Ask Mr. Lohnes (dedicated to answering random racing-related questions)

[Ron Ward]

Dear Mr. Lohnes,

For years, we have known that the air pressure in a pair of drag slicks can be affected tremendously by direct sunlight. As the sun bears down on the black rubber, the air inside the tire heats up and expands, increasing tire pressure. This can cause one slick to have a greater tire pressure than the other and as we all know, this is not desireable. Hence, many vendors now offer tire covers that can be secured to the fenders to keep the sun's rays off the tires.

Now for my question: What is your take on the effect of sunlight on the FRONT tires of a vehicle and the effect of increased tire pressure on rollout in the staging beams?

Cordially,

Ron "The Voice" Ward

[Tazracing]

Re: Ask Mr. Lohnes (dedicated to answering random racing-related questions)

none

[Brian Lohnes]

Re: Ask Mr. Lohnes (dedicated to answering random racing-related questions)

I think it absolutely has an effect on roll out. If the tire grows it automatically shortens the rollout, right? The dudes who are really good and win a lot (you know, the ones I WASN'T :D) always seem to check the pressure on all four corners. One of the old racer's tricks, especially on tracks where the physical beam roll out at the track may be a big sloppy is to juice the tire pressure up front.

I'd have to think that a front runner would not have the ability to grow like a slick, but if the air inside got warm and expanded, growing the tire a little, it sure would shorten up the roll out, and if you were a knife edge reaction time guy, show you the red eye of loserdom.

My take anyway.

Brian

[squirrel]

Re: Ask Mr. Lohnes (dedicated to answering random racing-related questions)

If the pressure in the front tires is already high, then they are not going to change size noticeably with a bit more air. Rear slicks have low pressure, doesn't take much of a change in pressure to change the shape of the tire when it's so soft.

[Ron Ward]

Re: Ask Mr. Lohnes (dedicated to answering random racing-related questions)

On a similar topic, the NHRA rulebook requires the wheelbase of a vehicle (measured from centerline of rear wheel to centerline of front wheel) to not differ by more than 1" from the left side of the vehicle to the right side. Although no reason is given for this in the rulebook, my guess is it is to limit rollout in the staging beams so as to not allow a car to "get a run" at the beams, thus reducing ET. Though this has a negligible effect in bracket racing, in the heads up world of drag racing - especially in classes like NHRA Pro Stock where the entire field is separated by only a few hundredths of a second - this can make a tremendous difference.

Mr. Lohnes, have you ever seen a vehicle measured for a possible wheelbase infraction in the tech department?


Regards,

Ron Ward

[SpiderGearsMan]

Re: Ask Mr. Lohnes (dedicated to answering random racing-related questions)

who is lucille lee ?
can I have denver shutz for 100 alex ?

[Brian Lohnes]

Re: Ask Mr. Lohnes (dedicated to answering random racing-related questions)

On a similar topic, the NHRA rulebook requires the wheelbase of a vehicle (measured from centerline of rear wheel to centerline of front wheel) to not differ by more than 1" from the left side of the vehicle to the right side. Although no reason is given for this in the rulebook, my guess is it is to limit rollout in the staging beams so as to not allow a car to "get a run" at the beams, thus reducing ET. Though this has a negligible effect in bracket racing, in the heads up world of drag racing - especially in classes like NHRA Pro Stock where the entire field is separated by only a few hundredths of a second - this can make a tremendous difference.

Mr. Lohnes, have you ever seen a vehicle measured for a possible wheelbase infraction in the tech department?


Regards,

Ron Ward

Never seen anyone called out on the offset front end rule. I know that lots of the dragster guys run the 1" offset, but I have never heard of anyone being called down and protested for it.

I used to check the 3" rule a lot when I was the race director at NED. I had a 3" tall block of wood and would occasionally check cars that ran beam breakers or just looked to be sitting way low. Never had any fail, but DAMN some were tight!

