Just installed performer: No Power?

[CManT1914]

Still not following. Most of the air flowing into the upper intake is cool air coming from outside of the car, at ambiant air temp. The air added by the EGR is hot exhaust gas fresh out of the scalding hot header - recirculated, combusted air and exhaust gases. So deleting the EGR pipe without telling the computer would lead to cooler (rather than hotter) air temp in teh combustion chamber than the computer expects. The EGR valve still opens, just no air flows in because it's capped off.

I guess it's not an issue for me (for whatever reason) because I have been running it like this for a few weeks with no issue. But I got a little concerned when I read your comment about part throttle detonation.

I know exactly what you mean. I thought that exact same thing a while back, but for some reason that's the way it works. Although you can imagine that incoming air is already usually 150+* before it ever even reaches the throttle body (as recorded by the IAT sensor), so it heats up QUICK on the way in.

 

[SM0k3]

I checked and set the timing WITH a light and i did retorque the bolts 3 or 4 times, I even took the upper back off after a bit of driving and checked them again...


Anyways during lunch time at work i decided to check under the hood with a friend and I THINK i hear a vac leak in the front area of the intake but not sure....I felt around but didnt feel anything so ill try carb cleaner tomorrow.

 

[SM0k3]

nevermind...my dumbass crossed wires 3 and 4.....it runs fine now and got damn did that manifold make a difference. thing is quick now....

 

[Synned]

yay!

 

[Killercanary]

Good to hear you got it figured out! Shift it at 5500 now!

 

[CManT1914]

lol, when I replaced my cap/rotor, I accidentally put my wires on backwards. Glad to hear you figured it out.

 

[18mustangs]

Still not following. Most of the air flowing into the upper intake is cool air coming from outside of the car, at ambiant air temp. The air added by the EGR is hot exhaust gas fresh out of the scalding hot header - recirculated, combusted air and exhaust gases. So deleting the EGR pipe without telling the computer would lead to cooler (rather than hotter) air temp in teh combustion chamber than the computer expects. The EGR valve still opens, just no air flows in because it's capped off.

I guess it's not an issue for me (for whatever reason) because I have been running it like this for a few weeks with no issue. But I got a little concerned when I read your comment about part throttle detonation.

I did what you did with the EGR and my car pinged like crazy at part throttle (milled heads with no EGR=bad). I reinstalled the EGR when I did the Fox conversion (I had no EGR bung on my LT headers which preveted me from using an SN EGR setup) and that stopped the pinging. The EGR system was designed by engineers much smarter than you or I in engine design in order to reduce emissions by cooling combustion cylinder temps which reduce the production of NOXs. It seems counter intuitive, but the hot gases have unburned fuel which fattens up the mixture a bit. The computer kicks in a lot more timing in order to compensate for the presence of the slightly less combustible EGR gases. If you merely cap off the EGR without turning it off in the computer, the computer is still adding a lot of timing for the EGR gases which are no longer present allowing detonation to occur at part throttle (EGR is only used at part throttle and not at idle or WOT so it doesn't hurt your track performance and gives you better gas mileage too). Of note, just because you don't hear it pinging doesn't mean that it's not, especially if your car is rather loud with regard to the exhaust note. So you should either reconnect the EGR system or turn it off with a tweecer.
Tim

 

[CManT1914]

Tim said it just like I was trying to, lol. He knows more about the EGR system than me. Good explanation Tim, I'll remember that for the next time somebody asks about EGR.