4 link ?

Shocks, Springs, Brakes, Frame, Body Work, etc

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awesomebill

Re: 4 link ?

Post by awesomebill »

Hey Todd, Been reading this post and I have some cheap fixes for your problems. I assume you have video of this killing the tire problem you have? The LR tire gets a free ride downward because of the driveline configuration. The RR is always the problem child by the fact it is trying to be lifted. This happens to every car where the drive shaft turns counter clock wise looking from the rear. The reason this happens is because your shock setting verses your bar configuration verses a good hooking track, is allowing the rear to plant too fast. If you slow the extension of the shock down a little, or raise the tire pressure a little at a time you can fine tune for good results. Being you are dropping a hammer on the susension with the clutch, you are working your stuff to death. Great way for racing but some small changes will help. An Anti roll bar will do wonders, front h/d sway bar will help with the twisting and keeping the front end level and applying load evenly. You can change the bars all you would like, but you can only move them so far with the stock suspension and you already have stated it is killing the tires. If you could extend the stock 4 link out to meet at some point, it would never intersect. I do not recommend raising the front lower bar, I would raise the upper top rear position. I do not know how much lattitude you have with your adjusting capabilities. As far as scaling your car, it is what it is. You can only move so much weight around with the coil overs. As far as preload, if your upper RR bar can be adjusted, more preload, shorter upper RR bar, will help hold the RR tire on the ground thus causing the left rear not to be hit so hard and will produce even pressure on both rear tires. Video the left and right rear tires until the tires leave in about the same compression factor. Once you get that down and the car still goes straight, you can work with the shocks at different levels of track bite to allow the rear to move guicker or slower in the downward or even upward motion. There is a world of info to be learned by the video of the slow mo of what happens to your car when you let the clutch out. Try it and watch, you will be amazed just how the chassi works.
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Re: 4 link ?

Post by BillyShope »

I'm afraid I'll have to disagree on a few points:
awesomebill wrote:If you slow the extension of the shock down a little....
Shock absorber force is a function of relative velocity. In other words, they only are of use when the axle assembly is moving relative to the rest of the car. Since this is such a short time...compared even to the sixty foot times..., tinkering with shock settings is of only minor importance to the dragracer.
awsomebill wrote: An Anti roll bar will do wonders, front h/d sway bar will help with the twisting and keeping the front end level and applying load evenly.
When you install a front h/d sway bar AND an anti-roll bar, you're working against yourself. One of the two primary purposes of the anti-roll bar is to increase the rear roll stiffness relative to the front roll stiffness. See Page 20 of my blog:

http://home.earthlink.net/~whshope

awesomebill wrote:If you could extend the stock 4 link out to meet at some point, it would never intersect.
The only way they wouldn't intersect is if they're perfectly parallel. (And they're not.) And, a mathematician would say that even the parallel links meet at infinity.
awesomebill wrote: As far as scaling your car, it is what it is. You can only move so much weight around with the coil overs.
With adjustable coilovers at all four corners, you can achieve virtually anything you want. Of course, the sums of fronts, rears, and sides must each remain constant. A dragracer without wheel scales is without a primary chassis tuning tool.
awesomebill wrote:Video the left and right rear tires until the tires leave in about the same compression factor.
Unfortunately, the usefulness of video is very limited. Video simply does not reveal force magnitudes; only their effects. To achieve adequate analysis precision, you need to use a traction dyno. Again, see another page at my blog.

Didn't mean to "jump all over you," awsome, but you brought up some points which I felt needed comment.
Ed-vancedEngines

Post by Ed-vancedEngines »

Lol. Well Mr Billy,
Being as we are all pals here, I guess I can disagree with you on a couple or three of your responses too. Huh?

Hmm' I waited awhile and you did not tell me to go ahead or not, so I guess silence means for me to speak my piece. :)
Shock absorber force is a function of relative velocity. In other words, they only are of use when the axle assembly is moving relative to the rest of the car. Since this is such a short time...compared even to the sixty foot times..., tinkering with shock settings is of only minor importance to the dragracer.
This one I have a hard time even believing you are saying. Rear shock absorbers are literally one of the most important suspension items you can ever buy. Why do you think we and by we I am meaning all serious high horsepower racers, are wasting (?) $600.00 to even $1,800 dollars for a good set of rear double adjustable shocks???

