|
|
04-30-2024, 01:28 PM | #23827 | |
Private First Class
97
Rep 130
Posts |
Quote:
As with all fasteners, wheel studs and bolts are held in tension, and slightly stretch when installed. After they have been cycled between full torque and then released several times, they eventually lose their elasticity and no longer properly hold tension. While this can’t be seen, it can be measured by precision instruments. Heat also works to embrittle and oxidize metal and brakes generate an incredible amount of heat under hard use. If you are a regular track day participant, it is our recommendation (echoed by many seasoned racers) that you replace your studs annually. A few of us have been discussing the Schroth harnesses, so regardless of which comment convinced you to pull the trigger, I'm glad it did. Make sure you run a HANS with the harness, as you can cause more harm than good if you aren't using the system correctly. A factory 3-point allows your body to kind of "wrap around" the shoulder portion of the belt, which spreads load across your body. With a 4-point or higher, the inertia is sent to your neck (as your torso will have much less movement), which leads to basilar skull fracture. Last edited by jmeenach; 04-30-2024 at 02:29 PM.. |
|
Appreciate
1
CamasM3e933224.00 |
04-30-2024, 03:01 PM | #23828 |
Private
75
Rep 71
Posts |
The QuickFit Pros have an extension sewn into the driver’s right side shoulder strap which is designed to shear and extend the strap partially in an impact, effectively replicating the flexing forward movement of a 3 point restraint. This converts the forward shear of the head on an immobilized torso into axial distraction of the head on the neck as the torso flexes forward. That forward flexion of the torso is also what prevents the submarining that is a risk with any 4 point harness.
So you should be ok without one if using a QuickFit Pro, but I would agree with the statements above that you’re better off with one. If using any other 4-5-6 pt harness that is not a QuickFit Pro, definitely need a HANS to keep your head firmly attached to your neck in the event of an impact. |
04-30-2024, 04:08 PM | #23829 | |
Major General
1580
Rep 8,077
Posts
Drives: 11 E90 M3 Individual
Join Date: Mar 2006
Location: Houston, TX
|
Quote:
__________________
2018 F30 320iX Melbourne Red
2011 E90 M3 Monte Carlo Blue 2004 E46 M3 Imola Red 2000 E36/7 Z3 Steel Blue |
|
Appreciate
0
|
05-01-2024, 06:56 AM | #23830 |
Second Lieutenant
126
Rep 291
Posts |
jritt@essex
Saw this post on a different board, wondering if this is chassis dependent or broadly applicable "Your best bet is to focus on choosing a brake fluid that has a dry boiling point high enough to handle what you're planning to throw at it on the racetrack. With modern brake systems, wet boiling point is no longer as relevant as it once was. Today's systems just don't absorb as much water, as rapidly, as they once did. Also, fluids with a high wet boiling point don't always necessarily offer the best pedal feel due to their chemical composition. I can't tell you how many times we've switched a professional racing driver away from SRF and over to AP Racing and had them instantly tell us how much better their brake pedal feel was. We (Essex) recommend AP Racing and Ferodo Racing brake fluids. We currently supply brake fluid directly to NASCAR Cup, IMSA, and IndyCar teams, club racers, HPDE drivers, etc. AP Raciing R3 was the gold standard for quite a long time, and now many teams in the elite racing series use AP Racing R4. The AP Racing range in particular has something for every need and budget. For many HPDE drivers, the AP Racing Rad-CAL R2 is the best bang-for-the-buck. It has a high enough dry boiling point to handle what many HPDE guys throw at it, without breaking the bank. We also keep thousands of bottles on the shelf and ready to ship from our Charlotte, NC warehouse at all times, so it's there when you need it most." Need to change out fluid and SRF isn't an option.
__________________
|
Appreciate
0
|
05-01-2024, 08:44 AM | #23831 | |
Major General
2450
Rep 5,912
Posts |
Quote:
Below is a picture showing a fastener being preloaded + an applied load that puts the fastener far past its yield strength and when unloaded it has a slope almost identical to the pre-yield stiffness/slope. However, each time it is re-preloaded, you start to get more displacement/strain until it reaches its ultimate strength and ruptures. The engineering stress-strain (or load-disp) curve shows the stress reducing with increased strain/disp because engineering stress always references the original unstressed cross-sectional area; however, if true stress-strain are used then you see the stress continually increasing until reaching the ultimate strength. This is because true stress is calculated using the instantaneous cross-sectional area which is decreasing with increasing load beyond the yield strength. The calculations that I’ve performed on the 5-bolt wheel-to-hub bolt pattern shows approximately 10% of the applied lateral bending load is carried by the bolt/stud as an increased axial load (total axial load = applied load*% of applied load carried by studs/bolts + preload + thermally-induced load). It also, conservatively, shows the preload of grade 12.9 (and even 10.9) has sufficient preload from all five bolts/studs is sufficient to prevent the wheel from rotating on the hub (i.e., a lateral load + local bending due to shear are not carried by the studs/bolts). If the joint had gapped than the stud/bolt has to carry almost 100% of the applied axial load + shear load + bending moment due to shear and wheel applied torque.. Last edited by M3SQRD; 05-01-2024 at 03:17 PM.. |
|
Appreciate
2
CamasM3e933224.00 RalliartRsX12.00 |
05-01-2024, 08:53 AM | #23832 |
.
1958
Rep 1,920
Posts
Drives: E92 M3
Join Date: Oct 2016
Location: MN
|
jritt@essex post is broadly applicable for track use.
I like Motul RBF660 for the price but plenty of people use RBF600 as well. Usually one of the cheapest brake fluids with a high dry boiling point.
