50 replies to this topic

[dirtstudent2]

I read no mention of on track problems which might need to be solved.

 

My first thoughts when something's perfect on the track is it's too tight, bound at least a little too much to the track.

 

If it is too tight, then shortly into the race your likely going to be able to over work tires.  If that's the  case it takes us back to the first reply on here by Legend.

Edited by dirtstudent2, 17 August 2015 - 11:34 AM.

[LM RACING]

When a car typically isn't even on the rr spring anymore coming off the corner how is a stiffer rr going to produce more drive ??

maybe im wrong? But in theory the farther the car is over on the right rear it would pull traction from the left rear. when coming off the corner you want to be rolled over on the right front and standing on the left rear. With the stiffer rr spring it would keep it more balanced as the car lifts. But then again you are the one who studies this religiously and can show it on paper.

[buckboard]

We have no weight on the neutral bar.

[The Legend]

As the car rolls right the right side 4 links lose angle when they lose angle the thrust angle is no longer pushing up on the frame which pushes down on the tire generating traction. People some times chain the rr down or use mega rebound shocks on the RR to prevent the rr links from gaining angle on exit and in a perfect world on smooth conditions adding my drive coming off. The chain idea is absurd to me and I have never seen it on a top touring guys car I was just using that example to say why a stiffer rr is not going to improve his drive coming off

[dirtguy200948]

So you goanna take advice from a guy who finished dead last every week at ppms? He gets beat by cars 10 plus years older than his.

[LM RACING]

So you goanna take advice from a guy who finished dead last every week at ppms? He gets beat by cars 10 plus years older than his.

Dont knock his knowledge. He is very informed on all aspects of chassis set up. And could help you understand it. Lack of seat time is the cause for his results.

[dirtguy200948]

The 44 will smoke him any day.

[The Legend]

I was horribly loose ... And I still drove past the 44 ... It's not that I don't know what I'm doing its that I hardly ever race . I showed up at the track 10 minutes before hot laps with no tires ready... You can only do so much when you have a couple hours a week to work on your car ...

[dirtguy200948]

May be you need to devote more time to your car than your kits. Like they say races are won in the garage

Edited by dirtguy200948, 17 August 2015 - 01:43 PM.

[dirtstudent2]

Legend, what you write reads to me your in a position to find someone you trust and pay them to prepare your car, as instructed by you.

[Chrome Horn]

He does have someone, Richard G the best plumber in the Burg!

Edited by Chrome Horn, 17 August 2015 - 03:13 PM.

[racer67x]

maybe im wrong? But in theory the farther the car is over on the right rear it would pull traction from the left rear. when coming off the corner you want to be rolled over on the right front and standing on the left rear. With the stiffer rr spring it would keep it more balanced as the car lifts. But then again you are the one who studies this religiously and can show it on paper.

I always thought of it a somewhat different way..the RR is already going to be the dominate tire coming off a turn full throttle due to the solid rear and the forces of the engine rotation.you add left rear bite to counter act that and keep the LR tire planted.like you said its trying to lift the LR so you add wedge RF to LR,the RR somewhat takes care of itself so you soften it to adjust sidebite...
either way unless the rear isn't locked if one tire breaks loose you lose them both.

[LM RACING]

I always thought of it a somewhat different way..the RR is already going to be the dominate tire coming off a turn full throttle due to the solid rear and the forces of the engine rotation.you add left rear bite to counter act that and keep the LR tire planted.like you said its trying to lift the LR so you add wedge RF to LR,the RR somewhat takes care of itself so you soften it to adjust sidebite...
either way unless the rear isn't locked if one tire breaks loose you lose them both.

but with the momentum of the chassis rolling over I would think that a lighter spring would counter act the wedge. If you put the heavier spring in it don't roll on the rr as hard and keeps the wedge in play. But then the car wants to drive to the wall so it needs free up in the middle. Just my theory. I could be wrong lol.

[dirtstudent2]

You all are talking about springs and especially what to put in the RR,  I have a question.

 

What does a spring do?

 

I have always thought of springs as setting the limits for chassis movement and and storing energy when compressed.  Soft or strong, a spring can only compress and store what's offered to it.  So beyond setting limits for chassis movement, they are also able to release their stored weight, energy or what ever you want to call it, over a shorter distance with stronger springs or a longer distance with softer springs.  Which I suspect is the only reason it can be said stiffer springs react quicker.

 

I've been told by many that with a late model it's get on the RR and go, until your go is reduced because the RR gives out.  Then if you want to maintain the same amount of go, your only option is to get more work out of the LR.  If the LR then gives up your done, because all weight then moves to the already over worked RR and it's already either slipping or on the verge of slipping.

 

I don't know squat about late models but if your LR has given up the only thing I think might be for sure is your not going as fast.  

 

If your not going as fast, then forces to break loose both the RR and the  LR are reduced, so maybe... if your out of forward bite but going slower, throw a softer spring at the RR to slow down release of weight, crank the left end of the axle forward as much as you can and if possible crank the right end of the axle back as far as you can, dropping the front end out as far as you can over the bank of the track, to dump weight also on the LR.  ... I have no clue about it, but what you all wrote is interesting and I like to think  about how stuff "might" work.

 

And yes what I wrote proves I don't have a clue.  It will be interesting if the thread starter get's his needed forward bite and if he does I'd sure like to hear what it is he thinks did it for him.

 

edit:  Your measuring ride height and angles at the back, isn't that just to maintain thrust is aimed where it's most beneficial to applying power/forward bite?  That gave me another question.  Where do you aim the thrust, ahead of the contact patch, at the contact patch or behind it?  And if you do get forward bite out of the whole deal, does the winding up of the tire providing your slip ratio effect where you initially should aim thrust?  I pretty much feel it must, but I think it's probably a non issue, but just thought about it and asked.

