I'm about to purchase a rb exhaust header for my '79 and had some questions-

- will it bolt directly up to the heat exchanger? There are a whole bunch of pipes coming out from it and i was wondering if it came with all the block- off plates and stuff for it

- what will my emissions system be like? I know the thermal reactor will have to be taken off, but anything else, like the air pump?

-will the finish come off the header so it becomes all rusty?

- what kind of sound increase am i going to experience?

Thanks
rbf41128gt

 

The 79/80 models had what's called a Thermal Reactor which is basically just a cast-iron enclosure that gets cold air (from the Air Pump) pumped into and around it. When the Thermal Reactor is working correctly, that cold air helps to burn off any unburned fuel in the exhaust. When you add a header, it completely replaces the TR, the Connector Pipe to the middle-pipe, and the AP connections won't be going anywhere. You can pull your AP out to clean up the install somewhat. The header will use the four standard (14mm) nuts that match the studs in your engine block.

You might want to consider purchasing the presilencer from Racing Beat, as well, as it will help to quiet the exhaust tone and take out the harsh 'tinny' sound that you get from a rotary exhaust.

The emissions will not pass a state test, if your state requires it. On my SE with Header/Presilencer, the values were *almost* double the state allowable. Once I put the stock monolithic/catalytic converter back on, the output dropped to less than 1/3 of the state allowable - huge difference.

The header finish is a 'parkerized' black coating that will come off fairly quickly with the high heat inherent to our engine exhaust. It will develop surface rust somewhat, but that doesn't negatively impact performance. If you live in a freezing state that uses road salts, that could pose a problem over the long-term, but I doubt it. The tubing is VERY thick.

Sound increases are substantial, but mostly only when you get on it - the secondaries will open and allow more fuel to be burned resulting in greater exhaust volume and noise. If you're just driving around town, it will definitely sound different than stock, but it's not 'rice' loud, particularly if you get the presilencer. HTH,

 

Thanks for the info!!!

 

The top left nut on the thermal reactor is a bitch to get to. It took me about 2 hours to finally break it loose. There is not enough room to fit a socket. And a swivel doesn't work either.

I put a header on my buddies 79 and it went a lot smoother because I onbolted the intake manifold first. I didn't want to have to deal with that damn nut again. You do have to drain the coolant and put in a new intake mani gasket if you go that route.

You can remove the Air Pump and Air Control Valve when you put the header on. You will need a block off plate for the ACV.

-Marques

 

should I go for just the header now without the presilencer, or wait to get the entire exhaust system?

 

Send the header to JET HOT for their JET HOT 2000 coating.No more rust, and holds up to the rotary's heat. Also claimed to reduce underhood temps somewhat. Go to JetHot.com for more info. I had my turbo manifold coated with this coating, and it appears to hold up well.

 

Get the Crome looking one, they hold up preaty well.

 

Got the JET HOT chrome looking finish on my intake manifold.. but according to JET HOT, the 2000 coating is best for rotary exaust applications. The chrome looking finish is only good to about 1400 degrees. The JET HOT 2000 black or grey is good to 2400 degrees.

 

If you plan on getting the whole Racing Beat system eventually, I would hold out and buy it all at once instead of buying it peice by peice. It should be chaeper to buy it all at once. If you don't want to remove the intake manifold to put on the header, buy a Craftsman swivel head 14mm socket and it should come off pretty easily. It seems like like I spent an hour trying to get that one damb nut off before breaking down and buying the swivel socket. There isn't enough room to use a universal swivel adapter on a regular socket.

 

The thermal reactor nuts require a special tool shown in the factory service manual.
I made the equivalent from a distributor wrench. This is a tool made to provide access to the hold down clamp bolt on a typical V8 engine. They are usually made with a 3/8 drive coupler in the center and a 1/2" box end at one ond and a 9/16" box end at the other. I heated the 9/16" end and bent it to the 45 degree angle to work on the stock 14 mm nuts on my 1979. The tool can still be used for it's original purpose as well.

 

If you want to make/buy a special tool then by all means do it, I think taking the manifold off is the most efficient way. Taking the intake manifold off takes about 10 minutes...then the nut is out in the open.

Marques

 

thanks for the info/ warning about it. I'm probably going to save up my money and just get the entire thing at once. When you add up the price for gaskets and everything, it's about 150 cheaper than buying everything seperatly.

 

Sounds like a good plan.