gottadrive

I bought my 87 n/a about a month ago and
I have been running some fuel injector cleaner through to try and clean up the injectors, I was having the flooding problem, but it seems to have fixed it, however now when I first start it up, it does the rev upto 3k for a few seconds then as it is coming down it just keeps going and dies. If I tap the gas as it is coming down it settles down and idles nice. Why would it start doin this all of a sudden?

Next, I was looking over my exhaust and noticed it is stock to the second cat, but after that it is a Y to some generic pipes and mufflers it seems. No 3rd(big) cat. How is this effecting my performance, if it is at all? Would a cone type air filter comliment this? There are no other mods that I can see, and I don't really have money to do too much, just looking for maybe a little power.

Last, if my 5th and 6th ports are not opening, how much would this effect my performance.

Thanks to all, this is a great site!

TurboMike

i was under the imperssion that all rex's had 2 cats and not three. Less cats gives you more flow, but no cats will cause your 5th/6th ports to not open. Not having 5th and 6th ports will give you less top end power, an air filter could give you a couple horses.

gottadrive

I thought all rex's had 3 cats, 2 smaller ones and one larger one.
So if you have no cats, you 5th and 6th ports won't function at all?

MazdaRx7Power

ok they come with 2 precats and 1 huge cat. if your gonna hollow them out then just tie ur 5th & 6th ports down. you'll lose a little low end but hey its better to lose a little low then all ur power on the high end.

gottadrive

I'm not hollowing anything, it's just that the huge cat is gone. Replaced with some generic pipes. Do you think I need to tie my prots down for just that??

rico05

You have no back pressure, whcih causes the ports to not open, and thereby chokes the engine for air in the high RPM range. Either get a stock cat setup, or wire open the ports.

MazdaRx7Power

yeah i agree with rico.... u have no backpressure so the best thing would be to tie the ports open.

TurboSmoke

mine idles high when i first start it up then as it warms up it idles less

MazdaRx7Power

thats normal at first it idles at like 1.5 to 2 and as the car heats up the idle will go to normal.

gottadrive

How do I go about doing this?? Also would a cone filter help in this situation, or is it bad if you don't have a cold air box?

MazdaRx7Power

on the passenger side theres to actuators. they have little rods on them that u can push down. u tie those down and the ports are open... sort of looks like a lever that u push down to detonate some tnt...

gottadrive

how do you tie them down?? if they are just rods, what could you use to keep them from coming up?

MazdaRx7Power

take some wire and tie them down anything that can with stand the heat of the exhaust temps. just hold the rods down with your hand and tie them.

gottadrive

I did some searching on this and there are alot of differing oppinions on this, is it really gonna kill my low end power? and is it gonna help my high end if they are not opening at all now? Is there a way I can test them first to see if they are working?

MazdaRx7Power

ok u lose a little of ur low end probably not enough to notice. if u dont tie them open then u wont have any highend and the car will be struggling. the ports allow more air at higher rpms to get into the engine.

MazdaRx7Power

you can put a dab of grease on them and go for a little drive if they work it will be smeared most likely they wont be working because of you not having the main cat.

Green

I have NO cats, just a straightpipe to my Ypipe and stock mufflers.. My ports open perfectly fine....
there are 2 precats (small) and 1 main cat on a stock RX7....
AND wiring the aux ports open would NOT be the best thing to do
2 better options (1 more difficult)... There are some links on how to do it, but I don't know them off hand.. you can search for em..

set it up so your AIR pump opens your aux ports...

OR just remove the aux port SLEEVES... You will PROBABLY notice loss in low end torque(I've never had them wired open so I don't really know) ... all in all I think best is to have the ports working properly....

BTW I do know that having your ports stuck closed will DRAMATICALLY decrease performance,, I think I heard you will have a hard as hell time getting to 5000 rpms if ports are stuck closed? (again I don't really know cuz my ports work fine. always have)...

gottadrive

i can get to redline and beyond with no problem, so if that were true i would think my ports would have to bbe working