Track forum general chit chat.

[Bimmer Barney]

Originally Posted by roastbeef

corner balance is just adjusting ride height while the car is on scales to get it as even as possible, right?

i don't understand how some cars have so much rear rake, but then i look at my car with a decent (eyeballing it) looking front leaning rake with a very small relative difference between the front/rear weights.

It's because the "balance" you're trying to achieve is cross balance. LF+RR=RF+LR. Shifting weight forward or aft wouldn't change the "balance." The purpose is to make sure the car turns left and right equally (or intentionally manipulated to do one better than the other), allowing separate adjustment for braking stability and over/under steer bias via rake and dampening and aero.

[roastbeef]

Originally Posted by Bimmer Barney

It's because the "balance" you're trying to achieve is cross balance. LF+RR=RF+LR. Shifting weight forward or aft wouldn't change the "balance." The purpose is to make sure the car turns left and right equally (or intentionally manipulated to do one better than the other), allowing separate adjustment for braking stability and over/under steer bias via rake and dampening and aero.

i assumed people were trying to balance front to back as well. some cars really look a lot lower in the rear.

[roastbeef]

Originally Posted by spxxx

You savage... Those carbon doors are a dream of mine, just a little worried without a full cage/nascar bars but the insane weight savings make it tempting.

You mentioned something about electric power steering in your build thread, mind DM'ing me more info?

its on the list, but its going to have to wait. OG Shark was working on a kit, last i heard...

basically, you use a specific mercedes electric power steering pump and ditch the pulley pump. you run a couple lines to the cooler and rack like normal and still enjoy the same steering feel, but free up some power through efficiency.
its been a while since i did some reading on this, but i think the 2010-13 cars can ditch the power steering pulley and a/c and just use a different belt without drama.


and a side note about the carbon door safety... take a peek at the braces next time you have the door card off. i just wasn't worried about it. i also daily drove a smart car for the last six years, so, there ya go.

[roastbeef]

Originally Posted by DRLane

Incredible. Assume that's with the wheels?

Last time weren't you ~3200 without wheels? So the doors, conversion, interior, seats, saved 200lbs?

i believe the car was on wheel stands, but i'm not sure what they weigh.

the rear m359's with the 295 tires are 52lbs each though... fronts are around 45lbs if i remember correctly. i doubt the wheels were on, there was no way my car was 3,200 with wheels on with all the crap in it still.

doors saved 70lbs (including cards), headliner and insulation was about 11, rear cards were 5lbs plus 3lbs for the crap underneath them, idrive was just 1 pound, but the radio was about 6, center console was 9lbs, carbon trunk saved 23lbs, i can't find my pics of the seats on the scale, but lets call the seats 50lbs to be conservative... then maybe 3 more pounds of miscellaneous drilling. oh, and a few pounds for the washer fluid tank, nozzles, and tubing.

the single hump dash netted about 17lbs. that includes about 5lbs of firewall insulation, drilling the dash tube, one cupholder delete, ducting delete, passenger airbag delete, and glovebox delete. that figure does not include the speaker, radio, or idrive screen.

so all of that puts us at about 200lbs. i still need to just get rid of the a/c compressor, fan, and all that crap. i'm somewhat worried about defrosting, but thats rarely a problem...

[spxxx]

Originally Posted by slcook54

The big items I'm not willing to touch (yet) are speakers, AC and doors. Those all come with compromises but are good for that next 150+ lbs.

My next ~50 will likely be
- carbon door cards
- carbon trunk
- m24 hood
- Karbonius or m24 plenum
- mjunkee armrest (ordered)

Once you've done the obvious items, you start to see diminishing returns and a ton more $$$

I was at 3403lbs with roughly 4 gallons of gas. Post cage and seats I'm expecting to drop at least 100lbs. Would like to get to 3,200-3,250.

The under seat subs are pretty heavy, I'm fine with one set of tweeters haha... I typically just listen to airpods anyways.

AC will never go, unless I ball out on with a full-on electric racecar AC system (never happening). I assume I'm right at 3,300 but really want to get it weighed soon.

[kyippee]

I've been away... tracked my stock F44 M235i xDrive Gran Coupe this weekend at Thunderhill West. 9 second difference vs. the M3 I sold

what a difference - gives me appreciation for different car setups!

https://f44.bimmerpost.com/forums/sh....php?t=1952120

[omgzirra_exe]

i should be able to squeeze down in 32xx... all this weight talk is making me anxious i want to start doing it, but the pinnacle cage is way out still.. and i don't want to repeat the work lol.

[spxxx]

Originally Posted by roastbeef

i assumed people were trying to balance front to back as well. some cars really look a lot lower in the rear.

I think that's intentional. I've seen/heard some pro team mention the idea of running the rear lower... My assumption is with that with our 65/45 distribution it's advantageous to run a reverse rake to help reduce rear-end grip loss during weight transfer under braking?

