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Thread: Laminar's M3 5.0 swap: Fünf-Null

  1. #551
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    Race weekend update! I was able to get everything on the right rear suspension torqued to spec on Friday night. The one problem I had was that the upper control arm bolt was too short and didn't go all the way through the nut, but it couldn't possibly have been swapped with the camber bolt or the shock bolt, so I couldn't figure out what I was doing wrong. Then suddenly I realized that there was one more bolt I left out - the RTAB bolt. I bought a new longer bolt to replace it since I reinforced the bracket, so I went and found the bolt I thought went to the RTAB - turns out that was the upper control arm bolt. All better.



    With everything bolted back up, I dropped the car down and set the rear toe to exactly where it was before I started all of this so that the toe would (hopefully) be centered. Then I went and opened it up to 1/4" total toe in.



    After that it was back to the corner weights.



    I wasn't happy with where it landed last time, I kept dropping the front left wheel to get to weights balanced and I ended up with a height that was definitely going to rub. So I cranked that side up a full turn and made sure the lower control arm was level, and went about adjusting everything else to get it inline.

    Here's where I landed with 3/4 tank of fuel and 210lb of sand bags in the driver's seat (sorry it's in kg):



    It probably has about 12 gallons more fuel than I've previously weighed it with, as I haven't been driving it lately due to...obvious reasons. So that accounts for about 100 extra pounds in the total.

    Total: 3430lb
    Front-Rear: 52.0/48.0
    Left-right: 51.0/49.0
    Cross: 50.0/50.0

    Good enough for me! I adjusted the front sway bar endlink, attached it, and checked to make sure the weight didn't change, which it hadn't, so it was good to go. Saturday night I went to pick up the trailer I had reserved and checked in for, though I was about an hour late as I got stuck at a 6 year old's birthday party. Turns out they gave my trailer away, which is not awesome. They did find a dolly for me to rent, which was...not ideal, but fine.



    I swapped the rear tires out to the old street tires so I wasn't putting pointless miles on the race tires.

    This was my first event in the M3 on these tires, so I was pumped to see what they could do. There were fewer racers than normal at this event - several regular guys were out at an endurance event so I was a class of 1 for the day. We were back at the drag strip, and I was racing first heat so I didn't know what a fast time was. Right from the get-go I noticed huge grip - the course flowed well and had about as much variety as you could get from a dragstrip circle combo. It felt like a typical first run where I was figuring out the course and pretty far from the cones, time was a 36.8. In my first couple of braking zones I had NO brakes, a consequence of the BlueStuff pads. But from the second run on they maintained enough heat to feel great.

    The next run I pushed a little harder and landed a 36.4. As I coasted past the timing trailer they held up 1 finger - got a cone somewhere dang. Wait...no...they were saying I was currently in first. WHAT. I follow that up with a 36.00 and a 36.1. I ended the heat in first place by about two tenths. The next heat came up and a couple of drivers started creeping up on me. A great driver in an STH Focus ended with a 36.09 and an ND Miata landed a 35.90 on his last run, he had me by a tenth.

    I went out for the second heat knowing I hadn't yet explored the real grip limit of the tires, that I could be smoother, and that I was nowhere near hitting the cones. My first run out was a 36.02 and I was worried that my curse of never getting faster in the afternoon was still with me. I knew that I could launch harder at the beginning as I wasn't spinning the tires, and again I knew I could get even tighter on the cones as I still hadn't hit a single one. Next run...35.409! I followed that one up with a 35.5, 35.5, and a 35.423 - I'm consistent, and I still hadn't hit a single cone, which was actually kind of disappointing. I was in first by a half second ending my heat, but the other guys had 5 runs to catch me.

    The ND Miata squeaked out a 35.394 to get me by 0.015, and the Focus ST cracked off a 35.1, 35.2, and 35.1 to seal his victory. Third overall is not bad! My best showing ever. Looking back, that same Focus ST beat me at our first event by 2.8 seconds on a 60 second course, and now I was just a few tenths behind him. The tires and suspension setup made a huge difference and I think I'll be competitive in my class once the other guys come back.

    More about those tires - these are a 255/40R17 RT660 where I've typically been running a 245/40 Bridgestone. It was in the mid-90s outside and I ran the tires at 30-31psi hot, wear was showing right at the arrows on the sidewalls.

    I rolled all four fenders in anticipation of more rubbing. I think my front left still rubbed a bit as it's the lowest. The rear outers didn't rub, but I could tell in the tightest of turns that the rears were rubbing...turns out it was on the inside! The left tire rubbed on my muffler and the right rubbed on the inner fenderwell.





    I'll probably massage those two spots for a bit more clearance, as I don't want to space the wheels out any more and run back into outer rub.

    I think it's safe to say the RT660 has just as much grip as the RE71R. It also looks like the center rib tends to chunk in a similar manner. I didn't see it after racing on the RX-8, but something about yesterday's weight, power, or heat increase got them.



