HarshGuy

iTrader: (6)

You gonna join in on the Mullet Challenge?

SA_Racer

Guys, this is realy freeking me out.

I have a MI2 chassis with a tweak problem that I cant seem to sort out.

The chassis plate on its own is perfectly flat, When I assemble the car its still seems flat, I removed the bodymounts and set it down on the shock towers and there is still no rocking affect at all.

My shocks are all the same lenght and equal dampening/rebound, and I have checked all hinge pins to see if they are bent but all seems fine, shock springs are as close to being the same lenght as one would expect.

Now here is my problem. based on the above the car should have no tweak problems, however when I set my ride height and then put the car on the tweak station (MIP) its way off. I then set the tweak for the buble to be centred but then my ride height is 1mm higher on one side of the car vs the other side. so I end up with a car that has 4.5mm on the left side and 5.5 mm on the right side

I have traced my steps but just cant seem to find the problem.

I am using lowered towers and TRF shocks.

your help is much apreciated
PJ

STLNLST

iTrader: (32)

you might want to check your shock shafts. Also make sure that your droop isn't causing some of the problem. Jon Kerr will be along shortly to give you a real good suggestion.

cornerspeed

Is tweaked on the track?

King-G

SA racer, have you tried physically moving weight around in the car?

Roberto Falcon

iTrader: (18)

I have had that problem with all cars I have owned that you will have more preload on on side of the car than the other... I thought that was normal ?

cornerspeed

Possibly a bent upper shock mount screw?

Jon Kerr

iTrader: (17)

Could be a bent upper mount like Donny mentioned, but I've found that my MIP station can be VERY inconsistent. Believe it or not, take the bearings off that the pivot bar sits on and clean them out and oil them. If they're sticking, it'll give strange readings. I had a similar issue once with mine. I had the car flat as can be. I'd check the tweak on a flat surface by lifting it from the center of the shock tower and it was straight as can be. No sign of tweak on the track either. But I put it on the MIP, and it says it's way off. I cleaned out the bearings and made sure that it was balanced properly, and it worked. But it's still not that consistent for me. I don't even use one anymore. I use the lift method after everything you mentioned. If the droop is equal both sides and the surface is level and flat, it works very consistently.

Jay Dub

Do you use setup wheels, or are you using mounted wheels and tires? I have found on more than one occasion that the amount of air gap, as well as tire scrub can give inconsistant readings. Try setting your car up with just rims (no tires) and see if that helps (another option is to sauce your tires and check yout tweak while the tires are wet). One other quick check is to readjust your shocks so they look equal (collar spacing, rebound, length, etc.) then put them on the car and check your tweak (don't adjust anything). Then swap shocks left to right and see if you get the same reading. If your tweak swaps sides with the shock change, then you know what your problem is. I find whenever I have a similar problem, it is almost always a mismatched set of springs or a sticking shaft. After that, try to tweak your car without sway bars connected. Hope this helps - Jeff

heavy

iTrader: (23)

Does anyone know why on the EC the right side steering post doesn't go right up and get braced in the top deck like on the Mi2. I'm assuming there is a good reason for it but I just can't see it at the moment. Maybe something to do with the designer flex of the top deck or ????

SA_Racer

Thanks Guys, you all gave me some great ideas, ill try them out tonight when I get home and let you know the outcome

I havent checked my to see if my shock mount screws are bent so Ill do that. my shocks feel smooth and not sticky at all, but a rebuild isnt a problem so Ill do that and check the shafts then.

Ill also clean the MIP station bearings and verify its balanced properly then see what happens.

I dont use setup wheels but ill try the rim idea

Ive tried moving weight around, but that didnt help, I have tried with and without sway bars

I also checked the droop screws and they were fine, I think I have enough here to keep me going for tonight, ill keep you all posted

Till later
PJ

IslandBwoy

I posted something regarding this not too long back and the reason is that the right post tends to get bent a lot of the time without you even realizing it due to battery shift or just a good hit on the track. The problem with that is that when that post goes up through the top deck as originally manufactured and the post is bent, it will put pressure on the top deck causing tweak. This is a problem several of us have ran into and have elected to run the shorter post as a result so that no tweaking occurs if the posts get bent.

refer back to posts around this period:
BENT POST

IslandBwoy

@ SA

I also had this problem with the BMI chassis and found some inconsistencies with tweak measurements. On my car i found that the right rear of the car was heavier laterally and the left front was heavier laterally (YES IT WAS TEAKED DIAGINALLY) No matter how many times i rebuilt the car. I even took it to the LHS and they were as puzzled as i was. Regardless, as strange it may sound i simply gave my car a firm twist while holding the towers and the chassis in my hand and everything is good after further tightening the screws on the top deck and relevant parts of the chassis. Now i can take apart the car and rebuild it without issues.

PS. See if you can get a set of light weight scales to see if you truly have a tweaking problem. Make sure your surface is flat as well as leveled before testing with those however. That is what i use and now wheels carry the same weight left to right.

jimnew

Stud?????
I thought that was you?

HarshGuy

iTrader: (6)

So for you Scheuy guys that want to watch and hear how STLNLST does at the "Mullet Challenge", we should have it all set up to do so (assuming everything works as expected ...look here: http://www.rctech.net/forum/showthread.php?t=98407