Kansas E46 Fanatics listen up!

Originally Posted by tnord

just placed an order from BW, if anyone has an RTAB tool i can borrow, please email me. willing to pay in beer unless you're name is Andy.

tnord42@hotmail.com

Nice, what rtabs did you get. Anything else fun on the order list?

powerflex RTAB, OEM FCAB in housings, bimmerworld lifetime RSM.

tires are bald. want to make sure everything is good before i spend a pile of money on new tires. would really like to get some 18'' CSL style/ARC/V710/etc wheels at the same time, not sure if i'm willing to spend the money though. if i could find a used set in good shape i'd jump all over it.

Originally Posted by tnord

powerflex RTAB, OEM FCAB in housings, bimmerworld lifetime RSM.

tires are bald. want to make sure everything is good before i spend a pile of money on new tires. would really like to get some 18'' CSL style/ARC/V710/etc wheels at the same time, not sure if i'm willing to spend the money though. if i could find a used set in good shape i'd jump all over it.

If you check out m3forum you should be able to find a used set of arc8s for a good price. Only bad thing is most of the guys running those are using them for the track so a square set of 18x9.5 is what most run, not sure how many staggered sets there are. Probably have to run -3+ camber to fit those and i know yours is a street car.

The guys af gfperformance can hook you up with some vmr's for cheaper than anywhere else.

As for that rtab tool i know kevin (sly1types) has one but he's had bad luck in the past letting people borrow it. I know bimmerworld rents one as well, not sure on the price.

i'm finding a couple options if i wanted to go the squared route, but that just seems excessive for a street car. and i hate tramlining which i bet the wider front tires would encourage.

i'll check out gfperformance, thanks for the heads up.

Originally Posted by tnord

i'm finding a couple options if i wanted to go the squared route, but that just seems excessive for a street car. and i hate tramlining which i bet the wider front tires would encourage.

i'll check out gfperformance, thanks for the heads up.

Yeah its way to excessive for the street and the tramlining is pretty bad. Most of the guys that daily and track find it to be a good option becuse with the staggered setup from the factory the understeer is pretty bad and the wider front track and camber needed to fit them eliminate that.

You ever plan on tracking the m or just dailying it? No need to really since you have the miata, it really is a good car in stock form.

Keep talking guys, good read!

the miata is pretty much gone, but no real plans to track it. with 95k miles i need to spend the car/toy money on basic maintenance items like bushings, brakes, mounts, coils, etc rather than sillyness like $2500 for an exhaust setup. i'll upgrade it ways you'd never really notice like the 330d short shifter, PF RTABs, rogue trans mounts, and lifetime RSMs i've bought so far....and in the future stainless brake lines and other small stuff but it'll stay pretty mild.

if people want to fix understeer seems like the way to do that is through proper corner weighting and playing with spring rates/bars rather than throwing big round heavy bricks on the front of the car. at least on the miata at reasonable power levels, anything bigger than a 205 race tire (more like a 225 in a street tire) actually slows the car down.

Originally Posted by tnord

the miata is pretty much gone, but no real plans to track it. with 95k miles i need to spend the car/toy money on basic maintenance items like bushings, brakes, mounts, coils, etc rather than sillyness like $2500 for an exhaust setup. i'll upgrade it ways you'd never really notice like the 330d short shifter, PF RTABs, rogue trans mounts, and lifetime RSMs i've bought so far....and in the future stainless brake lines and other small stuff but it'll stay pretty mild.

if people want to fix understeer seems like the way to do that is through proper corner weighting and playing with spring rates/bars rather than throwing big round heavy bricks on the front of the car. at least on the miata at reasonable power levels, anything bigger than a 205 race tire (more like a 225 in a street tire) actually slows the car down.

This for sure is a car that loves good maintenance.

Completely agree but most of those guys run stock suspensions or basic coil overs, nothing that gives them the ability to change spring rates. Most also dont have the experience to be messing with sways and to be honest there are few that corner balance. The racers seem to be the only ones that corner balance.

Having the ambility to rotate tires is also a nice benifit that you gain from running a sauare setup, for those that are budget minded. Its definitely a give and take between finding a balance between aero drag from the wider tires and max mechanical grip.

