Can someone please tell me about exhaust back pressure thats supposed to open the auxillary ports in my 90 model

ive heard lots of different opinions about how i should NOT run headers as i will lose the required back pressure to open these ports thanx and hi from Australia.

well i have an 88 that needs the backpressure for the actuation. I have Racing beat headers and full exhaust, and i have enough backpressure for the secondaries to open up...you shouldnt have a problem.

thxs for answering that i have always wonder that!https://www.nopistons.com/forums/pub...IR#>/smile.png

no prob..=) i have the small pipe coneected right after the headers...https://www.nopistons.com/forums/pub...#>/BURNOUT.gif

What small pipe?

and how can u have any backpressure when useing headers unless you drive around with tennis balls stuck in your pipes.

series V 7's are '89 + right? anyway series Y cars auxilary ports are opened by air pump/ solenoid combo. what opens the solenoids i'm not quite sure. '86- '88 run off exhaust backpressure.

yes im curious too, what small pipe>????

I suppose this is why most places just sell a midpipe....

There is a small hose (maybe 1/8" or 1/4" ID) that connects to the header pipe from the 2nd exhaust port. You only need 2 - 3 psi to open them. Or if you have a cat. converter you can run a split air tube from the cat.

Yep. on the 86-88 13B's the secondaries open up using a small amount of pressure from the exhaust. Yes, i do have headers, and yes, it obviously has atleast 2-3 psi of pressure in the pipes, it does have that back pressure in there. and i dont have tennis balls up in my ****. Like ILUV wrote, its a small tube/pipe wutever that connects to the exhaust to get pressure from the exhaust to open up the ports...Im not on crack. Sorry...didnt realize you have a 90. MY BAD..

wasnt there a company that was making some kind of electronic gizmo that opened the ports up at certain rpm?

And how do series 5 owners remove air pump etc if this opens the ports

p.s i cant just wire dem open cos its a auto and i need what little torque there is to offer

Try this site it has some info on getting around the six port actuation... http://homepage.mac.com/jburger/jaysrx7/6PortSolution/



It says it is for 86 - 88 rx7s I don't know for sure if it'll work on a 89 - 91

https://www.nopistons.com/forums/pub...#>/BURNOUT.gif

I used the air pump on my 87 n/a engine. Went to home depot got a water hose spliter vavle (and some misc items to make the hoses fit) and adjusted the vavle to give enough pressure to open the ports after 4k.



Most of cost like 5 bucks for everything.



C

FC3s.org



they have details on how to do the actuation a few different ways...



good site too

U only really want to do that if u had no Backpressure, and no airpump = straighpipes. https://www.nopistons.com/forums/pub...1047683785.gif

Listen to that, back pressure, you guys really want back pressure? Back pressure kills your power on the mid to top end. I Had no back pressure and I didn't run headers.



C

How did u have no back pressure? Yea but backpressure also helps low end. So what good is having all the power top end? well i suppose when u race u shift from 4500-7000.