Speedmerchant Rev.4
02-26-2007, 09:36 PM
#1172
droop was equal on both sides. I'm wondering if maybe the chassis itself is messed up somehow. I just put the old skool front end back together on the car, and with NO camber shims there's 4.5 degrees negative camber on the right front, maybe a degree negative on the left. I've never had so much negative without putting shims in. To get the camber equal and the axle heights the same on both sides I've got a millimeter and a quarter of height shims under the right arm and a camber shim on the INSIDE to reduce the negative camber. On the left side I've got just a quarter of a millimeter height shim and NO camber shims. I've never had to shim an old skool front end so differently to get it right...
02-26-2007, 10:47 PM
#1173
I would start by putting on a new set of old school arms. I had one set that was almost that bad before. Also double check your front axles.
02-27-2007, 01:35 AM
#1175
If you're worried about the chassis being flat you can check it with a straightedge or flat surface like a piece of glass. I would check just the chassis itself and with all the parts bolted to it. Maybe something is pulling the chassis out of alignment when the screws are tightened down.
-James
-James
02-27-2007, 03:39 AM
#1176
Did you countersink the front screws holes more than factory?
I know if you use a hand drill instead of a drill press, it's really easy for the countersink to go off center.
I know if you use a hand drill instead of a drill press, it's really easy for the countersink to go off center.
02-27-2007, 04:56 AM
#1177
I didn't countersink the front holes. I'm not worried that the chassis isn't flat, what I'm thinking is it might be damaged in the front arm area, but it looks fine to the eye. I'll have to disassemble the car to really check it on a flat surface tho.
02-27-2007, 05:43 AM
#1178
New Skool front end
My only advice after everything else checked out, is to take that new style front end off. There will always be some slight camber and caster differences with the old skool but the fact that they stay straight, and dont twist in a hit is huge. For major races, I use notebook paper shims under one side of the arm or the other, depending on how it measures up with a straight edge (usually a credit card). For standard club racing or even practice, its not enough for me to worry about it.
Everyone on the team, without exception, has gone back to the old skool after trying the dynamic strut. It works great until for some strange reason the car gets tweeked. 100% of the time when the old skool goes back on, the tweek goes back to normal.
With that being said, I have also never had 4.5 degrees negative camber without something else being bent etc. Did you take the axles out of the steering blocks when you checked them? Do you have a steering block with a bit of slop in it? I just checked my car with a header card shim in both sides, and its about 1.75*, and 2* respectively. Is your chassis split where a screw goes through that secures the front end??
Thats officially everything I can think of that could make your car tweek....
Beavis
Everyone on the team, without exception, has gone back to the old skool after trying the dynamic strut. It works great until for some strange reason the car gets tweeked. 100% of the time when the old skool goes back on, the tweek goes back to normal.
With that being said, I have also never had 4.5 degrees negative camber without something else being bent etc. Did you take the axles out of the steering blocks when you checked them? Do you have a steering block with a bit of slop in it? I just checked my car with a header card shim in both sides, and its about 1.75*, and 2* respectively. Is your chassis split where a screw goes through that secures the front end??
Thats officially everything I can think of that could make your car tweek....
Beavis
02-27-2007, 06:12 AM
#1179
About the only thing that seems left for you to do is strip the car down completely, and check the chassis on a glass table.
02-27-2007, 07:54 AM
#1180
Take a straight edge like a level part of the tweak station and put it going from front left to rear right and see if there is any gaps. Do it the same for front right to rear left.
02-27-2007, 07:54 AM
#1181
I'd give up on the MIP tweak station. I have been using the pennies on the front wheels trick for a long time with great results. In case you don't know, here's how it works... Put your car on a flat surface and lift the front end with your finger tips to let the heavy side of your front wheels roll to the lowest point, also make sure they can spin freely. Next thing I check is that there is no preload on the springs. I do this by slightly lifting on the tweak brace, one side at a time, noting when one spring lifts off the ball, and when the other compresses. I back the screws out so that the springs just touch the balls.
Now we are ready for the pennies (or your choice, just make sure you're using the same type on both wheels). Put them on top the front wheels just past center. I prefer to put them so that they are just aft center towards the back of the car. Using an xacto knive or hex key, lift slowly and note which penny drops first. Tighten the opposite side tweak screw a little and loosen the same side tweak screw by the same amount. The idea is to not introduce pre-load into the springs, and keep the car balanced. Each time I reset this to recheck, I lift the front end by the axles to let the heavy side of the tires go to the bottom again, rest the chassis back on the flat surface, then tap on the antenna to settle the chassis.
When I am done this method, my car always feels the least tweaked, to the point that I can notice how much my poor servo doesn't like to center anymore from all the abuse I have put it through.
I am not saying the MIP doesn't work, just that I have much better luck using the coin method over a tweak station.
Now we are ready for the pennies (or your choice, just make sure you're using the same type on both wheels). Put them on top the front wheels just past center. I prefer to put them so that they are just aft center towards the back of the car. Using an xacto knive or hex key, lift slowly and note which penny drops first. Tighten the opposite side tweak screw a little and loosen the same side tweak screw by the same amount. The idea is to not introduce pre-load into the springs, and keep the car balanced. Each time I reset this to recheck, I lift the front end by the axles to let the heavy side of the tires go to the bottom again, rest the chassis back on the flat surface, then tap on the antenna to settle the chassis.
When I am done this method, my car always feels the least tweaked, to the point that I can notice how much my poor servo doesn't like to center anymore from all the abuse I have put it through.
I am not saying the MIP doesn't work, just that I have much better luck using the coin method over a tweak station.
