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Old 02-06-2006, 05:41 PM   #12676
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Originally Posted by TRF415boy
He he I saw Ed calling you pete so I took the liberty of doing so aswell, we have both raced at Stafford mod national (what a crap week end that was for me) but I don't think we spoke there.

Anyway I think you are getting very much confused. grip is grip, lack of grip is lack of grip. A car can have a lot of grip and be unstable, or lack grip and be unstable, same goes with it being stable. Stability relates to the way the car handles, we say an unstable car to be oversteering, and a stable to be understeering or neutral.

Then there is the amount of grip your tyres produce. We can decompose it in two : lateral grip and forward/aft grip. The former is commonly refered simply as grip, the later as traction.

The amount of grip that a given tyre will produce depends on the vertical force applied to it. The higher the force the more the grip, this follows a linear slope, until the tyre limit is reached. When it is reached the grip decreases drastically.

And so lateral grip in corner depends on how much vertical force is applied to the tyre. This is a relation between the roll centre's position, the centre of gravity's position and the stiffness of the suspension. In general the stiffer the springs, the higher the force, until the tyre limit is reached, in which case the tyre will lose grip all of a sudden.

A good technique to find the best springs is to try and go stiffer and stiffer until the car starts to loose grip unexpectedly, then go back to the stiffness below. However, this will give a very edgy car so you have to make sure you can actually drive it. A car with soft springs will have more give and allow mistakes, it will also react slowly, a stiff car won't allow mistakes and will react quick.

This is for a given roll centre, raising the roll centre will have a similar effect on grip than softer springs, but without the loss in reaction time. The car will also have less tendancy to slow down in corners (good for stock, not that good for mod on technical tracks). So when using soft springs a higher RC might help with transitions.

A special case is when using way too hard springs, then the springs prevents the car from rolling, which results in the outer tyre not being as loaded as you'd expect and actually loose grip. Some people use this phenomenon on high grip carpet, sometimes along with high RC, and it does help with grip roll but makes the car very edgy. I think this is why a lot of people say if you grip roll then go harder on springs, and i think it's the wrong method. As TRF Racer said, to prevent grip roll going softer is the easiest way, raising the RC is another way, angling and shortening camber links also helps.

Roll bars are a bit of a gamble game for me. Sometimes they decrease grip and make the end of the car concerned more progressive, sometimes they increase grip. They do though always make the car transition more slowly. On buggies you'll hear people tell you to use roll bars with softer springs on bumpy tracks. I have tried a soft setup with roll bars, a harder setup without the bars and then with the bars round ashby (quite bumpy track), and the harder without bars was the fastest.

I hope I didn't lose you guys, good efforts to those who have read it all.

Damn dogg thats how you spit knowledge. Good stuff!!!
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Old 02-06-2006, 06:21 PM   #12677
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Wait and see what Ed and I are working on re-spring rates
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Old 02-06-2006, 08:50 PM   #12678
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New carbon parts from Tech Racing:

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Old 02-06-2006, 09:21 PM   #12679
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New carbon parts from Tech Racing:

Wow, there sure is some shock adjustment on those shock towers. And the carbon plate that replaces the aluminium part over the spur gear looks interesting.
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Old 02-06-2006, 09:36 PM   #12680
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hey EJ
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Old 02-06-2006, 11:36 PM   #12681
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Quote:
Originally Posted by Jimmy Jacobson
hey EJ
What's up Jimmy
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Old 02-07-2006, 01:50 AM   #12682
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Hello,

Anyone tested the Square rear hubs on their MS/MSX?? (part# STV-42MS/STV-43MS)
Just wondering whats different and if they are handling any better....

Thanks!!
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Old 02-07-2006, 01:54 AM   #12683
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Quote:
Originally Posted by TRF415boy
The amount of grip that a given tyre will produce depends on the vertical force applied to it. The higher the force the more the grip, this follows a linear slope, until the tyre limit is reached. When it is reached the grip decreases drastically.

And so lateral grip in corner depends on how much vertical force is applied to the tyre. This is a relation between the roll centre's position, the centre of gravity's position and the stiffness of the suspension. In general the stiffer the springs, the higher the force, until the tyre limit is reached, in which case the tyre will lose grip all of a sudden.

A good technique to find the best springs is to try and go stiffer and stiffer until the car starts to loose grip unexpectedly, then go back to the stiffness below. However, this will give a very edgy car so you have to make sure you can actually drive it. A car with soft springs will have more give and allow mistakes, it will also react slowly, a stiff car won't allow mistakes and will react quick.
Someone agrees with me!

That's the point I was trying to make - that stiffer springs give you more cornering grip until the tyres reach their limit.

