i'm getting a rb header
what else do i need to install it? i know gaskets but ...

i noticed that the rb header has a rectangle at the end of the pipes do i just weld the straight pipes to that?
what do you guys do?

i'm going to run straight pipe back to a supertrapp
88 na

 

You could just weld the rest of your exhaust to that but I highly recomend you buying one of their flanges and weld the rest of your exhaust to that so you can bolt your exhaust to your headers. That is what I have done on my car. My exhaust is in 3 pieces and is a 15 minute job to remove from the car in case I need to swap a clutch.

Because you plan on running the pipes back to a single supertrapp you can do a bunch to change where some of your horsepower comes on by changing the length between the motor and where the two exhaust pipes collect into one pipe. The longer your exhaust stays as dual before it collects the lower (in RPM) in the powerband it will move some of your horsepower. This is desireable for auto-x and road racing. A short distance will move some of your horsepower higher into the RPM range.

And to give you an idea of how long it can remain dual before collecting some ITS cars have exhaust pipes that run from side to side under the car before collecting because the lenght needed is longer than the car itself.

 

I think you get 'er backwards there, chief.
Collected earlier moves the torque peak down, collected later gives more top end. -WG

 

Errrrrrrrrr Wankelguy is right. rpv, buy the flange, it'll line up good and be easier to install/remove the system should you have a problem.

 

Gentlemen,

Please don't laugh me off the forum for asking, but while we are on the subject of headers, what effect does wrapping the headers with heat insulation wrap (2" wide fiberglass weave type stuff) have?

I did it to my RB header and presilencer before installing them, mostly to keep them from heating up the engine bay when left bare.

My front rotor got carbon locked after putting the header on and an apex seal is now stuck "open" so I can't tell. It runs on the back rotor (noise level went WAY up!). I am just wondering if anyone has had experience with exhaust wrap. A co worker of mine said that it keeps the exhaust gasses hotter which allows them to flow better. Sounds like the theory of how a rotary engine loses combustion heat to the inside surface of its oblong shaped combustion chamber, making ceramic coated rotors and housings a more beneficial idea than if put on a piston engine.

 

I always thought the reason for wrapping headers was to help keep the underhood temperature down so the motor would get cooler, denser air.

 

I'm pretty sure partstrader is right, but I'm only going off first hand experience with the five or so exhaust setups I have fabricated for my car. So maybe I'm wrong, but when I first made the switch from a short primary to a long primary system, the power did move lower in the rpm's, torque came on lower and the midrange had more strength, I also lost power above 7000 - those are all official butt-dyno firgures. The exhaust was the only variable at the time, so it was a controlled experiment. It is possible that the scientist in the lab that day made some bad calculations, but that's the story as he remembers it.

 

Its for both reasons stated. It keps underhood temps down, allowing the engine to run cooler. It also has the effect of keeping the heat in the exhaust pipe, allowing the gas velocity to remain higher for better scavenging. It will shorten the life of your headers, especially if you race (i.e. lotta time at high rpm's.). Not a huge concern, but something to be aware of.

 

Howdy, Jeff!
Say, did you ever try the ATF or Techron treatment on that sucker?
You know, when people would take the air pumps off of thermal reactor equipped cars, the TR's inner chamber would get red-hot and after shutting down the motor, if the apex seal "parked" in the exhaust port, the heat would transfer back into the motor and de-tension the apex seal spring. That's one reason why I don't wrap my headers, because I'm concerned about possible heat retention problems. Plus, I'm cheap.
On the subject of short-primary vs. long-primary systems, Racing Beat used to recommend the long-primary system only for those using ported motors, stating that they would give little improvement (if any) over the use of a short-primary system when used on stockport motors. In recent years, they seem to have changed their position somewhat, now saying that the power increase with the long-primary system on stockport motors may be slightly higher than the short-primary system, but that all the gain is at high rpms. This is of course assuming that the RB setup is used.
The long-primary system is definitely the way to go on streetported motors, though.
And, the demands of auto-x competition are really quite different from those of road-racing. In auto-x, you want the power to come on earlier (lower torque peak) so you don't bog coming out of tighter corners, this is especially important with rotaries. Plus, you don't spend anywhere near as much time at full throttle as in road racing. Just my two-cents worth. -WG