Cars sped up question

[Bubblegum]

After watching 2 days of racing online I think I have hit my limit. Today we raced two cars in the open scout graphite division and two in family. We did ok but did not make the next round. The two family cars were bsa parts out of the box and we used lead weights. The two scout cars were our back up cars with after market axles, wheels, and thin.

I was unable to see all of our races but they got faster after each of their first heats. Our best car went from 3.0510 (first run) to 3.0088 (fifth or sixth run).

I wonder if we would have continued to speed up. I wonder if I had run more at home the car would have broken the 3 sec barrier. This was my only goal today.

Any advice on how long to run graphite to hit the sweet spot before a race? I guess I will clean and regraphite and just run until the speed slows.

Kind of thinking out loud.

 

[TRE]

Were the slower runs on inside lanes? Out side lanes are faster

 

[Vitamin K]

Sub-3 with all BSA parts and graphite is a pretty lofty goal!

We're you using any kind of axle treatment (e.g. Pledge or Sailkote) along with the graphite?

 

[Bubblegum]

I remember listening yesterday to two people talking about the outer lanes being faster. Today I was using an iPad and my smart tv covering the two tracks. I should have noticed lane positions but with all the technical issues with the live feed I was lucky to see what I did.

I will go back and rewatch to see.

I used the current axle prep techniques from here including pledge.

I guess I wanted to see how far my prep and skills have come vs buying speed online.

 

[TRE]

When I do graphite usually first couple runs are the fastest

 

[Bubblegum]

That makes sense that the first runs are fastest but I seem to speed up as we race. At districts we had the fastest run of the day with our second run, slowed on the fourth and got faster 5th through 7th runs.

Today the car, a different one than districts, got faster by 0.01 each run.


I have had several cars do the same thing and I don't understand why mine do it compared to the standard of slowing.

 

[Thinkin'Bout Racin]

That makes sense that the first runs are fastest but I seem to speed up as we race. At districts we had the fastest run of the day with our second run, slowed on the fourth and got faster 5th through 7th runs.

Today the car, a different one than districts, got faster by 0.01 each run.


I have had several cars do the same thing and I don't understand why mine do it compared to the standard of slowing.

When you add multiple lanes and multiple cars next to you, you can't compare times. The cars next to you could have been pulling you along or throwing bad air your direction and slowing you down. Plus the various lane may be faster or slower themselves.

The only way to know for sure which run will be the fastest is to run it by itself in the same lane with the car staged exactly the same.

I can make our graphite cars have their fastest run on run #1, runs #2 or #3, or runs #4 or 5. It depends on how I heavily I graphite the car and if I spin the wheels before running or not. So I graphite the car based on the anticipated number of runs and how stiff the completion is..

 

[Bubblegum]

I have thought about tbis whole scenario for a while now and I have always wanted to try and find the sweet spot for round 2 if I cannot reprep.

I just haven't spent the time or energy testing it.

 

[Wolfram Racing]

When I do graphite usually first couple runs are the fastest

That's odd, but like TRE said...it could be lane position. We started off fast and ended about 0.010 slower on the last run. Need to work on that. Same happened in the finals.

 

[derbydentist]

Looks like ballistic is the guy to ask if he has any advice - I think his kids took first in graphite and oil! Congrats Ballistic! Some really fast cars there!

 

[Bubblegum]

Thanks for the responses. I am trying to get ready for the scout race in NYC (yeah, yeah I know) and run at our max potential.

 

[Bubblegum]

Ok I went back and watched the video again. The lanes from our left to right were white black yellow blue red and green.

He raced in order:
White time unknown
Blue 3.0510
Red 3.0281
Yellow 3.0108
Green 3.0088

Black was not seen because the feed was down for several heats and this heat I think was between blue and red.

I could not see the entire run because the camera operator focused on the start, the cars dropped, and the view moved to the finish line. I could see the last 15 feet and noticed more wiggle the more the car ran.

This whole thing makes me think a little more steer like 5 inches over 4 feet and maybe an extra run or two before boxing up.

Am I on the right track? Other points to consider?

Thanks.

 

[Wolfram Racing]

Ok I went back and watched the video again. The lanes from our left to right were white black yellow blue red and green.

He raced in order:
White time unknown
Blue 3.0510
Red 3.0281
Yellow 3.0108
Green 3.0088

Black was not seen because the feed was down for several heats and this heat I think was between blue and red.

I could not see the entire run because the camera operator focused on the start, the cars dropped, and the view moved to the finish line. I could see the last 15 feet and noticed more wiggle the more the car ran.

