Track forum general chit chat.

[ThunderMoose]

Originally Posted by dparm

I'd like to play devil's advocate here: why does every performance car run staggered from the factory if square is superior? Wheel and tire sizing by the OEM is not arbitrary.

I feel fairly confident that the real fast corvette guys in NASA TT are running square setups. Like costas and Mosely. I'll ask Chet what he runs on FB.

Update - Chet runs 345/335 staggered...lol.

[BayE30]

IMO the reason manufacturers run staggered on RWD sports cars is for safety. Which scenario is more dangerous for your average driver? slight understeer, or slight oversteeer?

Obviously slight understeer is more manageable for the average consumer, which is what the staggered setup caters towards.

I have been running 275 square on my m3 for about 2 years now, and i love it. The reason i love it is that i DO NOT like to feel understeer in my RWD cars. Slight oversteer feels much more natural to me. I have not experienced any type of heavy steering, or tramlining as some others have. My m3 is a street car, which at best see winding mountain roads once a month. My track duty is covered by my e30, which obviously is running widest tire possible in square setup.

[Bartledoo]

Long shot here, but does anybody has a source other than kw for replacement torx camber plate bolts for the clubsports? A couple of mine are in less than stellar condition due to some overtightening by an alignment shop...

[StripclubDJ]

Originally Posted by Richbot

It's great. And if you don't like the balance, adjust with a rear spacer.

I use a 5mm rear spacer with my square setups. It is a noticeable improvement in power-down

Bro
What? Lol

[fsmtnbiker]

Originally Posted by Bartledoo

Long shot here, but does anybody has a source other than kw for replacement torx camber plate bolts for the clubsports? A couple of mine are in less than stellar condition due to some overtightening by an alignment shop...

McMaster.com pn 91294A287 - 5mm hex instead of torx. I swapped all of mine out. 25-pack is like $6.

Edit: torx pack of 10: 90236A169

[OG Shark]

Originally Posted by tsk94

Both have benefits. Square obviously allows for prolonged tire life from being able to rotate the tires all around. Staggered provides a more stable, planted rear end - more confidence inspiring and arguably easier to drive fast.

I started out on square 275 and really liked it. Then I moved to staggered 275/295 - also liked it. Now I'm moving to square 295 for this season and hoping for an improvement from the previous setup.

There is no right or wrong setup (square or staggered). There is however, an optimal setup for a given driver, car and track combination. Some people will prefer a staggered while others a square. A square setup can be tuned to be neutral or understeer just like a staggered setup can be tuned to be neutral or more oversteer biased. A lot more aspects come into play to determine handling balance then just the relation of front to rear tire size.

In my opinion, the fastest setup will be a staggered setup, where you maximize the widest possible front and rear tire for this chassis. Something like a 295/315 or 305/315. Tuned accordingly this will be faster then a 295 or 305 square setup as you will have more mechanical grip then the square setup counterpart. Since we are able to run a wider rear then front tire with stock bodywork. So for outright lap time and competitive events (racing or TT) this would be the way to go. I believe this is what OG Shark said he was doing with his car earlier.

For your average track day/HPDE guy though, I'd say go square. It's a proven setup that works and your tire life will be prolonged and save you a bit of money in the long run.

Exactly what I was getting at! No right, no wrong, just whatever works for you in your situation.

I do not think anyone is saying that a staggered setup is always better than square - just that it can be the better choice depending on the situation.

Originally Posted by ThunderMoose

My favorite was Andy Hollis with 275's front and 245 rears on his FWD Honda.

Andy was my instructor at my first ever HPDE way way back in Oct. '18. Was a great experience - learned a lot from him. Didn't sugarcoat anything - just would tell you exactly like it is. His emphasis on awareness with me still is always in my mind when I get on track - he really ingrained that into me & I'm very thankful he did. Think I'm very fortunate to have gotten a good instructor my first time out like that.

