small 1/4mile oval tips, transitioning from road racing

[Bcollins82]

If you just want to go play, buy some used tires from the fast guys. You can usually pick them up for next to nothing. No sense in burning up new ones when the car is that far off. But hey, not my money... lol

[rob burgoon]

and why start moving weight when you are that far under minimum already? Just bolt some on.. Does your track not have scales?

That weight is without driver.

[Bcollins82]

That weight is without driver.

Ah.. scale with driver or at least simulated driver weight. I know some people like to scale without, but I don't agree... You don't race without a driver, so why scale that way? It throws off percentages and ride heights both. So your ride heights are even farther off than I previously thought... Sit down in it and record the real numbers and let us know, then you can go from there.

[rob burgoon]

Ah.. scale with driver or at least simulated driver weight. I know some people like to scale without, but I don't agree... You don't race without a driver, so why scale that way? It throws off percentages and ride heights both. So your ride heights are even farther off than I previously thought... Sit down in it and record the real numbers and let us know, then you can go from there.

Yeah, in sports car land it's always with driver, but I kept coming across dirt setup stuff that listed numbers without driver, so figured that was a cultural thing. Glad to hear it's not too widespread, haha.

[Bcollins82]

Yeah, in sports car land it's always with driver, but I kept coming across dirt setup stuff that listed numbers without driver, so figured that was a cultural thing. Glad to hear it's not too widespread, haha.

Yeah, I've never understood why someone would scale a car like that. You can always spot them at the track because the LR is tucked up in the wheelwell and the RF is up in the air... It sure doesn't make things very repeatable.

[mod88s]

Ive raced on dirt for over 25 years and have always scaled without driver. I started doing it this way because that is how the manufacturer said I should do it. I would say the vast majority of dirt trackers do it the same way. There have been a couple of manufacturers lately(GRT) who say to scale with driver or simulated driver weight in car. It is up to the manufacturer and how the car was designed. Remember why you scale your car, to get to a good base set up. Then you tune from there. Also scale because it can identify problems elsewhere in the car. Or incase you damage the car you can get it back to the base set up. Absolutely no problem scaling without driver or driver weight.

[Bcollins82]

Ive raced on dirt for over 25 years and have always scaled without driver. I started doing it this way because that is how the manufacturer said I should do it. I would say the vast majority of dirt trackers do it the same way. There have been a couple of manufacturers lately(GRT) who say to scale with driver or simulated driver weight in car. It is up to the manufacturer and how the car was designed. Remember why you scale your car, to get to a good base set up. Then you tune from there. Also scale because it can identify problems elsewhere in the car. Or incase you damage the car you can get it back to the base set up. Absolutely no problem scaling without driver or driver weight.

Scale your car with a 225 LR spring, sit in it and measure ride heights, wheel weights, etc.. then do the same with a 175 LR scaled the same without the driver. When you put the driver in the car the ride heights, wheel weights, and bar angles will be different when you hit the track with different spring rates.... I realize some chassis builders tell you to do it like that, but its not the most consistent, repeatable way to do so. You are correct, it's just a baseline, but I want the most consistent baseline possible. So in my book, there is a problem scaling without the driver. Just my opinion...

[rob burgoon]

If I wanted to scale without driver and I was willing to cut some corners, I would scale once with & without driver, and measure how big the difference was (weights, ride heights, bar angles). Write down these differences and now you have a way to guess at what the car would be like with driver. For example, if the LR sags about half an inch and you gain 1% left and 1% rear, now you know to set your car up without driver to have the LR half an inch too high.

Not terribly precise, but helpers aren't always around.

But yeah, sand bags or a patient human with a book in the driver seat is probably best for setup.

