Track forum general chit chat.

[M3SQRD]

Originally Posted by P1zzaboy

I’m not inventing it. Maybe I don’t remember the number of bolts correctly. I loosened my subframe to ease the installation of new engine mounts. Right after that went for an alignement and couldn’t get similar camber readings on both sides. Went back home, loosened the subframe again, pryed a little to one side, went back to alignment and was able to get it perfect.

I didn’t go back and read all old posts…do you have camber plates installed?

As for the subframe, there’s practically no play in the front subframe. If there’s as much play as you believe there is, wouldn’t recentering your subframe from its recently reinstalled position to its newly recentered position most likely cause the camber to increase on one side while reducing it on the other side?

[M3SQRD]

Originally Posted by derbo

I have to figure out where I got these numbers from but they are in my spreadsheet.

Spring motion ratios
Front 0.96
Rear 0.576

Damper motion ratio
Front 0.96
Rear 0.813

Sway bar motion ratio
Front 0.96
Rear 0.56

Is the rear sway bar MR listed above correct? Unless I’m not looking at the sway bar motion relative to wheel motion correctly, shouldn’t the rear sway bar MR be closer to the damper MR than the spring MR? Above, the sway bar MR is lower than the spring MR.

[derbo]

Originally Posted by M3SQRD

Is the rear sway bar MR listed above correct? Unless I’m not looking at the sway bar motion relative to wheel motion correctly, shouldn’t the rear sway bar MR be closer to the damper MR than the spring MR? Above, the sway bar MR is lower than the spring MR.

I honestly don't remember where I got the numbers from or if I derived it. I need to revisit it and see how I got it.



https://www.hpacademy.com/assets/Cou...atSheet_03.pdf

M3SQRD maybe you can check this?

[M3SQRD]

Originally Posted by derbo

I honestly don't remember where I got the numbers from or if I derived it. I need to revisit it and see how I got it.



https://www.hpacademy.com/assets/Cou...atSheet_03.pdf

M3SQRD maybe you can check this?

They’ve incorrectly defined MR. It should be the inverse of their MR. Correct definition is MR equals motion of component (i.e., spring, sway bar, damper) divided by wheel vertical motion.

Sway bar equivalent vertical stiffness calculation does not affect the MRsway measurement/calculation -

MRsway = vertical disp sway / vertical disp wheel
Ksway_wheel = Ksway_eqv * MRsway^2

MRsway is based on suspension geometry (for small angles cosine of the angle is ~1.0 but in reality the sway bar moves in an arc, not purely translational) so the relative position of the sway bar and wheel positions.

[bigjae1976]

I have never had a track recovery vehicle spin in front of me...until this past weekend

[DRLane]

Originally Posted by bigjae1976

I have never had a track recovery vehicle spin in front of me...until this past weekend

Damn, y’all ran up on that last truck too.

[bigjae1976]

Originally Posted by DRLane

Damn, y’all ran up on that last truck too.

I know I was trying to process what the hell was happening. Confusion mostly...is the truck really spinning off?

[roastbeef]

Originally Posted by bigjae1976

I know I was trying to process what the hell was happening. Confusion mostly...is the truck really spinning off?

that guy will never hear the end of that. probably the only recovery truck to get black flagged.

[okusa]

[QUOTE=bigjae1976;30854717]I have never had a track recovery vehicle spin in front of me...until this past weekend

Would you mind sharing what you used to brace your windshield? I need to install something similar.

[bigjae1976]

[QUOTE=okusa;30855434]

Originally Posted by bigjae1976

I have never had a track recovery vehicle spin in front of me...until this past weekend

Would you mind sharing what you used to brace your windshield? I need to install something similar.

A piece of aluminum angle with some foam between the windshield and aluminum. I made a bracket screwed to the sheet metal at the bottom. It’s hose clamped at the top to the roll cage. Would be better to weld a tab to the windshield bar. The brace was born from driving the car and seeing the windshield flutter at 80mph in an alarming manner.

[omgzirra_exe]

Originally Posted by roastbeef

that guy will never hear the end of that. probably the only recovery truck to get black flagged.

send a recovery truck for the recovery truck

[okusa]

[QUOTE=bigjae1976;30855445]

Originally Posted by okusa

The brace was born from driving the car and seeing the windshield flutter at 80mph in an alarming manner.

Exactly the reason for my asking

[roastbeef]

what exactly is needed to remove the hvac clump under the dash? i'm talking about the center vent cluster, heater core housing, and blower motor. i know there is a panel on the firewall that needs to be replaced... but what is involved besides that?
how do you go about plugging or removing the heater core?

[VicS5]

Originally Posted by roastbeef

what exactly is needed to remove the hvac clump under the dash? i'm talking about the center vent cluster, heater core housing, and blower motor. i know there is a panel on the firewall that needs to be replaced... but what is involved besides that?
how do you go about plugging or removing the heater core?

I’m also starting this adventure and looking for guidance. I think I’ve gathered from this forum how to delete the AC compressor, but I’m vague on how to cap or loop the various hoses that feed the heater core and compressor.
Condor Speed Shop makes firewall panels for HVAC delete.

