My car is a 96 z28, stock as far as i know, except for an 1LE intake elbow. I am pretty much stumped on this problem. The car will do fine at WOT or when you are a bit more aggressive on the throttle. If i'm just trying to cruise or if im sitting in my driveway and powerbrake it to about 1200 rpms, the car will bog down to 6-700 rpms then pick back up, and will continue to do this until I give it more gas or just let off the pedal. I've hooked it on our fasttrack scanner and checked everything out while making the car bog, and the only thing i find is the egr valve will go from 25% to 50, 75 then 100% really fast, then back to 0 when the engine bogs and picks itself back up. if i give the car just a bit more gas past the bogging, the egr stays at 100% and the engine doesnt bog. Is the egr at fault here, dirty with carbon perhaps? No codes pulled, and im stumped.

On another note, what are some minor mods I can do to help me out in the quarter? Best times so far are 14.5 @ 102mph. most of the time its a 14.7. I'd love to hit the high 13s.

Thanks for your time guys, btw I was referred here from the LS1.com boards, this place has a much larger community for the LT1 guys

 

What kind of 60' are you pulling in the 1/4? I ran a 13.7 with Moroso CAI and Magnaflow catback. 2.4 60' time. Obviously the motor itself may make some difference, but with the right driving you can get in the high 13's with minor bolt on's

 

Forgot to mention it also has a 3" borla cat-back exhaust. I haven't raced at the track, but my buddy threw his gtech in and the last ran i made with it in was a 14.7 @ 101mph with a 0-60 5.9 (spun bad). Since then i put a 1le intake elbow on (mine was cracked severly at the tb side) and I also had a full tank of gas at the time. It does have a k&n, no cold air, just a k&n to throw into the stock box. I'd love to get the bogging down, but i figured while trying to get that figured out i might as well add on a few goodies.


Has anyone had any luck with the hypertech programmers? I was also refered to madz28.com a while back, but i dont have time to send off my pcm (daily driver) and i dont have $150 to spare for a core charge.

 

Check out your knock counts with the scanner. Knock will cause the PCM to pull timing which will cause bog.

Hypertech is a waste of money.

 

Checked the knock, The counter was in the 3xxx. So false knock? I run premium gas...why would it be getting false knock.