Is that WITH or WITHOUT your fat head in it??????

 

Yes, yes it is. $1800 brand new. At this point, I don't really care. I've got enough turbo cars already, and I figure I might as well see how much I can screw with this one. I am having an issue though figuring out just how much I can obtain from each. I've got 155rwhp to start on the GTUs, so roughly 180bhp. Now if I run a eaton to 13k rpm, it should be pushing roughly 700cfm. Factor into that how much it sucks ***, and it should be moving around ~600 to be safe? Which is effectively twice as much air as the engine should be pulling around 8000rpm (which will be my new 'effective' redline). After this, I get lost. Figuring out just how much pressure that is (with heat, compression, etc), and how much more power that would yield, I've got so many mixed results it's driving me crazy. But regardless, if this doesn't work, I'm simply going to get pissed off and see if I can't get 400 out of a whipple.

 

2 things.

First of all, spinning an eaton to that speed (unless maybe a Gen V) is going to be past the point of diminishing returns. An MP112 might be a LOT better for you, even a hybrid setup (M90 case with extension and MP112 rotors).

That price on an 2300AX doesn't include a snout does it? If so, where'd you find it? I'm looking for one for my other car...

 

I would buy the kit if I had a lot of money. I'm talking like 20-30 grand just lying around waiting to be tossed into a money pit.


btw- Jaared

That quote of me in your sig lol!

 

The SC m90 was still relatively effective up until 12000, after that it started to fall off dramatically. The porting yeilded good results running them up to about 13000. After about 13500 they pretty much run out of steam again. Again, this is what I've seen, talked about, and been discussing with people. I've seen numerous dyno runs with them running up to 13k and still doing OK, I think that's about their limit. I'm still a bit weary about what I can squeeze out of this damn thing. Someone shed some light on the couple of things I'm missing. I know very little, and I admit it.

 

Well, it WILL run "efficiently" with proper velocity stack porting of the inlet and cleaning up the outlet, but that efficiency is still going to put out VERY hot air. Hot enough to knock on my 8.5:1 compression 3.8L piston engine. Knock a LOT on hot days. That WILL kill a rotary in a hurry. I can name several people off the top of my head that have blown holes in pistons with hot boost. The other thing to keep in mind is overall efficiency of the engine. The more heavily ported it is, and the better your exhaust system is, the more air you can push through properly. We're not talking turbos here. You only need as much boost as your engine can use. Also, with a roots, you want a very short distance from the end of your blower to the point where the air enters the combustion chambers. The roots can't compress air within itself (screws can, that's why they rock) they compress it in the manifold, more manifold means more air to compress, and that'll mess with the efficiencies as well.

Obviously the thing to do is hook it up (short intake runners) and start playing with pullies monitoring outlet temp and knock, and air/fuel. I'd run a modular pulley setup. Keep in mind I'd like to see this setup work, it'd be cool.

 

I guess we're just going to have to see. If not, the whipple will be my newest friend. Any idea's on how I could go about figuring out a 'rough' idea of how much power I could suck out of this thing? I've seen about 60 different methods of guessing, and I just wish I could have an accurate way of figuring out just how this is all going to turn out, rather than wasting time going from setup to setup. If you're on AIM, feel free to hit me up. SonikRaT

 

Well, here's the thing. The M90 is pretty efficient (relatively speaking) to about 10K. Keeps blower temps low enough that I'd not expect detonation. If you can figure out how much air your engine will use per revolution, then compare that with the air output of the M90 per engine revolution, and optimize the temperature to boost output to get the most power with the least risk of detonation. I'll see if I can find some RPM/outlet temperature graphs I had laying around here.

 

To drasticaly reduce the length from the blower to the inlet, you could run without an aftercooler.

To reduce the charge temperature after the supercharger,

Can a methanol/mixture be misted in to the s/c intake as can be done with a turbo?

When done to a turbo this can bring surprising temp reduction.

 

10k would be roughly 500cfm. I believe a rotary engine draws ~310cfm @ 8000rpm. As far as the only available graphs I have seen, the temp should be around 230F before the IC @ 10krpm

 

water or alky injection works very well with roots. make sure you inject AFTER the blower though. it can do icky things to the coatings on the rotors.

Removing the aftercooler (which is usually only 1" or so of additional space below the blower) would do very little to decrease plenum volume or runner length. It's total volume is around .25 cubic feet or less when you count in the core. The difference afforded in temperature drop is more then worth the difference. You realize this is an air/water device, not air/air right? The air just blows through water cooled heater core fins, like how your A/C works. Same principle. Matter of fact, guys have used freon systems to cool the core instead of water. Seems to work well.

still looking for those charts.