Mr Billy have you been away from Drag Racing completely over even the past 25 years or longer? Or do you not work with high horsepowered drag cars? We found benefits in tuning with shocks well past 30 years ago.. Pro Stocks have been using adjustable shock dampening and slightly changing the ride ht as a means of fine tuning suspensions since the late 1970's with double adjustable shocks. Now in the year 2006 They still are but with higher technology on some of them. We are working with cars with 1,700 horsepower to well over 2,200 horsepower with 4 links and I can assure you that the high quality double adjustable shock method of fine tuning and tweeking in is the only way to get it right when any sort of bar adjustment would be far too radical of a change. We are hooking with some customers at 1,700 horses and getting traction on Micky Thompson True 10.5 tires. Don't even think about trying to convince me that shock adjustments mean nothing on a drag car. Do you ever even get close enough to any serious 4 link car now to see the adjustment holes in the brackets? In NHRA Pro Stock and also IHRA Pro Stock you will see that on most of the bar adjusting holes for possible locations the paint is not even worn off. The paint is not worn off because most rear suspension fine tuning adjusting is done with shock dampening changes after the car has been baselined in.

Sorry for not talking more with diplomacy but that answer of yours just went all through me. The shcok on a drag car is critical to get a great launch and is also very critical for safety too. Changes in shock valving adjustments can also be beneficial in any drag car. Take your old Pinion Snubber Super Stock Mopars and the way they launched. Add some modern technology to just the shocks and I can assure you a better 60 ft and ET. The old stuff did work and did and still does look awsome but there is far too much time wasted in monkey motions and over planting the tires on those cars.

O' boy here we go again;
A dragracer without wheel scales is without a primary chassis tuning tool.
Unless they are professionals or are very bucks up, even today most drag racers do not own individual wheel scales. The scaling a car that many now think is very critical, is still limited in that the car will not stay the way it was scaled, once any suspension pre-load adjustments are made. I like wheel scales. They are a nice thing to use as a tool for a reference or to even jack weight for a beginning baseline. It is when the car is at the track and what works to get the car to go down the track is what is important. You can change the way a car needs right rear pre-load by simply adding to or taking away horsepower. I did say that wheel scales are something I consider to be very useful while in the shop to get started on a baseline. I have gotten use to not having wheel scales for many years so to me it just does not seem as important as younger racers feel it is. I got used to finding my weights and percentages in the old fashioned methods. Maybe if I had wheel scales available to me anytime I wanted to use them, I would feel different about thier importance of a necissity.

Here we go again, Disputing an engineer. :)
Unfortunately, the usefulness of video is very limited. Video simply does not reveal force magnitudes; only their effects. To achieve adequate analysis precision, you need to use a traction dyno. Again, see another page at my blog.
A video is one of my most liked tuning aids. In single frame advance, I see things happening that my eyes could never pick up. Your chassis dyno article is very interesting. But it seems to me as something to use for getting a beginning baseline. Nothing beats the actual car in action. What I do like to supplement a good 3/4 rear biased video is for those with the financial means to buy and use them is shock travel and spring load cell sensors connected to a good data logging device. Even for track side tuning if I know in advance I might be tuning we will bring video cameras and a TV screen to play back on.

Because of the triangulated angles used to loccte the rear end side to side, you can not do any pre-load adjusting on any top bar. Most stock suspension classes will not allow you to change any bar mounting position either. You can change your ride height though and by lowering your car you will efectively be moving the bar attaching positions as seen by the tire and rear suspension. It can help some. A Chevelle factory 4 link is a very good place to use an anti-sway bar. In this case you can use the anti-sway bars to help set right rear tire pre-load. That car wants right rear and left front pre0lod.

To all who read this. These are only my opinions and my experiences.

Ed
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Post by BillyShope »

A few years ago, the aluminum processing industry spent millions to get rid of the sodium fluoride waste they generated. Then, someone hit on the idea of spending a few dollars in the right places and suddenly every city's water supply needs those same fluoride salts to protect the children's teeth.

