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Author Topic: Setup Help
Ryan Verified Driver
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Region: San Francisco
Car #: 71
Year : 1994
Posts: 39
Status: Offline
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I've a 1.8 SMT and I'm having trouble with the setup of the car. As it sits right now, the car has decent rotation during the first half of the session, but goes to mid corner to exit push both in high speed and low speed corners during the second half of the session. I tried full soft rear bar which helps initiate the rotation early into the corner, but mid corner to exit push still exists. So I'm not at full stiff rear bar which helps a bit. I guess the next step would be to run some toe out in the rear, but heard that no one really runs toe out on SMTs with R888s.

Running normal camber settings for R888
zero toe front and rear
3/16"-1/4" rake
2-3psi split front to rear (tried both 37 and 41psi)
full stiff rear bar
miata cage endlinks (properly set)

any suggestions?

Thank,
Ryan

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Cajun Miata Man Verified Driver
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Region: Houston; SWDIV
Car #: 15
Year : 99
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Ryan,

Well there is a few pieces of setup information you left out, but if I understand you correctly, it rotates ok, but then goes off.

A wild guess without the other data would be that you are running the front tires off. Do you have a tendency drive it in hard?

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Ryan Verified Driver
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Region: San Francisco
Car #: 71
Year : 1994
Posts: 39
Status: Offline
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It rotates ok, but it could still rotate a bit more. it hasnt gotten to the point where the car has scared me or gone super loose. i also thought about the possiblity of running the front tires off. i know if i'm driving at mazda raceway laguna seca, that i tend to overdrive turns 2, 8, 10, 11...maybe 5.

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Keith in WA Verified Driver Made Donation to Website
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Region: NWR / Oregon
Car #: 88
Year : 95
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You did leave a couple of pieces out that could help diagnose your problem. It rotates OK compared to what? The way you've had it in the past? I drove some little F2000 cars and tried to drive my SM the same way. Aint gonna happen, at least for me.

What's your ride height and what track are you getting the push on? I probably can't help you on the given track but I had a big problem earlier this year set too low for the track where I'd hit the bump stops and generate a ton of push mid way through the corners. Providing a bit more detail on what you're running and where may help people who know their setup on that track point you in the right direction.

(edit: Oops, my bad Laguna is the place. Plenty of people have driven there and can probably tell you if it's setup or driver.)

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Keith Novak
(Will work for tires)

Ryan Verified Driver
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Region: San Francisco
Car #: 71
Year : 1994
Posts: 39
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I believe I was running 4.75" of front and rear ride heightat the beginning of the race weekend, then went up 2 turns on rear ride height by race day. That session felt better than the previous session, but still went to a mid corner-exit push as soon as i went to full throttle.

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Keith in WA Verified Driver Made Donation to Website
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I caught something I didn't notice before. The problem starts well into your session? Suspension settings won't change during the session but pressures and temps will.

Since most people don't decscribe handling in terms of the way the car wants to rotate (I'm thinking you've driven some open wheel cars or carts), it could be you're asking a poor little Miata to behave like a formula car, overcooking the tires and causing them to go off.

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Keith Novak
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Ryan Verified Driver
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Region: San Francisco
Car #: 71
Year : 1994
Posts: 39
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i'm wonderinging if adding a little rear toe will help the car rotate so i dont overcook the front tires. i guess i never really noticed this problem with the RA-1s since they were more forgiving and the R888 dont like to be slid. it could also be when i transition from off throttle braking to full throttle, i might be shocking the car with all sudden weight shifting. maybe i need to transition from off throttle to full throttle a lot smoother?

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Tvance13
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Car #: 85
Year : 2001
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Assuming you have the correct tire pressures, I would suggest making an adjustment to the rear bar. Move one side to the middle and the leave the other at soft. If that doesn't work try and move them both to the middle. I am guessing you have too much rear end grip at full soft. We had the same problem on our 2001 and this corrected it. You should be running 1/8" toe in on the rear.

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Kim Hinson
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Car #: 06
Year : 1999
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Did you check the tire temps

davew Verified Driver Made Donation to Website
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You have left out a lot of info.

You say "normal camber setting". What is "normal"?

You say "3/16-1/4 rack". At what ride height and with what upper perch package?

Is your stated tire psi hot or cold. Taken how long after you come off the track?

What are your ride heights and corner weights?

You mention you went up 2 turns. Did you check the camber (which should have went in the + direction) or toe which should have changed also.

My suggestion is to put a generic/baseline set up in the car.
-3* camber all around. or close
1/8 toe out in front and 1/16 toe in in the rear.
set crossweight to less than 15 pounds
Set ride height to 4.75 with 99 hats all around. If rear is slightly higher that's ok. But not front higher.
Set rear bar middle middle.

This setup may not be optimised, but it is close enough to take the car out of the equation.

Have someone in the pit lane to check hot tires with a fast final lap. Run for 10 minutes, check pressures and adjust to a baseline of 38. Run another 10 minutes and readjust to 38psi.

Take a break. Your driving will be more consistent with rest.

Now leave the car alone and work on the driver. I think you will find you are chasing a driver issue. Most of us will start overdriving the car as the session goes on. Our confidence goes up, our aggression goes up and our stamina goes down.

If the car feels good at the start, make sure you are hitting all your marks. Most peoples fastest lap is between lap 3 and 5 if traffic is not an issue. So the brake point on lap one may be different from lap 5. You may need to adjust.

A couple posts up you say "a mid corner-exit push as soon as i went to full throttle." If you are waiting untill mid corner to be full throttle you are too late. This confirms that you are very possibly overdriving the entry. You are going in too fast, the car does not respond like you want, your brain says "more gas". But the car pushes anyways.

Put some toe out in the front, this will make the car turn in (rotate) better. Put a little toe IN into the rear. This is a great way to stabilize the car after initial turn in past the apex.

A lot of people (including the site owner) promote zero toe. It takes an exceptional driver (like the site owner) to drive these cars with zero toe front and rear. Get the car to handle and it will be faster down the straights. Once you get this part happy, then try for less toe to bring the drag down/speeds up as you fine tune YOUR prefered setup.

FYI, this basic setup has won a lot of races and set a lot of track records.

Dave

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Sean Allen Verified Driver Made Donation to Website
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Maybe this is just caused by the overly large front sway bar the 1.8 runs? What ever happened with the proposed rule change to allow the 1.6 front bar?

Jose Bonet Verified Driver
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Region: CCR - 61
Car #: 79
Year : 1992
Posts: 46
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I would try running different air presures before changing rear toe. ie softer cold pressure up front and / or higher cold pressure in the rear.
Good luck

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Jose Bonet

Jose Bonet Verified Driver
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Region: CCR - 61
Car #: 79
Year : 1992
Posts: 46
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I would try running different air presures before changing rear toe. ie softer cold pressure up front and / or higher cold pressure in the rear.
Good luck

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Jose Bonet

   

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