I agree 100% with a lot of this. I consulted on a 2 car team this past season. And the builder says to use an 11" spring but very light. Trying to get these guys to understand what everything is doing has been frustrating at best. They are stuck with the mentality that "his cars are best so we do what he says". You mentioned the modlites and when we were doing them changing up the tables was huge. But all those guys have that single way of setting them. Pay attention to this yall. Lay down under the car and just study. Look at it all and figure what and why. You will find speed.
I am new to "Factory Stock" car racing running a metric car with Limited adjustment rules. I Would Love to see some simple videos of quick go to adjustments at the track to get the feel you are after. Ride Height adjustments / LR bite as the track starts to dry slick. Learning a lot from your videos!
Not for sure what you are look for but, I do like a 12" 900 in a Hobby Stock car. (front) but as far as a RR 12" spring vs a 13" I think you would have more luck moving weight. If I got wrong as to what you were asking please let me know.
Gen x mastersbilt we’re built without a lot of structural support. Same as 2011-2014 warriors and a lot of cars from that time. They were built with “chassis flex” in mind, mostly because small hp crate racing was huge. That was a trend of it’s day because we were yet to learn what we have today and didn’t know how to get that out of suspension. That trend produced cars that have a lot of chassis fade over time.
Any advantage for an asphalt Pure Stock with stock type springs and non rebuild shocks to run differing spring heights. 3;8 mile medium banked asphalt track - Colorado National Speedway
Yes, it will be for the wedge, to load the tire diagonal of the one with a taller spring. Need more RR, adding a taller LF or shimming it will add load to the RR.
You say shortening a spring induces weight transfer. This is not accurate. The only things that affect weight transfer are weight, acceleration, height of center of mass, and track width. Per the weight transfer equation. What you’re talking about doing is actually making the roll center migrate towards the shorter spring.. as it migrates towards the shorter spring it travels along the axis of the instant center. This causes the roll center to raise (the axis of this instant center is sloping downward to the center of the vehicle) the result is a higher rear roll rate. The increase in roll rate is what drives the increase in RR wheel weight. As it decreases front biased roll rate distribution (I can deduce your front springs are a considerable amount stiffer) to something more neutral. Weight transfer is the total amount of weight that shifts from left to right. Roll rate distribution determines whether it goes to the RF or RR. You can run a shorter RR spring or a stiffer RR spring and both will accomplish the same thing from a wheel weight perspective. I’m sure I could come up with some differences but the only significant difference I can think of is that a shorter spring will likely cause the LR to travel further into droop as the roll center migrates to the right. Hope this helps. Good luck
So to change spring table with sliders in the rear you need move the slider down? Also if a guy wanted to use a shorter spring with a slider does that really do much?
I know this is unusual, but im stuck with running an 11" RR spring due to the way the rear clip is made. LR is 16" 175lbs. Cant seem to keep the LF on the ground no matter what when there is a cushion or track is slightly tacky. Would going up unusually high on the Jbar pinion side help counter act the fixed spring table situation? Currently have a 225lbs RR spring
Yes, it would but not the adjustment I like the best. The 11” spring is allowing weight to move to the rr more than if it was a 13” would. In order to keep the LF on the ground you will need to increase the RR spring rate to a 250 or a 275lbs spring. The shorter the spring on the RR the easier it is to move weight in that direction.
This is where it gets hard and you have to use springs (LR) to help make transfer. It also helps if the guy building the car has a bit of sense in getting some weight up in the car.
@@jaynealgofast can you do a follow up video and expand on that a little more. With a 13” spring on top of axle tube, what would be the preferred mounting location of lower shock eye? If we swap to an 11” spring, should the shock be lowered? Thanks Jay, great videos.
@@jaynealgofast that would be great, looking foward to it. couple other things i'd like your opinion on, maybe you can work into the video's. rear shock placement ahead/ behind rear axle? is there any info to be gained using the load stick on the rear corners? on a typical 3000# hs/sc i see front rates from 500#'s up 1100#'s, is there a relationship between front % and the proper rate selection? for example, which is better for grip on a 3000#, stock eng location, 45% frt. 500-600 rates or 900-1000# rates.
I agree 100% with a lot of this. I consulted on a 2 car team this past season. And the builder says to use an 11" spring but very light. Trying to get these guys to understand what everything is doing has been frustrating at best. They are stuck with the mentality that "his cars are best so we do what he says". You mentioned the modlites and when we were doing them changing up the tables was huge. But all those guys have that single way of setting them. Pay attention to this yall. Lay down under the car and just study. Look at it all and figure what and why. You will find speed.
Understanding the WHY will win you races.
