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I've read about log style systems that it works well on, what about one that's divided all the way to turbo? (S475 ) wastegate will be a 60mm. Isn't the whole hostile side basicly under same pressure? No less than 10 lbs if you think that makes a difference. Anybody done this??
You are right, stupid questions deserve stupid answers
Are you familiar with the kb racing set up?, it places the wastegate in a 90 degree bend long before the turbo and even before it meets up with the other bank, and works very well
Now because I understand that's it's an apples to oranges comparison, well..... I guess that's why I asked lol!
So conventional wisdom obviously gives a resounding "no", but how much boost is one bank of cylinders capable of?
Could the driving force of one bank being bled off be enough to keep the psi on a stock 6.0 with a s475 between 15 and 20 psi??
Is there just many varables??
As someone who used to tool around in a 67 Caddy in high school, I whole hardly give you two thumbs up! Be forewarned, the right rear will always be bald for some reason.
Why not put the waste gate right at the turbo flange? You could undivided them?
I might do that, that would be easiest, I wanted to run divided, and will prob make a merge for the wastegate, but was wondering about doing something a little different. Thanks for the props!
A few years ago Saab made a V6 turbo, with one turbo and fed from only 3 cylinders. A strange concept, and it never really took off, but it did make it into production.
Not quite the same as what you're proposing though.
IMO there is no sensible reason to try what you are proposing though. That isnt to say you cannot try it, but there are no sensible reasons for doing so.
I'm running a KB log with my wastegate down on the passenger side crossover. Boost creep is a concern with all the discussion about placement but I think the application and turbo selection is a big part of it. With my research limited to feedback from the 2 top truck log builders and the internet, an S475 at 15-20 psi should not have an issue with a single bank wastegate.
My question is why the divided setup? Why not build it like the KB kit?
It's my understanding from guys on the forums that have done both, (divided ,and undivided) that the divided setup spools faster, 4/600 rpms, witch would be nice, as this car is mostly for the street. Dont want to make unessacary work, just want to be as efficient as possible. Anybody have any input on that?
It's my understanding from guys on the forums that have done both, (divided ,and undivided) that the divided setup spools faster, 4/600 rpms, witch would be nice, as this car is mostly for the street. Dont want to make unessacary work, just want to be as efficient as possible. Anybody have any input on that?
A proper divided twin scroll setup on a 4cylinder will spool better. It would be almost physically impossible to achieve the same on a V8 due to cylinder firing orders.
A proper divided twin scroll setup on a 4cylinder will spool better. It would be almost physically impossible to achieve the same on a V8 due to cylinder firing orders.
I did learn that also, but it vas v8 guys that claimed earlier spool times seperating the banks. Got a big boat to get moving, any little thing I'm willing to trylol
If you dont have the 60mm gate yet(doesnt sound like you do), get a pair of 38's or 40's, and put 1 on each of your divided hot side tubes. done. yes it adds the cost of another gate, but it will for sure control boost properly
Best to keep it simple and not "reinvent the wheel". You would have varying back pressure loads on each cylinder bank, which would do "funky" things. You'll have MUCH more than 10psi drive pressure. Usually a little more than twice the boost you're running. 33-45 psi or so at 15-20psi.
60mm is too large and overkill no matter which route you go. For the price of a 60mm WG you can get two 38mm units.
Keep it simple. 2" piping and 2 38mm WG's fully divided here. Works great, runs 8's on a 370" motor. I can get my boost down to 8-9lbs with the current springs. I'm sure I could get it lower if I wanted.
[QUOTE=Forcefed86;18959094]Best to keep it simple and not "reinvent the wheel". You would have varying back pressure loads on each cylinder bank, which would do "funky" things. You'll have MUCH more than 10psi drive pressure. Usually a little more than twice the boost you're running. 33-45 psi or so at 15-20psi.
60mm is too large and overkill no matter which route you go. For the price of a 60mm WG you can get two 38mm units.
Keep it simple. 2" piping and 2 38mm WG's fully divided here. Works great, runs 8's on a 370" motor. I can get my boost down to 8-9lbs with the current springs. I'm sure I could get it lower if I wanted.
Is the 60mm(witch I do have =) to big because of not wanting to run less than 10lbs psi? Please eloborate.
Alot of 6.0/s475 combos I've seen use the larger gate or dual gates like you said, and I've always thought the reason was if you wanted to run very low boost, and not have "boost creep" issues , witch I also understand has alot to do with placement also. I really want to do full divided with a merge for the wastegate
if you make a merge to run the single 60mm wastegate you will lose ANY benefit you gained by keeping the hotside divided.
I run 2 40's on a divided hotside and it works very well. I recomend it
Is the 60mm(witch I do have =) to big because of not wanting to run less than 10lbs psi? Please eloborate.
Alot of 6.0/s475 combos I've seen use the larger gate or dual gates like you said, and I've always thought the reason was if you wanted to run very low boost, and not have "boost creep" issues , witch I also understand has alot to do with placement also. I really want to do full divided with a merge for the wastegate
The whole point of dividing the banks is to keep the pulses separated. If you use 1 gate it defeats the purpose, allowing the pulses to mix at the WG merge. If you run divided you need 2 gates.
If you excessively large on the WG, control is more sensitive. Lots of guys use a 60mm gate. I'm not saying it's going to hurt anything. Its just not needed. For a "divided" setup. 2 38mm gates is plenty for something like your building.
So use the 1 60mm you have with a standard merge, or get 2 gates for the divided setup.
If you want to use a single gate on a divided system, just Y into it from each side and divide the section to the gate. It's quote common on 4cyl applications to avoid the complication of two gates.
On a V8 though...really dont see it many any real difference.
Kerrdogg had a setup like that, but it's not common practice or easy by any means for a novice builder. Much cheaper and easier to use 2 gates IMO. Easier even than making a "good" merge.
Built one in the housing itself too...
Last edited by Forcefed86; Sep 10, 2015 at 09:52 AM.
I like the gate in the housing, does it work well?
I had read an article done by turbosmart, and they actually recommend against it, claiming that it's to "disruptive" any thoughts?
I think it will work plenty well for what you're doing. There may be small turbulence losses, I can't imagine you'd feel them in your application. I'd be afraid I wouldn't have the skill/precision to do a nice job of it in my shade tree garage. If a weld came loose on something like that It would probably wreck the turbo.
It also involves welding on cast iron which is usually a bad idea. That said all the cast LS manifolds I've welded held up great.
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divided scroll, single bank wastegate? ? 
