I've been trying to break into the 11's since last fall. There have been limited times when the weather has been right and each time I find one more piece of the puzzle out of whack.

Last fall I found I couldn't run a 8# lower and 3.25" upper on my KB without slightly lifting a head so that night was wasted. I went home and put my 6# lower back on an no more problem. A little bit of coolant around the cap and on my air filter outerwears was not a good thing.

I had a 2400 stall put in last fall after playing with different launch rpms this year, I finally found the sweet spot. In the process of that I realized my QTP's were done. I couldn't always feel them slipping but I knew my 60' times were not what they should be plus the rubber was really thin. I bought a new pair and solved that problem.

Here is a run from a couple of weeks ago first time out with the new rubber. I ran a best of 12.15 but it seemed like it was short shifting on my race tune. I datalogged it on the street the next day with the QTP's on to find it shifting at 5450 on the 1-2 shift and 5250 on the 2-3 shift. I need to get it to 5600 on both shifts like the race tunes before the KB. If the weather doesn't cooperate I might have to wait until the fall.

http://media.putfile.com/1215-Run

 

Cure
One set of valve springs and put the 8lb'er back on then go run 11.80's or so
Dale
PS....the 8 lb pulley isn't the cause of the head lift...well indirectly it is

 

Dale,

I had 65,000 miles at the time so the springs are probably even weaker than when new.

I don't suspect detonation being the culprit. For safety I ran it on the winter tune the first and only pass after putting in a little over 3 gals of 104 unleaded as usaul when it's below 70 degrees. The winter tune has 16 degrees of slope timing My race tune had 18 degrees of timing across the rpm range. I bumped it to 20 degrees running the same fuel combo with the 6# lower and had no problems. I've got one of those freak trucks that won't respond without the timing. I just wanted to slip backup on it with the KB because I didn't know what to expect. I'm only running 1 more # of boost than the ported Eaton so it makes sense that it could take the same amount of timing with the cooler charge coming out of the KB.

I would go the built motor route before I would mess with the springs. I know with 70,000 miles and 6 years there is only so much I can ask for out if this thing. It's been a good and dependable daily driver for what I've put it through on the track and the street so I can't complain too much.