 

I usually see late models when a track slicks up bring down their LF.  I guess it's to help get weight over on the LR too.  But if your short on traction to begin with, I would think you want to bring the LF down and not really engage it hard with the track.  You'll want it there for a place to help hang weight over onto the LR, but if you also put it too hard into the track, won't it working with the track and having to be pushed by the rears, eat some of your much needed forward bite?  I'm out of questions.  ...

 

thanks for reading this bull and my dumb questions, sorry to waist everyone's time. 

Edited by dirtstudent2, 17 August 2015 - 04:25 PM.

[cumminsman08]

You all are talking about springs and especially what to put in the RR,  I have a question.
 
What does a spring do?
 
I have always thought of springs as setting the limits for chassis movement and and storing energy when compressed.  Soft or strong, a spring can only compress and store what's offered to it.  So beyond setting limits for chassis movement, they are also able to release their stored weight, energy or what ever you want to call it, over a shorter distance with stronger springs or a longer distance with softer springs.  Which I suspect is the only reason it can be said stiffer springs react quicker.
 
I've been told by many that with a late model it's get on the RR and go, until your go is reduced because the RR gives out.  Then if you want to maintain the same amount of go, your only option is to get more work out of the LR.  If the LR then gives up your done, because all weight then moves to the already over worked RR and it's already either slipping or on the verge of slipping.
 
I don't know squat about late models but if your LR has given up the only thing I think might be for sure is your not going as fast.  
 
If your not going as fast, then forces to break loose both the RR and the  LR are reduced, so maybe... if your out of forward bite but going slower, throw a softer spring at the RR to slow down release of weight, crank the left end of the axle forward as much as you can and if possible crank the right end of the axle back as far as you can, dropping the front end out as far as you can over the bank of the track, to dump weight also on the LR.  ... I have no clue about it, but what you all wrote is interesting and I like to think  about how stuff "might" work.
 
And yes what I wrote proves I don't have a clue.  It will be interesting if the thread starter get's his needed forward bite and if he does I'd sure like to hear what it is he thinks did it for him.
 
edit:  Your measuring ride height and angles at the back, isn't that just to maintain thrust is aimed where it's most beneficial to applying power/forward bite?  That gave me another question.  Where do you aim the thrust, ahead of the contact patch, at the contact patch or behind it?  And if you do get forward bite out of the whole deal, does the winding up of the tire providing your slip ratio effect where you initially should aim thrust?  I'm feel sort of sure it must, but I think it's probably a non issue, but just thought about it and asked.
 
thanks for reading this bull and my dumb questions, sorry to waist everyone's time.

Im not sure i can answer all of those questions, but i might be able to clear things up for a few... Lets back track because it seems there is alot of confusion on weight transfer and such... Lets look at weight transfer on a latemodel... Try not to say weight transfers from RF to LR that is where the confusion sets in.. See weight transfer as Front to rear, and side to side..
for example: lets say we soften the RF from a 400 to 350, what does that do? allows weight to transfer on rf more but at the same time more weight transfers to right side gives more weight to RR and can cause you to lose drive off... to gain that drive back that we lose to help entry you have to look at your bar angles and lets see if i can explain bar angles and thrust angles without losing anyone..

dirt student2:You must remember the rear ends of these cars DO NOT load the tires via the springs for the most part on exit they load the tires via (the bars) using thrust angle. You move to upper bars to effect roll steer somewhat but your upper bar angle gain is what loads your tires. Your upper and lower bars when angled if you draw and imaginary line that extends each bar until both bars intersect take that point and draw a line back to the center of your contact patch that is your thrust angle thats why when you raise the left upper bar you gain traction on the LR and are tighter on throttle.. when you raise the RRU it makes you looser because it loads the RR tire more.

[cumminsman08]

buckboard:
What feedback are you getting from a decent crew guy, stance of your car as you feel your car is going away? Are you sure your getting those 1325's into the track, ive found the 1325 to be a pretty up and down tire depending on the track surface.. possibly go with a 1300 lr... And if the track is really slowing down by feature time are you making the proper shock adjustments to compensate? need more info to really pinpoint the problem..

[buckboard]

Dirt student, during the heat (with our current heat setup: Hoosier 1200's on the rear) the car could and would run high and low and mid track. Made our feature changes: reduced stagger to 3.5". 1325s across the rear. Adjusted rear bite to add approximately 50# of bite to the rear. Dropped both right side bars one hole.
During the heat, the right front of the nose was just grazing the track. After said changed the right of the nose was at least 2-3" off of the track surface. Just an observation standing in turn one watching the car.

[buckboard]

Cumminsman, I am the crew, head wrench, and the guy that sweats his butt off every Saturday. Lol! I don't know if I'm doing everything right. He does like the feedback he gets from gas double adjustable shocks that he never felt from oil filled non adjustable doo jollies.
And it's a very abrasive dry slick track. And the right rear will need flipped for next Saturday. Left rear is pretty much just missing the tits.

[BURNS76SS]

latemodels work diagonally so the more you load the rf getting in the more lr weight transfer you will have getting in the gas so the more lr bite the more the tighter it gets so I say up your lr bite  (2003 rocket book basic high wedge for 220 to 240 lr bite 55% left 55% rear 55% cross for dry slick track ) lr 275 rr 225 lf 500 rf 400 now I know you don't have a rocket but its a good reference

[BUTTBEAK]

If your looking for more forward bite...... with slick track conditions.......your looking for something that doesn't exist. (without adding a lot of weight and/or downforce,weight is counter productive, and downforce should be maxed out almost always).

 

Slick track conditions are conquered by getting corner speed back up, time to change your thought process/goals.

 

..........BTW, all shocks used today are oil filled.