I know most of the guys that run nasa and scca run a 275 on 18x10 square setup which is what i run. It seems to be a good combination between grip and drag. Im also a big fan of the tire rotating though so there for sure may be something better. I also know that turner ran a 275 on a 17x9.5 back when they ran the e46 in grand am.

Good stuff! Eating it up. 17x9.5 sounds way better, than 18x10 with the same tire.

Originally Posted by xixixi

Good stuff! Eating it up. 17x9.5 sounds way better, than 18x10 with the same tire.

It would, but they were custom made bbs's so you can imagine how expensive they were. Most 17's wont even fit the oem brakes let alone a bbk o any kind. I found that a 275 on a 9.5 has quite a bit of side wall flex and is a bit balooned. I like it better on the 10.

Originally Posted by PerkM3

It would, but they were custom made bbs's so you can imagine how expensive they were. Most 17's wont even fit the oem brakes let alone a bbk o any kind. I found that a 275 on a 9.5 has quite a bit of side wall flex and is a bit balooned. I like it better on the 10.

Can we talk about how much brake is too much? Could you run a little smaller rotor with a better caliper. To produce the same effect? I can't deny your personal experience. I'd be really interested in the science behind tire size/brake set ups.

a square setup might be the best, i don't know. i just figured with that much under the giggle pedal that you'd end up with something larger in the back than the front. it is a bit of a porker though, so that much tire up front might really help with braking. another thing i hadn't considered was the front suspesion geometry. in the miata you get a fair bit of "active" camber, meaning as the shock/spring compresses you actually get more camber. not sure how the geometry changes on the front of these things as it goes through the range of motion. i *think* it's pretty static.

....and then there's the toe consideration. if you can drive, you actually set it up to be a bit squirrely to get it to turn in like a bastard and you can get your right foot back down quicker. you might not reasonably be able to do that with the M considering the higher top speeds you'll be seeing....which again bigger tires might help with. the highest braking point speed i ever saw at road atlanta was 120 down the hill into 10a. i'd bet if i just took my street M out there it'd see 140+.....getting 3000+ lbs woah'd down from 140+ is a good bit hairier than 2200lbs down from 120.

i'm talking myself in circles here with setup considerations all essentially for nothing else than to entertain myself while watching TV.

Originally Posted by xixixi

Can we talk about how much brake is too much? Could you run a little smaller rotor with a better caliper. To produce the same effect? I can't deny your personal experience. I'd be really interested in the science behind tire size/brake set ups.

Now that's a long converstation, I'm actually reading a couple tuning books right now but to be honest I haven't gotten to brakeing. The way I understand it though is it just depends and every application is going to be different. What are you looking for? Street? Track? Drag? It's all going to depend but it comes down to braking pressure which is the force it takes to exceed the mechancial grip the tires have with the road surface. Basically how much force it takes to lock the wheels or go into ABS. Next is heat, every brake combination has a sweet spot in terms of temperature and you have to find out what that is (manufacturer) and find a way to stay within it. You want to have the minimum size rotor, minimum size caliper, and stay within that operating temp range. That's the perfect system.

Enduro cars are going to need big brake systems because not only do they have to last longer but they have to withstand more heat over a longer duration of time. A sprint car of TT car is going to be able to have substantially smaller brakes, they may see the same heat as an enduro car but for a fraction of the time. A drag car needs only to have a braking system that stops the car once, no repeated stopping.

I guess to answer your question, yes, you can have a system that is too much and not enough. In this book I'm reading there are formulas that basically take into account the cars weight, force, mechanical grip factor, and you can determine the piston size, rotor surface area required, and so on. All you really need is the weight of the car, pad/fluid operating temp (and I mean recommend range, not max temp), tire size and rating, and you can get pretty close in terms of ideal brake setup. It wont be ideal, all of this type of stuff needs testing but it would get you close.

Hopefully that helps.

Originally Posted by tnord

a square setup might be the best, i don't know. i just figured with that much under the giggle pedal that you'd end up with something larger in the back than the front. it is a bit of a porker though, so that much tire up front might really help with braking. another thing i hadn't considered was the front suspesion geometry. in the miata you get a fair bit of "active" camber, meaning as the shock/spring compresses you actually get more camber. not sure how the geometry changes on the front of these things as it goes through the range of motion. i *think* it's pretty static.