Similarly, if I was selling shock absorbers, I'd want every dragracer to believe they were essential for peak performance. But, if the rear suspension is set up for no squat or rise, the axle assembly doesn't even move relative to the rest of the car and the shock absorbers might just as well be back on the dealer's shelf.

Since the rear suspension linkage is capable of carrying all of the weight transfer, it really doesn't pay to do much of anything with either spring rates or shocks at the rear. Now, at the front, it's a different matter! Since all of the weight transfer, at the front, is carried through the suspension springs, 10/90 shocks can be used to allow the front (and the car's center of gravity) to quickly rise. (It's going to rise to the same height, eventually, with 50/50 shocks, of course.) More importantly, a higher rate spring can be used on the right front (relative to the left front), which allows dynamic cancellation of the driveshaft torque.

If wheel scales and the traction dyno are used back at the shop, there's no reason to touch the suspension at the strip. With the traction dyno, you will verify that you have equal rear tire loading on launch. You can't do any better than that, so it should be "hands off" at the strip! You can kill excessive wheelstands with tire air pressure if a ballast shift isn't possible.
awesomebill

Post by awesomebill »

I have not a clue as to where you can come up with that synopsis of a drag car not responding to shock settings or even any of your points you have so graciously pointed out. I have to disagree with all of them. If I had to leave any one of 4 shocks off the car to race, I would quit. The scaleing of a car that you seem to think is so important is only for a certain hp at the time you set it up. Add more HP and what happens to the chassis? It wll most definetaly respond in a more forceful matter. The forces are different every time you increase any of them so a different scaling for every level would have to be implemented or the car would most diffenately go to the right. I have seen many cars set up to run naturally aspirated and when a small shot of nos is applied the car can not make it down the track. So if your 1 scale fits all theroy is applied this would certainly cancel it. Every time you increase torque or say reduce stall speed or make a higher gear change the chassis will react differently. You might as well throw away the scales if anything you wanted to leave out because with the HP and Torque estimated for the scaleing, you are only guessing at best. As far a watching a video of the suspension at work for the car at the track with the HP you are dealing with is one of the most important factors you could use. Take Don Burton, he has one of the best leaving NOS BBF P/G cars in the country all on a true 28/10.5 tire. NOS and blown cars are the worst to tune. Most times we have to take power away on the hit or go into severe tire shake. Even soft hitting turbos have to work around the set up to get it right. As far as shock setting of extension and rebound, a double adjustable shock is the only thing to put on a chassis!. After the car has driven the rear into the ground on the hit, the rear has a tendendsy to rebound back up to quickly and then blow the tires off. You can slow the compression factor down and correct this. The only chassis that would work with your theory would be a hardtail dragster or altered. And even then, they are a big shock at work as 1 unit because of the ability to flex. The only other factor to address is moving weight around with the coil overs. You can only move about 60-75 at the most corner to corner weight without making a dangerous car when you let off the throttle. I have seen some guys move the spring rates around and so when you lift on the gas at the end, the right rear tire now becomes a brake and pulls the car right into a top end spin. Some of your workings of suspension may work with low HP stock style 10 second and higher drag cars with no power, but you get 1500 + hp to use your theory then your doing something. We run these cars all the time with great success. The sway bar issue does cause some slight intersection forces but the reality is a car that works way better. An Anti roll bar is one of the best bandaid fixes for the novice racer and chassis tuners you can get, not to mention they are now standard hardware on most chassis. I have to agree with ED about everything he post. He does have a certain understanding of a working chassis that I have found no where else. There are many other secrets that people hold and do not choose to loose but as far as simple tuning aids for the gentleman who ask, these ones I have listed will help him greatly if he applies them correctly or have someone who could help him. These are just some things we have found that works on a real car at a real track on a real day.
Ed-vancedEngines

Post by Ed-vancedEngines »

Mr Billy,
Please do not get us wrong or give up on we uneducated average old men.

I may not be agreeing with a lot of your advice or theories but I do really enjoy reading and looking at the many tech articles on your webpage.

http://home.earthlink.net/~whshope/index.html

Awsome Bill and others that link is for you to just go check it out. Some pretty profound line of thinking going on there on his webpage.

