Impressive answers to my questions, thanx. Really like the power curve. Couple suggestions ---

With 360WHP, you're in the "danger zone" for cylinder walls. Especially with 28PSI boost. Going for 36PSI is inviting disaster, even with 9.5:1 CR pistons.

With that kind of power, you might consider HR 9 plugs --- https://www.ngk.com/ngk-93253-r2556g-9-racing-plug shop around for better pricing. NGK has a good write-up on plug heat range and they suggest one range colder for each 75 - 100 HP increase --- see attached. I'm using HR 10.

What part of AZ do you call home?


https://cimg9.ibsrv.net/gimg/www.nor...7c9fddd4e8.jpg

I live in Queen Creek. I’m sure the cylinder walls will give out at some point. Not sure it’s worth it to me to disassemble the whole motor to send the block out and get the support system put in lol. Might just run it till it dies! Definitely will try the colder plugs.

You could always grab a spare block from a junk yard, I can get a complete mini engine from mine for $150. I’m planning to grab an extra engine or two and a few transmissions as backups for my build, possibly will sleeve a block.

That’s a valid point. Might look into that.

Following this thread with extreme interest, as I have been over the years, just a little less so recently as I’ve been playing with a new (very fast) toy (AR Giulia Quadrifoglio).

I haven’t stepped up to the Garrett or WMI yet, but I’ve done quite a few things. I especially like the suggestion of getting a spare engine and transmission from the junkyard, as I’m on my fourth and second respectively.
Thanks for the spark plug info as well, OBW.

Maybe it’s time to rejoin the R56 maxout club!

Time for an update. Car is running good. Had it at a Shift S3ctor event in Coalinga, CA earlier this year, a ½ mile standing start top speed event. Coalinga is real close to sea level, so I had a significant performance improvement over my usual 4400' driving. I actually broke loose at launch, first time since lightening the flywheel. Surprised me so much, I missed all my shifts during the first run and only turned a 136 MPH in the ½ mile. 2nd run there was a ½ hour delay just before my turn and I shut the engine down. When it came to my turn, I forgot to turn off the ASC --- too busy resetting the data-logging and video camera. With my torque-steer and hi RPM power, ASC kicked in every shift and I only turned a 126 MPH. After that episode, I saw the que for a third run was about an hour long, outside temp was getting in the 90's, no shade for the spouse to wait in, and I was totally frustrated, so we decided to call it a day and drove over to wine country. Chalk this speed event to experience! As for event results, I was probably the only 4 cylinder engine of about 150 cars, most of which turned at least 150 - 200 MPH --- Lambo's, Corvettes, big-block Fords and Chevys, etc, some exceeded 200 MPH.

Couple days ago I experienced a check-engine lite. Found a P2A35 - Front O2 Dynamics Min along with a bunch of misfire codes. Reset the codes and drove home. Got home and found another code, P2A93 - Front O2 Pump Signal, this one by itself, no misfires. About a year ago, the rear O2 sensor was replaced, damaged wire and too short to repair. Bought an NTK brand, about half the price of an OEM version. First thought was, these two brands aren't compatible. Second thought was "foreign" sourcing made it "age" differently than the OEM front sensor. Common sense and local current events finally won --- cleaned the engine air filter to remove all the CA fire smoke particles, and removed the front sensor for cleaning too. For the last couple months, our Air Quality Index has been anywhere from Moderate (51 - 100) to Hazardous (300 - 500) --- air has been thick with smoke particles. Used K & N cleaning fluids for the filter, and a cloth to wipe off the sensor. Took it for a test drive this AM and no codes. Blind luck? Temporary fix? Delaying disaster? TBD!

My "test drive" this AM was to a local airstrip that doesn't have a lot of traffic. Talked with the manager about using their facility for another hi speed run or two, sometime in the next couple months, using a recently acquired Dragy Performance box. Should only take a half hour or so max for a couple runs --- find a starting point, measure off and mark the ½ mile, ensure smooth level clean path etc, then do the runs. I expect engine performance to be my normal at 4400' but lots less air density, to compensate for the Mini's lousy aerodynamics. Hope to get up to 150 - 160 MPH --- TBD. They suggest waiting 'til Nov - Dec when air traffic is less and it should be safer for all involved. Winter air temps will be better too.

Whether or not my codes were caused by smoke particles plugging the air filter, this is something anyone experiencing heavy smoke from the recent west coast fires should consider --- clean / replace both air filters, engine and cabin. Our other car is getting new filters in a couple weeks.

Really want to see what you run 60-130 wise with the draggy. Couple cars in the mid 8s on the leaderboard, they don't say what HP they're putting down though. I've done a couple of custom 40-100 runs and the best time I've gotten is a 8.29 with a little bit of brake boosting with a 2300 DA.

I'm planning on setting the Dragy for the most popular ranges --- all except the ones from launch, i.e., 0 - 60' or 0 - 60 MPH. These are the ones where I'm "No Contest", don't even try. Still haven't really looked at this leaderboard, just took a quick glance so don't know who's doing what, or what to target. I'm not gonna be competitive in all ranges 'cause I'm still pretty much OEM weight --- all seats, glass roof, etc.

Update:

Finally got out to a local airstrip with my Dragy. Made two runs and can’t use either of them. Clutch started slipping halfway thru the first run, and was just barely holding on as I finished the second. Limped home and trashed all the results. Next day I did a couple checks to ensure it was a slipping clutch —- set parking brake then tried to drive —- didn’t move and engine didn’t stall. Pedal has normal play, and there was no grinding between gears. Fluid is OK.

OSG clutch and flywheel is about ten years old and has seen 300+ ft-lbs torque since mid 2014. It’s rated at 300 so I guess I’m lucky it’s lasted this long. Engine is running great, virtually no oil burning and about 38 - 39MPG on long trips. However, after eleven years of building this beast, the time has come to call it quits. Rather than throw another $2K and a couple days labor at it, for a new clutch, I’m putting it up for sale. Since I started modding (and learning), I’ve spent over $50K in parts and outside (not mine) labor. Here’s a link to the NAM listing —- https://www.northamericanmotoring.co.../market/358461

Here’s a list of my mods and their cost. Some items have been repeated due to a blown engine and other failures, but are not included in this list, only final results, i.e., pistons were replaced twice, two blocks have been bored, etc. Also mentioned are “left-over” parts, either good items replaced with upgrades, or new / improved upgrades that are being included in this sale. Now let's see if I did this post and ad correctly ---


https://cimg7.ibsrv.net/gimg/www.nor...6c01d2cf89.jpg

Oh wow!!

Damn, end of an era. Was really looking forward to seeing what it would put down numbers wise. Hopefully it goes into some good hands.

Was this the single or twin STR? I can’t believe how well my single STR OSG has held up to the abuse I’ve given it.

Single STR. In use for ten years and 61K miles. Note they're rated for 300 ft-lbs torque. I've exceeded that for at least the last eight years. Twin STR is rated for 500 ft-lbs but I don't remember seeing those available ten years ago. Mine was delivered without the flywheel locking hole --- one of the last produced without it. When I called to complain, they acknowledged the defect and said it was being added to current and future product. After using a scrap flywheel to set timing, I eventually had a shop add the timing hole and re-balance it. Been working fine since then --- 'til now.

Some reason I thought you had the twin. But I do want to let you know. They do have a overhaul kit and it replaces the clutch and plate for $800 or so. I did this when I switched from the OSG touring to the STR. Just reused the flywheel. It can be reused once for a overhaul. Obviously you would have to pay to have it done if not doing yourself.

Yes, I'm aware of the overhaul kits. I've contacted OSG and asked about adding the twin o'haul kit to the single flywheel. Waiting for a reply. If not, I'll probably go with the single kit. Still considering all the options.

No it’s different. I’ve already asked.

Very sad to hear you're putting in the towel. Would have liked to have seen some 60-130 times as well as 1 mile runs! Maybe take a break for a couple weeks and come back with a cleared mind! You might regret selling the car when its gone!

Thanks for this forum! I am looking to build my Clubman - not 520HP though :)

Time for another update ---

As I expected, there were no takers on a dead MCS, so I decided to bite the bullet and fix it. Could have parted it out, but then I'm stuck with a carcass that would eventually need to be hauled away --- no space around my tract home to store it either, and neighbors would have a fit. Previous major repairs were done by pulling both engine and tranny as a package. This time I pulled only the tranny. What a PITA! First time pulling the front subframe, and I couldn't find a tranny jack to rent. Had to borrow parts from a couple friends jacks, but eventually got it out. Found the cause of slippage and took a few pics ---

Notice the rough inner edges of the mating surface --- missing material. Same condition on the opposite side.
https://cimg9.ibsrv.net/gimg/www.nor...ec9302a629.jpg

This is about half the missing material. There was another "chunk" about the same size, and all kinds of "dust" spread throughout the housing. These 1" - 2" chunks crumbled when touched.
https://cimg8.ibsrv.net/gimg/www.nor...9e57b90737.jpg

Looks like the flywheel got overheated too.
https://cimg7.ibsrv.net/gimg/www.nor...ee8250dfb7.jpg

Here's the OSG STR2C flywheel. Notice the method used to accept the crankshaft locking tool.
https://cimg1.ibsrv.net/gimg/www.nor...e2077091b3.jpg

Now that it's back on the road, it's going back on the market. I'm just getting too old to be crawling around under a car. Here's a link to the edited NAM marketplace ad --- https://www.northamericanmotoring.co...61#post4617807

Nicely done brother. That's a good 10 hour job first time... add some extra in there if your a bit OCD. Hmm... while I'm in here. LOL
All things considered the single held up surprisingly well seeing as what it was tasked with. It deserves a burial with honors. I think you'll be happy with the twin. It's a bit more noisy than the single, especially when cold. Once warm she'll be quieter and easy to feather. Plus she won't slip for love nor money..

I suggest a proper memorializing is in order :

https://cimg6.ibsrv.net/gimg/www.nor...0d03f7aa6.jpeg

Thanx Lou, I spent a lot more than a few hours doing this. All my mods changed the symmetry of the parts locations, so a lot more disassembly was required. That plus figuring out how to drop the subframe --- first time event. Clutch operation is quite bit different --- lots more positive and quicker engagement. Gotta get used to quicker launching --- feathering is almost impossible. Maybe when I get used to it. First couple outings, I had a "tire chirp" or two 'cause it grabbed so quick --- never had that happen before. Plus, at our age, she's a lot more fragile and less tolerant of quick starts. Clutch noise isn't noticeable --- too many other noises. Only have a few miles on it so far, 91 octane is about $5.10 so we use the wife's car mostly.

Njaremka, afraid I'm too lazy to clean the dead one up, put it back together, then find a place to hang it. Besides, a 20+ lb wall hanging would be too risky in my garage. Gotta admit tho, yours looks pretty good on the wall.

It makes for a cool conversation piece, if nothing else. I only used the pressure plate, and used hot glue to stick the clock mechanism tot he back side.

Final update to all my threads!

Just returned home from the local "muscle car" dealer --- talked them into taking the Mini off my hands. Since it's catless, with no A/C in NV, and there's only a couple counties where emissions aren't checked, resale is going to be slow, even with their resources. I was able to get just over book auction price, which was $2450. At least I can claim a whole lot of fun, along with a fair amount of grief and pain. Learned more than I care to admit, plus made a few friends, both local and on-line.

Not completely finished with it tho, still have some left-over stuff to get rid of, so I'll be using the NAM Marketplace a bit more. Just gotta organize it all, then post it. I plan to continue browsing the build and gen 2 sections, and comment occasionally, but no more builds. I'm moving on to cars more appropriate to the extremely Old BW set, like another used Lexus.

Many thanx to those who provided useful help during my build, especially EurotechsAZ --- tuner, parts provider, advisor, and most knowledgeable on-line troubleshooter.