[admranger]

Originally Posted by kyippee

I've been away... tracked my stock F44 M235i xDrive Gran Coupe this weekend at Thunderhill West. 9 second difference vs. the M3 I sold

what a difference - gives me appreciation for different car setups!

https://f44.bimmerpost.com/forums/sh....php?t=1952120

You should be able to learn more in the lower hp car. It's still stupid fast compared to what I started in ('87 325iS), but the newer M cars are too easy to go too fast in, without really knowing what you're doing.

Less brakes, more momentum, earlier on the throttle, smoother everywhere = fast

Seems like the trainer could give you the cues a second earlier to process them, but still pretty handy.

[kyippee]

@admranger definitely much faster than the first car I tracked/autox'd in- an E46 325!

Was fun learning how much the car and tires can take, but also kind of sad how much slower things happen.

What impressed me was that the cooling system worked well when ambient temps hit 95-105F. Engine oil temps went to 245-255 but it did pull some power. Stock brakes held up really well with just SRF fluid!

Muffler discolored in a section, and tires were not happy at >200F

[omgzirra_exe]

Originally Posted by spxxx

I think that's intentional. I've seen/heard some pro team mention the idea of running the rear lower... My assumption is with that with our 65/45 distribution it's advantageous to run a reverse rake to help reduce rear-end grip loss during weight transfer under braking?

the m3 naturally has more rear rake on purpose, suppose to help with grip/braking.

[roastbeef]

Originally Posted by spxxx

The under seat subs are pretty heavy, I'm fine with one set of tweeters haha... I typically just listen to airpods anyways.

they are relatively heavy. all of my speakers loose in a cardboard box weighed about 22lbs. i expected it to be more.

[dogbone]

Originally Posted by spxxx

I think that's intentional. I've seen/heard some pro team mention the idea of running the rear lower... My assumption is with that with our 65/45 distribution it's advantageous to run a reverse rake to help reduce rear-end grip loss during weight transfer under braking?

Ummm 65+45=110…..just sayin’

[Bimmer Barney]

3573#

Only lighter-than-stock parts on my car are:
Wheels and Tires
Front Calipers
Suspension
Exhaust
Front Rotor Backing Plates

Added weight with:
Front Lip and Rear Trunk Lip
Brake Cooling Hoses

Otherwise this is fully stock trim and half a tank of fuel on an E90 single hump, slicktop, DCT car. Even left the floor mats in.

BUT…my yellow seatbelts add 10hp (to the wheels!)

[spxxx]

Originally Posted by dogbone

Ummm 65+45=110…..just sayin’

Hahaha don't tell anyone that I work in data analysis and studied math in school

55/45 distro*** dunno why I had the number 65% stuck in my head.

[omgzirra_exe]

does anyone know what possibly caused this smear? that's circled in red. The last I drove it was on a small canyon road, but I barely was on the brakes hard... did sit in small traffic behind an RV though...on the way down.

going to take the brake pads out and check when its not 100F outside...

it's only on my driver rotor.

[Bimmer Barney]

Originally Posted by omgzirra_exe

does anyone know what possibly caused this smear? that's circled in red. The last I drove it was on a small canyon road, but I barely was on the brakes hard... did sit in small traffic behind an RV though...on the way down.

going to take the brake pads out and check when its not 100F outside...

it's only on my driver rotor.

Can brake rotors get swamp a$$? That's usually what causes my smears

[omgzirra_exe]

Originally Posted by Bimmer Barney

Can brake rotors get swamp a$$? That's usually what causes my smears

LOL

[Redd]

Originally Posted by omgzirra_exe

does anyone know what possibly caused this smear? that's circled in red. The last I drove it was on a small canyon road, but I barely was on the brakes hard... did sit in small traffic behind an RV though...on the way down.

going to take the brake pads out and check when its not 100F outside...

it's only on my driver rotor.

Looks like disc bluing to me. Usually from high heat.

[turbo_joe]

Originally Posted by roastbeef

its been a while since i did some reading on this, but i think the 2010-13 cars can ditch the power steering pulley and a/c and just use a different belt without drama.

It was the very early years that could swap things out easily. 09+ need to either do full electric setup for PS and ditch PS pump and AC, or you can run the PS pump from an M5 with some work and find the right belt.

I have the parts laying around to ditch my AC using a merc pump, custom lines/brackets etc.


My car as it sits is 3200lbs with an 8 point roll cage, just a driver seat, 1/4 tank of gas, and half gutted dash, no door glass, and lexan for the rear and quarters. I am about to wide body the car but ditch the AC and hoping to offset that weight and I need to add my fire suppression. I have to stay over 3425lb with me in the car.

[admranger]

Originally Posted by spxxx

Hahaha don't tell anyone that I work in data analysis and studied math in school

55/45 distro*** dunno why I had the number 65% stuck in my head.

I thought you gave 110% like all the pro athletes do. I am disappoint.

[Evice]

One more video. My chonky m3.

3320# weight with a half tank, about 360whp. All stock engine. not PB, but a decent lap.