What might have changed is the roll/moment center location between the two spindles. That's not to say one is better than the other, you just need to evaluate the new arm angles, both upper and lower, with the change to the Sweet spindles. It could be that with your car, the new spindles caused a change in the MC and made the front end stiffer. Going back to the previous spindles will tell you if that is the problem.
Another thing, using 9-inch tires on 10-inch rims causes the tire to not have a full footprint when using the same tire pressures. You might try reading the tire temps and if the middles are cooler (like I suspect they might be) then add a pound or two to each tire to get the middle to have better contact. As you move the sidewalls out with the wider wheels, the middle will bend inward towards the axle or spindle pin. More pressure will push the middle of the tire out and compensate for that.
I have a feeling that the Sweet spindles will be better in the long run than the Pinto spindles for strength and design. Try to work with your arm angles using the Sweet spindles and improve your moment center design to get the car to turn better. Generally speaking, the lower arms should be at or less than 2 degrees and the right upper arm should be at or above 12 degrees with the left upper arm more than the right one by 5 or 6 degrees.
British F2 Stock Cars
We subscribe to Circle Track magazine from the UK in the digital format. We race British F2 stockcars (www.briscaf2.com). As a background, we race on asphalt 1/4-mile left-turn tracks without banking. The cars have a minimum weight of 640 kg and about 170 bhp. We run13-inch wheels of 5.5j on front and 8 or 9j on rear. The main chassis rails are at 410 mm.
My question is this: We are currently building a new car and wonder if there is an advantage in building the front right suspension with antidive and the front left with the opposite (i.e. geometry that promotes dive)?
Our thinking is that this will help the car turn in on braking into bends and straighten it on acceleration. Is our thinking logical and do you think it would work? Are there any downsides?
I know about your cars and how they are setup. I have been conversing with a couple of teams running F2 in the Netherlands for a few years now. The method of introducing pro-dive to the left front is something that is done in the U.S. by asphalt Late Model racers to get the LF to come down onto the bumpstops quickly for those types of setups.
I see no advantage for you to do that. What will happen for you and your setups is that the pro-dive will tend to reduce loading on the LF on entry braking and possibly cause the car to push, which is the opposite of what you are looking for.
The use of antidive is advisable because it reduces frontend travel under heavy braking and therefore reduces sudden camber change associated with chassis dive. We usually use about half the antidive on the LF as we have on the RF. And remember that the upper arm mounting angle, as viewed from the side, is much more influential for antidive than the sideview angle of the lower mounts.
Thoughts For Short Track Promotion
I thought that maybe as racers and fans alike, we should start off by doing small things in order to educate people about our sport. I'm amazed at how many people have no clue what we are talking about when we mention the different series involved in dirt track racing (i.e.; Hornet, Street Stock, Late Model, Sprint, and more).
For example, one time I was at my barber shop and Tony Stewart was on TV leading a NASCAR race. There were about 12 or so people watching the race. I thought that this would be a great opportunity to talk about how Tony Stewart is a great driver in a Dirt Late Model or Dirt Sprint car. Sad to say, not one person knew what I was talking about.
I tried to explain what a Dirt Late Model and Dirt Sprint car are and no one got it. Thus, I think if the magazine could do something simple such as add a poster with each monthly magazine, that would allow us to do things such as have the poster put up at our barber shop (salon, for the ladies) and it would be a conversation starter and help give us the opportunity to talk with people about our sport.
Actually having an image for people to see while we explain/educate would help them better understand what we are talking about. My barber already stated that he would be willing to hang a poster in his shop. I know I would be able to hang one in my break room at work and a friend of mine who owns a Sunoco gas station is willing to hang one on the front glass of the store.
This is just an example of things we could be doing to help our sport. I personally would be willing to pay extra for my subscription if it included a high-quality poster with each issue so that I would be able to get the posters out in the public eye.
You just might have a good point there. I know even in our local newspaper in none other than Daytona Beach, Florida, there has historically been little if any mention about the local short tracks. New Smyrna Speedway recently went with the NASCAR sanctioning, and since NASCAR is located here, all of a sudden, we get NSS coverage.
Most newspapers that are located near where there are short tracks do not support those tracks. We need to find out why. It might be the promoters who don't entice the local sports reporters to pay attention to the racing. Many local businesses support local racing and those same entities are potential advertisers in the newspapers.
When the local papers and television stations come to understand that their support for the racing might just translate into revenue from advertising, we might then see more attention paid to the sport called stock car racing. Let's get busy getting the word out.
I'm amazed at how many people have no clue what we are talking about when we mention the different series involved in dirt track racing (i.e.; Hornet, Street Stock, Late Model, Sprint, and more)