i was wondering... i own a 1988 mazda rx7 with a small street port and stock exhuast besides for the RB street header... I took my air pump off and i cut some of the rats nest out however i still have the EGR connected... I reinstalled the 5th and 6th sleves and ACV which i had blocked off to try to achieve the 130mph some of u guys have got with stock fc's... anyways... the idea came to mind that maybe if i add the air pump back it might power back the EGR valve helping more air into the engine by then helping with the car hitting 130mph? Is my dumbass tehory right? or will bringing the air pump only result in cleaner air? Im also running premix... an dmy tranny ahs been rebuild... what coudl be causing the loss of power upper end? maybe the 5th and 6th are not working right?

 

oh before all that and with closed 5th and 6th ports i could only get 120mph... i tried it again after all that and got to 120mph again noticibly faster yet cant break that barrier...

 

wow im lost... first the egr only works at low speeds and idle to dillute the air for better emmissions... 2nd the air pump only pumps air into the cats so they do not overheat.... neither one of these affect the car at high speeds... well your air pump will if you have the cats because you will clog the cats if you removed it


and if you closed the 5th and 6th ports ... thats said to be about 20 hp loss on top end so no wonder you cant go past 120.... wtf do you want to go that fast for anyway? its just asking to get killed

 

Air pump has nothing to do with egr. EGR air would lower power if anything, not raise it.

Are your 6 ports open?

 

nope they are closed

 

i see...

 

i think i should closed down the egr... and try to re-lube the 5th and 6th slevves and actuators...

 

Why not just wire them open for a run. Almost any exhaust leak or variation from stock on an s4 will result in them not working properly on their own.

 

thank you kevin... i will try that

 

********As the gases flow through the pellets or honeycomb, they start to burn rapidly, and the temperature can reach 1,600 deg. F. Extra oxygen in the exhaust stream is needed to support the blaze, and that may be provided by a very lean air/fuel ratio, pump-type air injection, or an aspirator valve setup.***********

Above seems to be the purpose of the airpump injecting air into the exaust PORTS.

 

EGR recirculates used burnt exhaust gases into the engine. this inert gas causes a less dense air fuel ratio resulting in a cooler burn but also results in less power output, it is not a huge difference but it is an emission control device to help reduce NOx. NOx is a poisonous gas to humans but the output from gas engines is so minute, they just try to limit it going into the atmosphere..

just a little info on your EGR system, it will slow you down if it is hooked up but not much.

you should have the air pump hooked up if you have a catalytic converter still or your cat will eventually fail, it needs the added air to help burn the fuel efficiently.

 

thank you gusy for all ur knowledge... an dfor not flaming me... I think im gonna just find a block off plate for the EGR and get a presilencer form racing beat and a resonator for added pressure and re work on the actuators... does dis sound like a good idea? Also thanx again for ur help!

 

If you are going to make a bunch of posts, right after each other, please use the Edit button and edit your original post. There's no reason to make 3 posts in the span of 8 minutes.

 

This info is basically correct, but the EGR valve is only operated when the engine is under load load. Put your foot down and it shuts off, so there is no loss of performance from having an operative EGR system, but there is a reduction in average fuel consumption.

 

I don't get it. My car, mostly stock (i.e. no internal mods), topped out at 142mph. That was before gutting the cats and switching to a TII trans.

 

your speedo is wrong. the top speed thing has been discussed many times and there is no way anything other than a TII or a heavily modified NA (read: ported) is going to hit 142 on a flat road.

maybe if you were going downhill with a tail wind as they say but otherwise, your speedo was off a bit.

 

yeah what PUre said... also read above i said i own a 88 S4... u own a S5 (89-91) U BIATCH! thats why u can probably max 140 or so maybe thanx to ur lighter rotors. I HATE YOU .. why are u faster ( just kidding bro)... anyways i dont know i think is just my actuators not working right...