Jeff20B

You've already seen the tranny mount. Can you see the downpipe at the right of the first pic? It's a little over a foot long. The manifold and downpipe are nearly as long as the 20B header, and close in weight.

Racer X

Nice pics jeff.keep us posted as this little car comes along.

Jeff20B

Ok.



I planned out the entire exhaust system for both engines today. I even have a contingency plan if the 20B is too quiet. It probably won't be a problem in NA mode, but you never know.



I have three Rotary Engineering glasspacks that are around 15 years old and still work. Man, I would pay good money for some new ones for my other vehicles. Too bad RE is no longer in businenss. Anyway, they range in length from 15, 18, and 26 inches. The 26 incher is too long for this car, but I think I can mount it perpendicular beneath the fuel cell. It's stuffed with some sort of rotary resistant fiberglass, so it'll act as a heat shield. Besides, my MG has a 26 incher behind and within two or three inches of the stock, black, metal tank, and it's never been a problem. I think the plastic of the fuel cell should be ok, even though the glasspack will be mounted below. Heat rises. I'll keep an eye on it.



I also finished plumbing the fuel system today. I've just gotta run some power wire. I'm going to flush out the lines tomorrow and then add another fuel filter to protect the carb from any debris that may still be in the lines between the pump and the carb. I already have a filter between the tank and the pump. They're Fram G3 which are a tight fit in 3/8" fuel line. Rotaries list G12 filters (5/16" line), so I've gone one step up in size.



I have some 2" exhaust pipe and several U bends. Since this is for the 13B, 2" is ok for now. Should I bother with 2 1/4" or 2 1/2" for the 20B? It would mean cutting off the welds from the glasspacks and starting over. I'd rather not redo the whole thing. Do you think an NA 20B will be ok with 2" front to rear with my straight-through glasspacks? I know, I know, backpressure is the devil and all that, and there should be very little in this system, other than the bottleneck of three pipes going into one. Thoughts?

Racer X

On a 3 rotor I would say you need a 2.5" system.Even my 13b NA has a 2.5" system.Damn 20B would be loud with a 2" system

Jeff20B

I think you're right. I'll have to get some 2.5" stuff. Do you know if Racing Beat sells 2.5" material in that .125" wall thickness?

Jeff20B

They don't sell any 2.5" stuff. I guess I'll just build a 2" system with what I've got here for the 13B and then rip it all out when it's time for the 20B. At least now I'll be able to use both 26 inchers for maximum quietness.

Racer X

I bought some cheap exhaust pipe from an exhaust shop for like $80 and the walls were thicker than the stock pipe it had.

j9fd3s

yeah normal 2.5" pipe is fine

Jeff20B

Maybe I could prep the RE glasspacks and then take the car down to a muffler shop and have them fab all the bends and stuff in 2.5"? I suppose I could weld on an 18 incher behind the header and hope it's not too loud? Yeah, I'll get a couple 2.5" flanges and go from there.

Jeff20B

I want to hear how loud the car is with the stock 13B exhaust manifold and one 26" RE glasspack before I continue building the exhaust.



All I have left to do is mount the 16" E fan, wire it up (with a relay), and run a wire to the back for the Carter fuel pump. Then I can fire it up.