I just got my spearco guide to intercooler and was wondering if any of you guys have some input. The flow charts are based off of engine size. So my question is, should I go with 1.3L. Considering we have combustion on one rotor 75% of one rotation (rotor), I think we should assume a larger engine. Let me know what you guys think

 

Well I know little in this subject area, but clearly a rotary doesn't breath like a 1.3L piston engine does. I would suggest you find some engines with comparable power/breathing characteristics. We don't want this turning into another 'is a rotary a 1.3L or 2.6L.'

 

It is a 1.3L. However, it does breathe more like a 2.6L because unlike a piston engine the power cycle on a 13b is 270*, where as a piston is 180* of the crank rotation.

 

The cfm will be more accurate, especially if you want to compare the intercooler stats at different rpm's. If you don't want to figure out the cfm on your own, then 350cfm will be close to your max figure.

BTW, the 13B is most comparable to the 2.6L / 160 CID.

 

yeah I was figureing 450 CFM for a water to air sparco just to be on the safe side.

 

Ok, so those CFM #'s listed are NA cfm's and not boosted CFM? I'm shooting for about 400 rwhp out of a 60-1 or something similar....ahhhh..so many assumptions. Core 2-192 looks pretty good, as do quite a few others. Pretty much any of the cores that they list for $518.00 looks good..DOH.

I also need to figure out where to route the IC pipes. Right now it's looking like making a hole where the old battery vent pipe was and another where the fuel pump relay lives. It seems to use the Greddy kit, you have to ditch the windshield washer tank. My IC will be limited to the space between the *frame* rails in the area right where the horns are located, just infront of the oil cooler.

so my core with endtanks and outlets (top view) would look kinda like this

\______/

 

You could do it like this... top view. Using mandrel bent pipe it shouldnt choke the air much. Or you could have the end tanks welded differently.



These guys have an excellent lay out of the different styles you can do
http://www.extrememachinesperformanc...ercoolers.html

 

wow thats is a great website dr0x!

 

Oh, sorry about that, I forgot that the Spearco charts are based on piston-head cfm numbers as opposed to actual cfm flow through the IC, which means that Icemark's 450cfm would be more correct for a street-driven RX-7. As far as I can tell, they are using the cfm at the intake and then correcting for efficiency. Now that I'm looking at the charts, I also notice that all of the flow rates are based on 6,000 rpm (dang piston engines). Anyway, a ghetto formula for approximating the Spearco charts for a rotary engine at 10psi would be something like CFM = (CID * RPM / 1409). That same formula should be about right for a piston engine if you divide your answer by 2. It's not going to be exactly correct, but it should be close enough to show a trend on the chart, which is all that you should be looking for anyway. Like you posted, there are many assumptions.