YOU OWE ME 10 SCREENS!!!!!

Fixed!

Good point! :lol:

Your welcome. Just dont forget who planted the seed :hello:

If any mod moves this thread it should be Flash.

And it should be done in :secret:...



:lol:

Not sure that would be appropriate....Rob might end up calling Daves thread Bad Middle Finger :catfight:

FIXED

Don't be shy Tracky. :headscratch: Or are you a :secret:agent for BMF sent to derail the Torino:lol:

:cheers:

Hey Rob,

I agree with this statement: That difference in scrub between a 30 and 35 series tire of the same section width on the same wheel would be pretty minimal and in real world probably insignificant.

I have had talented race drivers we developed to the nth degree ... with amazing feel & feedback ... that can tell you if you changed the tire 1/4 pound of air pressure, .030" of bump stop shim, which suspension corner stopped traveling 1/16" earlier than the other or if there was extra clearance in your ring & pinion gap ... and that's not even a tiny bit exaggerated. :thumbsup:

A Crew Chief/Tuner can have a lot of confidence in those situations. These particular drivers & I won a lot of races together. :gitrdun:

And on the other hand ... I've seen drivers that couldn't tell you if they hit a pothole or not. So I think "noticeable" is also relative. :confused18:

.

Rob is probably going to have to worry more about swells than pot holes. Although if he does take his boat out on the road, I'd hate to be in it when he hits a pot hole with his hellaflush rims.

Matt your still mad about that beer aren't you? :twak: I knew the pot holes are what led you to the Rubicon set up :lmao:

So is the Mustang going to be track only?

:cheers:

Couldn't possibly be mad about the beer. DG isn't the only beer snob around here, although he might be the beer snob captain around these parts. Makes sense really. Our cars are kind of the automotive equivalents of beer tastes on champaign budgets.

:secret: :flashie: :secret: Thats absurd. I have absolutely no idea what you're talking about :whistling:


:cheers:

:y0!:

Ron

Since the exercise is maximizing tire grip and we have been speaking of that exercise with a 200tw DOT tire.

If I tune the suspension to obtain the best balance possible with the DOT 200tw tires but then switch to a sticky compound tire such as a Hoosier R compound in the same proportional stagger does that warrant more spring, ARB and associated shock dampening?

Since the increased grip of the tires would allow for higher cornering speeds the forces working on the suspension should increase. I would think this means at a minimum more bar would be needed.:headscratch:

I would think you could use a similar spring package to control the pitch of the cars weight which is static but add more bar to deal with the added force from the increased cornering load.

Since I only really care a bout the 200tw tires for the RTTC or Goodguys type events a Hoosier R compound may actually be what I really tune for.:drive:

I'd like to understand the logic behind a slick vs street tire tune better. I'm sure others won't mind reading that little diddy either.:thankyou:

:cheers:

Sorry Gae :theresa:

:lol: Your killin' me dude :lol:

Dont mind me...Carry on......Please :popcorn2:

The way this thread is going hopefully Ron's suspension spreadsheets have factoring to compensate for driver reaction times. :popcorn2:

Hi Rob,

---------------------------------------------------------------------
Ron

Since the exercise is maximizing tire grip and we have been speaking of that exercise with a 200tw DOT tire.

If I tune the suspension to obtain the best balance possible with the DOT 200tw tires but then switch to a sticky compound tire such as a Hoosier R compound in the same proportional stagger does that warrant more spring, ARB and associated shock dampening?
Yes. Of course someone can simply switch tires & run the car to its limits. But if the car if going to be optimized with 200TW tires ... and also with Hoosier R6 race slicks ... the optimum set-up will be different.

Since the increased grip of the tires would allow for higher cornering speeds the forces working on the suspension should increase. I would think this means at a minimum more bar would be needed.:headscratch:
You will want to make changes in 4 areas. All requiring a small degree of work, but nothing complex. I'll outline it below.

I would think you could use a similar spring package to control the pitch of the cars weight which is static but add more bar to deal with the added force from the increased cornering load.
Sway bars are not enough. Because as you increase the traction of the tires, the car will experience a higher degree of weight transfer under braking & acceleration.

Since I only really care a bout the 200tw tires for the RTTC or Goodguys type events a Hoosier R compound may actually be what I really tune for.:drive:

I'd like to understand the logic behind a slick vs street tire tune better. I'm sure others won't mind reading that little diddy either.:thankyou:

Sure. Here goes ...

Assuming, we start with DOT tires of 200TW ... and dialed the suspension in thoroughly until we declared it was "optimum" & we could "find no more" ... then we put on Hoosier R6 racing slicks of similar height, width, sidewall size & wheel backspacing to maintain the same front & rear track widths ... here is what we would experience with no suspension changes:

1. On corner entry braking, the front suspension will compress quicker & farther & the rear suspension will rise quicker & farther. The car will experience more weight transfer from rear to front ... and may, or may not, lock up the rear tires easier, depending on several suspension factors. The car will have excessive pitch angle, excessive loading of front tires & excessive unloading of rear tires.