__________________
|
Appreciate
1
e92BMW///M3126.00 |
05-01-2024, 09:26 AM | #23833 | |
Major General
2450
Rep 5,912
Posts |
Quote:
|
|
Appreciate
0
|
05-01-2024, 03:36 PM | #23834 |
Private First Class
90
Rep 140
Posts |
Do any of you guys run an oil catch can? I noticed my plenum inlet had a bit of oil in it. As I track my car I’d like to ensure this isn’t an issue.
|
Appreciate
0
|
05-03-2024, 08:30 PM | #23836 |
Private
12
Rep 69
Posts |
It's been a few years since I've been on track but I recently purchased an e90 m3 and I'd like to get back out. The car is an 08, has had rod bearings/TAs done (as well as a bunch of other stuff - oil filter gasket, oil separators, iacv and lines, valve covers, vanos covers, more). It has 108k miles.
Something to be cautious of or full send? I'm tentatively signed up for a day on May 24. |
Appreciate
2
omgzirra_exe1542.00 1FastSicilian503.50 |
05-04-2024, 12:35 AM | #23837 | |
Friends don't let friends ESS
3224
Rep 888
Posts
Drives: '11 Lemans Blue 6mt Harrop e90
Join Date: Dec 2020
Location: Camas, WA
iTrader: (0)
Garage List 2011 E90 M3 [9.00]
2003 Porsche 911 Turbo [9.75] 2019 BMW X5 xDrive40i [0.00] 2013 Mercedes E550 ... [0.00] |
Quote:
But other items specific to the e9x m3? Full send, Happily tracking mine at 135k. The only thing that has come up in 8 sessions was the cowbell noise. Mine resolved after replacing the giubo. |
|
Appreciate
0
|
05-04-2024, 09:37 AM | #23838 | |
Colonel
1573
Rep 2,871
Posts |
Quote:
|
|
Appreciate
1
GSEN82061.50 |
05-04-2024, 11:08 AM | #23839 | |
-Frank
504
Rep 695
Posts |
Quote:
On a serious note, just make sure you have the proper brake fluid and pads.. Street bads and oem fluid can be a recipe for disaster on track.
__________________
2005 M3 - SilverGrey/MT - SOLD
2013 E92 M3 ZCP AW/IR-BLK 2022 Ram 1500 Laramie Night Edition - leveled/34s IG: @_frank_stone_ |
|
Appreciate
0
|
05-04-2024, 12:17 PM | #23840 | |
Major General
2450
Rep 5,912
Posts |
Quote:
Definitely agree with starting with fresh fluids/oils everywhere for a car with > 100k miles. Track pads + high-temp brake fluid is needed for track use. |
|
Appreciate
0
|
05-04-2024, 02:22 PM | #23841 | |
Private
12
Rep 69
Posts |
Quote:
Glad to hear people have been having success at higher mileage. I know that’s sort of known acceptable on s54 cars, I wasn’t sure about these. |
|
Appreciate
1
1FastSicilian503.50 |
05-04-2024, 06:43 PM | #23842 |
Private
75
Rep 71
Posts |
For those of you thinking about adding lightness…
AC compressor, condenser, and lines (19.66#) parcel shelf (12#) SAP (4.68#) EVAP cannister and hoses (6.7#) Windshield Washer tank (2.16# + fluid) Headlight & level sensor delete (15.18#) Heater core, AC core & dash HVAC (16.66lbs) this excludes the servos and wiring previously removed |
Appreciate
3
|
05-04-2024, 10:49 PM | #23843 | |
Lieutenant General
11592
Rep 12,736
Posts |
Quote:
__________________
Instagram; @roastbeefmike
|
|
Appreciate
0
|
05-04-2024, 11:10 PM | #23845 |
Lieutenant General
11592
Rep 12,736
Posts |
aah, i see. thanks.
__________________
Instagram; @roastbeefmike
|
Appreciate
0
|
05-05-2024, 12:20 AM | #23846 |
Private
51
Rep 88
Posts
Drives: 2009 M3 DCT coupe white/beige
Join Date: Nov 2010
Location: Los Angeles
|
Rod bearings, weight balance, align
Haven't posted in a while.
I took Roast Beef Mike's advice and took my car over to Malek at MRF Engineering (949) 472-4496 Very impressed with Malek and he does great work. He is one of the few who really knows the E92 and finally a correct 4 wheel alignment with the SPL control arms with weight balance. My rod bearings weren't as bad as I thought they would be, at 56K miles. A few SPL arms had to be changed, a previous mechanic had overtightened some bolts resulting in cracks. I have not tracked the car in years, now on Pilot Sport 4S tires, 275/30/19 front and 295/30/19 rear. The car drives straight now which is nice. He also bled the brakes, had a tiny bit of air in the rear lines.
__________________
Regards,
72dan |
05-06-2024, 07:26 AM | #23847 |
First Lieutenant
421
Rep 303
Posts |
Picked up a tow rig project this weekend. A '94 Chevy 3500 with a 454 swap, cammed, .30 over, and with a Holley carburetor. The poor carb tune prevented us from getting past 7 miles with it, so it had to get towed to a shop. Going to be a minute before it's tow ready, but it's got good bones. |
Appreciate
1
DRLane3996.00 |
05-06-2024, 10:33 AM | #23848 | |
Colonel
1553
Rep 2,081
Posts |
Quote:
__________________
Current '21 DG X5MC, '22 X5M50i, '11 E90 M3
Recent Past '12 E92 M3 ZCP, '08 E93 M3, '18 F80 ZCP, '04 E46 M3 I think I have an M3 problem. |
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|