Originally Posted by ThunderMoose

I feel fairly confident that the real fast corvette guys in NASA TT are running square setups. Like costas and Mosely. I'll ask Chet what he runs on FB.

Update - Chet runs 345/335 staggered...lol.

Different animal when you are able to fit 335 fronts - they are not having to downsize the rear in order to run square. I would love to try that on the M3 but not sure if it will get past the < 3" fender flare rule

[kyippee]

On the square vs staggered street topic, it makes sense to me if I think of the steering implications with a wide front setup. Tramlining and heavy steering is annoying for most drivers. Annoys me if I ever drive on 275 or wider fronts with this car on the street.

More annoyance = less buyers

[Bimmer Barney]

Ok next question. WTH is happening here. Mrs. Barney walked out to the garage and came back in casually saying "oh btw you car is leaking something"

What!?!?!???

So I go out to the garage and find some drips coming from the rocker area in front of the rear passenger wheel. Clean, slight green tint. Not slick, smells like water. I didn't taste it (but I probably will).

Jacked the corner up and looked under the plastic and didn't see anything, just some wetness as if I had washed the car. I haven't washed the car in a week and a half. When the back corner was in the air, the drip moved to the underside corner of the rock panel behind the front wheel, same side.

Dipped a paper towel in the coolant tank to compare color. Coolant is bluish, this is pale greenish. Not the same. Almost looks like the same color as windshield washer fluid?

I'm a pretty good mechanic but this has me stumped! I put a cup under to catch the drip. It's just dripping...amount shown is after a couple hours.

[roastbeef]

Washer fluid is near the passenger side fender vent.

[Bimmer Barney]

Originally Posted by roastbeef

Washer fluid is near the passenger side fender vent.

Right. So then I couldn't figure out how it could possibly result in a steady drip at the rear of the rocker panel.

[Bimmer Barney]

Update: I tasted it. Didn't have have a glycol type texture. Tasted like shit. Definitely not just water. That was a terrible idea. Proved nothing.

Haha.

[roastbeef]

Originally Posted by Bimmer Barney

Right. So then I couldn't figure out how it could possibly result in a steady drip at the rear of the rocker panel.

Leaking into the rocker and dripping out towards the rear?

[Bimmer Barney]

It's in the front area though, so how would it get to the rocker panel? I'll check it out.

Possible identification: while rinsing with listerine repeatedly I had an epiphany. I remembered that BMW equipped our cars with leaf catchers in the lower corner of the windshield/back corner under the hood! What if some water got in the leaf catcher!? So I poured some water in there and it drain out through that rocker area. Behind the front wheel. That could explain how water got in there.

[Bartledoo]

Originally Posted by fsmtnbiker

McMaster.com pn 91294A287 - 5mm hex instead of torx. I swapped all of mine out. 25-pack is like $6.

Edit: torx pack of 10: 90236A169

Thank you sir. You have all of the good info lately.

[Richbot]

My car, with about 100lb of weight lost at or behind the rear axle (exhaust and battery and wheels) scales out at 52/48 with me in it. Because of my seating position and the midships location of the driver's hip point on this car, driver weight seems to affect cross more than front/rear

Originally Posted by Bimmer Barney

It's in the front area though, so how would it get to the rocker panel? I'll check it out.

Possible identification: while rinsing with listerine repeatedly I had an epiphany. I remembered that BMW equipped our cars with leaf catchers in the lower corner of the windshield/back corner under the hood! What if some water got in the leaf catcher!? So I poured some water in there and it drain out through that rocker area. Behind the front wheel. That could explain how water got in there.

Yeah I was going to say, that looks like algae-filled water to me

Try sticking it in a bottle and spinning the bottle around windmill style in your hand like you're trying to get the last ketchup down by the opening, and see if it stratifies

and take video, obviously

I continue to recommend against taste-testing leaks from automobiles

If your car had a sunroof I'd say sunroof drains maybe? but nope

The only other thing I can think of is maybe the battery tray has collected water without you noticing (this happens more than you'd think when seals start to dry out). There's a very, very small drain so it might take some time to get down to the rocker, but it also would be behind the rear wheel, not in front, soooooooo....aliens?

