It's been done before. I don't see how drive pressure could ever be a issue as far as there being to much.
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It's been done before. I don't see how drive pressure could ever be a issue as far as there being to much.
I've seen it once before, and it didn't work out so well. I think Andrew will get it to work though. I could never figure out just how the piping was supposed to work on this thing....
I have been wanting to do something like that on a triples setup but with a little more of a twist. Maybe one day.
Cool build I can't wait to see it done!
Cool build I can't wait to see it done!
I've seen it once before, and it didn't work out so well. I think Andrew will get it to work though. I could never figure out just how the piping was supposed to work on this thing....
That setup is piped differently than Andrews truck is. Custom autos blue trucks triple setup had one atmospheric flowing into two primary chargers. It didn't work out so well, and the piping across the motor was originally going to go to intercoolers over there but it never worked out.
Here's where I see a possible problem. Typically, a compound turbo setup will have the highest drive pressure before the secondary stage (between the cylinder head and the turbo(s)), and the pressure will drop a little in the hot pipe between the two stages. Since most quality and properly spec'd turbos see about 1:1 drive to boost ratio, we can assume the drive pressure will be close to whatever boost it is putting out. So if the atmosphere turbos are putting out 40 psi of boost, drive pressure should be somewhere around the same. Now the secondary would further compound this up to maybe 80 psi, but in order to do that, it would need around 80 psi of drive pressure. There is no way the drive pressure can get that high without it being even higher in the manifold.
In no way am I saying it won't work or hasn't worked, I just can't make sense of HOW it could or does work. I looked for some other examples of this setup but came up empty handed, so I started a thread on CompD asking about it. Maybe I'll get a better explanation there.
I have been thinking of doing this with the big turbo in the valley. I don't see a problem with it, because you still have the same amount of exhaust gas going through the system no matter what way you plumb it. You will still need a gate around the small turbo, it just will not drive big turbo.
I would think you would need a pressure drop across the turbine wheel. I would really like a little more info in how it works.
I hope you don't take my questions as insults. I think it's an absolutely beautiful build. It's just different from anything I've seek before, and I'm trying to understand how it works.
I've been pretty sick for a few days so I'm a little fuzzy here. So your saying there won't be enough drive pressure to spool the 55 and if there is enough it will be to much? Or am I reading your post wrong? The 1.1 ratio sounds great and is ideal but it's rarely the ratio people are actually running even though they "looked at the gauges". The only thing i'm worried about is getting the 42's lit and that has been talked about from the start and we have some things to try if that's the case.
I don't know what will suffer. I'm no turbo expert and never claimed to be. I just look at the setup, and I can't see how it would work. In my mind, a turbo works by building up pressure on the inlet side of the turbine wheel to drive the compressor, and the pressure differential across the wheel is what causes it to spin. The larger the differential, the harder it tries to push it creating more boost. I don't know if either, neither, or both stages would have trouble. I just look at it and can't make sense of how it would work. All I know is it is different from every compound setup I've ever seen, and I assumed there was a reason they are built the way they are. Like I said, I'm not saying it won't work; I'm just trying to understand how it does.
I'm curious if one bank can lite a gt42? I think it can work. The exhaust pressure will be higher on the 42's for sure but it still has to travel through the turbine of the 55 to get out. I would think you could run a tighter housing on the 55 and make it work pretty well. Shouldn't be any restriction in the 55 for those 42's to blow into. Sounds like there is more than enough fuel and Nos to make sh*t happen:thumb:
I'll say this. When it leaves MA it WILL spool no matter what we have to do to make it. At least a few times anyway 
I'll say this. When it leaves MA it WILL spool no matter what we have to do to make it. At least a few times anyway
Haha don't you even curse old faithful!!