    They don't have as much feedback as I'm used to. There were a couple times where it took me a tick or two to realize the car was pushing. It could be that the breakaway is so progressive that it wasn't obvious. The times when I did push badly at the sharp turnaround at the end, I noticed they seemed to skip over the pavement more than slide, but that could also be due to a lot of front camber. Overall the car never got out of sorts, and the fact that I was pushing as hard as I ever have and never hit a cone tells me they are great about going where I point them.

    They do seem to weigh more than the Bridgestones - for the same 255/40R17 size the RT660 is listed at 2lb more. The difference to a 245/40 would be even greater, and even just hoisting the wheel/tire combos around I can tell they are quite a bit heavier. This could be partly due to the extra cheater width - the 255 is more like 260mm wide.

    Even in the heat and with several runs in quick succession due to our small heat size, they didn't grease up and get slippery - my afternoon runs were very consistent. The RE71 guys had the tire sprayers going all afternoon. The added thermal mass of the RT660 may be helping with its heat capacity.

    The other thing I'll be interested to see is how these hold up across heat cycles and runs - can I get two full seasons out of them or will they be done after one?

    The last thing I need to address is a "sproing" sound in the front suspension when I turn the wheel. It's like the spring is trying to rotate and binding up, then getting loose. I'll need to check everything out, as I want to make sure it's not something worse. The last two times I've heard a weird noise from the suspension, it's been a mount ripped out...
    Last edited by Laminar; 06-14-2021 at 10:16 AM.

  2. #552
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    Oh, and I did also want to mention heat. It was a hot, hot day. After each run the coolant temp was about 200 degrees. It would hang there for quite a bit as I idled in the grid. I started popping the hood and found that temps dropped down to 195-196 pretty quickly with the hood open. The guy behind me said that it was obvious my hood vent was working as he could see the heat emanating from it at all times. 200 degrees max isn't bad at all, and even in the hottest conditions I still had 25psi of oil pressure at idle. I'm running 15W50 Mobil 1 which seems to be holding everything together so far.

  3. #553
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    I do enjoy your posts! Excellent work!

  4. #554
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    Quote Originally Posted by Laminar View Post

    The next run I pushed a little harder and landed a 36.4. As I coasted past the timing trailer they held up 1 finger - got a cone somewhere dang. Wait...no...they were saying I was currently in first. WHAT. I follow that up with a 36.00 and a 36.1. I ended the heat in first place by about two tenths. The next heat came up and a couple of drivers started creeping up on me. A great driver in an STH Focus ended with a 36.09 and an ND Miata landed a 35.90 on his last run, he had me by a tenth.

    I went out for the second heat knowing I hadn't yet explored the real grip limit of the tires, that I could be smoother, and that I was nowhere near hitting the cones. My first run out was a 36.02 and I was worried that my curse of never getting faster in the afternoon was still with me. I knew that I could launch harder at the beginning as I wasn't spinning the tires, and again I knew I could get even tighter on the cones as I still hadn't hit a single one. Next run...35.409! I followed that one up with a 35.5, 35.5, and a 35.423 - I'm consistent, and I still hadn't hit a single cone, which was actually kind of disappointing. I was in first by a half second ending my heat, but the other guys had 5 runs to catch me.

    The ND Miata squeaked out a 35.394 to get me by 0.015, and the Focus ST cracked off a 35.1, 35.2, and 35.1 to seal his victory. Third overall is not bad! My best showing ever. Looking back, that same Focus ST beat me at our first event by 2.8 seconds on a 60 second course, and now I was just a few tenths behind him. The tires and suspension setup made a huge difference and I think I'll be competitive in my class once the other guys come back.

    More about those tires - these are a 255/40R17 RT660 where I've typically been running a 245/40 Bridgestone. It was in the mid-90s outside and I ran the tires at 30-31psi hot, wear was showing right at the arrows on the sidewalls.

    I rolled all four fenders in anticipation of more rubbing. I think my front left still rubbed a bit as it's the lowest. The rear outers didn't rub, but I could tell in the tightest of turns that the rears were rubbing...turns out it was on the inside! The left tire rubbed on my muffler and the right rubbed on the inner fenderwell.


    I'll probably massage those two spots for a bit more clearance, as I don't want to space the wheels out any more and run back into outer rub.

    I think it's safe to say the RT660 has just as much grip as the RE71R. It also looks like the center rib tends to chunk in a similar manner. I didn't see it after racing on the RX-8, but something about yesterday's weight, power, or heat increase got them.


    They don't have as much feedback as I'm used to. There were a couple times where it took me a tick or two to realize the car was pushing. It could be that the breakaway is so progressive that it wasn't obvious. The times when I did push badly at the sharp turnaround at the end, I noticed they seemed to skip over the pavement more than slide, but that could also be due to a lot of front camber. Overall the car never got out of sorts, and the fact that I was pushing as hard as I ever have and never hit a cone tells me they are great about going where I point them.