[dparm]

Originally Posted by SYT_Shadow

Square is superior *for the track*. I do not run square setups on my street cars, namely because I do not need to pull 1.4g entering an offramp. I don't like square setups on the street because it makes the steering too heavy for my tastes.

Originally Posted by tsk94

Both have benefits. Square obviously allows for prolonged tire life from being able to rotate the tires all around. Staggered provides a more stable, planted rear end - more confidence inspiring and arguably easier to drive fast.

I started out on square 275 and really liked it. Then I moved to staggered 275/295 - also liked it. Now I'm moving to square 295 for this season and hoping for an improvement from the previous setup.

There is no right or wrong setup (square or staggered). There is however, an optimal setup for a given driver, car and track combination. Some people will prefer a staggered while others a square. A square setup can be tuned to be neutral or understeer just like a staggered setup can be tuned to be neutral or more oversteer biased. A lot more aspects come into play to determine handling balance then just the relation of front to rear tire size.

In my opinion, the fastest setup will be a staggered setup, where you maximize the widest possible front and rear tire for this chassis. Something like a 295/315 or 305/315. Tuned accordingly this will be faster then a 295 or 305 square setup as you will have more mechanical grip then the square setup counterpart. Since we are able to run a wider rear then front tire with stock bodywork. So for outright lap time and competitive events (racing or TT) this would be the way to go. I believe this is what OG Shark said he was doing with his car earlier.

For your average track day/HPDE guy though, I'd say go square. It's a proven setup that works and your tire life will be prolonged and save you a bit of money in the long run.

This is what I was getting at. Any time I see blanket statements like "X is best", it makes me pause because there's no context provided. People misunderstand or think there is a one-size-fits-all answer to their problem. Tracks are different, driving styles are different, conditions are different, and everyone's cars are different. I have always started with the OEM setup as a baseline and adjusted based on what didn't fit my situation.

Originally Posted by BayE30

IMO the reason manufacturers run staggered on RWD sports cars is for safety. Which scenario is more dangerous for your average driver? slight understeer, or slight oversteeer?

Obviously slight understeer is more manageable for the average consumer, which is what the staggered setup caters towards.

I don't really buy that, given that every car these days has very sophisticated stability and traction control systems. Those systems will step in plenty early on anything stupid you do on the street. More experienced drivers will have the instinctual reaction on how to correct over/understeer on the track (and are probably turning much of that stuff off anyway).

The OEMs choose wheel and tire sizes very deliberately and after significant testing. There are of course NVH and cost considerations, but the car is being tuned to handle a certain way. This is very complex and requires involvement from the suspension team, chassis team, electronics team, etc. For a track car maybe some of those things don't matter, but completely discarding all of the R&D the OEM has done is not the approach I take.


Just my two cents. Always appreciate the dialogue in this forum.

[roastbeef]

I theorize while a ton of research and development goes into suspension and handling, they do want to build understeer into a car. It's simple- understeer is easier to recover from than oversteer. The average person is going to jab the brakes when the car isn't doing what they want it to do. When understeering, that usually fixes the problem, when oversteering, a spin is likely.

[roastbeef]

About 18 lbs down so far gents. Trunk liner, sound deadening, deck lid trim, and some fasteners.

[roastbeef]

Anyone have any insight for removing the rear floor carpet? It extends under the front seats and center console... I'm hoping the seats and console don't have to come off.

[evilspiritM3]

Originally Posted by roastbeef

Anyone have any insight for removing the rear floor carpet? It extends under the front seats and center console... I'm hoping the seats and console don't have to come off.

They have to come off to get it all. It's a PIA if you don't do it in order by removing the console first.

Or you can get your scissors out.

[roastbeef]

I have some nice garage scissors, but I'll only do that if I can get it all.

[Bartledoo]

I tore my rear carpet out, like a savage.