 

Which roots are you using? T-Bird? 230 F is VERY hot... assuming ambient of 72F for that, that's a 158* increase. Imagine that on a 95 degree day, 253 degrees... that's some HOT air.

 

Yeah, an s-ported t-bird m90. That was the only info I can find at the moment. The Eaton website shows a delta T of ~130-140, but I'm not sure which generation that's for.

 

Okay, I know the 3rd gen (GTP) is about 15 degrees cooler then the T-Bird on typical, and the Gen V (new GTPs) is about 25 degrees cooler then that, so take that as you will. I'm also not sure what Eaton is showing, though I'd venture a guess it's their best (Gen V). FWIW the S-ported ones are the best of the oldies.

 

So in your opinion, what do you think I could squeeze out of that damn thing @ lets say 12K rpm? (640cfm).

And damn, did we threadjack or what?

 

Yeah, just a little, but it's relevant info, as he's looking at a very similiar setup, so I don't feel to bad. :P hehehe

Annnyway, I think at that CFM, you're gonna detonate. I am first to admit I don't know forced inductionon the rotary very well. Maybe if Aaron Cake could jump in on outlet temps that the N/A motor can tolerate non-intercooled.

I'd expect on a 90 degree day, temps nearing 280* F or more at the outlet. I really doubt the engine can take that heat without detonation. Ya know what I'm saying? It's not a matter of boost (if it was 200 degree air, I think it could take it) it's a matter of temperature. Same problem I fought (until the aftercooler was added).

I think this info is helping people, otherwise I'd take it to PM. But with all the roots (cheap hehe) S/C talk lately, I thought some real life experience, research and facts might help everyone. See, even us V8 guys have love for the rotaries.

 

Haha, don't forget I've also got a turbo N/A running just as crazy (if not more) than Aaron. 14psi on the stock 6port block. My outlet temps on that were 210+, after the IC they were around 150ish. Which is kind of what I'm hoping my monster IC will do (even though it's going to wipe out more efficiency)

 

Now think about 70 more degrees without the I/C. :O That's the roots setup.

Now think the 150 degrees without an I/C and instanteous boost. That's the screw charger.

Ah HA! Found it. This is for a Gen III M90.



Close to a 200 degree delta T at 13K RPM. Porting may drop this 15-20 degrees peak. That's still 275* on a 95 degree day. Apex seals would not love you.

 

But I am intercooling it. With my massive greddy IC. This is going to suck some life, but it should keep my temps around 130-140 with ease.

 

so air/air eh? That's gonna turn that M90 into a big fan though. That'll be like having a 20 cubic foot intake manifold... You're gonna have to spin that thing a LOT to get any boost out of it. I've seen it attempted before, but I'm not sure of the results. Definitely keep me up to date on how it turns out.

 

give me the diet recipe
or be my (car's) personal trainner

 

http://www.superchargersonline.com/p...pple_headunits

Are the "nose drives" what you're talking about? The price on the blowers seems a little premium, but the price for the nose drives doesn't seem bad.

 

Well, considering that I'd be spending my budget on getting a TII and only have about $2500-$3000 from my NA being sold, I don't think I would have too much money to spare on buying lighter components or removing things. And the difference in curb weight between an S4 TII and an S4 NA is 225 pounds right off the bat. I don't know about you, but 225+ pounds is a lot to me, although maybe not to you.

Also, for the people giving me **** about not doing a TII conversion - to do it right and get it up to the HP levels camden has suggested, it would cost more. Also, I don't think anyone has managed to source and install a TII motor and tranny along with a ton of aftermarket parts in three weeks without going to an outside source for labor, so you can add even more money on to that.

And to the people telling me to buy a Turbo II - if you can find a TII with a brand new paintjob and a fresh motor, then get it to around 240rwhp (safely) and then buy a good set of wheels and a set of Toyo tires, plus add on Cusco Zero IIR coilovers, Eibach swaybars, strut braces front and rear, good racing seats, and a good head unit, all for a total of $5800, then by all means tell me how it's possible. I hate being a dick but I hate being told that what I'm doing is a waste when I honestly can't see why.

 

I don't doubt that the kit will make power with injectors and a safc and tuning, but add the cost of that and then consider for how much less you could have swapped a tII drivetrain. I really doubt that the stock cluth, tanny , rear in a NA can handle 240 wheel I estimate 150 in my na and i've broked axles. But upgrade the the tii tranny and rear and i bet you'll have a very solid car and fsat too but it would all cost too much for most of us

 

Yeah, that is one conscern, that the transmission will hold up. I already have a max single disc exedy clutch, so it's going to be a batter of the transmission.