Eventhough I am not in circle track racing, I can appreciate the thought concept of this one too.

http://home.earthlink.net/~whshope/id16.html

I see on your webpage that you were once with the Ramcharger Team. If I may ask when was that? I followed a lot of what they did by way of magazines when I was a young man and before when I was a kid. I also had the opportunity to see them in person a few times. I was at Cecil County Dragway the night that the altered wheel base fuel injected Coronet broke into the 8' second range. I really doid enjoy that style of matchracing. I kind of wish we had it now. A lot of the thrills was just watching the show the cars and teams was putting on just getting ready to make a pass. There is nothing like watching tires smoking with hard power while at the same time the front is way off the ground. . I loved the old style matchrace race prep including getting the tires ready and doing the burn outs to layt down the fresh rubber and then getting in the middle of your tracks to make the pass. Modern crowds don't know the thrills they missed.

Sir;
I do not try to be a know it all or a smart alec. I am just talking from things that are working, and also about things that do not work so well. I do like the ant-roll bars but can get by without them because we did get by without them before they were invented. They are a nice aid though.

I hope we will continue to dialog with and against one another in friendliness. If I have spoken to you out of turn or wrongly,
I believe I have.

I ask your forgiveness.
Ed
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Post by BillyShope »

Ed, I respect all that the racer learns through experience. At the same time, I respect that solid groundwork established, through the centuries, by scientists and engineers. Those matters discussed in my blog are not theories, but merely applications of sound engineering practice. The traction dyno, for instance, is an application of the principle that, for analysis, a static force can be substituted for an inertial force. This was used by young David, before he went out to meet Goliath, when he tested his sling by putting a foot in the pocket and pulling hard on the leather thongs, but was not formulated until d'Alembert in the nineteenth century. It is the balance of moments and forces that the engineer seeks in his analysis and these nulls are valid regardless of the moment and force magnitudes.
awesomebill

Post by awesomebill »

That was and still is exactly true, but David did not slay the Giant with a Colt 45 Magnum. He used what was at the time available to propel the stone with enough force to crush threw the skull of Goliath. Now if David had the rubber band or even now the Bow & arrow, and God forbid the 45 Mag, he would not of had to run to the battle line to face him but he would of had to at least get familiar with the new weapon and find out how it work, kicked, sailed threw the air and so on. With out practice or even experience with what you are working with all other is just opinion. With todays power adders, you can pretty much rule out a lot of the old theories. They never had 1000 lbs of torque + to deal with even has much as 10 years ago with a 10.5" tire and 3000 lb cars. What worked well 10 years ago is still working for 10 year ago HP. My theory is proven by appling NOS to the same chassis car that is faster than 10.00. The car does not like the added forces and would have to be rescaled as you seem to think 1 scale job does it all For larger amounts of forces at work at the time you are using them with the now common 3.55 gear and 28-33" tire cars and torque convertors that do not slip, things will have to be changed because just in the gear to tire to weight factor and having to run 200+ with a 28" tall tire means the combination will put triple the amount of energy to the driveline. Tim Oharo purchased a beautiful 69 Camaro from TM race cars and when he put that big AJ 481X in it, he had the car go to the left pretty hard when he let off the button. He call Tim and Tims response was quit playing around with it and hit is with some power. This statement did not register with Tim O until he stepped up the power level and boom the car went dead straight. Now what force caused this? The act of opinions, knowledge, suggestions, theories etc, are great to kick around and everyone can learn something from them maybe. I enjoy reading and responding to different areas I am somewhat familiar with and will post from time to time. Please feel free to contact me any time with any questions or answers either one of us can learn from
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Post by Silverback »

Wow, what a handful… Reading through this I see 3 pretty clear lines of thinking that are completely different, Ed’s, Billy’s and Awsome’s. While what I think mostly seems to line up with Ed’s, I would suggest that all 3 are probably valid approaches, they just address the issues from different angles, and result in different attitudes about what works and even what is really happening based on what hole you dig yourself from the getgo (where you start with tuning).

