I just checked out a set of BD twins, they're used w/ about 1500 miles I think, look brand new, & I can get one heckuva deal on them if I want them, just want some feedback from those of you who have experience w/them, esecially towing. & I was also wondering how far down I could wastegate them to save my headgasket for awhile until I could save some $ for studs, If I have to I guess I could slide the plate back to control boost somewhat?? but anyway, just wanted to know what ya'll thought of the setup before I shelled out a bunch of $$$$ Thanks, Dusty

 

i have them on a 24valve and I will nevr go back to a single again. I do too much towing for a single and the fuel I am dumping at it. I need boost at low rpms. Get them. You can turn the boost down by adjusting the wastegate or buying a boost elbow to turn it down.

 

Dusty, trust me, you don't want them....but tell me where they are and I'll take them so you don't have to ask questions anymore about them....ok ?

kinda out of sight, out of mind type thing ??

 

Are they one of Signature600's twin sets?

brandon.

 

How do you do that? Not being a wisea$$....would like to know. I keep hearing this in different threads, but to my knowledge, boost elbows, MBC's (manual boost controllers) and wastegates in general, can only be adjusted for more boost....not less!

I have been watching threads on BD's twins for a few months and am interested for the future. I like keeping my 4" exhaust and keeping my tranny's heat exchanger with their system...but I suspect they will still run hot EGT's if over 500 hp? They don't appear to employ an external wastegate venting exhaust into the bottom turbo. Anyone know?

RJ

 

rj, I know they don't have an external wastegate.

 

They dont! Then what is this little thingy that comes off the top turbo, has a 1/4" spacer that brought my boost down from past 60 to about 57psi. If I wanted less boost, then there is a threaded rod from the doo hickey that you turn which gives it less boost. Or there is this brass kind of looking thing, that has an elbow which screws into this big chrome wheel looking thing with hoses hooked up to them. Maybe you could take that little 90 degree brass looking thing and put this other brass thing in there which has a six shaped loooking screw. You turn that and the boost either goes up or down according to where you want it. There is the blue tube that goes to this "not present" wastegate. There are two different kinds of wastegates that they used. I had both. The 1/4 plate is the one I have now. The threaded one has more adjustment.

 

The kit comes with the 1/4" plate on the wastegate. If you want less boost, you take the plate out. I was running way past 60psi so I took it out. Now that I changed gears, I am going to put it back in for more boost. I can keep my truck wot through the whole rpm's in sixth gear and never get above 1300. Pulling is a different story. I have to let off after some SERIOUS hills through the mountains. That is pulling over 15,000 lbs. For the camper I never have to let off. That was before I even swapped to 4.10's. It runs even cooler now.

 

The top turbo has a wastegate that can be adjusted like you said. An external wastegate is usually mounted on the exhaust manifold or onto a machined spacer that goes between the manifold and turbo. From their guys usually run another tube from the ex-gate to bypass the top turbo completely and dump ahead of the bottom turbo to help it spoolup. If you go to www.powerbypoole.com their are pictures you can look at of an external wastegate setup.

 

Thanks. How much of a boost drop did removing the plate give you? Do you know your HP/Torque?
RJ

 

I went from 65 or so- 57,58psi. My gauge only goes to 60 but it would go way past 60 before I took out the spacer. 508/1070

 

Looking at their site, looks like I have the exact same thing on my top turbo.