World Ford Challenge

suggestion

Test N Tune

Start out with 50LBS in the fronts.
Make a few shallow stage passes to see where your RT is..hopefully with FULL front tires your going to REDLIGHT
Then you can pull 1-2 lbs out of the fronts until you find the "sweet spot".

Shallow staging is the most consistant SPOT to be..IMHO
It's hard to "bump" into the same spot everytime.. unless you are VERY GOOD at bumping.

So work on getting a good RT in shallow stage, even to the point of redlighting.. then you can decrease your front pressure which will increase your "ROLL OUT"..

Rinse, Lather Repeat
 
XLRVIII said:
Here is another "train of thought"....
If you have a 4 position chip you can dupicate the same tune in positions "0 and 1".. but on position 1 put the "idle speed in drive" to 1000RPM's.

prestage in the ZERO position, then flip the switch to "1".. wala.. instant launch RPM with no disctraction.. and no drama.
WALA!
Click to expand...

Thats a good idea! :D
 
J said:
Thats a good idea! :D
Click to expand...

I haven't tried but supposedly you cant dial much more than 1k into the idle speed in drive. so setting it at 1200-1800+ pretty much wont work

the software says it "wont do" over 800ish..so I felt lucky to get it up to 1000 and didn't try "any higher".

1000 has been my "preferred launch" rpm for quite some time so I was pleased!
 
XLRVIII said:
suggestion

Test N Tune

Start out with 50LBS in the fronts.
Make a few shallow stage passes to see where your RT is..hopefully with FULL front tires your going to REDLIGHT
Then you can pull 1-2 lbs out of the fronts until you find the "sweet spot".
Click to expand...

I presume you mean 50 psi on stock sized tires? I used to air up the front stockers to 40 psi. Now I have these front 'skinnies'...

mini-DSC01352.JPG


mini-DSC01355.JPG


... Dunlop Racing 5.50 x 16 vintage tires. The issue is I can not find any max tire pressure rating for them except a 'recommended maximum pressure' of 30 psi. I currently have 35 psi in them.

I have noticed slightly better times using these since they are about a 35 pound tire/wheel combo compared to the 50 pound stocker combo.

But I have also been told they are very 'touchy' in the beams compared to stock tires. Makes sense to me.
 
I wouldn't worry.. PUMP EM UP!
well actually that tire at 35PSI probably has a better rollout than a stock tire at 50PSI.

But for comparisons sake.

When they are "seating a tire on the bead" there is about a 60PSI blast of air.

So if they will take a "shockload" of 60PSI they for sure would hold a sustained pressure of 50PSI.

Back in my autocrossing days in Showroom Stock you had to run the stock sized tire on the car,
we ran the stock gatorbacks at 55PSI and yokohama A008R's at 60PSI.
and the BFgoodrich R-1's worked best at between 45-50.

higher pressures made for a stiffer sidewall...the pressure differences were due to different sidewall stiffness on each of the tires.
(sorry off topic per usual)
 
I launch my car at 2200-2500 rpms so the idle speed trick won't work. I could set up a rev limiter in drive though and flip the switch when I launch. I already have a 3800 rev limiter in P/N.
 
yea a MSD two step set up with a WOT switch would do the trick.
Once WOT is activated the two step goes to the "high pill".

Wouldn't be "legal" in a footbrake no electronics bracket class, but would be ok for TNT.
 
Actually a 2 step is OK at the local tracks I attend most times IF I run with the 'Slick Class'. If I run in the 'DOT Class' or 'Street Class" then I don't think electronics are allowed.

It's frustrating trying to compete footbrake style against the electronics guys. But on occasion, that's how the classes are setup. There is one local All-Ford event I attend where the perennial winner is an early model Cougar setup to race with full electronics.

I hope to soon get a WOT switch for other purposes, so I may look into the 2 step further down the road.
 
The reason I use 45-50LBS in a stock tire is to decrease the amount of "tire" that is in the beams... which gives them a "quicker or smaller" roll out.
{takes less time for them to ROLL OUT of the beams)

As you inflate the tire it gets taller and the bottom portion of the tire that is in the beams gets smaller.

The small tire you have, has a better rollout, meaning the part of the tire that is "in the beams" is smaller giving you a faster reaction time because the tire "moves less" before it unblocks the rear beam. that is "quicker or less" rollout.

Where I am going with this, is.. if your already running into redlights..contrary to what I said above, after thinking about it..

you probably want to DECREASE your front tire pressure to have "more tire" in the beams, which will increase your rollout thus making your RT slower by a small margin.

It'll take some TNT to "find the sweet spot".. keeping in mind that if you run TNT during the daylight hours, your RT's are going to get better as night falls.

For instance.. if I'm cutting .030-.050 lights in the day, I dont adjust anything either physically with the car, or mentally in my mind.

Because when it gets dark.. those .030's will be .00's, because your eye picks up the light FASTER in the dark than it does in the day.

Like last friday night.. I was cutting .030's-.040's in the daylight.
By round 2 it was totally dark.

same staging spot, leaving exactly the same as before.. I cut a .0005 light.

Which is FAR TOO CLOSE for my blood, so I dropped 2-3 LBS out of the fronts and went to .020's for the next round.
 
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