bender

iTrader: (4)

The car comes standard with 2mm riser plates which the suspension mounts sit on.

You can alter the roll centre depending upon whether or not you use the riser plates and how many shims you add, to alter the distance between the suspension mounts and the chassis.

Fairly common practices include adding a 1mm shim to the rear riser plate (giving 3mm total) and removing the front riser plate altogether and only running a 1mm shim (giving 1mm total).

jimnew

From the limited testing that I, along with ottoman, have done, this is what I have found on carpet.
-If you raise the front rear toe block (the ones by the steering) to get antidive the car will turn in better and have less mid to exit steering.
-If you lower the front block to get antidive, it does just what the name implies, the car is more stable on entry (doesn't let the car dive) and has more steering mid to exit.
It all has to do with the roll centers
Although, like someone mentioned earlier, this is really dependent on the driver and his/her driving styles and hopefully mine isn't that far off from everybody else .
Hope I didn't come off sounding like a dope, but this is what I have found.
Later
jim

jimnew

Ottoman,
I'm going to Vegas, it will finally be nice to meet you in person
Later
Jim

Cole Trickle

Thanks, then I dont have to worry about buying riser plates

Ragarding "fairly common practises...", with wich kínd of tires/track surfaces do this apply to? All surfaces, or is it better on only some? I'm running rubber tires on carpet.

seaball

iTrader: (9)

cole,

i've tried to illustrate the recommendation i had with the use of some poor spelling. keep in mind that this is most applicable to foam tire carpet racing where your turning circles won't usually go below 5-1/2 feet in diameter. you can play with shim size until you get the throw you want. though unsightly, this simple fix has increased the durability of my car ten-fold. thanks, pw.

- harold walters

Cole Trickle

Thanks Seaball, that cleared things up.

I'm on a very tight track, so I'll basically look for the least possible steering throw to race with. Now I have a nice starting point, great !

John_S

hey cole by what your describing have you thaught about trying a one way, because iv heard there very good with rubber tires on carpet as you want the most corner speed possible

Jay Dub

When adjusting the suspension mounts up or down, it is also important to understand that you are changing many other things. One of these is camber gain. By raising the rear mount, you are increasing the camber gain over the "stock" setting. This (in high traction situations) will usually make the car more aggressive off center, and give more traction in the corner because the tire contact patch will stay flatter on the racing surface thru the corner. Unfortunatelly with all the other things changing with this adjustment (castor, roll center, bump steer, weight transfer, etc.) it is nearly impossible to predict how your car will respond to this particular change. If you drop the front block, theoretically the oppsite will occur. You still have to deal with all the other changes occuring though. -Jeff

Cole Trickle

Thanks for the suggestion, it's already on my mind... I'm pretty sure I'll get a one-way... I've raced a lot with one-ways, and I'm simply addicted to the way the car handles with a one-way.

However, I want to get a feel of the MI2, before doing so. I have to have a good starting point, setup-wise, before mounting the one-way.

Unfortunately, there dont seem to be many setups on the net for rubber tires on carpet. I've found one, though, which looks very promising - as far as I can see, without have tried the car myself

Cole Trickle

Thanks. I believe I'll try out with the stock riser plates, since that's what's used in the setup I've found for rubber/carpet.

One question though: What do you mean with "more aggresive off center"?

Cole Trickle

Can someone provide a link to where I can read about experiences with the BMI chassis?

Thanks.

cyrrus

iTrader: (5)

Hey guys, for all you guy/gal's that are running TFR shocks on there MI2. Just a quick question. I'm planning on picking up a pair when I head over to the mainland. What type of screws nuts, or what ever will I need to mount them correctly . I'm planning on purchasing Pdub's mounts very soon. So I'm going to have to go Ghetto style for a bit. So any info would be great. Oh by the way I do have the carpet towers already. thanks . Oh by the way does any one have a good recent setup for stock/19turn. Plus what a good starting point for gearing up for pinion size and spur gear. for both stock and, 19 turn. I do have the spur addapter and right now still running every thing stock. xcept for some aluminun parts.

Cole Trickle

Gearing depends on the track, and also motor - there's differences on stock motors. My GM use to have a tooth or two less on the pinion, than my P2K's.

Rule of thumb: Car should reach top end at approx. 2/3-3/4 down the longest straight. If it's a tight track, you might like to go one tooth lower on the pinion. Wide track, one tooth more.

And the motor shouldnt run too warm/hot. I like to keep my motors below 60 deg. celsius.

cyrrus

iTrader: (5)

thanks cole. just a question, when would you go up or down a tooth or two on your spur gear. that the equation that most puzzles me.

Cole Trickle

If the motor gets too warm/hot, I would use a smaller pinion.

If temperature's not a problem, I go for speed. Be aware, that higher top end doesnt always mean more top-end. It's in the infield, most races are won. So acceleration out of corners usually means a lot more, than top-end. But still, it's a matter of finding the sweet spot. The thumb-of-rule is a good guidance

If you need more acceleration, use a sligthly smaller pinion. And I've seen examples, where a smaller pinion also resulted in higher speed - this can occur, if the gearing makes the car too "heavy" for the motor.

So, first, I would check temperatures. It should be possible to touch the motor, without burning your fingers.

Second, I would try to find a fellow racer, which drives almost as fast as myself. This makes it's much easier to se what the results of changing gears are.

You may find the car is a little harder to race with a lower overall gearing (smaller pinions). If so, ease up on your trigger finger

I hope I didnt made it too complicated - it shouldnt be. So feel free and ask again, if nessecary.