BMW Compact Build

Did I ever get you measurements of the spacers I added to my 40s to get things in a reasonable range? IIRC it was three washers.

Dave

My home computer is fubar'd so a buddy of mine edited up some video of our race a couple weekends ago. Not my finest driving as I realized Saturday afternoon that my brakes were no longer capable of locking up the tires, so dialed it back a bit on braking zones for Sunday's runs. Still managed to stay out in front of the other 2wd rally guys by ~6 seconds.





On the brakes - turned out that the front master cylinder was starting to leak past the seals and onto the floor and my 'firm pedal' was actually the pedal bottoming out on the mount. Got a new master installed and bled last night so I've got no excuses this weekend. Hoping for a little moisture on the road so its not super dusty. Current 2wd record is held by a Neon SRT set a few years ago.

Dave

Quote
DaveK
Current 2wd record is held by a Neon SRT set a few years ago.

Dave

Nice video.

And good to have goals, even better when achieved... So go stomp that current record....

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I be sorry as a muthafucka I did, still sorry I did n' hustled ta peep what tha fuck I holla'd a lil' bit better, or at least try to.

Edit:

Quote
DaveK
Hoping for a little moisture on the road so its not super dusty. Current 2wd record is held by a Neon SRT BMW Compact set a few years ago yesterday.

The day wasn't without issue...more piccies when I get a chance to dig into the damage (not crash related).

Dave

Quote
DaveK
Edit:

Quote
DaveK
Hoping for a little moisture on the road so its not super dusty. Current 2wd record is held by a Neon SRT BMW Compact set a few years ago yesterday.

The day wasn't without issue...more piccies when I get a chance to dig into the damage (not crash related).

Dave

nice edit^ new record even with issues? what was the old record, and what did u set?

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I be sorry as a muthafucka I did, still sorry I did n' hustled ta peep what tha fuck I holla'd a lil' bit better, or at least try to.

Quote
mke723

Quote
DaveK
Edit:

Quote
DaveK
Hoping for a little moisture on the road so its not super dusty. Current 2wd record is held by a Neon SRT BMW Compact set a few years ago yesterday.

The day wasn't without issue...more piccies when I get a chance to dig into the damage (not crash related).

Dave

nice edit^ new record even with issues? what was the old record, and what did u set?

The finish was as rough as we'd ever seen it (exposed bedrock) and I think the death knell was keeping my foot firmly to the floor whilst crossing it. On practice days I'd backed out of it a little bit there but still think I weakened it some.

Working on a full writeup of the event with pics and everything, but we knocked a couple seconds off the old record (believe it was a low 3:38 and we ran a high 3:35), so nothing earth shattering. The AWD guys were 5 seconds behind the records they had set back in 2011, but the 2wd record was a bit older, dating back to 2007 or 2009, can't quite remember.

Best part about the race is that we're seeing so many people bringing rally cars out.

The 2wd class was 7 cars and 6 different makes/models were represented:

Toyota Celica (FWD type)
Subaru Impreza (FWD)
Honda CRX x2
Acura Integra (turbo)
VW Jetta (VR6 swap)
BMW Compact (S50 swap)

The AWD class was also 7 cars represented by:

Subaru Impreza GC x4
Subaru Impreza GD x3


Dave



Edited 1 time(s). Last edit at 05/13/2013 09:31PM by DaveK.

Need to thank my wife (and navvie) Allison for knocking out the post event recap. The formatting isn't carrying over to the forum post terribly well, so if you'd like to see the prettied up version, please feel free to check it out on our website: http://racekern.com/temple-canyon-2013/

We got some good seat time in with the Colorado Hillclimb Association at Pueblo Motorsports Park a few weeks ago, but this weekend was the first real hillclimb of the season. Temple Canyon, located just outside of Canon City, is a fun and challenging all dirt road. Since we’ve taken a number of years to get the BMW ready for dirt racing, we missed out on this race it was great to be back!


The BMW hanging out in the natural habitat of Canon City

Practice went pretty well as we got to know the road again. There were a few cautions for mud pits since we’ve been getting some rain. Those dried out quickly, but sadly that meant so did the tacky road surface as well. The last run of practice day got cancelled because of more rain and hail. Oh well, means beers and hanging out a little earlier plus, our time from our last run had qualified us 1st in Rally 2WD.


A little taste of the twisty & narrow road

Upon arriving for Race Day the next morning, folks started noticing they had been tagged with Caswell stickers. Not sure who the culprit is, but no Bill sightings at the race. After noticing ours on the trunk, I was just going to pull it off, but Dave and I made some “enhancements” to the sticker instead.



We put on some fresh tires on (for those of you that know Dave well … aren’t you proud of him?!) and were ready for Run 1. It was already hot and dry. First run went very well – surprisingly. We felt like we got a few corners better than practice, but a few others not as well. We expected a similar if not worse time from qualifying. Instead we went from a 3:42 to a 3:35. That was enough to break the standing 2WD drive record for Temple Canyon. That’s 2 for 2 on breaking records this season!


