]

i have mine turned up pretty far and am running about 27

Hey TMA, I have seen your comments before about the 27 PSI and I am curious about that.

I turned my pump up one turn and am getting 12 PSI boost max. Is it purely a matter of turning up the pump even more to get more boost and power?

I already drive it by the pyro and don't let it get above 1100 deg, keep a close eye on it. I would like more power if that is all it takes.

 

[tm america]

beerslayer you probably have a c or d turbo .thats pretty common for one of those turbos with the fuel turned up.my motor is labeled as a 465 1d but it has a lds427 turbo and the injectiion pump is different to. i believe when it was rebuilt to lds specs at the depot in 92.if you have a c motor it.s not gonna take much more fuel than you are running now.since they dont have ceramic coated pistons like the 465 1d and lds do.there are a couple other guys with the same set up as me and they to are getting 20+ psi out of their turbos with the fuel turned up. .so dont try to get the same readings as me just do the best you can with whats on your truck . and you are prettty close judging by the egt you have .it.s all about the combo .if you have a ldt 465 1d you can switch out to a lds 427 turbo and turn the fuel up you will double the boost and see a huge increase in power

 

[ken]

The LDS turbo with the waste gate won't give you anymore boost pressure than a D will. When the pressure gets to a set point the wastegate wil open and slow the turbo. The advantage of this turbo is it will produce more boost at lower engine speeds. Allowing you to hold a gear longer before a downshift.

 

[tm america]

exactly right ken the waste gated turbo is limited what max boost will be.how much boost have you been able to get out of one of the ported d turbos it seems that is a big mystery

 

[tm america]

for those who dont know the lds 427 turbo is a non waste gate turbo it looks similar to a d turbo but the compressor side is much wider and flater

 

[ken]

My goal with boring and porting the casings is to increase flow. More CFM's. This helps lower EGT's. The more air flow the more fuel can be added. Boost is controlled by heat. The more fuel the faster the turbo will spin. To a point. Untill it starts to cavatate. My figures are based soley on the flow bench. My M35 has served as a test bed also. But at 19PSI the head gaskets blow. No matter what gasket i use. Mabye because i don't have a TD block?

 

[ken]

TM, 27PSI is pretty impressive! What elevation do you live at?
Jesse, I'd like to know what temps and boost you get with your turbo. Espacily when pulling at higher elevations. It would help alot with my research