'90 W250--'89/91/92 Ramcharger

[ellis93]

Well, he's not real big on spreading info on it so I'm not going to blurt out anymore about it but that's what he told me.

All guys lie about the size of things,especially to women

[Tacoclaw]

An older M112 map, though I don't think you could really call it a map.



The same site also has this little fellow, which says that the M112 uses 60hp to spin 12krpm at 10psi



And this fellow, which doesn't mean crap to me but it is info so I'm stashing it here.



And this too, because it would have been nice to have it a week ago...



Pfffft, running off that map there's not a snowball's chance of getting 70lb/m out of a 112.

[Tacoclaw]

Dang, even more stuff. Once you start digging there's all kinds of crap!

[oldestof11]

The turbo doesn't care what is being pushed into it. IE, secondaries in compounds.

Delta is your temp at pressure and RPM. Useful in sizing things for certain HP.

[Tacoclaw]

Yeah, but once it spools in this layout it's not getting anything pushed into it. That's why the larger turbo blows into the smaller one. A turbo with a 2.6 inducer can only draw in so much air, so what you do is have a turbo with a larger inlet push air into it. The larger inlet is able to draw in more air.

Since this layout is simulating having the smaller turbo in front it's a completely different scenario. Sure it will be making boost before the 52 spools but once it does it will then be like making the HX52 suck through an HX40. I'm not worried about 95% of my driving time with the truck, just the very occasional full throttle, full RPM run.

[oldestof11]

Well, looking at the maps you have the possibility of flowing 700cfm. Now find out how much the bypass can flow and see if those combined flows match the 52. If not, you need to source it from elsewhere.

[Tacoclaw]

Yeah, it's really not looking good... I'm about mathed out, and even with me starting to get generous in certain areas to attempt to make it work it still ain't promising. That bypass valve was something I never thought about, but it looks like a pretty small hole. I'm betting it could really move some air if it was being blown through, but if the turbo has to suck through it it's capabilities aren't nearly as great.

That 700CFM is at 12k rotor speed, which is the max recommended, sustained speed for them according to Eaton, and for my engine only turning ~3500 it would take almost a 4:1 pulley setup to get there. Pulleys are something I haven't put much thought into yet.

[oldestof11]

I can help with the math. I hate it but happen to be really good at it.

[Tacoclaw]

I learned a couple lessons so far tonight, Anyone who packs a supercharger in a box with packing peanuts is a sadistic bastard. I literally just spent 20 minutes getting all these little buggers out of this thing...

Second, this thing is freaking huge. It's about 4 inches taller than I figured it'd be, and once I got to looking at it I realized that it's about 6 inches longer than it needs to be. The rotors only go about halfway back through the case, the rest of it is all for the air intake and I assume to be able to cover the valley on a V8..

Third, this booger is heavy. This may not be something I can just throw in alone like I have everything else I've done.

Meh, I've got to split a RC apart so I can make some room in the shop.

[PToombs]

Taco, what is the reason for the blower pushing air into the turbo, instead of the turbo pushing the air to the blower? I thought about it and can't see where it makes any difference.

[dazedandconfused]

Carl was having issues with the rotors in the supercharger flexing when boost was being pushed into it.

[Tacoclaw]

Well, the gist of it is that a blower is an air pump, if you compress the air it's moving it's going to be that much harder for it to move, using more HP and just being rough on the blower. There's also the thought that the blower may possibly restrict the output of the turbo, though I don't see that being a problem with mine being so similar in size.

I'm honestly debating on going back to my original plan and running the blower afterwards. A lot less math involved and it will work, just not optimally. I'm just wondering whether there will even be room in that area since this thing is so giant.


Carl said he didn't have this problem until the 55psi mark, so worst case scenario I'll just gate the HX off around 40psi or so.

[turboram]

On some detroits the turbo pushed through the blower .check out this one
http://m.youtube.com/index?&desktop_uri=%2F

[Tacoclaw]

^ Yeah, but their a GM so people expected them to blow up all the time anyways/
I'll be doing it that way and not looking at it again until the blower explodes.

Now then, here's some pics to put a size to this thing:


Not gonna happen.


Here's where I plan to try it at for now. Point the compressor down and do a 180* loop into the inlet of the blower, then run a pipe over the turbo inlet tube and bring it right into the middlecooler. I'll be milling off that part that sticks out of the bottom, it's to mount a heat exchanger core into but those things are hella expensive so it's just in my way.



I'm not positive on this yet either as I don't know if I'm going to keep the manifold flipped or not. I'll have to see how the HX sits in there both ways and decide then.

[dazedandconfused]

Just a question for me but if you put it on top of the valve covers how high does it stick up? Could the hood be closed?