That being said:
toddcalo wrote:I have a bracket car I race , Ill give a brief discription of the car Its a71 chevelle 12 point cage 355 small block car wieghs 2850 with me in car best et is 9.84 134mph 11 inch face on tire 29 tall 5.56 gear leave at 7500 rpm stick car 4speed lenco. best 60 foot time is 1.36. I recetly have been questioning my rear control arm angles after reviewing a video tape I noticed the rear tires are getting hit real hard.
I may just be a little slow but I don’t think that you’re really clear hear about what the problem is. 1.36 is quite a decent 60’ time and most people wouldn’t be complaining, so I’m wondering what you’re really expecting from the car there. By “hit hard” do you mean that you’re hitting the tires with a lot of power and they’re just not holding or do you mean that they’re distorting a lot coming off the line?
the rear suspension is basicaly a stock setup that has been made adjutable. cuentley the lower arm is at 4.5 degrees up in the front the top is pointing up 2 degrees in the front. [ lots of anti squat ?]Im going to move lowers to 3 degees up in the front and leave the top where its at. does any body have any sugestions, on angles?
I don’t know that anyone here did the math but barring working the numbers (too late for me to give it a serious effort), it sounds like you don’t have _that much_ antisquat. Just estimating that your rear upper and lower pivots are 10” apart, that would put your point of intersection over 229” forward roughly 8” above the upper pivot point on the axle (unless I really messed up in my fuzzy headed trig).

Generally you’d have a downward angle on the front of the uppers to bring the antisquat numbers up.
Ive been reading whatever I can get my hands on, one thing that Im still not quite understanding is the instant centers relationship to the neutral line , does it matter if the instant center is 5inches in front of the rear tire or 5 feet [provided they both intercect the neutral line at the same distane above or below]
I can’t think of a way that it does matter in this discussion… possibly in a handling situation, but as long as you don’t have excessive preload somewhere or a failure I doubt that any of this will effect things to the point that you can’t get into the turnaround and return lane ;)
Ed-vancedEngines wrote:If youhave capability to get the car professionally 4 wheel scaled at a chassis shop that gives you more information to begin with. BUT if you have to poor-boy it.
I know that this became irrelevant later in the discussion (he had scales), but in case someone is doing a search, you can poor boy corner weights. What you need to do to do it is to make an arm with a pivot at one end and a “seat” for the tire to sit on 2/3-3/4 of the way to the other end and then a pad on the other end to put on a plain old bathroom scale. The weight read on the bathroom scale will be 1/3-1/4 (depending on where your wheel pad is) of the corner weight of the car. You can really pore boy it using one scale as long as you raise all the tires to the same height as the assembly with the arm and scale holds the tire you’re measuring.
In my little mini-seminar I tell you how to easily find your actual center of gravity and how to use that information to figure yoiur percentage of front/rear weight distribution. With that information and by knowing more about your car and full diriveline clomonation wheel size tire size and type etc, you will be able to at least get a baseline established as a starting point.
Are these little mini seminars available online? If not can you email them to me? Thanks.
After you take it to the track in my opinion getting good close up left side 3/4 angle video of your car doing a launch is a very good suspension tool or aid and all racers should video and watch thier cars in slow siingle frame advance motion. There are several reactions that will happen too quick for your eye to pick up or to register in your mind that the video will show.
I’ll have to agree with this being the best tuing aid out there. Sometimes you think you know all the theory (engineering concepts) that apply to the situation and you still see something that isn’t explained. Finding that going frame by frame in a video gives you an indication when you should be looking for another problem even though “everything should be right,” and if you’re the type it is also impetus for some of us to go out and figure out what it is that we don’t know about what we’re seeing so we can explain it.
toddcalo wrote:I do have acess to wheel scales and I have a recent video as you descibed the tire wrinkels it makes one and ahalf revolutions before the car appears to move, the front tire lifts agout 6 to 8 inches , carrys them for about 10 feet , the back end lifts slightley this produced a 1.42 60 foot time. I may be wrong thinking its hitting the tires to hard but just looking for some input thanks.
Can you post or email the video?