2. On corner entry "turn-in" ... while still braking ... the car will react/respond quicker, turning the front end of the car into the corner quicker. The car will experience more weight transfer from inside to the outside. Body/chassis roll will increase & be excessive. The biggest amount of weight transfer increase will be from the inside rear tire to the outside front tire. The tires on the inside of the corner will be underworked & the tires on the outside of the corner will be overworked ... the front more so than the rear. The car will lose traction on the inside rear tire & become loose ... unless the driver adjusts by braking softer & earlier during "1".

3a. If the driver does not adapt ... and the car gets loose on corner entry ... one of two things will happen (neither good). Either the driver "corrects" for the skid ... by turning the steering into it ... which adds cross weight & grip. At the point the car "catches" regaining grip ... the car angle & steering angle are F#%&*@ ... so after the car "catches" it will push like a dump truck through the middle of the corner ... and probably snap loose on exit. Or, if the driver doesn't correct the steering, the car will simply spin out.

3b. So ... assuming the Driver adjusts to brake softer & earlier keeping the handling neutral on corner entry ... when the steering is "set" & on its arc for the middle of the corner ... and the driver releases the brakes ... the car will experience slightly more roll angle, which was already excessive, due to the increased grip on the slicks . What happens next is dependent on the rebound valving of the front shocks . If there is not enough, the front will rise & the rear will settle too early*, causing the inside rear tire to reengage too early* & the inside front tire to become unloaded too early* ... leading to a mid-corner push condition.

Additional shock "low speed" rebound valving will help this situation by delaying the transfer*, as will the other tuning changes I'll outline. While on track, the driver could help this situation by lengthening their braking zone. Meaning get off the brakes later ... and use slightly less braking pressure, to arrive at the same corner speed. Do not confuse this with trail braking.

4. When it's time to pick up the throttle ... mid-corner, while the car is still turning ... the car will transition weight transfer to the rear ... and increase the car's roll angle, just until the driver starts unwinding the steering wheel. This may, or may, not lead to a push condition on cornering under throttle, depending on the timing* of weight transfer from the outside front tire to the outside rear tire. If the WT happens too spoon, it will push.

5. Soon after the driver starts to roll on the throttle, they start to unwind the steering wheel progressively. This will shift the transfer weight ... just as progressively from rearward & outward to simply rearward, by the time the car is accelerating straight. Again, this may, or may, not lead to a push condition on exit under throttle, but depending on the timing* of weight transfer from the outside front tire to the inside rear tire. If the WT happens too soon, it will push.

So ... what do we do? Drink beer. :cheers:


Or, we could make these changes to optimize the set-up on the slicks:
A. Change to stiffer rate front & rear springs.

Note: If ... IF ... the front shock compression valving is adjustable enough ... we may be able to slow the rate of weight transfer from rear to front enough ... to restore the compression rate & distance to optimum ... and we may not. The "range" of the shock adjustment may simply not be enough. Frankly, going from 200TW to Hoosier R6's I doubt it. The only shock I know with that much range "might" be the JRI's.

B. Adjust your front & rear sway bars to stiffer settings ... or install bigger sway bars in the front & rear.

C. Fine tune the shock valving.
* Shock valving is the key tool for controlling the timing of events.

Fronts: Increase the rate of low speed rebound valving & fine tune the rate of compression valving to optimize the rate of front compression in dive with the new stiffer front springs.

Rears: Increase compression valving to slow the roll angle transition & help the car turn.

Note: If the car is still pushing on exit under throttle ... stiffen the high speed rebound valving on the front shocks and/or reduce the low speed rebound valving of the rear shocks a little.

D. Fine tune the car's front to rear grip balance by raising the rear roll center a little with your adjustable track bar or Watt's link.


How much change to achieve optimum? You won't know until you test. Just like you won't know what optimum is with the 200TW tires until you test also. :)

A experienced tuner like myself can get you in the ball park, but when you start pushing a car to its limits ... that when you truly find out what the car wants.

Important note: Lazy racers want to make one big change, and that is not optimum .. far from it. The only way to keep the car "happy" & truly optimized is making small to moderate changes in all these areas I've outlined.

Sometimes true optimum requires small amounts in other areas too, such as brake bias, track width (think thin wheel spacers) toe/ackerman, slight changes in ride height and/or rake, etc.

Make sense? Got questions ?



.