Seems like staging the car at an angle (which would only be only possible with a short wheelbase/door car) would get the same results, but in the end would probably cost you in lost ET from having to "drive" the car back into the groove.

Brian

[JeffMcKC]

Re: Ask Mr. Lohnes (dedicated to answering random racing-related questions)

We had 3/4 of a inch in Docs 52 Chevy for the added roll out. The larger the front tire the larger the roll out Front end of the Car was done By Billy Graham or the Million Dollar Baby Funny Car Fame, I did the back of it after and Larson came in after me.

[oj]

Re: Ask Mr. Lohnes (dedicated to answering random racing-related questions)

1" offset is standard, advanced et stuff. If your competitor has it and you don't all else being equal you will never, ever beat him.
You need to worry about other things than heat-affected rollout on the front tire, to clear a point if heat increases the tire diameter it adds to the rollout, not decrease, the tire gets bigger and wil take another micro-millisecond to trigger the beam.

[BangShiftChad]

Re: Ask Mr. Lohnes (dedicated to answering random racing-related questions)

I have seen a car get protested over offset wheelbase before while it was in tear down. It was a Super Stock car, and it was almost 2" if I remember right. They knew they were cheating and went so far as to move the fenders so that gaps were uneven so it didn't look so off. It was way off though and you could see it by going from one side of the car to the other. They got bounced. And then got bounced some more when the rest of their inspection was done. They had put fake casting numbers on the heads in order to use better heads. Not a good move. They didn't race for a couple years after that. NHRA wasn't happy.

[ksj1]

Re: Ask Mr. Lohnes (dedicated to answering random racing-related questions)

There used to be an S-10 S/S truck that the offset was more than the rules allowed.He told me they warned him 3 times before he changed it.

[JeffMcKC]

Re: Ask Mr. Lohnes (dedicated to answering random racing-related questions)

I have seen a car get protested over offset wheelbase before while it was in tear down. It was a Super Stock car, and it was almost 2" if I remember right. They knew they were cheating and went so far as to move the fenders so that gaps were uneven so it didn't look so off. It was way off though and you could see it by going from one side of the car to the other. They got bounced. And then got bounced some more when the rest of their inspection was done. They had put fake casting numbers on the heads in order to use better heads. Not a good move. They didn't race for a couple years after that. NHRA wasn't happy.

http://www.castheads.com/

Brzezinski Racing Products has made a nice living doing just that

[Dynoroom]

Re: Ask Mr. Lohnes (dedicated to answering random racing-related questions)

I used to check the 3" rule a lot when I was the race director at NED. I had a 3" tall block of wood and would occasionally check cars that ran beam breakers or just looked to be sitting way low. Never had any fail, but DAMN some were tight!

Brian

For all the kids out there waaayyy back in the late '60's & early '70's before the rear engine dragster (yep, the motors were in front then ;)) some guys ran a torsion bar front end with winglets on each side of the axle to "hold the front end down" in a wheelstand. We'll it seems these winglets not only held the nose of the car down but pushed it down, almost touching the track surface, going through the lights about 10" before the front wheels.

I've got pictures but you know what a pain it is to load to photobucket then back to here when your still stuck with dial-up service.....

[CDMBill]

Re: Ask Mr. Lohnes (dedicated to answering random racing-related questions)

On a related note, I've seen a number of cars with a little blade or vertical splitter mounted low in the front, not low enough to trip the staging beam, but supposedly low enough to trip the beams in the traps. Are these legal? Are the finish line beams set to trigger at higher points off the ground than the staging beams?

[CDMBill]

Re: Ask Mr. Lohnes (dedicated to answering random racing-related questions)

Unrelated question: I've come around to the idea that a diaper or containment pan is a good idea for sportsman cars, even slow ones like mine. I realize that there is an expense and I do not believe sportsman cars should have to have anything remotely like an annual certification.

What trend do you see? Will these become standard soon at all tracks?