Does the tire tread actually make 1-1/2 revolutions before the car moves or does the wheel seem to? I’ve had the situation where the car hit bruitally hard off the line but had too much antisquat (for the rest of the setup, softer sidewalls and possibly some tuning could have made it useable…) and a few feet out the tires would get pushed down into the pavement so hard that they would literally bounce up and the car then felt like it was on marbles. It’s not uncommon for fox mustangs with Lakewood and similar bars to hit so hard off the line where you’ll see the wheels actually contacting the pavement and bouncing.
BillyShope wrote:Again, when viewed from the side, the instant center (IC) is determined by visualizing an intersection of lines through the pivots for the upper and lower links. If the intersection (instant center) is above the no squat/no rise line, the rear of the car will rise on launch; if below, it will squat. To answer your specific question: For a given IC height, the further forward, the more severe the squat.
If you’re answering his question the I disagree… if you’re just making the statement in a vacuum of the rest of the comments here then sure. His question appeared to be does the actual location of the IC effect squat if it results in the same anti squat percentage as a different IC location. The answer to that, as far as I know is that it doesn’t. to do that you’d have to move the IC up as well as forward, but you could have a situation where the IC is much further forward then another setup and still have the same IC and I believe will basically react the same way off the line. The forces in the suspension links will most likely be significantly different, but the end result, the force applied to the chassis/axle will be the same.
The presence of either squat or rise is undesirable in a dragracing car for either causes an oscillatory loading of the rear tires. With either squat or rise, vertical force components are acting between the rear axle assembly and the remainder of the car.
I don’t think that I agree here. I think that this is where the differences of opinion about shocks and tuning come in between the three different outlooks presented here. Different cars at different power levels, different tires… react differently to different antisquat percentages.

As tires get softer and the suspension tuning, especially the rear suspension is able to control what is happening better higher anti squat percentages are more useful/usable. On a car on radials with little suspension travel and limited tuning (most performance street cars) high antisquat percentages get you into trouble, they just bounce the tires off the pavement, but as you get more and more drag oriented that becomes less and less the case.
If you were to lie on your back beneath your rear bumper, reach up and grasp that bumper, and then pull down, you would be simulating the action between the rear axle assembly and the remainder of the car with squat. You'll notice that the pressure on your back decreases. In fact, if you're acrobatic enough, you can chin yourself on the rear bumper. But, with the larger forces involved in squat, the rear of the car accelerates downward. So, imagine that this has occurred and you're still on your back, pretending that you're the rear axle assembly. The rear of the car is coming down and will crush you unless you can provide sufficient force on the bumper to stop it. Now, the pressure on your back is greater.
You totally lost me here… I read that 4x trying to figure out what you were getting at and best that I can figure you’ve got the forces experienced backwards (unless I got unnecessarily hung up on “you would be simulating the action between the rear axle assembly and the remainder of the car with squat…”
Applying these experiences with bumper and back, we see that a car that squats first removes a portion of the loading on the rear tires and then, as the car approaches the bottom-most position, adds to the loading of the rear tires. Since the shock absorbers and friction are acting to stop the motion, the first effect (the unloading) will be greater than the second effect (the loading), but both will continue for a few milliseconds. (Since the greater effect is the first, some prefer a car that rises on launch, but to achieve maximum performance from the tires, you want to avoid "upsetting" them with oscillatory loadings. It is best to totally eliminate squat or rise by placing the IC on the no squat/no rise line.)
Ok, I agree of this assessment of why stay away from squat… put simply “if the car squats you have the least downforce on the tires at the beginning where most cars can put the most torque into the tires and need the most traction,” but you do not explain why more is also not good. Yes, as the total torque applied lessens down the track the force pushing down lessens, but not as much of it is needed at that point to keep the tires from spinning and the downforce should stay proportionate to the torque applied (say if you have a late spooling turbo that doesn’t blow off the tires till the top of second gear), which is beneficial, as long as you don’t run out of suspension travel or what the tire sidewalls can deal with.

