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Old 05-10-2012, 03:02 PM   #3571
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As it was once explained to me (not sure if its correct),,, that adding shims under inner and outer ball studs, in theory, makes the camber link longer. it doesnt physically make them longer but in the reactive camber, it acts like they are longer. also as the car center line rolls, the tire roll is more dramatic allowing the largest surface area of the tire to contact the track quicker around a corner. so if you are running -2 camber and higher ball studs, getting the tire to 0degrees camber around a corner is much quicker with the higher links. in theory helping generate traction.


ish.........dont quote me.




Quote:
Originally Posted by NUCRPTRACER View Post
Martin let me better explain myself.. If you run 3mm inboard and 3mm outboard at the same time what does that actually do? It would seem that the RC would be the RC at that point as the link angle would be the same just higher right? Or is that just a fractional change? Just trying to figure out how shimming both up does for the car..
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Old 05-10-2012, 06:52 PM   #3572
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thankyou for the help my serpent is getting better, while still being very lose it has improved and it is more predictable
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Old 05-10-2012, 08:17 PM   #3573
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Originally Posted by Robert_K View Post
Martin,

Superb piece of explaning. And as far as I know, I expierence the same. But How can you connect this with cornerspeed. As far as I understand with a lower rollcenter the car has the highest cornerspeed. But am I correct?

Regards Robert
Assuming you have a good balance to the car meaning the car is not pushing or has too much oversteer, then since a higher RC gives more lateral grip, a higher RC will give you more coner speed.

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Originally Posted by Benzaah View Post
Martin, some questions regarding your asphalt set up. Interesting to see you end up with 3mm of shims on the V2 steering. Did you work up to this? How was your front tyre wear(ring of death)? I'm keen to try it this weekend at practice but there are a few gaps Im hoping you can fill. what brand oils are you using? what holes are your shocks running on the towers? What wheelbase shims were you running in the rear? and how much EPA did you run on the transmitter?
Regards Benzaah
Yeah...i worked up to 3mm on the v2 shims. The more shims, the less dynamic toe out (ackerman) you get as you turn the wheel...giving the inside tire a smaller slip angle...which for most tires will give you more steering.

shock oil - was xray - because that's what I had...they are all good.
i always run my shocks in position 3 from inside on the front and position 4 from inside on the rear. I have tried other settings and always come back to that location as it seems to give the best feel and car balance.
I run the standard kit shims for wheelbase.
I run linear steering on my radio and make sure that I have complete mechanical throw on the steering so that the knuckles touch the chubs on full turn.

Quote:
Originally Posted by NUCRPTRACER View Post
Martin let me better explain myself.. If you run 3mm inboard and 3mm outboard at the same time what does that actually do? It would seem that the RC would be the RC at that point as the link angle would be the same just higher right? Or is that just a fractional change? Just trying to figure out how shimming both up does for the car..
I wondered if that was what you meant...sorry...I meant to answer that question as well. If you raise the inboard and outboard by the same amount of mm then this lowers the RC. The reason for this is that Instant Center (IC) is moved further out.
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Old 05-10-2012, 09:18 PM   #3574
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If I raise my rear roll center I will get more steering but if I lower my rear roll center I won't get more traction?
I thought I was getting it
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Old 05-11-2012, 06:24 AM   #3575
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Hey guys, I'm after some advice on building the rcx shocks. Ive watched the videos that were previously posted and initially had no issues building these shocks. This issue is only from the shocks from my LE kit as i have a standard kit set that are fine. The issue i have is that whatever position the shock shaft is once i have them together i cannot push the shock shaft past this point. It's like it bottoms out but this happens right thru the rebound range. When you force it past the point the oring near the thread blows out. The other thing it's doing is when you set almost zero rebound and fully extend the shock shaft it sucks back into the shock. I've just replaced all the orings as I thought these may be the problem but I'm having the same issue. While continually rebuilding and cleaning them I've ended up ruining the foams as well but I've read a few posts where people are building the shocks without the foams. Any help is appreciated
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Old 05-11-2012, 10:55 AM   #3576
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Originally Posted by rdlkgliders View Post
If I raise my rear roll center I will get more steering but if I lower my rear roll center I won't get more traction?
I thought I was getting it
Let me see if I can clarify things here.

