Reaching for that next level..

Don,
I've always followed my Dad's recipe for consistancy.It seems to work very well as LilDemon can attest and verify.
My Dad has always run his cars on the very rich side.His theory has always been a lean car will show bigger variations that a rich car. He also dialed back the timing. Of course this meant he wasn't squeezing every last HP out of the combo.But it insured he would be consistant and the car would run cooler. He must have been on to something... He won over 400 rounds of bracket racing and was a 3 time Goodguys Hot Rod Champion.All in the span of 5 years running a limited schedule from the cool of winter to the heat of summer his dial did not vary more than .15
I applied the same theory to my Dart....went lots of rounds. But the best example was witnessed by Bill (LilDemon),My car was stored in my trailer for a whole year...March Meet to March Meet. I rolled it out with a 10.77 on the window,aired up the tires,threw in fresh fuel. Then went out and went 10.771 on the first pass.
We also clean our air bleeds with WD-40 after every 3 passes....you would be suprised how semi-clogged air bleeds can affect performance.

It just takes time to dial in your package.....make minor tweaks to your program or tune up.

Looks like the 4th pass of the day is when it really slows down. Could be heat related.

Something is off, my car varies a bunch throughout the day if I drive it to the track, but over hundreds of passes I've learned to get a handle on what its gonna do and I can dial accordingly.

Does the car always lose the ET on your 4th run? Or is it random?

Don,I think you are on the right path. Dont sell yourself short. Your reaction times are getting consistent and that for many is a big hurdle. Once you can get and maintain that consistency you can do things mechanically to change those results.

I also think the logbook is going to show you things that you may not be seeing just looking at slips. Once you right it down, put it on the pages and start to digest the info you will undoubtedly find a pattern. I think you will be surprised what you find. Try to write down as much info as possible in there, I have found when bracket racing information is King, you can never have to much. I thank Moprbilly for that tidbit of knowledge.

As we discussed this past weekend a fat race car tends to be a happy and consistent racecar. Not always true but I think with a car like yours it will be the trend. I think especially in street cars or dual purpose rides it tends to work best. I think the results are showing that. Things to think about that you will not see with the instruments you have. Trans temp, and that can make a WORLD of difference in ET's. Things like oil temp are also something that affect consistency. One other thing to consider are the temp of the intake, and if you have a mechanical fuel pump maybe you are having issues once you put some run time on it. One last thing I cannot stress enough is weather data. Weather plays a huge role is consistency. Certain combinations dont like certain things. For example my car does not like a lot of humidity, if the humidity goes up my car will loose more ET than with any other single weather change.

To ehlp get a handle on it go here and check the weather against the slips you have.

http://www.dragtimes.com/da-density-alti...rect+ET+and+MPH

Collect that info and then write it down in your logbook and start crunching numbers. I think you are going to find a common denominator once you look hard enough. This is not rocket science, but sometimes it can seem like it is.

Thanks to everyone that contributed in this thread.. You all gave me a lot to think about and things to keep an eye open for.. and for that information, I cant thank you enough.. But in this case, something else is going on with the car..

The last time the car ran consistent, which was 3 days of racing in March of this year at MATs in Vegas, the wind, temp and DA was all over the place and yet every single pass, a total of eight for the weekend, everyone was in the 11.7x range..

I get the car back home, pull off a couple of consistent runs back to back and then boom, the car loses a 10th which puts me on the trailer.. The first time it happened in Apr, I shrugged my shoulders and said that was wierd.. but now that its happened for the second time, I know there is something wrong with the car, but cant seem to get a handle on where to look..

Do you run and air filter? I've seen more than one engine slow slightly because of dust sticking to the entry of the air bleeds. Especially if your tune is that dead on (ie Stock Eliminator/brackets). I used to hit the carb with carb clean down the air bleeds as a first step to diagnosing. Also pay attention to fuel level in the tank.

Hi Davey.. I was wondering if you were gonna chime in.. glad you did!!

After the race in Apr, the thought of low fuel did come up.. so this last weekend, I made sure there was at least a 1/4 tank for all runs..

Regarding the air bleeds.. I need to change the bleeds to improve the idle and thats on my list to do, but I do not normally clean the bleeds.. That is something we will be doing on a regular basis from now on..

Don you know you're beyond my realm...lol I'd go to 1/2 tank too. Think of it as another 20lbs on the tires.

My daytona did the same thing several years ago and like you it was usually 3rd or 4th pass of the day. My car was always super consistent until this problem started. Reaction times suffer,60 ft suffered,and of coarse the et suffered. My problem ended up being the sprag in the converter. Sent it out for a rebuild and problem solved. It only acted up after a few passes and the fluid was warm.

The second race you listed was the Infineon Memorial day race, right? I don't know if I would use that for a case of car inconsistancy. Measuring wind speed I was seeing a headwind of 4-7MPH at the last time trial, 10 to 15MPH in the first round and the same with gusts to 20 in the second round. My car started the day with a 10.36 and was running 10.44 in the first round. Days like that I just sandbag, play the top end and hope for the best.

Another thing about Infineon, they always have a long break (sometimes 2 hours) between the classes last time trial and eliminations. Keep a close eye on oil and trans temps. I like to drive the car around during the break like it was morning pre-race warm ups. That seemed to help out alot with first round consistancy.
-Tom.

Listen to this guy he knows what he is doing...But then again you are in the same class as he is

What converter do you run? Do you mix fuel? Keep at it, it will come around!!

I always forget about yuor converter. Definitely a place to not worry about spending money. You need to throw cash at it to get a good piece.

Thanks again everyone.. a new converter has been ordered and we'll see what happens..