Wow! I don't look at this thread for a few hours and it takes off.

I've never understood why front toe-out works so well. I can understand why it would would help with initial turn-in (heck, one of the tires is already "turned-in" slightly before you've initiated the turn), but in the middle of a sweeper, I would think that the tires would be fighting each other.....which I think would reduce traction.

minihune: I put this in the Solo 2 thread, because if I put it in the G-stock or H-stock thread, we'd be leaving someone out.

I've never understood why people use a tire pyrometer for stock class autocross. I can see using it if you can legally run camber plates, but since we can't, wouldn't a data aquisition device be better? Something that gives an overall measure of grip (g-force).

I've always felt that tire pressures are very subjective. Some people like high pressures (makes car very darty) and some people like lower pressures (makes car easier to drive, but can wear tires out faster)

 

nobody has mentioned the effect tire pressures have on the overall spring rate of the suspension. Why?

Pyrometers give you an idea of when you are in the ballpark with correct pressures. It has nothing to do with the camber (which you cannot run, as noted) in stock class.

I ran different setups for each national level event in 2006. Tire pressure varied by 40psi between Atwater and Topeka.

I will offer my setup sheets for sale once I sell the 05 GS championship car.

Grant

 

Check post #10 of this thread, spring rates have been mentioned.....once.....

I am going to disagree with you on pyrometers though.....they can be a very important tool in determining camber...even though in the discussion of stock classes there is not much to be done....insufficient negative camber is going to show up as elevated outside tire temps and low inside tire temps.


I'm not sure purchasing someone elses setup sheets from a different car and different driver is a good bang for your buck mod...but thats only my take on it....

Respectfully,

Jason

 

Jason,

I think you misunderstood my point about a pyrometer. In GS or HS camber is not the issue on the Mini, most every owner will set the maximum available. Does that mean you no longer need a pyrometer?

Of course not. You still use a pyrometer to confirm you are running the correct pressures. Sure the outside edge is going to read high (due to the lack of camber) and the chances of equal readings across the tire are slim (but possible - high pressure, lots of front toe).

Your pyrometer will also tell you which drivers are working the tires harder, which driver is running in the optimal temp range for that tire, and which driver is not pushing hard enough.

Short of a stopwatch, the tire pyrometer is the most useful tool available to a race engineer. Not unusual to see pyrometers used in gokarting where the rear axle is solid with zero camber adjustment - why are they using the pyro?

You may not think my setup sheets offer much bang for the buck, that is your opinion. do you have an idea how many wins my Mini has had in the last two seasons? National Tour/ProSolo and Nationals wins?

I guarentee there are two particular items contained in my setup sheets that would have saved our fellow GS competitors lots of head scratching. But if you want to figure it out yourself on your own dime, go ahead, and best of luck to you. I have used previous owner setup sheets in many forms of racing inlcuding the Indy Racing League. I have setup sheets for race cars going back 15 years.

 

Lots of front toe-out probably gives you even pyrometer readings across the face of the tire.....because your scrubbing the tire all the way around the course. But that doesn't mean that you're getting the optimum grip.

What am I missing here?

 

My new MCS is fast and nimble. However the pedal placement is less than ideal for heal towing. Ideally the brake pedal would be lower so that under hard braking the brake pedal would be on the same plane as the throttle pedal. Have any of you hot shoes made such a modification?

Thanks,

Bruce S
2006 MCS/LSD

 

Probably not. For one thing, it's not legal in stock class to change the pedals. Also, for autocross, heel-toe isn't very important. Any course requiring a downshift to first gear is lame, and IF you have to make a 3rd -> 2nd shift (which I never have in my Mini), it's pretty easy anyhow and you don't need to heel-toe.

 

I've never actually done the "heel" "toe" technique. I've always used the left side of my foot and the right side of my foot. That works well for me with both our Miata and the Mini. I can threshold brake and still rev the throttle.

Maybe give that a try?

 

I'm not here to call into question how competitive your car is, how fast you are as a driver, or how much racing experience you have....I never did that, thats not the point.


mitchman started this thread as open discussion with free exchange of information, I don't think you being hush-hush about your details and offering to sell setup sheets belongs here. Those of us who want to share information and discuss the what/how/why of whats going on with our cars stand to learn a lot here. As an engineer, I want to understand the reasoning behind any decision I make setting up my car, so to me, blindly going to a setup because it worked for someone else isn't the best way to go. I'll leave it at that.

Back on topic,
For me, "heel toe" is more like "left and right side of my foot" like mitchman. For autocross, I normally left foot brake anyways, but a few times I have used this heel toe to make a smoother downshift from 2 to 1 or from 3 to 2. When I'm doing a track day on a road course, I pretty much heel toe 100%.


Jason

 

Funny how fast a thread dies when someone shows some attitude (not you Jason).

Anyway, let's talk about front sway bars. There's two schools of thought:

1) Larger = less body roll = less camber change = more grip in the middle of the turn.

2) Smaller = softer front roll rate compared to the rear = more oversteer

Or does it effect other aspects I'm not thinking of?

