Low RPM boost?

[Firepower354]

Has any one used a Garrett GT25 or similar? 4.9L@1700RPM cruise, 3000RPM max, and the calculators say it's all I need. Draw-through, with very short tracts should give good mixture atomization, and thus even distribution, it seems? 4-5 PSI should more than make up for added heat losses and provide a decent torque boost? Volvo, etc, come on boost at low revs, so maybe a BB6 can? Would a blow-through, intercooled setup be better?

 

[country fried 6]

with that low of boost you can probably do just fine without an intercooler, intake temp shows only 140*F using the squirrel performance calculator. horsepower at 5psi max shows 200hp intercooled, 185hp no IC. for 15hp might bo worth doing and intercooler though, that woud require a blowthru setup.

just curious, why you plan to do a draw-thru?

i'v been mulling over the idea of a build similar to the one you propose and keep having the thought that a blower might do the low rpm job a bit better. thoughts on that?

 

[Firepower354]

Draw-through w/o intercooler seems like it would stir up the mix better, making for more even mixture. Or maybe not? Smokey Yunick's Vapor Cycle? Lots of hot air, but a few ideas that I might try. Also would allow propane fueling, should the need arise. I have a big water tank, too. I may play with hot v. ambient water temps.
I bought one of these, in case:
http://cgi.ebay.com/ebaymotors/_W0QQcmd ... MEWAXQ3aIT

Blow-through seems easier, in some ways, I suppose. Lots of room for an intercooler, and a turbo mounted to a coated F700 manifold should be the ticket. Intake side to the front. Very short plumbing. Velocity v. restriction calculations are needed for SP180 use, if I find one.

 

[LateApex]

Best of luck with the build. You should be happy with the extra power.

But then, you're going to want more power someday. If that happens, it'd be good to be able to upgrade, so maybe keep that in mind?

 

[Firepower354]

Best of luck with the build. You should be happy with the extra power.

But then, you're going to want more power someday. If that happens, it'd be good to be able to upgrade, so maybe keep that in mind?

Well, maybe if I do a hotrod, later... E350-based RV only has to maintain 55-60MPH and do so on the least fuel possible.