There is also another thread that outlines swapping the guts between an S85 PS pump and a S65 pump to enable reversing the rotation of the pump on cars built post 5/08. S85 PS pump swap

[amg6975]

Originally Posted by VicS5

There is also another thread that outlines swapping the guts between an S85 PS pump and a S65 pump to enable reversing the rotation of the pump on cars built post 5/08. S85 PS pump swap

Glad that may be useful. The frankenpump has many track days on it now and has been flawless.

[okusa]

Originally Posted by amg6975

Glad that may be useful. The frankenpump has many track days on it now and has been flawless.

No need for an S85 pump, just an early build S65 one. See here: https://www.m3post.com/forums/showth...1988142&page=3

[VicS5]

Those early build S65 pumps come at a premium. Twice the cost of the newer S65 version or the S85 model.

[amg6975]

Originally Posted by okusa

No need for an S85 pump, just an early build S65 one. See here: https://www.m3post.com/forums/showth...1988142&page=3

Yeah definitely but they are way, way more expensive. Really wasn't too hard to make the hybrid which is essentially exactly the same thing.

[Cmassey3]

What keeps y'all tracking this platform in 2024?

I've been bouncing around a few ideas for the next step for a more dedicated track car vs gutting my street M3.

I keep coming back to M cars since they're cheaper than Porsche, but the overall package is pretty well suited for track use, especially in terms of oil system durability in stock form when not running rcomps. Also the community and aftermarket is great.

[Ximian]

Originally Posted by Cmassey3

What keeps y'all tracking this platform in 2024?

I've been bouncing around a few ideas for the next step for a more dedicated track car vs gutting my street M3.

I keep coming back to M cars since they're cheaper than Porsche, but the overall package is pretty well suited for track use, especially in terms of oil system durability in stock form when not running rcomps. Also the community and aftermarket is great.

1. I'm still having fun driving it. My G80 is a ton of fun on track and I'm still far from the limits of it. As odd as it is to say it about the E92, "driving a slow car fast" is a lot of fun with a lot more margin for error.

2. I can fix pretty much any issue I'll have with it at the track without too much downtime. My large bins of spare parts (from driveshaft guibos to front wheel hubs and wheel speed sensors to random bolts) took years to assemble and getting to the same level with another car would probably be 10k+ in parts.

3. I've already put enough money into the car as an "endurance build" that I will be driving it until something significant fails. I'm not worrying about any fluid starvation issues, even with slick tires because the biggest design issues have been fixed.

4. The cost of going to a higher performing platform is too high. How much do I want to pay to go some seconds quicker? Close to or over 200k for a 2016 GT3 RS or newer isn't worth it if that's the only reason.

This is the first year I'm paying to have the car stored somewhere for the winter. Perhaps not seeing it for months instead of the usual dealing with it being in the way in the garage is helping me maintain a positive opinion on it.

[tdott]

Originally Posted by Cmassey3

I've been bouncing around a few ideas for the next step for a more dedicated track car vs gutting my street M3.

I was at the point with my M3, about a month ago I made the decision to NOT go crazy with it.

Instead I picked up an E92 328i 6MT and I am building it into a Spec E9X car. Hopefully towards the end of this year I am ready for Comp licensing and then W2W racing with NASA and/or FARA in the SE region.

The good thing about Spec E9X is that it's up and coming, as the series gains more traction more and more will be looking to get into it. Some are planning to swtich from SE30 and other spec cars as E36s/E46s are becoming more costly and harder to find. We'll see how it goes.

[tsk94]

Originally Posted by Cmassey3

What keeps y'all tracking this platform in 2024?

I've been bouncing around a few ideas for the next step for a more dedicated track car vs gutting my street M3.

I keep coming back to M cars since they're cheaper than Porsche, but the overall package is pretty well suited for track use, especially in terms of oil system durability in stock form when not running rcomps. Also the community and aftermarket is great.

Modern vehicles, while more capable (some much more capable), are also much more disconnected to drive.

Almost everything is bigger and heavier. With the exception of maybe GT4/3, but that's a completely different price bracket...
Nothing besides a few domestic offerings has a V8 - but nothing with a high-revving V8.

I feel the E9X M platform offers one of the better options available for someone wanting a track capable platform, with strong aftermarket support, that's reasonably priced, reasonably fast, and still has a driving experience where you feel connected to the car but in a modern-ish platform.

I went from my previous E92 M3 to an F82 M4 for a few seasons. And that platform is so much faster and more capable, but it's also way less connected to drive and less fun, in my opinion. The F8X gen feels bigger and heavier, and much less connection between the car and driver due to electronic steering vs. hydraulic, and a turbo motor, that while offers much more power and potential for power, has lag and misses the instant response of the NA V8, or the earlier NA straight 6's.
I've since converted my M4 back to stock, and have picked up another E92 M3 to build for track use. For me, it's a much more enjoyable platform to track if outright speed isn't a primary concern and the driving experience and connection matters more.