I just down loaded the video of the day.....to gave copy to my son as he flies back to Portland Oregon in 1/2 hour. Don't know what happened, but your first run has disappeared. It looks like the first 15-20 cars to run were lost. Don't know if the son hit a button to erase and start again or what. BUT here is what I do have on your second and thrid run.

2nd run...you had run the RPM's up and then released on the second yellow.....REAL BAD TIRE SPIN...then you got off it had traction..then got back on it and spun badly some more. I think you said you had dropped them down to 25 psi at this point.

3rd run...you started spinning as you left the line and continued to spin for the first 40-50 feet. I think you said you had dropped the psi to 20.

Should these tires be dropped lower than 20? Did the supplier give you any guidelines on what psi to run? Last year I had dropped the BF drag radials to about 25 and didn't spin the amount you were. We ran these dry without any burnouts. We lowered them to 20 on the last run of the day and dropped a 1/10 last year.

I would think that you MPH should have been much higher when you crossed the line with the setup you have. Isn't there someone up in Roseville that can dyno tune. I think the new injectors may have had an impact.

I will put this video together over the next several days and shoot it up to you. Nice finally meeting you...your car really looks good. So maybe next year we will both be on the track.


John

 

just did a quick search on tire pressure and many are dropping the psi to 15 pounds to 18.

 

If you're only running 96.8 mph, you're probably not making enough HP to run 13.5. Long tubes and dual exhaust makes a big difference, just keep your stock exhaust handy. My best time in my 86 is 13.79 @ 100.4. I didn't finish the Superram install on my 86 ,so I took my 99 today.
Sounds like your tires just weren't working. What kind of pressures and burnouts were other drivers with the same tires doing?

 

Thanks John,

Too bad you lost the video of the 1st run. I thought I had that C5. But he caught up to me and beat me. You might be right about the dyno tune. There is a guy around here that can do a road tune on C4s. I talked to him a couple of weeks ago. It could be the new injectors have me running a little rich.

But as you noticed and the video shows; my biggest problem today was traction. It may have been caused by an inexperienced driver. I can't blame MT.

It was nice to meet you, John

Fred

 

I looked for your C4 today. A few guys told me to heat them up and run them down to 15 or 16 lbs. I got discouraged after the 3rd run and left.

I noticed that there was all kinds of Vettes runing long tubes today. Maybe it's time to get a second exhaust. Smog is every 2 years. If I could get rid of my exhaust, I could add about 25 HP.

But that might give me more wheel spin.

 

Not to burst your bubble, but I HIGHLY doubt that you'll pick up 3.2 mph from better (cooler) air. 3.2 mph at your level would be astounding.

One thing that's curious to me is that you're running 13.7's - 13.9's on a 2.0+ 60' time, yet at only 96 mph. 96 mph is usually in line w/a 14.0 - 14.3ish, on a 2.0ish 60'. This makes me wonder if your car has more in it, power wise, and you are squandering it on the shift points? You are coming out of the hole w/a softish 60', but still some how netting a great ET/Trap ratio -as if you had slicks and a 1.6-1.7 sixty foot. Seems like you're pulling HARD from maybe the 60 to the 330 maybe and then doing poorly after that?

What this guy is saying backs up what I'm saying:
And this:
...but I bet Paul didn't get that 13.79 on a 2.0+ 60' time! In short, if your car is pulling 13.x's w/a 97 mph trap, on a 2.0 60' or worse, that tells me that it's pulling REALLY hard somewhere on the track, and not very hard....somewhere else.

We need all the info!

 

You're right about that. I noticed that today. It's like it stops building power too soon. Something is holding it back at the end of the track. Could it be the shift points? My 1st run was 1.988 60' 96.837 MPH 13.947. My 2nd run was 2.145 60' and 94.263 MPH 14.2. My 3rd run was a 2.310 60' and 95.583 MPH 14.6.

 

I don't know. You still haven't posted your shift points at all.

If you want the best help this forum can offer, do yourself a favor and post ALL of the data, from ALL your time slips in one place, at one time, and then include shift points and any other relevant "drivers notes" from each run.

So far, all I know is that you ran a 13.7 previously, now a 13.9 at 96.8 on basically a 2.0 sixty. And you ran some other runs w/sixties in the 2.1+ range and traps around 95.

How about giving it all to us in one post so we can really tell you something?

 

All my best 60's have been by launching off idle. Loading the convertor always made me spin as you have done.
I have run 1.7X's on 24lb. MT's are so soft you only have to clean them off. A big burnout v a little scrub has no effect on my 60 ft times.
Have even driven straight to the line when I knew tires were clean and dy ; had no spin.

 

I think I need to talk to tuner. There is a tuner here that drives a C4 with a big block. last time I talked to him I was in the middle of installing new injectors. I told him I was changing the rear gears and installing a new Vigilante torque converter.

He told me to get everything done and call him again. He actually rides with the driver with his laptop. He said he would probably work on my car all day and adjust everything.

Also, I'm gonna start looking for an exhaust system for off road use only.

 

At minimum, spin the tires to clean them off.

 

The real problem is the temperature change between your best run of 13.7 and your current run of 13.9. A 60 degree temperature swing is huge and I would expect your car to run mid 13's with 30 degree air. You also need to lower your tire pressure to 15 lbs and do a short burnout to prevent them from spinning. My car has a completly stock supension and with 15 lbs of pressure on BFG drag radials I can pull low 1.5 60 ft times. I have heard that MT radials hook better the BFG's so you should not be spinning.

 

echoing some of the previous posters... tires need to be between 14-18 lbs, and you need to do a burnout to clean the tires off (not a Funny Car style smokefest, but a 2-4 second cleanoff). All my racecar needs is a 3 second burnout, and it's good for 1.32 short times

 

You're right, I need to learn how to drive with the new gears and torque converter. I also need to do a little more work on the car.

I'm convinced that I can get this car to go faster. I'm a little discouraged but I'm still looking at ways to lower my ET.

 

My 13.79@100.4 was with a 2.19 60. My car is a 4+3 and I have to drive it off the line to keep the street tires from spinning.

 

If you want a dual exhaust let me know. I have a complete bolt on system here in the shop I can make you a killer deal on.

 

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