02-27-2007, 07:59 AM
#1182
Originally Posted by timmay70
I'd give up on the MIP tweak station. I have been using the pennies on the front wheels trick for a long time with great results. In case you don't know, here's how it works... Put your car on a flat surface and lift the front end with your finger tips to let the heavy side of your front wheels roll to the lowest point, also make sure they can spin freely. Next thing I check is that there is no preload on the springs. I do this by slightly lifting on the tweak brace, one side at a time, noting when one spring lifts off the ball, and when the other compresses. I back the screws out so that the springs just touch the balls.
Now we are ready for the pennies (or your choice, just make sure you're using the same type on both wheels). Put them on top the front wheels just past center. I prefer to put them so that they are just aft center towards the back of the car. Using an xacto knive or hex key, lift slowly and note which penny drops first. Tighten the opposite side tweak screw a little and loosen the same side tweak screw by the same amount. The idea is to not introduce pre-load into the springs, and keep the car balanced. Each time I reset this to recheck, I lift the front end by the axles to let the heavy side of the tires go to the bottom again, rest the chassis back on the flat surface, then tap on the antenna to settle the chassis.
When I am done this method, my car always feels the least tweaked, to the point that I can notice how much my poor servo doesn't like to center anymore from all the abuse I have put it through.
I am not saying the MIP doesn't work, just that I have much better luck using the coin method over a tweak station.
Now we are ready for the pennies (or your choice, just make sure you're using the same type on both wheels). Put them on top the front wheels just past center. I prefer to put them so that they are just aft center towards the back of the car. Using an xacto knive or hex key, lift slowly and note which penny drops first. Tighten the opposite side tweak screw a little and loosen the same side tweak screw by the same amount. The idea is to not introduce pre-load into the springs, and keep the car balanced. Each time I reset this to recheck, I lift the front end by the axles to let the heavy side of the tires go to the bottom again, rest the chassis back on the flat surface, then tap on the antenna to settle the chassis.
When I am done this method, my car always feels the least tweaked, to the point that I can notice how much my poor servo doesn't like to center anymore from all the abuse I have put it through.
I am not saying the MIP doesn't work, just that I have much better luck using the coin method over a tweak station.
02-27-2007, 08:08 AM
#1183
Originally Posted by Trips
Okay, here's a weird one, maybe someone else has run across this...
Sometimes I put my 4.5 on the tweak station (I use the MIP, it's always been accurate for me) and it shows the car way off. I have to run the left tweak screw almost fully down and the right one fully up to get it to sit right on the tweak station. Then on the track the car is horribly tweaked, big understeer in the left turns and hooking in the right turns, jsut as you'd expect with the tweak screws that way.
I'll put the tweak screws back to even or close, and even tho the tweak station says the car is off it drives fine on the track.
Other times, the tweak station and the track behavior are in complete agreement. any ideas what might be going on? This one's really got me scratching my head...
Sometimes I put my 4.5 on the tweak station (I use the MIP, it's always been accurate for me) and it shows the car way off. I have to run the left tweak screw almost fully down and the right one fully up to get it to sit right on the tweak station. Then on the track the car is horribly tweaked, big understeer in the left turns and hooking in the right turns, jsut as you'd expect with the tweak screws that way.
I'll put the tweak screws back to even or close, and even tho the tweak station says the car is off it drives fine on the track.
Other times, the tweak station and the track behavior are in complete agreement. any ideas what might be going on? This one's really got me scratching my head...
02-27-2007, 08:31 AM
#1184
Originally Posted by timmay70
Sorry, I was replying to the post quoted above...
02-27-2007, 09:51 AM
#1185
Thanks everyone for the replies. The axles are indeed straight and the steering blocks are not sloppy.
I'm pretty much convinced I'll find something along the lines of chassis damage around the front end mounting holes or a warp in the chassis. I have crashed this car hard enough to bend a set of axles which I have replaced with new ones. When this car was new, all my old skool arms ran right at around 0 degrees camber without any shims, yet they all run at 4 to 4.5 degrees negative on the right side now without any shims. I'm sure I'll spot some sort of damage in the front of the chassis with a good close inspection.
I'll probably order up a new chassis just for good measure. In the meantime, let me mention that I've always believed in the tweak station over the penny drop method because I've always believed that tweak should be checked with the car resting on the suspension. I do know that in the real world the penny method works for a lot of people. For what it's worth, I usually do both at the track... and the times the car has been driving tweaked even when the tweak station says it's straight, the penny method also says it's straight. About the only thing I can think of that would fool both the tweak station and the pennies would be a cracked or split chassis, given that the front end parts are all new and straight and there's no binding anywhere.
I'm pretty much convinced I'll find something along the lines of chassis damage around the front end mounting holes or a warp in the chassis. I have crashed this car hard enough to bend a set of axles which I have replaced with new ones. When this car was new, all my old skool arms ran right at around 0 degrees camber without any shims, yet they all run at 4 to 4.5 degrees negative on the right side now without any shims. I'm sure I'll spot some sort of damage in the front of the chassis with a good close inspection.
I'll probably order up a new chassis just for good measure. In the meantime, let me mention that I've always believed in the tweak station over the penny drop method because I've always believed that tweak should be checked with the car resting on the suspension. I do know that in the real world the penny method works for a lot of people. For what it's worth, I usually do both at the track... and the times the car has been driving tweaked even when the tweak station says it's straight, the penny method also says it's straight. About the only thing I can think of that would fool both the tweak station and the pennies would be a cracked or split chassis, given that the front end parts are all new and straight and there's no binding anywhere.