SE autocross and suspension thread.

[pictsidhe]

Accessed with the odometer reset button. I forget the exact dance to get into roller mode. Turn car on and long press the button until it pops up a menu. Then more long and short presses.

Roller mode disables most safety things. ABS, stability. The car will still limit wheelspin by cutting power, however.

 

[pictsidhe]

We've never had an event at night here in Honolulu. Great job, keeping the tires right at the limit. I always run my GS class SE in sport setting at events. Also beat lots of "faster " cars in higher classes. My only modifications are a set of Yokohama a052 tires. 1st season, I went with 205/50/16, and this season, I bought a set of 17" powerspoke wheels on ebay and mounted 215/40/17 a052's. I didn't notice much difference between the setups. They wear too quickly, so if we have a place to race next year, I'll be switching to 660's probably. Thanks for trying the arb. I was contemplating doing that, but will hold off until we get a permanent place to race. Our stadium is going to be demolished and rebuilt soon.

My ARB is forcing me to avoid overdriving. It gets somewhat entertaining if I go into a corner too hot now. I'm probably going to finish the year on this bar then decide if I am keeping it or finding something more subtle. It will help me learn to drive better, though.
My club lost their best venue last year. Danville airport. The previous year, someone had put their 600hp BMW through a shed after trying too hard to save it. Possibly related.

 

[SameGuy]

Possibly related

Hehe hehe hehe

 

[pictsidhe]

3 weeks ago, I attnded the North Carolina Autoctoss championships. I was midfield. I was merrily throwing the car around. Very safe course. Last weekend, a local event. It was cold. I struggled. First run was a hot mess, I spun the next two runs then tiptoed the last two. Decided the big bar was coming off. I do not want to daily through winter with a car this loose.
I pulled it off today and fitted an 918 bar with extra holes. The 918 is the softer sport suspension bar and two grades higher than the stock SE bar. I did a quick road test in the stiffest setting. It feels pretty neutral. Ride is drastically improved. The godawful squeaking is gone. Stock 918 setting should be pretty close to my modified stock bar, which I've done one winter with while keeping my underwear clean. The 918 was tough to drill. Extnding the flat area for the fresh hole took some effort. Bolt and washers barely touched it. My hydraulic terminal crimpers barely did anything. Two sockets, a bolt to keep them in place and my vice also didn't get very far. Two scokets, the bolt and my biggest hammer eventually got it done. My cats were decidedly unimpressed with that method, however.

Calculated stiffness
Stock SE: 164
Mod SE: 198 + 21%
918: 214 +30%
mod 918: 264 +61%
25mm: 550 +235%

I have a two day event next weekend to test it properly.

 

[Giosan]

3 weeks ago, I attnded the North Carolina Autoctoss championships. I was midfield. I was merrily throwing the car around. Very safe course. Last weekend, a local event. It was cold. I struggled. First run was a hot mess, I spun the next two runs then tiptoed the last two. Decided the big bar was coming off. I do not want to daily through winter with a car this loose.
I pulled it off today and fitted an 918 bar with extra holes. The 918 is the softer sport suspension bar and two grades higher than the stock SE bar. I did a quick road test in the stiffest setting. It feels pretty neutral. Ride is drastically improved. The godawful squeaking is gone. Stock 918 setting should be pretty close to my modified stock bar, which I've done one winter with while keeping my underwear clean. The 918 was tough to drill. Extnding the flat area for the fresh hole took some effort. Bolt and washers barely touched it. My hydraulic terminal crimpers barely did anything. Two sockets, a bolt to keep them in place and my vice also didn't get very far. Two scokets, the bolt and my biggest hammer eventually got it done. My cats were decidedly unimpressed with that method, however.

Calculated stiffness
Stock SE: 164
Mod SE: 198 + 21%
918: 214 +30%
mod 918: 264 +61%
25mm: 550 +235%

I have a two day event next weekend to test it properly.

Thanks for getting back to me. Let me know how your next event goes.

 

[SameGuy]

while keeping my underwear clean

My favourite Clarkson interjection is "a little poo came out!"

 

[pictsidhe]

1st day with the rear bar downgrade. It's an upgrade, I'm faster. :-D
I've gone 3psi higher on rear tyre pressure than when I had the stock-ish bar on. I suspect that the big bar may have retuned the nut behind the steering wheel. Depending on how I enter a corner, I can get under or some oversteer. One tightening corner I would drift down to its apex with a tiny bit of throttle to limit deceleration, then power out. Lovely. Those were hard and ugly with the bigbar. I do feel like I've lost a bit of exit drive, but I'm apexing faster and in far more control. Hopefully I'll have a slippery event to test this bar's poo rating. I used to do well at those, before the bigbar. The downgrade bar's stiff setting so far seems like a decent compromise. I may want one a little stiffer, but certainly not the 25mm one that I took off.