Higher Rear Roll Center -> less steering because the rear has more lateral grip
Lower Rear Roll Center -> more steering because the rear has less lateral grip

Cheers.
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Old 05-11-2012, 11:03 AM   #3577
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woah, I'm confused now. That seems contrary to everything else I've read and understood about roll centers.
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Old 05-11-2012, 03:02 PM   #3578
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Quote:
Originally Posted by Benzaah View Post
Hey guys, I'm after some advice on building the rcx shocks. Ive watched the videos that were previously posted and initially had no issues building these shocks. This issue is only from the shocks from my LE kit as i have a standard kit set that are fine. The issue i have is that whatever position the shock shaft is once i have them together i cannot push the shock shaft past this point. It's like it bottoms out but this happens right thru the rebound range. When you force it past the point the oring near the thread blows out. The other thing it's doing is when you set almost zero rebound and fully extend the shock shaft it sucks back into the shock. I've just replaced all the orings as I thought these may be the problem but I'm having the same issue. While continually rebuilding and cleaning them I've ended up ruining the foams as well but I've read a few posts where people are building the shocks without the foams. Any help is appreciated
Not sure if this will help, but this is my shock build procedure.
First, I use all the foams,o-rings, etc.

1 - Pick what brand of oil and thickness you plan to use, but I never mix brands once the shock is built. I use MM oil, and that's it. My reason here is that its consistent to me, and some oils don't mix well.

2 - I make sure the foam is well saturated with oil. Here is a couple of things to note though. First, no matter how much you soak the foam, until its used a couple of times, its never completely saturated. Same as conventual shocks are, that no matter how well they are assembled and bled, when new, there is still air trapped under the piston, that only seems to dissapate after the shock is run a couple of times. So with that said, once the foam has been soaked and ran a few times, I don't take them totally apart if I'm doing a shock oil change. I will let them sit and wipe the excess oil that drips off but unless the foam is damaged I never touch them again. My thought here are that this is such a small amount of oil that it makes no difference in the final shock build and only makes more work and more likleyhood of bleed issues.

3 - I cut a piece of fuel tubing about 1/4 inch long and slit it to go over the shock shaft. This is used to limit the amount I push the shock shaft in during the bleed process, but also keeps it consistent between all the shocks. This also allows for the thickness of the lower spring cup and part of the shock stroke that you'll never use anyways.

4 - So now I fill the shock, but only to the threads as when the cartridge is inserted everything above the threads is pushed out anyways. I will screw the cartridge in until there are about 3 turns left for it to be locked down. Push the shaft all the way in until it hits the fuel tubing and screw the cartridge all the way in as it pushes the last of the excess oil out.

5 - I hose them off with motor spray and they are good to go. Usually they have little to no rebound or suck back.

This is the way I have done them since the start, its quick, clean and consistent.

Again, not sure if it will help you, but hope it does.
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Old 05-11-2012, 03:37 PM   #3579
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Quote:
Originally Posted by rdlkgliders View Post
If I raise my rear roll center I will get more steering but if I lower my rear roll center I won't get more traction?
I thought I was getting it
Quote:
Originally Posted by Martin Crisp View Post
Let me see if I can clarify things here.

Higher Rear Roll Center -> less steering because the rear has more lateral grip
Lower Rear Roll Center -> more steering because the rear has less lateral grip

Cheers.
Quote:
Originally Posted by Steve S View Post
woah, I'm confused now. That seems contrary to everything else I've read and understood about roll centers.
Ask 6 people about roll center and you'll get half a dozen different answers. The catch is the terminology used and this can be confusing. Lateral grip or the definition, is a fine line between the most traction of one tire, inside or out and the actual sum of both tires combined to give you the feel of grip.

I think that this from Suzuki,

"As it was once explained to me (not sure if its correct),,, that adding shims under inner and outer ball studs, in theory, makes the camber link longer. it doesn't physically make them longer but in the reactive camber, it acts like they are longer. also as the car center line rolls, the tire roll is more dramatic allowing the largest surface area of the tire to contact the track quicker around a corner. so if you are running -2 camber and higher ball studs, getting the tire to 0degrees camber around a corner is much quicker with the higher links. in theory helping generate traction."