....and then there's the toe consideration. if you can drive, you actually set it up to be a bit squirrely to get it to turn in like a bastard and you can get your right foot back down quicker. you might not reasonably be able to do that with the M considering the higher top speeds you'll be seeing....which again bigger tires might help with. the highest braking point speed i ever saw at road atlanta was 120 down the hill into 10a. i'd bet if i just took my street M out there it'd see 140+.....getting 3000+ lbs woah'd down from 140+ is a good bit hairier than 2200lbs down from 120.

i'm talking myself in circles here with setup considerations all essentially for nothing else than to entertain myself while watching TV.

The problem with that is just fitment. Right now with 275's in the rear on a 10" wide wheel with +25 offset with -2.8 camber and it's tight. I'm sure with some fender work and custom offsets you could fit a 295 and still maintain the proper camber based on pyrometer readings. I've seen one guy running a 305 rear but it was with crazy negative camber, something that wouldn't be good for what we're talking about. I'm guessing if we are talking just tire size and mechanical grip a 275/295 would be ideal. I think most just run the 275 square because of the positives such as rotating, cheaper tires, and the fact that you don't have to modify the oem fender.

You are correct on the suspension geometry and the fact that the e46 m3 being static. Currently with my setup (I know all will vary and mine is pretty stiff) but I run -3.5 front and -2.8 rear and my temp readings are dead on with the 275 square setup. I'm not sure why some are different but from what I've seen the M3's suspension is pretty static under load.

I've never been to Road Atlanta but I know last time out at Heartland Park I hit an average of 135 down the main straight and pushing 140+ heading into the kink on the back and I know that's much slower than what you'd see at Road Atlanta. You're right on the braking, it's very nice having that fat rubber up there to slow this thing down.

I know there are a ton of ways to setup a car and one persons setup might not suit anothers but the way I set up my M is to be pretty stable under braking/turn in. My car loves a lot of trail brake, I'm heavy on the trail to rotate before the apex then try and give the trottle a quick blip near the apex to help point the car at that exit then get hard on the throttle. I've found that the quick blip allows me to instead of rolling on the throttle more smoothly and gradually to really get on it hard. I've tried a couple different setups and this is the one I found to suit me best and help reduce my lap times.

I'm not as familiar with momentum cars like the Miata but I would think with the M that making it squirly at turn it wouldn't be something to do. I understand the reasoning behind it, or correct me if I'm wrong, but you want to carry as much speed into/through the turn (thus being a bit loose) because the hp is a bit less and you don't have the power to get out of the corner if you over slow the car on the entry. With the M I find it more important to get the car turned and on the throotle asap. I guess that's the point with all cars though, be on the gas as much as possible. I guess with a lighter car being a bit looser wouldn't be as bad.

:lurk:

applying to college:

unless you get in a really unique and competitive environment, with production based cars 99.99% of the time you're not going to want to go with a smaller rotor setup. even in SM where the brakes from earlier models are smaller but still big enough for the later cars i still don't know that i'd do it. when you start messing with calipers then you get into the math with brake torque, master cylinders, etc.

as far as setup goes i guess it comes down to basically setting the car up to turn as quickly as possible where you can still control it and maintain confidence. however, the quicker you get the thing to turn and pointed in the right direction, the quicker you're back on the giggle pedal. "slow in fast out" is nonsense. it's fast in fast out.

Originally Posted by tnord

unless you get in a really unique and competitive environment, with production based cars 99.99% of the time you're not going to want to go with a smaller rotor setup. even in SM where the brakes from earlier models are smaller but still big enough for the later cars i still don't know that i'd do it. when you start messing with calipers then you get into the math with brake torque, master cylinders, etc.
as far as setup goes i guess it comes down to basically setting the car up to turn as quickly as possible where you can still control it and maintain confidence. however, the quicker you get the thing to turn and pointed in the right direction, the quicker you're back on the giggle pedal. "slow in fast out" is nonsense. it's fast in fast out.

Any place online I can read about this?

i don't know, i've never really looked at it. i'd just start googling stuff.

Hey guys.. just wanted to say I have posted a thread for another meet come October 20th in Columbia this time