Furthermore, the rear rising tends to have the second beneficial effect of preventing skying the front tires, which although cool and a clear indication that you’ve transferred all the available weight to the back tires, doesn’t usually get you down the track the fastest.
Perhaps a more significant problem, with a beam axle RWD car, is the disparity in rear tire loading caused by the driveshaft torque. Many racers attempt to cancel this torque with some form of static preload, but a much more desirable method is to cancel it dynamically. With the proper suspension asymmetry, it is possible to completely cancel the driveshaft torque effect (unloading of the right rear on launch). For more information on the various ways to do this, visit my blog:
Huh, I’ll have to post something about this after I read what you have to say there, possibly in a different thread (unless you what to address it here since it has already been mentioned), and that is the difference in how preloading through an anti roll bar and through air bags effect this…
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Post by Silverback »

Ed-vancedEngines wrote:A burn-out instruction mini- page or seminar, I think could noy be very correct to try to do because of all of the many a differing variables with different transmission differences, different tires, tracks, track conditions, and even the differences in your tire conditions.
I’d say the first and major consideration is what will the transmission/drivetrain setup that you’re using tolerate with minimum wear/damage. With automatics I always liked how Transgo actually lists how you should be doing the burnout with that tranny after you install their parts… gotta love that from a company that isn’t officially a bunch of racers…
;)
If anyone watched the TV Episode or the Internet showing of Pinks Tv when Trevin Lindsey in the White 70 Camaro ran against the Chassis shop from, I think it was Conneticut with the sweet BB Chevy Nova was as near of a perfect example as I could use to show how to not do a burnout. On every burn out the driver was coasting out of the water with a little roll of water in front of his tires. His tires were wet when he was trying to launch. ON every pass that car turned the tires several times before they started to hook. He might have won if the driver had done good burouts and the chassis work was tweeked in better. It is rumered here in Dallas that the better car lost. Who knows.
Are you just commenting on doing a burnout in the water or something more than that?

My suggestion for most people is a little different then yours, but it seems to work exteremely well for me and simple enough to learn. Roll through the water, but do your burn out as far forward as you can that you’re still sitting on wet pavement but not in the puddle, the “water box” is just to get your tires wet to facilitate things, it is not a place to do a burnout. I set the mirrors so that they are both looking right at the tires, and usually watch the driver’s side one more (if it’s doing what it’s supposed to then the passenger side is also, usually), start the burnout and shift up into whatever gear I intend to do the actual burnout and usually there is a distinct difference in the quality of the smoke coming off the tires when they’re at temp, at that point I release the brakes and roll out into the dry and you can tell if you got it right by sound and how the tires load down when you roll into the dry, easing out of the throttle as I go (if I was john force and could justify that kind of burnout for what I was doing I’d do that since I believe the “easing out” part that I do is frowned upon by some converter manufacturers, and can be hard to do with a clutch if you’re not used to it).

At that point I know what the tires will do on the line by how they acted as I rolled into the dry area and dry hops are irrelevant, even harmful (they cool the tires unless they resemble more of like a second burnout, and if they do then it’s hard to get the tires as even as you would if you started with them wet). I don’t ever remember not feeling right rolling out, but if I thought that I was significantly cold, then I’d probably do a second burnout if I can (not usually possible at most of the tracks that I run at).
DRivers need to get used to adjusting their burnout proceedures to the varying conditions of track temps, and tire condition, I still see guys doing the hard tire scorching smokey smokey high tire speed burnouts with the big high horsepower cars when the track temps are over 130 degress and even in the 140 degrees their burout proceedures are the same as if the track temps were 80 degrees. When the track is so very hot the tires don't need to be. When both the track and the tires are extremely hot you end up with melted balls or little particles of rubber between them and the friction coefficient is decreased. Hot tracks with good tires, just clean the tires in a medium tire temp burnout.
If you get used to my “watching the tires/smoke” deal then this is irrelevant because in those super hot conditions usually you’ll be there right away, where on a cold track you’ll have to burn the tires a little longer to get it to look right. Same with the set of hard and even somewhat wasted tires you sometimes get stuck with if you’re not on a pro racer’s budget.
[i][color=navy][size=92] Mark[/size]
[size=75]aka: Silverback, WS6 TA, JYDog, 83 Crossfire TA, mpikas, mmp...[/color][/size][/i]
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Post by Silverback »

Ed-vancedEngines wrote:On this subject of too mny heat cycles, I might let everyone know that doesn't. Neer let your race tires be on the pavement or paved floor during any winter freezes. That will kill the rubber even on new tires.
Huh, why? (not that I doubt you but I’m wondering why?)
[i][color=navy][size=92] Mark[/size]
[size=75]aka: Silverback, WS6 TA, JYDog, 83 Crossfire TA, mpikas, mmp...[/color][/size][/i]
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