 

Wouldn't it affect the effective spring rate of the suspension for going over bumps as well? For instance, wouldn't a stiffer front bar make getting traction and braking more difficult on a very bumpy surface because the two sides of the suspension are tied together "tighter" with a stiffer bar? I don't know if that makes sense - but my understanding is that the swaybar ties one side of the suspension to the other side, so as one shock tries to compress, the swaybar resists compression on that side, or encourages compression on the other side.

 

MuGami, I thought mods invalidated the warranty? How do you get alignment parts replaced with tire, and suspension mods in place? Just curious, I don't even have my car yet!! Just a couple more weeks, hopefully!

 

A smaller front bar gives you less transitional response but more mechanical grip.

 

I would suggest either going with the stock MCS bar or a 22.5mm front swaybar. Anything smaller makes transitions a bit too slow, anything bigger, unless your on ultra-grippy concrete, will induce unwanted wheelspin IMHO. Although, I suppose it would be somewhat course dependant as to which bar would be best, so, I guess it depends on where you run and what your plans are. I know for HPT(nationals site), a Largeish bar would most likely be a bad thing. :-)

 

Interesting points about the car transitioning too slow. Here's something else to think about.....

TURN EARLY! hehehehehe

Actually, I'm kind of serious. Obviously, a 5+ cone slalom is going to kill a car that transistions slowly, but most courses only have 3 cone slaloms and you could adjust your driving (turn early) to make up for a softer front bar. Plus, the softer front bar will help you put down the power on corner exit.

I can't believe an adjustable front bar isn't available. You could adjust depending on the course design and level of grip.

 

Thats a good point, an adjustable front bar would be great. I wonder if its not possible with the stock droplinks since a different setting might require a different length droplink. Hmmm, it sure would be nice if it was possible.

Your also right IMO when you say the driver can drive around the slow response with a small bar, but IMO I still think a 16mm is too small, and on some courses, you can't just drive around the slow response since the car won't be settled by the time the next transition comes up, even if you do just turn early IMHO.

I guess it would be highly course dependant, some courses you could drive around it and some you couldn't. It kinda goes the other way as well, if you have a 22.5mm bar and it doesn't sweeper as good as a 16mm, you have to just get through the sweepers and then dominate on the rest of the course. Basically, in stock class, competitors are always driving around the inabilities of the car, so, one would have to decide which works best for their surface and driving style. For me, I like the 22.5mm bar best on average, even for my STX car.

 

So how does the jump between the 24mm and 22.5mm bar compare to the jump between the 22.5mm and the 16mm bar?

 

Thanks for starting this Mitchman! Good stuff for a new guy....

 

YakiMni, check your email!

 

24 to 22.5 = 1.5mm
24 to 16.0 = 8 mm (too much)

The 16mm might have worked on the pre '05 cars, they seem to have been sprung a little stiffer. How much I couldn't answer, I haven't been able to get that info. You need to remember the suspension acts as a package. Spring rate, front bar size and shock settings. The 16mm bar is a $200+ question that not many have been willing to try.

 

$200? A buddy of mine said he can get one for $80.

 

http://new.minimania.com/web/Item/NM.../InvDetail.cfm

If you can get it for 80 JustGo4it

 

Where did you get your Leda's from?

 

Lets say your on an asphalt course and you have some very slight wheelspin coming out of a couple sweepers, the 22.5mm bar will eliminate that very slight wheel spin and help your Mini get out of those sweepers a bit quicker, and, at the same time it will still allow you to transition acceptably IMO. The 16mm is just too much, its sloppy. One of the reasons it was possibly OK on the pre-05's was because they didn't have LSD, and, it helped eliminate the massive wheelspin that those Mini's experienced which was a major problem. Sure, one could drive around the wheelspin, but, its not as quick as not having any wheelspin at all. I don't know, maybe for most drivers, the 24mm is better on the 05+, but, I personally like the 22.5mm being on Asphalt 90% of the time. Its completely course dependant though. I'd guess between the two bars, your only talking .1 or so either way. Its not like your going to run .5-.75 quicker on one bar or the other. Basically, what I'm saying is, there are more important setup details such as alignment, wheels, tires, Scrothe Harness from SoloRacer.com etc... When a competitor gets all those mods installed and wants to experiment after a season or so, maybe the swaybar is a good mod to see which is prefered. :-) Heck, I'd guess that 50% of competitors might not even notice ANY difference at all after the smaller 22.5mm bar is installed. AND, its not a mod that you want to do just before the Nationals IMO. One keys to being fast is just hoping into your Mini and KNOWING what its going to do at any given corner before you even execute it, and, not thinking about it while your doing it. Thats why its good to get your setup and leave it for several events. OK, I'm getting off topic. lol

 

OasisT: Great description! Thanks Craig! Personally I've always had trouble focusing on driving fast (correct line, brake points, etc...) AND trying to get a feel for the changes I've made to the car. I either throw the run away or don't remember what the car was doing. (I guess that's what test and tune days are for)

JustGoForIt: A friend of mine said he has an "in" with a local dealership. That's the price he bought his 16mm bar for from them.

I bought the Leda's used from Jake (see post #36 in this thread). But I sent them off to Racer's Edge to be modified a bit. Why?