[ask0329]

Rob, I feel at times i was in the same situation as you and here is what i've done. My car is a 4-link imca mod. We always run on dry slick. I too ran a 602 although I did not have to. My track was 1/3 mile moderately banked D. I ran 5:29 gears and would hit the rev chip at 6200 on occassion. Not too often but every now and then. Why? Cause my overall setup was bad, I was spinning the tires and in expierenced. I really think you would be fine going to atleast 5:29 gears and a 6200 chip. As for setup, I was out to lunch pretty much every race. Its taken me close to 4 years to get the car dialed in mostly cause it was home built and I was knew. Finally a fella started helping me who was the only other guy that ran a metric clip, with metric lowers and metric spindles. The last few races have been night and day and the car is a million times better. I too had an underslung car and was hitting it. I cut that right out of there probably 2 years ago now. We just put an additional bracing bar from the tail section up. As for setup, what these guys are saying is right on the mark. Ride heights slightly higher on the left than right. if you have a chevelle clip 850 is way too high. Thats a spring for a metric clip with metric lower. The differnet clips and lowers have different motion ratios due to their length. One last thing, when the new fella started coming over to my garage and wanted to make all these changes that i just thought where bizaar I was really put off by it. The more I got to thinking I said to myself, we have 3 races left, I'm not racing for points. What do i have to lose? So we threw every change at it he told me to do and my god, I'm so happy i did.

[mod88s]

Scaling without the driver is just as consistent as scaling with driver. The only difference is the driver is not in the car on the scales. Whether you scale with or without driver, you set the numbers to where you want them on the scales, then you go race the car. You make changes to the car based on what the car tells you on the track. Whether the driver was in the car or not during scaling wouldn't make any difference in the world on your thought process about what to changes to make. If the car was loose on entry, you need to tighten it up. If it was too tight on entry, you would make changes to loosen it up. How you scaled the car makes absolutely no difference, as long as you do it the same way every time.

[Bcollins82]

Scaling without the driver is just as consistent as scaling with driver. The only difference is the driver is not in the car on the scales. Whether you scale with or without driver, you set the numbers to where you want them on the scales, then you go race the car. You make changes to the car based on what the car tells you on the track. Whether the driver was in the car or not during scaling wouldn't make any difference in the world on your thought process about what to changes to make. If the car was loose on entry, you need to tighten it up. If it was too tight on entry, you would make changes to loosen it up. How you scaled the car makes absolutely no difference, as long as you do it the same way every time.

I understand your theory, and there have been a lot of races won that way. But I just explained in detail why it is not as consistent to scale without driver weight. Its not just theory, you actually pull on the race track with different ride heights and wheel weights if you scale without the driver and change spring rates. I don't want to go through figuring out what my ride heights will be with different springs so the bar angles and wheel weights are the same after a spring change. I find it much easier to just have the weight in there to begin with. There is a reason all of the major late model manufacturers scale with driver weight.
It seems like it is a lot more common to scale without the driver out in imca land so I haven't ever dealt with a builder that recommend scaling without driver weight. I'm curious, do they give you different percentages and ride heights for different driver weights? I mean, if you scale without driver and one guy weighs 150 and the next guy is 250 that's a huge difference in wheel weight and ride heights... It seems like that would make it harder to share info between drivers of different sizes as a builder. Maybe I'm just worried too much about getting the heights and weights exact...

[mod88s]

Ive raced all over the country including nascar modifieds, and won some races here and there so I have experience outside of IMCA land as you put it. I have heard very few manufacturers recommend scaling with driver or driver weight. It should take you about 2 races to figure out what springs to run in your car so Im not sure why you are so concerned with ride heights and bar angles after changing springs. You make it sound like you are changing springs all the time which I don't understand why you would have to do that. Once in a while I might make a RF spring change at the track depending on track conditions. But its not rocket science to get it back to the same ride height and wheel weights. I guess keep on keepin on if you want to go through the hassle of simulating driver weight. If it keeps your mind at ease and you feel its the magic ticket, keep on doing it.

[Bcollins82]

Ive raced all over the country including nascar modifieds, and won some races here and there so I have experience outside of IMCA land as you put it. I have heard very few manufacturers recommend scaling with driver or driver weight. It should take you about 2 races to figure out what springs to run in your car so Im not sure why you are so concerned with ride heights and bar angles after changing springs. You make it sound like you are changing springs all the time which I don't understand why you would have to do that. Once in a while I might make a RF spring change at the track depending on track conditions. But its not rocket science to get it back to the same ride height and wheel weights. I guess keep on keepin on if you want to go through the hassle of simulating driver weight. If it keeps your mind at ease and you feel its the magic ticket, keep on doing it.