The Race Day timing board

We had been hearing some pretty awful clanging sounds throughout practice. Our exhaust had some issues at Pueblo and we had taken it off. Hangars were reinforced before Temple Canyon and we chalked up the noises to ‘self clearancing’ due to the slightly less hangar sag. It started to sound really bad after our first Race Day run though and Dave got the car up on jack stands to have a look. Turns out our Supra differential was starting to crack its custom mounts! No bueno. Everything was still intact, meaning it was repairable with reinforcement. We didn’t take the risk of a second run given we felt lucky to have noticed it when it was in a relatively easy fixable state. If we took another run and it busted through, like it wanted to, the repair would become much nastier and more expensive. Furthermore, if it did bust mid run, that sort of loss of control of the car could result in a season-ending type crash. Temple Canyon is unforgiving, and there are only so many piles of kittens (picture at the end if you don’t know what I’m talking about). Feeling good about the first run, we saved our car and hoped we could hang on to first place. After our class took their second run without us, we were pleased to see that 3:35 hang on to win the race.


Devon (AfroThunder) Dobson captures a nice action shot!

Overall it was another great weekend racing, thanks for reading!

Dave

Did you ever come to any conclusions on your brakes Dave? Watching Rogers in-car his was doing the exact same as my car was on Conner entry on that second left turn. I ended up with the bias at full front, and lengthening the front master cylinder rod another full turn. It seemed to help a bit at least.

Whats the brake problem?

The issue with the brakes was simply bias being off. I've never really played with it, but after installing the new master cyl for the front brakes, the car was totally different. Braking from a 5th gear straight into a 3rd gear bend the first time resulted in massive tail wag. I let it swing right, left, and when it when right again I put the loud pedal to the floor and dropped the front left into a ditch. Worked ok and didn't lose much time, but the tail wag wasn't confidence inspiring.

For the next run I twisted the balance bar a few turns towards the front and it was much better on the last run. I'd like to go to CORE and do some experimentation with it to really get it dialed in, but for that run it certainly fell into the 'good enough' category.

Dave

I think it took me about twenty laps at CORE to dial in my balance bar where I liked it. It was a little tail happy though when I got to Rally Colorado where there was a little more slippery stuff out there and not as much traction. And naturally brake fluid on the adjuster (overfilled, doh) combined with CORE dust led to stuck adjuster and not able to adjust on the fly with the dial, which led to a few really fun high speed wag wags.

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Grant Hughes

Ok folks - need some advice on differentials. Got the diff re-mounted in time for the hillclimb this past weekend.

Realized at the race that my LSD is no longer limiting anything other than forward progress. I rebuilt the diff a few months back with a kit from Weir (http://www.weirperformance.com/maxgriplsdkits.html) that bumped pressure from 550 lbs to about 1500 lbs by removing the factory spring and replacing it with a belleview washer. This is supposed to result in about 250 lbs breakaway torque.

With the rear end in the air, if you spin a tire, both move the same direction. With the rear on the ground and racing up the hill, it was a one wheel tire fire on the inside corner all weekend.

My thought is that with the washer instead of the spring, is it possible that the diff will need more frequent servicing as the diff plates wear? When I installed the kit, the diff plates all looked ok according to a mechanic friend of mine so I just cleaned them up and put them back in.

Any thoughts? Worth looking at getting new diff plates? Pros/cons on replacing with a spool? Figure welding is out since I started with an LSD...welding can only be done on a full open one, correct? I see both spools and mini-spools available, most in steel, some in aluminum. Would I be looking at axle breakage problems with a full locker?

Dave



Edited 2 time(s). Last edit at 06/03/2013 02:50PM by DaveK.

Quick:
If you wanna weld i have open housings.
Second, you can preload a bellevill washer same as any spring.

Third breakage no more an issue than with a super tight diff setting, however, if you break something at least you can get home with welded..Weirdly but get home.

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

We followed instructions on lash(?) when putting the whole thing back together. The kit did come with several different thickness spacers, so I'm assuming that's what you're referencing with the preload comment?

The car has been exclusively driven on low traction surfaces (ice tracks and dirt hillclimbs), so I expect that the diff has been working hard. Just seemed odd to me that it felt like it was working at the last race and all of a sudden it wasn't at this race. I had figured there'd be a slow gradual decline in its performance.

What is considered a super tight diff setting? Was I already at that range with a 250# breakaway?

Dave

Quote
DaveK
We followed instructions on lash(?) when putting the whole thing back together. The kit did come with several different thickness spacers, so I'm assuming that's what you're referencing with the preload comment?

The car has been exclusively driven on low traction surfaces (ice tracks and dirt hillclimbs), so I expect that the diff has been working hard. Just seemed odd to me that it felt like it was working at the last race and all of a sudden it wasn't at this race. I had figured there'd be a slow gradual decline in its performance.

What is considered a super tight diff setting? Was I already at that range with a 250# breakaway?

Dave

250 is getting up there, but there's no ramps like a Salisbury type or the ZF (or Kazz or Gripper) so on those the preload is the beginning and it goes up as it differentiates...

Low traction and tight means it doesn't slip like say on low--45-60 ft/lbs and lots of grip..So on asphalt it differentiates more, and that mean slip and eventually wear. So gravel is LESS stressful to the plates.. I have had plate look marvvy for 10 years on my massively powerful Saab.

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.