Anyway, heres my 19T setup from the weekend - as I said it worked very well.
My stock setup (which was the same except softer springs) just wasn't quick enough.
Attached Files
File Type: pdf SummerCup_19T_2006.pdf (398.4 KB, 122 views)
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Old 02-07-2006, 02:18 AM   #12684
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hi. i have a problem with my ms

it has a front one way.

when i have the wheels off the ground, i accelerate and let off. the front right wheel spins about 2 seconds longer than the front left wheel.

i have checked the cva's, put in new acer bearings and cleaned out the oneway. but still has this "problem"

any reason why it may be doing this?
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Old 02-07-2006, 02:32 AM   #12685
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If you have cleaned & re-lubricated your front one-way bearings and the steering knuckle bearings are new and have been flushed and re-lubricated and they are the same age and spin nice and free then you have nothing to worry about. Maybe if you run on a track that has more right turns than left or vice versa then one bearing may have broken in better than the other. Its possible that one of the one-way bearings just spins better than the other, that could be a number of things.

I take it you have swapped tires from right to left to make sure its not that ?

Unless its causeing you problems on the track then don't worry about it.
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Old 02-07-2006, 03:43 AM   #12686
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yeah its always the same side that spins slower.

i even swapped the cva's around . then i swaped the bearings around. i figure the only thing that was constant is the oneway. i suppose one side is spinning freer on one side.
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Old 02-07-2006, 07:35 AM   #12687
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Old 02-07-2006, 07:46 AM   #12688
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Quote:
Originally Posted by BringItOn
yeah its always the same side that spins slower.

i even swapped the cva's around . then i swaped the bearings around. i figure the only thing that was constant is the oneway. i suppose one side is spinning freer on one side.
Hmmm....this is happening on my 415 too. Which bearing are you looking at? the one on the hub or the oneway?
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Old 02-07-2006, 07:53 AM   #12689
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Quote:
Originally Posted by Eirik
Hello,

Anyone tested the Square rear hubs on their MS/MSX?? (part# STV-42MS/STV-43MS)
Just wondering whats different and if they are handling any better....

Thanks!!

I have the square hubs that I was running on my EVO IV on my MS and they seem to raise the roll center the entire axle and ball stud mount is raised up just a bit. I'm running the 1.5* hubs with zero inboard toe
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Old 02-07-2006, 12:26 PM   #12690
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Quote:
Originally Posted by TRF415boy
He he I saw Ed calling you pete so I took the liberty of doing so aswell, we have both raced at Stafford mod national (what a crap week end that was for me) but I don't think we spoke there.

Anyway I think you are getting very much confused. grip is grip, lack of grip is lack of grip. A car can have a lot of grip and be unstable, or lack grip and be unstable, same goes with it being stable. Stability relates to the way the car handles, we say an unstable car to be oversteering, and a stable to be understeering or neutral.

Then there is the amount of grip your tyres produce. We can decompose it in two : lateral grip and forward/aft grip. The former is commonly refered simply as grip, the later as traction.

The amount of grip that a given tyre will produce depends on the vertical force applied to it. The higher the force the more the grip, this follows a linear slope, until the tyre limit is reached. When it is reached the grip decreases drastically.

And so lateral grip in corner depends on how much vertical force is applied to the tyre. This is a relation between the roll centre's position, the centre of gravity's position and the stiffness of the suspension. In general the stiffer the springs, the higher the force, until the tyre limit is reached, in which case the tyre will lose grip all of a sudden.

A good technique to find the best springs is to try and go stiffer and stiffer until the car starts to loose grip unexpectedly, then go back to the stiffness below. However, this will give a very edgy car so you have to make sure you can actually drive it. A car with soft springs will have more give and allow mistakes, it will also react slowly, a stiff car won't allow mistakes and will react quick.

This is for a given roll centre, raising the roll centre will have a similar effect on grip than softer springs, but without the loss in reaction time. The car will also have less tendancy to slow down in corners (good for stock, not that good for mod on technical tracks). So when using soft springs a higher RC might help with transitions.

A special case is when using way too hard springs, then the springs prevents the car from rolling, which results in the outer tyre not being as loaded as you'd expect and actually loose grip. Some people use this phenomenon on high grip carpet, sometimes along with high RC, and it does help with grip roll but makes the car very edgy. I think this is why a lot of people say if you grip roll then go harder on springs, and i think it's the wrong method. As TRF Racer said, to prevent grip roll going softer is the easiest way, raising the RC is another way, angling and shortening camber links also helps.

Roll bars are a bit of a gamble game for me. Sometimes they decrease grip and make the end of the car concerned more progressive, sometimes they increase grip. They do though always make the car transition more slowly. On buggies you'll hear people tell you to use roll bars with softer springs on bumpy tracks. I have tried a soft setup with roll bars, a harder setup without the bars and then with the bars round ashby (quite bumpy track), and the harder without bars was the fastest.

I hope I didn't lose you guys, good efforts to those who have read it all.
I see were your coming from.
i think the best conclusion is we all have different ideas on different things.
explaining here is good and no flaming hehe.someone also may find a car faster when easier to drive so will recommedn a soft set up.
what one person knows may help someone,but that same person may not know something the other does.if that makes sense.
if we race at a track again come over and say hi,iam normally wearing TRF shirt unless its cold,always talking to adam rogers also.
out side we used HPI silver springs everywere and pretty much kept the roll centers the same as i said above.
i do like to have a consistant car from round to round and changing minimal stuff helps.
at carpet wars 2 day i didnt change a thing from round one to the last final.apart tyres.
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