what am i experiencing?
07-03-2011, 05:31 PM
#1
what am i experiencing? Car just got a cam and headers, all supporting valve train mods (specs and mods in sig). Also mail order tune by Keith/Bryan at pcmforless.
Heres the picture: Lets say your driving through a neighborhood with a 25 posted speed limit. lets say your going slightly uphil to so your on the throttle enough to maintain a speed of 25-30mph. Car is an A4 with a 3500 converter. While trying to maintain this speed the Rpms like to jump about, say 1700-1900 and back and forth, or 2300-2500. Enough that you can feel it.
I have an idea of what it is, but i dont want to put my ideas into other peoples heads. So id rather just get your response to the scanario i gave you.
As far as i know the car has no vac leaks.
Heres the picture: Lets say your driving through a neighborhood with a 25 posted speed limit. lets say your going slightly uphil to so your on the throttle enough to maintain a speed of 25-30mph. Car is an A4 with a 3500 converter. While trying to maintain this speed the Rpms like to jump about, say 1700-1900 and back and forth, or 2300-2500. Enough that you can feel it.
I have an idea of what it is, but i dont want to put my ideas into other peoples heads. So id rather just get your response to the scanario i gave you.
As far as i know the car has no vac leaks.
07-03-2011, 05:40 PM
#3
Could it just be cam surge? That cam is pretty healthy so that's my bet. Under stall rpm and unlocked it'll fluctuate a bit in rpm. I had to tune mine out personally. Mail tunes aren't going to be perfect.
07-03-2011, 05:54 PM
#4
Thats exactly what i thought it was. But can cam surge be that bad? (or is that even bad?). Even if im in park/neutral and give it maybe 5-10% throttle it cant hold a steady rpm. Say i try to hold it at 2000, it flucuates a little bit.
Ive read about cam surge, ive never experienced it though, and i wouldnt doubt that people can have different experiences when it comes to it. I just never knew it could be that pronounced. Duration wise my cam isnt anything large. Lift wise it is.
Wonder if i should throw Bryan an email. It feels like its got great power/torque, but ive been driving a 200hp v6 for the last 8 months. she is spinning the 315 nittos with some effort but not much.
Ive read about cam surge, ive never experienced it though, and i wouldnt doubt that people can have different experiences when it comes to it. I just never knew it could be that pronounced. Duration wise my cam isnt anything large. Lift wise it is.
Wonder if i should throw Bryan an email. It feels like its got great power/torque, but ive been driving a 200hp v6 for the last 8 months. she is spinning the 315 nittos with some effort but not much.