A wise man can learn more from a foolish question than a fool can learn from a wise answer.
Bruce Lee


I have plenty more foolish questions I'm just trying to make good use of the answers I already have to avoid being foolish. :drowninga: That might take some time.:confused59:

If only I had a picture of a new part I could distract everyone with.:flashie:

:cheers:

When that happens to me, I just post photos of very attractive women. :)

You never did tell me if my front wheels were "Jiffypop" or not.

Look at the one on the left in between the rolling tool boxes. The 5-spoke style is "flat" ... but it's all the way out to the edge with no lip. Does it have to "crown out" to be "Jiffy Pop" ... or does just having no lip make it "Jiffy Pop? :lol:



.

I've looked at this picture several times and I still don't see any wheels.:_paranoid

Ron in So Cal is the wheel guy. Maybe he can see them.

Well Gae I told you this was coming back on post 120 something:lol: It's just taken me Flash time to get to it.

First I planned the build and got the chassis and drivetrain, wheels, tires and Brakes. Pretty much have that handled so....:headscratch:

Now it's time to plan the tune so I can buy the springs, shocks and bars. I still have a little bit of rework to do on some parts :bang: after my recent education into what I didn't know about chassis tuning. :hello:

I'll have some more big updates in a few weeks. For now I just want to focus on chassis tuning.

Ron was going to walk through roll center and it's use as a tuning tool. :idea: OBTW Ron I see you changed the picture but I still don't see the wheels. :wow:

That is something I didn't focus enough attention on initially.:bang: I guess it fell into the yada yada yada column and got overlooked. Not the end of the world but if you really want your car to be tunable it is somehting you should be educated on.


:cheers:

Couldn't agree more and I'm glad you've seen the light. My only gripe is having to ask questions about my car in your thread. Just dont feel it's appropriate.

My feeling is that all of the info that Ron has posted that is in general and not specific to your car should be placed in a "Suspension Technology" sticky for all to go to.

It's unanimous, he for got to put the wheels in the photo!

LOL :rofl:


Yeah, Heather Rene is a hottie. :whistling:

She's one of the top girls doing event promos for us since 2006.

.

What I'd rather do, is leave all the info I created for Rob here ... and start another thread ... or threads ... specifically to discuss suspension set-ups & tuning. But Rob already asked about roll centers, so I'll post that here next. Than we can start a new thread or two.

.

I am definitely seeing some "jiffy-pop" after looking at that photo :lol:

She's 25?! I'm 25! We have so much in common!!!:idea:





On a side note, i need some asprin to get through all the technical data that i want to learn so badly!

That would be great Ron....Then maybe one of these mods could turn it into a sticky :thumbsup:

You'd like that wouldn't you :secret:

So where's all these parts updates I keep hearing about? :secret:

I know I will JerDog. It should eliminate the :beathorse :drama: on my thread about answers to my suspension questions.

How soon Gae forgets I posted an explanation of and a link to the instructions for his Accusmp on his thread that should have been a sticky in the Engine section.:lmao:

It's so F:censored: people have to go to his thread to read about his Accusump to learn about Accusumps when it is a general engine oiling accessory. :lmao:

I just gave you wheel pics last week Ron. :snapout: Like a said a couple more weeks. More parts are on their way.:mock:

How about a picture of my super stretched Michelin 285 on a 10.5" test wheel that Travis built for me when I was trying to nail offset and sizing. As Rubicon Matt would say hellaflush.

http://i291.photobucket.com/albums/l...psdbe1e023.jpghttp://i291.photobucket.com/albums/l...ps7a8c847f.jpg

:cheers:

You sure know how to push my buttons :lol:

There's an amazing new feature that was recently added.... just click on the "NEW THREAD" button at the top and see what happens. :twak:

That' funny right there. :lmao:

.

Holy crap!!!! All this GREAT technical advise in between thread high jackings, being a smartass without calling people names!! Why why... it's just like "YB" of old. I feel rt at home here. :grouphug:


Where the weak are killed and eatn????? :hello:

Modify old cars > new cars
Modify old threads < new threads

:hello:

That is a good point and a great idea. If the mods wanted to cut and paste that info into a sticky I wouldn't have an issue with that.

Does that feature create a sticky and allow me to copy and paste all of the "not specific to Rob's car" info that Ron has provided in Robs thread to that thread for all of us to review? Thats what I thought. :buttkick:

Let me put it another way....Say a new guy came along and wanted to get some info on suspension technology. Would he automatically know to go to Robs thread and get that info?

Either way....it's your baby....organize as you see fit.

.........And I'm starting to get real hungry :lmao: :lmao: :lmao:

If this sticky back and forth is makin' you thirsty, pm 'Flash68'.

:catfight:


:hello:

Let her eat Tracky ....LET HER EAT!!:drive:

Remember the dyno video upload issues? :bitchslap: