07-26-2024, 05:50 PM | #23 |
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I'm working off 14-year old memory here, but IIRC the oil pressure on a BMW 6-cylinder race car I ran would drop as low as 20 psi in T11 at Watkins Glen. This was with the throttle closed. I was first alerted to it because the car had a large, red, low oil pressure light just off the A-pillar. I asked the race shop I used about it and was advised that under that circumstance not to worry about it. After that, we raised the pressure trigger for that light to a pressure that I no longer recall.
The car produced a full set of data from a MoTeC ECU with all the necessary sensors. That enabled the shop owner, who had a masters in internal combustion engines, to note the oil pressure before and after it dropped to its low point and to conclude that the pressure wasn't an issue. Because a true loss of pressure could result in the need to replace a $15K engine, we installed a 3-quart Accusump. I'd do the same with my M240i if I was going to do anything serious with it at the track. They're (somewhat) cheap insurance. I'm guessing that generally the only time an autocross car might benefit from an Accusump would be if the oil cooler was punctured during a run, which seems almost impossible. A 6-cylinder, no expense-spared BMW SM autocross car that won two Solo II national championships I bought from the owner/builder didn't have an Accusump, so it's probably not something the weekend warrior need consider.
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2017 M240i: 25.9K, 28.9 mpg, MT, Sunroof Delete, 3,432#, EB, Leather, Driving Assistance Package, Heated Front Seats | Sold: E12 530i, E24 M635CSi, E39 520i, E30 325is, E36 M3 (2)
TC Kline Coilovers; H&R Front Bar; Wavetrac; Al Subframe Bushings; 18X9/9½ ARC-8s; 255/35-18 PS4S (4); Dinan Elite V2 & CAI; MPerf Orange BBK; Schroth Quick Fit Pro; Full PPF |
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07-29-2024, 11:33 PM | #24 |
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Thanks for the opinions AmuroRay and dradernh
Based on what I saw last event and considering I have the baffle installed. I'm not going to worry about it for now, but next time I do the pan gasket in 30-40k miles. I'll take a look at the bearings. This past weekend had good showing at the Philly Region SCCA 2-Day Event. It was a tight battle between myself, a Fiata and a more completely prepped G series M340i. Day 1 went to the M340i by 2 tenths or so. Tire pressures for the weekend were 32/34 and that seems to be what I've settled on for now. If I did a rear sway bar to help with roll and move the handling bias a bit more toward oversteer then I might be able to lower the rear pressures a little more to optimize for rear grip. Day 2 went better for me. I found that by Overlapping Braking and Throttle inputs I could for example drag the brakes slightly to improve transition performance of the car while slaloming. The stock shocks even in the stiffer setting struggle a bit with multiple transitions because of the softish stock springs. My 4th run was pretty quick and 5th came out a bit cleaner, which was enough to clench the victory in the class, but still some things to work on with getting behind on slaloms. I think with a hero run, the car is in striking distance of BS Class Supras now which were running about 0.5-1 second ahead. Sadly no data for my fastest run because I forgot to start it or the app bugged out. I think actually there is a viable niche for this car in SCCA Pro Solo S3 class which is a mix of BS Class cars and RWD STU cars.
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08-20-2024, 04:26 PM | #25 |
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Alright got a possible double header with the local BMWCCA and SCCA Chapters this weekend. Still debating if I do both because my gf might strangle me 😂.
2 weeks ago had my 2nd FTD. Now with a bit more seat time with the setup the benefit of the wider tires is starting to show. Cleared my nearest rival on this course by about 0.4s. I dread when that guy ponies up for an LSD for his 135. Still playing with pressures a bit, to recap when I first started this setup I was using 31/32 hot then 32/34 hot and now I’m finding time with 33/35 on the 255s. Before with 225 square I was running 35/36. The car really likes smooth overlapped inputs to get the most out of the grip. Last edited by rhop101; 08-20-2024 at 04:34 PM.. |
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08-27-2024, 10:04 PM | #26 |
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Hi All,
Ended up 7/62 raw time at the SCCA event on Sunday with a time of 35.855. Top 3 were in the 34.9 to 35.2 range. First half of the course was a difficult and more technical route with a very slow 180 turn and some tight corners. The back half of the course was much less technical and more flowing. Even though all my runs were within 0.5s of each other and my best runs were all within 0.3s, I never quite put all the elements together but on various runs I was quite fast in certain elements. Analyzing the sector times. The car on that day was capable of a clean 35.3 maybe 35.2 about 0.4 faster than my best dirty run. - if I had done the turn-around correctly. - if I also flew through the 8-cone slalom going just a tenth or so slower than my fastest run to miss any cones. There was one set of cones mid-slalom that were pinched by 9ft or so which made it tricky. The back half of the course and the start to the 180 were fairly consistent on my last few runs. Annoyingly my first run out was my best run at the 180 . Best clean run Fastest dirty run
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08-28-2024, 11:24 AM | #27 |
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09-16-2024, 09:41 PM | #28 |
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Bit late posting this, as the event was the prior weekend, but the updates must come. This might actually be the last event for the car this year. It was an interesting course. Fairly technical and a few tricky elements albeit less than last time.
Sector 1 was a series of slalom like transitions. Sector 2 was a large sweep along the back section with a lead-in cone that wanted to trick you into braking early. Sector 3 was a series of very fast offsets that led into a pinched offset which if you were late on entering it really cascaded time loss through the whole sector. This was followed by a pair of slow 180s separated by a very fast nearly straight section with an offset gate in the middle. Followed by a 2nd fast long sweep entering an off-camber right sweep into the finish. By the end of the morning runs I had the beginning and end of course strategy pretty well hammered out. I don't think I ever quite got the back sweeper really buttoned down, but I was decent through there. Where I was really losing time was the back section before the first 180. I was about 6 tenths off the pace. Through some discussions with the other competitors I figured out I was coming off the back section too fast. My 2nd to last run of the day ended up being my fastest and wasn't quite enough to get FTD. I missed it by about two tenths. I suspect - I didn't quite push hard enough in the back sweeper as you can see the g indicator drop inside the 1g ring - I should have held out in 3rd a little longer and just rode the arc out a bit more. - I could have just held onto 2nd in the back half of the course as going for 3rd didn't really gain me anything there. I really need to start the habit of checking my sector peak speeds in track-addict at least for a couple runs. The gearing on the 8-spd cars is a bit tricky because most of the courses on my home lot run toward the top of 2nd which is good and bad. Yes I can switch between 2nd and 3rd much more easily but if I was in a manual car. I wouldn't be in a position to need to shift gears at all. Toward the back of the course: - I was slightly late getting on the gas out of the 2nd 180 turn-around as you can see I left about 8 inches or so on the table on the left side cone exiting that corner into a fast large radius section, it just would make it just that hair-bit easier to get a bit more speed out of the section. - Finally I overextended on my rear grip in the last turn, trying to squeeze on the gas at the exit. Towards the end of the day another challenge would reveal itself. As you can see in the video it got a bit bright toward the end of the day as a local office building decided to try and melt the B group cars and our eyes. XD All in all. A great 2024 season! My driving has continued to develop and the car is now in contention for local event FTDs with potential for decent showing at larger regional events. The car still shows a bias toward understeer in general even with the 255 square setup. Overall I'm pretty happy with the stock suspension setup as its a good tradeoff between highway, backroad and AX. I might do a rear sway bar upgrade over the winter to balance the front/rear grip out a bit better and add a little more roll stiffness to the car, but I'm pretty happy with how the car is and that money might be better spent on an exhaust and keeping some money in my back pocket down the road for any track supporting mods. It's truly is incredible what a couple parts and a tune can do to the 235/240i cars. They really are do-it all cars. Although the 235 is done for the season my buddy wants a co-drive in his prepped Fiata so thankfully I get to drive a bit more before the fall weather sets in and things get chilly. The worn RE71RSs on the car might not like heat, but they don't seem to like the fall chill either XD.
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mchapter.na@gmail.com // Current Fleet 2015 M235i 8-spd ZF 2008 Honda S2000 Last edited by rhop101; 09-16-2024 at 10:11 PM.. |
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