I've been around a while too, but I have never been one to sit back and leave things alone. So yes, changing springs has been a common thing. It does keep my mind at ease knowing that from spring to spring, driver to driver, car to car, when the car rolls on the track you have an apples to apples comparison between them. No, its not rocket science to get it back to ride height after a spring change. My point is that if you have 2 different springs at the same static height and the same wheel weights without the driver, they will be different after you put driver weight in the car. Not to mention every driver in brand X not weighing the same. I don't think its rocket science to grasp that concept either... I have never accepted "we've done it that way for years" as an answer to any question. Even if doing it that way has been successful, I look at it as there's always room for improvement. I can tell you that people like Cj Rayburn, Keith and Tader Masters, and Mark Richards want their cars scaled with driver weight for a reason. The 4bar spring behind LR suspension is designed to make the LR spring act softer through birdcage rotation so the effects are magnified when you add driver weight. They are also sensitive to bar angles and wheel weights. So yes, I will keep on keepin on. I can even explain why without just throwing experience out there as my reason.

[mod88s]

I understand your point about having 2 different springs without driver that they will be different after you put driver weight in the car, I really do. Its a very simple concept to grasp. Im not arguing that. But you are completely missing my point that it is 100% irrelevant in setting up a race car. Whether you scale a car with driver or without REALLY doesn't matter, as long as you do it the SAME WAY, EVERYTIME. And listen to your builder. That's MY point. If you have a decent builder, they have already taken these things into consideration. For example, Most times they give a range like 52.2-52.5% left side weight. If you are a heavy fella, you would scale to the lower end of the scale and vice versa. I can start name dropping like you did and give you a list of 100 people and 10 different brand name chassis that do not scale with driver weight and tell you they do it for a reason too but whats the point. Just helps me prove my point, some people scale with driver, some don't.. REALLY doesn't matter. As far as stating your theory about what the 4bar spring behind is designed to do, that's a whole other can of worms.

[Bcollins82]

I understand your point about having 2 different springs without driver that they will be different after you put driver weight in the car, I really do. Its a very simple concept to grasp. Im not arguing that. But you are completely missing my point that it is 100% irrelevant in setting up a race car. Whether you scale a car with driver or without REALLY doesn't matter, as long as you do it the SAME WAY, EVERYTIME. And listen to your builder. That's MY point. If you have a decent builder, they have already taken these things into consideration. For example, Most times they give a range like 52.2-52.5% left side weight. If you are a heavy fella, you would scale to the lower end of the scale and vice versa. I can start name dropping like you did and give you a list of 100 people and 10 different brand name chassis that do not scale with driver weight and tell you they do it for a reason too but whats the point. Just helps me prove my point, some people scale with driver, some don't.. REALLY doesn't matter. As far as stating your theory about what the 4bar spring behind is designed to do, that's a whole other can of worms.

Lol so I guess that means you don't agree with my 4 bar theory either? Thats cool... I tend to look at things differently than most. And yes, I completely understand and agree with you that if you scale the same way, same car, same driver, same springs, you can be consistent scaling without a driver. But just saying if you are a big fella, you run the low side of the recommended percentages is just a shot in the dark to get you in the ballpark where you can tune from there. And that's why I will never understand why any builder can recommend scaling like that. They would have to have a ride height chart for different driver weights to keep a consistent ride height from car to car.... I can go to the track with car A, find something better, call guy with car B in another state that is 100lbs heavier and he can set his car exactly to the pound the same, with ride heights dead on, and we can share factual information and remove as many variables as possible. That is a reality that I have to deal with every week. It is consistent and it is repeatable. If you can explain to me how you do that without a driver in the car I'll owe you a handshake and a tylenol from doing the math to figure it out. Lmao