 

[pictsidhe]

A chilly event on Sunday. Maybe high 50s when I ran. There was a breeze too.
Car was setup same as event, with my rear bar at about +60% over stock SE. It was pretty loose but I failed to spin despite seriously ham fisting it in places. My times were reasonable. I PAXed a few people I didn't think I'd catch this year. Next weekend, last event of the season. Also a chilly forecast. I'll put my bar down to full soft for that one. Which is still a about 30% over stock. I definitely seems like the more grip there is, the more rear bar it likes. I think it's a reasonably competive car right now, the nut behind the wheel needs the most tuning.

 

[Giosan]

A chilly event on Sunday. Maybe high 50s when I ran. There was a breeze too.
Car was setup same as event, with my rear bar at about +60% over stock SE. It was pretty loose but I failed to spin despite seriously ham fisting it in places. My times were reasonable. I PAXed a few people I didn't think I'd catch this year. Next weekend, last event of the season. Also a chilly forecast. I'll put my bar down to full soft for that one. Which is still a about 30% over stock. I definitely seems like the more grip there is, the more rear bar it likes. I think it's a reasonably competive car right now, the nut behind the wheel needs the most tuning.

Thanks for the update. I'll be lowering my SE with the H&R springs when I get back from Australia. I've seen some hardcore custom cars here.

 

[Sktam]

New to the forum. Picking up my SE tomorrow. Has anyone here tried adding “packers” to the bump stop to adjust for the roll and give it some stiffness from the rear?

 

[Brawndo]

Direct answer: I don't anyone has tried that.

It's not legal in Street class to make the bump stop engage sooner than stock. You can exchange for a firmer one though.

The car actually rotates ok out of the box, then starts to get pretty fun with a rear bar.

 

[Sktam]

Direct answer: I don't anyone has tried that.

It's not legal in Street class to make the bump stop engage sooner than stock. You can exchange for a firmer one though.

The car actually rotates ok out of the box, then starts to get pretty fun with a rear bar.

Thank you. I did not know that. Currently want upgrade tires before I add a rear bar.


Sent from my iPhone using Inside EVs

 

[SE_PDX]

3 weeks ago, I attnded the North Carolina Autoctoss championships. I was midfield. I was merrily throwing the car around. Very safe course. Last weekend, a local event. It was cold. I struggled. First run was a hot mess, I spun the next two runs then tiptoed the last two. Decided the big bar was coming off. I do not want to daily through winter with a car this loose.
I pulled it off today and fitted an 918 bar with extra holes. The 918 is the softer sport suspension bar and two grades higher than the stock SE bar. I did a quick road test in the stiffest setting. It feels pretty neutral. Ride is drastically improved. The godawful squeaking is gone. Stock 918 setting should be pretty close to my modified stock bar, which I've done one winter with while keeping my underwear clean. The 918 was tough to drill. Extnding the flat area for the fresh hole took some effort. Bolt and washers barely touched it. My hydraulic terminal crimpers barely did anything. Two sockets, a bolt to keep them in place and my vice also didn't get very far. Two scokets, the bolt and my biggest hammer eventually got it done. My cats were decidedly unimpressed with that method, however.

Calculated stiffness
Stock SE: 164
Mod SE: 198 + 21%
918: 214 +30%
mod 918: 264 +61%
25mm: 550 +235%

I have a two day event next weekend to test it properly.

Yes MINI ought to be more forthcoming on spring and ASB specs and interchangeabilty with SE.

Can you really compete in GS class with non-stock/altered bars??

For a less-ambitious person, are there places to add shims in the ASB mounts to balance the corner weights?

 

[Brawndo]

You can do one sway bar in Street (it hasn't been called Stock for many years.). Can also change the them diameter 1" (but not the width) and the offset by up to 7mm. You can also legally do the BMW camber correction front knuckles if you're hardcore, but that's significant cost and labor for not much camber. I doubt there's any legal off the shelf dampers due to the height change.

The access to the rear sway bar mounts is restricted enough that it would be a huge pain to shim. I doubt there's any tangible benefit to doing that on the SE. Any F56 RSB will fit back there but the install is more difficult than on an ICE car because of the battery.

Again, the car is pretty fun with just a good set of tires. You're right in the torque sweet spot of the car on most courses. There's not enough wheel for the weight, and the power cut in sweepers likely keeps it from National level competitiveness but the dimensions and wheelbase make it a natural born killer on small local style lots.

 

[SE_PDX]

Again, the car is pretty fun with just a good set of tires. You're right in the torque sweet spot of the car on most courses. There's not enough wheel for the weight, and the power cut in sweepers likely keeps it from National level competitiveness but the dimensions and wheelbase make it a natural born killer on small local style lots.

Yes, I was not far behind a very consistent 2006 JCW in my first event (he gave me lots of good advice about the course beforehand), and I was on all-season tires. I believe the front tires eventually overheated, and the last run got lots of understeer. Next time I should be on Summer tires, and I will try to measure the corner weights to determine if there is any value messing with that.

 

[nowkent]

I don't know how to get the SE into "roller" or "test-bench" mode, but here's an article about this mode, which disables safety modes to enable testing on a roller-type dynamometer.