This whole thing makes me think a little more steer like 5 inches over 4 feet and maybe an extra run or two before boxing up.

Am I on the right track? Other points to consider?

Thanks.

You can log into the event website and get your time now. You can't see each runs time, but you know the average and all but one time, so you can figure out what that time was. White lane was pretty quick, so I would expect you to have dropped the blue lane time from the average.

If you had a lot of wiggle in your runs, more steer can help to a point. I don't know your car, so it's a little more difficult to say what you can and cannot do. Moving your CG forward will help if you can. Of course, the race isn't for a while...you could build a whole new car if you wanted.

 

[Bubblegum]

Thanks. I found the stats on the website.

After I run the car I may gut it and reuse parts to see if I can improve.

 

[B_Regal Racing]

I could see the last 15 feet and noticed more wiggle the more the car ran.

This whole thing makes me think a little more steer like 5 inches over 4 feet and maybe an extra run or two before boxing up.

Am I on the right track? Other points to consider?

Consider:
1) clean wheels of debris, graphite, and wax with mild abrasive pad/micromesh
2) check rear alignment
3) check steer; add more
4) rear wheel gaps too large; tighten gaps; check front as well
5) move weight forward (only adding a few grams to the FDW)
6) check rear wheels; hubs or edges deformed; replace
7) bore diameter not equal when measured at inside and outside hub; replace
8) repolish a new set of rear axles (diameter is too small)
9) repolish a new set of rear axles (rear axles slightly bent)

Could be any one or all of these things. 1 thru 5 are easy to do and usually can correct most problems.

 

[bracketracer]

Other points to consider?

I don’t know if steer alone is going to pick up the .08+ that you were behind? That six lane track in Omaha was running between .04 and .05 “fast”, the four lane track that the kids and adult open races were run was about .01 slower than the six lane, so if you didn’t crack 3 seconds there, you have a ways to go.
You said the scout car was on aftermarket wheels and axles, what weight wheels were you running and what diameter axles? You were racing against kids running 1.3g wheels or lighter,
I heard that the NYC race will only allow straight axles this year, no bending. You might verify that with the folks in charge and if it’s true, place your order with DD4H for a plug & play body now.

 

["The Fonze"]

Sub-3 with all BSA parts and graphite is a pretty lofty goal!

We're you using any kind of axle treatment (e.g. Pledge or Sailkote) along with the graphite?

A sub-3 run is not a lofty goal on the MA track. My guess is that the hill angle is steeper then 27.1 degrees. My son’s car on a league track with the correct hill angle runs 2.98’s but on the MA track it’s fastest time was 2.93xx. My point being is that even a 3.04x car would be sub-3 on the MA track.

The White lane was the fastest followed by the Black lane.

 

[Bubblegum]

Lots of interesting points so thanks. The car was built following our district's rules. I could have used faster componenets but am focusing on areas that will benefit us.
The block was from a bsa kit but was drilled with my SB pro 3 degrees rear and 0 front.
Wheels dynasty basx
Polished bsa speed axles
Tungsten cubes 12 in rear, 1 between rear axles, rest of cubes in front of rears.
Putty was added to make weight.

I got the cars back yeaterday, cleaned the wheels, and just ran 20 heats alone to see how long it would run.
Over the 20 heats the car slowed 0.099 seconds. It began to slow around heat 13 so somewhere a total of 20 runs is max for this car.
I took the first 8 runs and took the fastest 7. The car was 0.001 sec slower than before I sent the car in.
Then I incteased the steer by an inch, added graphite, and cleaned tbe wheels.
I ran the car 11 more heats and the wobble was greatly reduced. I took the first 8 heats and the 7 fastest and the car was 0.004 sec faster than before MA.

My next testing will address point 5. I was worried if my weights were too aggressive and plan on moving the putty around to see how that affects time.

I appreciate the help and please keep thinking out loud.

 

[B_Regal Racing]

Look at those 9 steps I posted previously for eliminating wobble. I may get you a bit more speed because the car is settled. Graphite is only good for 8 to 10 runs, so that slowing is somewhat expected. As a side note, I would not place a cube between the axles when you build your next car. Keeping the rear alignment is paramount. I actually brace the wood surrounding the rear axle to help maintain rear alignment. If you are looking for more rearward weight, consider purchasing a solid tungsten bar that fits in the rear instead of the 12 cubes.

 

[TRE]

You dont need more than 12 cubes behind the rear