I am new to "Factory Stock" car racing running a metric car with Limited adjustment rules. I Would Love to see some simple videos of quick go to adjustments at the track to get the feel you are after. Ride Height adjustments / LR bite as the track starts to dry slick. Learning a lot from your videos!
This is a hard topic to cover, but I will give it a shot, may take some time.
@jaynealgofast was u able to put out a video about this?
Great info Jay!
Thanks I am trying to do good
Well there was no talk about a 12 inch spring !? 😎
Not for sure what you are look for but, I do like a 12" 900 in a Hobby Stock car. (front) but as far as a RR 12" spring vs a 13" I think you would have more luck moving weight. If I got wrong as to what you were asking please let me know.
Ahh dirt latemodel might be heavier i know the xr1 is heavier than an 15 mastersbilt .
I thought due to more tubing ..mostly from building safer cars
Thanks for that info
Gen x mastersbilt we’re built without a lot of structural support. Same as 2011-2014 warriors and a lot of cars from that time. They were built with “chassis flex” in mind, mostly because small hp crate racing was huge. That was a trend of it’s day because we were yet to learn what we have today and didn’t know how to get that out of suspension. That trend produced cars that have a lot of chassis fade over time.
Sounds like good information to me
Good to hear!
Any advantage for an asphalt Pure Stock with stock type springs and non rebuild shocks to run differing spring heights. 3;8 mile medium banked asphalt track - Colorado National Speedway
Yes, it will be for the wedge, to load the tire diagonal of the one with a taller spring. Need more RR, adding a taller LF or shimming it will add load to the RR.
You say shortening a spring induces weight transfer. This is not accurate. The only things that affect weight transfer are weight, acceleration, height of center of mass, and track width. Per the weight transfer equation.
What you’re talking about doing is actually making the roll center migrate towards the shorter spring.. as it migrates towards the shorter spring it travels along the axis of the instant center. This causes the roll center to raise (the axis of this instant center is sloping downward to the center of the vehicle) the result is a higher rear roll rate. The increase in roll rate is what drives the increase in RR wheel weight. As it decreases front biased roll rate distribution (I can deduce your front springs are a considerable amount stiffer) to something more neutral.
Weight transfer is the total amount of weight that shifts from left to right.
Roll rate distribution determines whether it goes to the RF or RR.
You can run a shorter RR spring or a stiffer RR spring and both will accomplish the same thing from a wheel weight perspective.
I’m sure I could come up with some differences but the only significant difference I can think of is that a shorter spring will likely cause the LR to travel further into droop as the roll center migrates to the right.
Hope this helps. Good luck
LOL what he said. Thank
So to change spring table with sliders in the rear you need move the slider down? Also if a guy wanted to use a shorter spring with a slider does that really do much?
Yes the shorter spring in lowering the table too, the pivot point is the same and share load with the spring table.
I know this is unusual, but im stuck with running an 11" RR spring due to the way the rear clip is made. LR is 16" 175lbs. Cant seem to keep the LF on the ground no matter what when there is a cushion or track is slightly tacky. Would going up unusually high on the Jbar pinion side help counter act the fixed spring table situation? Currently have a 225lbs RR spring
Yes, it would but not the adjustment I like the best. The 11” spring is allowing weight to move to the rr more than if it was a 13” would. In order to keep the LF on the ground you will need to increase the RR spring rate to a 250 or a 275lbs spring. The shorter the spring on the RR the easier it is to move weight in that direction.
@@jaynealgofast thanm you!
What about a imca hobbystock 13in spring rules
This is where it gets hard and you have to use springs (LR) to help make transfer. It also helps if the guy building the car has a bit of sense in getting some weight up in the car.
@@jaynealgofast so softer rr to help it get over correct?
So my b mod shouldn’t be on both chains through the corner?
Not the RR so much, or not till late exit.
What about the shock placement on a stock car. Can a 9” RR be mounted to high?
Yes it can and it will hurt the car in the slick too.
@@jaynealgofast can you do a follow up video and expand on that a little more. With a 13” spring on top of axle tube, what would be the preferred mounting location of lower shock eye? If we swap to an 11” spring, should the shock be lowered? Thanks Jay, great videos.
@@davemadej6580 Okay I will do a video this weekend on stock car spring height. We will also release a series of 4 on each corner.
@@jaynealgofast that would be great, looking foward to it. couple other things i'd like your opinion on, maybe you can work into the video's. rear shock placement ahead/ behind rear axle? is there any info to be gained using the load stick on the rear corners? on a typical 3000# hs/sc i see front rates from 500#'s up 1100#'s, is there a relationship between front % and the proper rate selection? for example, which is better for grip on a 3000#, stock eng location, 45% frt. 500-600 rates or 900-1000# rates.