Look up a video about how to get an I3 into "roller mode" or "dynamometer." The process is the same. Just be careful if you drive it in that. It turns off a lot of the safety stuff.

 

[Giosan]

Look up a video about how to get an I3 into "roller mode" or "dynamometer." The process is the same. Just be careful if you drive it in that. It turns off a lot of the safety stuff.

I tried it last year during SCCA races. It gave me more power out of tight turns and the tires were spinning lots, but it also cut the abs completely and I was having a really hard time slowing down in a hurry without locking up, making lots of expensive smoke.
On another note, I had my 1st event in EVX last Sunday, after lowering on H&R springs and Bilstein B8 shocks in the back. I also mounted 225/45/17 Falken rt615's on Motegi Tracklights 17x8.5 42 et. I had some rubbing in the back and had to cut the plastic wheel well arch and also use some spacers under the spring insulators. Also cambered the rear wheels to the max. I wish I'd gone with less of a drop. Anyway, I came in 1st in EVX class, beating 2 Tesla model 3 performance and a model S plaid! That after being told I wasn't going to be competitive against them when I showed up. Next, I'll be installing adjustable camber plates up front for some negative camber to keep my tires from peeling like last year.

 

[SJA]

I tried it last year during SCCA races. It gave me more power out of tight turns and the tires were spinning lots, but it also cut the abs completely and I was having a really hard time slowing down in a hurry without locking up, making lots of expensive smoke.
On another note, I had my 1st event in EVX last Sunday, after lowering on H&R springs and Bilstein B8 shocks in the back. I also mounted 225/45/17 Falken rt615's on Motegi Tracklights 17x8.5 42 et. I had some rubbing in the back and had to cut the plastic wheel well arch and also use some spacers under the spring insulators. Also cambered the rear wheels to the max. I wish I'd gone with less of a drop. Anyway, I came in 1st in EVX class, beating 2 Tesla model 3 performance and a model S plaid! That after being told I wasn't going to be competitive against them when I showed up. Next, I'll be installing adjustable camber plates up front for some negative camber to keep my tires from peeling like last year.

Congrats that is awesome, way to show the Tesla's up.

 

[SE_PDX]

I got the new bar on.
...The battery prevents dropping the subframe to access the front ARB clamp bolt, but it can be pulled backwards instead if the track arms are disconnected...

Thanks again for the insights! How bad was it pulling the subframe back rather than dropping with gravity assist? Do you think it would have been much easier on a lift? Also, how floppy was the battery box, like should I be ready with a scissor jack or something to support it while abusing the subframe?

I ordered the 22mm NMeng. bar and Whiteline adjustable links. I did not spring for the grease fitting mounts.

 

[Green Gatsby]

F56 stock and aftermarket sway bar rates.
Standard on the SE is the 917 bar. This is also used on the cabrio with standard suspension. Cabrios run softer bars than hardtops.
891 is usually used on base models. 918 on some S's and JCW cabrio. 919 on newer S's and JCW hardtops.
Stock bars have quick codes of H4-H7.
Now I have one off, I can measure it a bit better. So numbers are little different to post 1. Somewhat lower.
Stock bar lever arm radius is 6 ⅛" my extra holes are at 5 ½"
My WMW hollow 25mm (actually 1"+powder coat) has holes at 5 ¾" and 6 ½" I've used these number for the stock and aftermarkets bars. Whiteline makes a solid 24mm, HR does a solid 25mm. There is a 23mm bar advertised, but it's actually 22.2 according to buyers. Most bars appear to be made from inch size tubing. So I've calculated from the nearest inch size. This is not surprising due to inch sizes still being industry standard. Yes, you get any size you want, but a standard size will be cheaper. I measured my 917. I see that bushes are available for 20.8, 21.4, 21.8 F56 bars, so used that for OD
There's also a 'Hardrace' 22mm hollow bar available. This may just be baby bears' porridge for our SEs. It isn't sticked in the USA, though. So $$$$$hipping...
These numbers are not super accurate. However, they were all calculated the same way, so should provide a decent comparison between bars.

Personally, I think a 25mm hollow is a bit much for an SE, especially with my skill level. I have done several nice full throttle drifts with it, though!
New stock bars a little under $200. I may grab a cheap 918 from eBay and add extra holes and see how that works. My stiffened stock bar was absolutely fine for road use. 919s are scarce on eBay. Maybe JCW owners aren't often tempted to upgrade?

Stock
917 H4. 164lb/in. 198lb/in
891 H5. 187lb/in. 226lb/in
918 H6. 214lb/in. 259lb/in
919 H7. 240lb/in. 291lb/in

Aftermarket
22 solid. 353lb/in. 440lb/in
24 solid. 464lb/in. 578lb/in
25 hollow. 550lb/in. 686lb/in
25 solid. 602lb/in. 749lb/in

Just ordered a 919 bar based on this comment, are there any measurements I can take for you that would be helpful before I put it in the car?