So really its what gives the best contact patch thru a corner, with the combined grip of both tires, that we are trying to get, of course without so much drag that the car is slow again or "overstuck"

If you where to take the setups like Martin comes up with and plug them into the Crewchief program, you can see in most cases, that the front and rear of the car are almost equal and balanced. From there some slight tweaks to get more steering or more traction is all that's being changed. This is why some of the things on his car, or the car in general terms, always seems to return to, as they seem to work the best for the car. Such as shock angles never seem to vary much, maybe one hole. Springs, maybe up or down two weights. Roll bars, same, up or down one thickness. Upper roll center settings in the rear 3/3 or 4/3, never much of a change. Front upper roll center long, and 4 and up to 5.5 on the inner. Yet the car stays very balanced. Springs will change the car feel for traction as well as response, but don't go wild with the split as it will throw the balance off and give you false feelings of loose or good traction. Lower roll center seems like low traction uses .5 or no spacers where high traction uses 1mm spacers. A car with 1's in the front and 0 in the back doesn't feel as balanced as a car with .5 all around and a ride height increase of .5mm and a increase of droop by 1mm all around.

Remembering of course, that a lower roll center adjustment is a very course change and a upper roll center adjustment is a fine increment.

So that's 5 of us, one more and it should be covered.
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Old 05-11-2012, 04:10 PM   #3580
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One thing I've noticed with this car as mentioned is that you'll find a baseline setup that works well, then basically just make small deviations based on tires, layout, grip, etc.

I literally took my fastest 17.5 setup, put a mod motor in, and practiced. The car was still great. I went up about half a pound on the rear spring.... that's it. I played with radio settings more than anything, specifically adding a bit more expo and removing a bit of steering EPA just to make the car a little easier to drive.

I also discovered that once I found the "money" setup for my track, I was basically adding/removing .5-1mm each round to the inside camber links and adjusting the camber accordingly, just to compensate for the increase/decrease in grip.

-------

Here's an example of when you might need more lateral grip/side bite as opposed to roll grip (increased weight transfer) with a loose car....

Drive your car very hard into the sweeper. If the back end sort of skates out, you most likely need roll/weight on the back tires. If the back end is sort of "thrown" around and breaking loose, you need a little more side bite. I had a setup that was pretty good, except for mid corner the back end was skating out. I tried both widening the rear width by 1-2mm and lowering the inner camber link slightly (both increase lateral grip). This actually made it worse.... so I went back to the previous setup, but this time I only moved the rear arms forward 1mm (puts more weight on the tires, thus a bit more roll). It instantly fixed the problem... the tires were loose because not enough lateral weight was being transferred to them.

I was working on a friend's car last night. It was a tad pushy in the sweeper, and through our chicane the back end was a little lazy to the point of breaking loose when the car was driven hard, but the front of the car was really good.... I stood his rear shocks up 1 hole and moved the inner rear camber link down about 1mm. This fixed it, BECAUSE it prevented the side weight transfer, which increases lateral grip. In this instance there was too much roll. He was able to dial a bit more steering into the car since the back end stuck better through the chicane, which also helped alleviate the slight push in the sweeper.

My experience is based on sometimes low/usually medium-bite carpet. The cars with too much roll or that are unbalanced in terms of roll center tend to be loose, and the cars with too much side bite traction roll on occasion. The biggest key is finding the balance with regards to roll, side grip, and how the car "feels".

Sorry for the ramble.... hope this helps
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Old 05-11-2012, 07:56 PM   #3581
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Thanks Again to all who chime in on this thread. It is not only my favorite thread because of the fact that the TC class is my favorite form of racing, It is also the place where I get the most useful information.
I am an eternal pupil in many forms and you can add car setup to that list.
I am amazed at the complexity of theese little cars and the knowledge base of the users of them.

It would be awsome to do a weekend race and classroom package with Gary, Martin and others......I would go.....
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Old 05-12-2012, 02:31 AM   #3582
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Now i am also confused , i was allways thinkin that a low RC gives more lateral grip.
And to increase streering , higher the rear RC to decrease lateral grip and increase streering.

Gonna give i a try on the track.
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Old 05-12-2012, 08:58 PM   #3583
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Quote:
Originally Posted by Martin Crisp View Post
Let me see if I can clarify things here.

Higher Rear Roll Center -> less steering because the rear has more lateral grip
Lower Rear Roll Center -> more steering because the rear has less lateral grip

Cheers.
make sense
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Old 05-12-2012, 09:10 PM   #3584
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thinking about it:

Higher RC nearest CG so the transfer weight is more "static" = less steering
Lower RC further CG so the transfer weight has more "play" = more steering
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Old 05-13-2012, 08:55 AM   #3585
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Hey guys,
I have an LE and I'm looking for parts, but I would like to stay with the orange anodizing. I can't seem to find anyone that stocks them. Can someone point me in right direction please??
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