I'm headed to the track again. Strokster, is headed out as well. We think we got the problem pinpointed and the parts arrived today to solve it. Secondary actuation spring is now standard, we are going to get it to come in much sooner with a different spring. Hope that's the fix. Bewteen that and the 40-50 deg temps, it's about as good an opportunity as we've had to get into the 13s!

cross your fingers...as usual, I just hope to get back under my own power!

I'd hate to test my new AAA membership, caliing from the track might look a little supsicious.

 

Hey, my State Farm insurance gives me one free tow a year. And so far I've had to make use of it.

Good luck at the track!

OBTW, on that secondary actuation spring, you dont want it to come in too quick, as you've got such a heavy vehicle. Typically the ligher the vehicle the flimsier the spring you run. I always ran the yellow one in my 360 when I ran a carburetor on it, and it worked good. I think the purple one would be good for yours.

 

Good luck guys. Strokster told be on the phone last night that he was sure you guys would get a 13 if you can kill all the gremlins. Got my fingers crossed.

-Scouder

 

Another good and entertaining night at the track. We didnt get that 13 yet. It is still stumbling at the higher revs. We went through several of the secondary springs, and settled on the long yellow. All those passes were in drive, short shifting with the 28" sticky tires. But, it still stumbled. Some springs were worse than others.

For the last pass, we cranked up the fuel pressure to 9psi, like we did last time with a little improvement. But, we had already put the street tires back on due to delays at the track. With the 30" street tires, and with me shifting, it ran our best time yet: 14.38 at 98mph....but it still stumbled on the back half of the track...

As for entertainment. Some girl on a motorcycle, dropped the bike in the parking/pit area, picked it up and it dropped the other way....Some guys helped her, and we all thought..."that was kinda wierd". later, she went for a pass down the strip on the bike, she bounced off the red-line in every gear, then proceeded to run clear past the 1/4 mile mark, past the first turn around and clear off the end of the track....The ambulances, fire dept. etc all came out and finally a helicopter. the announcer said that she was talking and moving and probably had a few broken bones. We still don;t know what that was all about...But, that was the reason for the delay, and the reason the street tires went back on. Anyway, she looked dang good in her leathers :-)

the trucks problem is a matter of how much time it spends at the higher revvs. It had no problem spinning to 5500+ on the last pass in 1st and 2nd. But, then layed down in 3rd. So, we think the ignition is good?? Timing was in the upper 30s, about 37 when wound up!

It acts like a fuel supply issue. I need to reroute some of the plumbing. And, I've got some O2 sensors and an A/F gauge to install, that might help.

My buddy Glenn, shot a digi-video of the 14.38 pass. I'll post it as soon as I get it. the cut-outs were open, so it could sound pretty good.

 

Congrats on another sucessful trip! Now come on over and dance with my snow shovel for a while. I've got the snow blower tuned and she can spit about 10-15 yards into the street

You're killing me! --Mike

 

the gal with the bike story is sad. I truely mean it.
obviously had no one to teach her anything, and ended up just friggin' sad.
i'd like to know her story.

This may be a real dumb question, but... are any of your plugs cracked?
Top end the truck is under a lot of load for a long time... kinda makes me think ignition related... and that more or less fuel was masking the issue...
But, it's a guess.

Good luck, hope you get it sorted out.

 

Cool!

Remember, you're pushing more air when in 3rd gear, and also your engine is sitting at higher rpms longer. All this results in more fuel being consumed. Did you look at your float levels? If they're set too low, it can affect flow by the needle and seat, as well as starting out with less gas in the float bowl.

 

Worst part, she was hanging out with other bike riders (probably a boyfriend or such), at a RV/Trailer setup that probably cost $150,000 or more with several bikes etc. You think somebody there would no how to teach a person the basics. Just one thse things that makes you go "Hmmmmmmm"!

 

bowl levels look pretty good. I'm no expert, but I think Strokster knows enough to say that was not an issue.

 

The float levels were actually on the high side, slightly above center in the window.

As far as ignition is concerned, typically that would show up at the same rpm regardless of gear selection. That last run, it pulled hard and clean thru 1st and second. Greg was shifting somewhere between 5500 and 6k. It only broke up at the top of third just short of the lights.

Greg, using 4650 race weight at 98 mph gives 341.57 hp to the rears. Isn't that real close to what the Dyno showed?

Use this link for several racing caluculators:

http://www.tciauto.com/tech_info/calculators.htm#0

 

Darn shame.

I'm sure you're more knowledgable in the matter than I.
I am curious...
What rpm is the truck thru the traps?

 

I think I was still coming in under 5000rpm. It will probably be closer to 5200on teh short tires and wit ha better launch and complete pull through 3rd...Maybe even 5500.

But, I think I calculated 5200 rpm wit hteh 28" rubber and 4.10s to be right about 105mph, so I doubt it will go quite that fast....but maybe :-) there is definitely a good bit left to gain at the launch and on the back end...

 

That's really great to hear you made it down again last night, with no incident to speak of. As well, it's a damn shame that girl didn't have anyone, at least it appears to be the case, to mentor her.
Anywho, keep us posted...I'm quite excited to hear what is causing the starvation at the top end.

-Patrick

 

the last good rear wheel dyno was 360rwhp. But, I think the truck is making even more power now. At least, as a driver it feels stronger than it it ever has before.

 

I put up a small page about track trips. the video is there. It's dark and shot from the pit, but its still kinda cool to see and hear it run.

http://www.thedreyerfamily.com/69f250/tracktime.htm