    They do seem to weigh more than the Bridgestones - for the same 255/40R17 size the RT660 is listed at 2lb more. The difference to a 245/40 would be even greater, and even just hoisting the wheel/tire combos around I can tell they are quite a bit heavier. This could be partly due to the extra cheater width - the 255 is more like 260mm wide.

    Even in the heat and with several runs in quick succession due to our small heat size, they didn't grease up and get slippery - my afternoon runs were very consistent. The RE71 guys had the tire sprayers going all afternoon. The added thermal mass of the RT660 may be helping with its heat capacity.

    The other thing I'll be interested to see is how these hold up across heat cycles and runs - can I get two full seasons out of them or will they be done after one?

    The last thing I need to address is a "sproing" sound in the front suspension when I turn the wheel. It's like the spring is trying to rotate and binding up, then getting loose. I'll need to check everything out, as I want to make sure it's not something worse. The last two times I've heard a weird noise from the suspension, it's been a mount ripped out...
    Glad you were able to sort it out. I just traded my 2018 S3 for a 2019 Miata RF Grand Touring, can't wait to autocross it this weekend. Going to get some Bridgestone Potenza RE71R's mounted on a spare set of wheels I picked up this weekend and just have fun.

  5. #555
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    Quote Originally Posted by AdamBath View Post
    Glad you were able to sort it out. I just traded my 2018 S3 for a 2019 Miata RF Grand Touring, can't wait to autocross it this weekend. Going to get some Bridgestone Potenza RE71R's mounted on a spare set of wheels I picked up this weekend and just have fun.
    Those ND Miatas are so fast it's just straight up cheating.

    Got a pic of me in the grid letting the thing cool down a bit between runs.


  6. #556
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    Quote Originally Posted by Laminar View Post
    Those ND Miatas are so fast it's just straight up cheating.

    Got a pic of me in the grid letting the thing cool down a bit between runs.

    I'll still likely use my E30 V8 for autocrossing in the XSA class, but the Miata should be a fun one till that build is ready. Getting closer every day thankfully.

  7. #557
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    Got the Mazda's brakes finished up and got it out of the garage so I could get the M3 back in. Two main issues I'm seeing - first is a springy "sproing" sound from the front left when turning the wheels. I couldn't see anything catching or loose or out of the ordinary. It may have just been the orientation of the spring in the coilover?

    And I think I'm down some power. I was out driving in the rain on my old old race tires and it actually DIDN'T break them loose in second, which is a bad sign. I'm still seeing some excessive lean-ness on the left bank. I enabled active fuel correction and it's showing good AFRs on the highway, but since it's just a bank average, it could be running three cylinders too rich and one super lean and it'd look okay. I checked the coils and wires and they all look good. I'll need to pull those plugs again and see if any look suspicious. I may also run some fuel system cleaner through this tank - the car sits a lot and could be getting some buildup. The fuel filter was new back in 2015, so maybe it's time to replace that. Failing all of those things, I may pull the intake manifold and either check for gasket leaks or just install new gaskets in case I have some unmetered air getting into a cylinder.

  8. #558
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    The plug on the #4 cylinder looked extra sooty, so I replaced it with a spare I had lying around. I pulled it again last night and it was looking dirty again.

    #4:


    #5-8:






    I retorqued the lower intake bolts. None of them were especially loose, but all took a little snugging.

    Did some more digging.



    Pulled the valve cover just to get a look. Nice and clean in there, rocker clearances still look good. Checked compression on the three accessible cylinders on this bank - 170, 180, 180. Swapped injectors between the problem cylinder and the one next to it. Snugged up the lower intake bolts again. All new plugs on this bank. The #6 plug wire looked like the coil connection was a bit shallow, it may have been making poor contact. So I'll redo that wire.

    Checked compression on the other side, 180-190. Went ahead and put new plugs in there too. Managed to pull apart a plug wire trying to disconnect it, so I made a new one. Rockers all looked good. Buttoned the valve covers back up, got my new plenum gasket on, got the UIM back in place.

    I'm going to hopefully get it all put back together this weekend and see if it's back to normal. The Mazda just bit it (shredded trans) so I need the M3 to just work for a while as the Mazda takes a longer stint in the garage.

  9. #559
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    Quote Originally Posted by Laminar View Post

    I'm going to hopefully get it all put back together this weekend and see if it's back to normal. The Mazda just bit it (shredded trans) so I need the M3 to just work for a while as the Mazda takes a longer stint in the garage.
    Well damn, that sucks. Hopefully you can get this figured out quick!

  10. #560
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    May have spotted the source of the lean bank. I pulled the upper intake off and snugged the lower intake down, those bolts like to loosen with heat cycles. Checked compression, 170-190 on all cylinders, which is hilarious for it being a 180,000+ mile thrashed junkyard engine. Put in new plugs, replaced a suspect plug wire. One plug looked sootier than the others, so I swapped that injector with another one. And then I swapped all four coils bank to bank to see if the lean condition would follow the coils.

    After putting everything back together and starting up, I turned the garage lights off to see if I could spot any arcing from the coils or wires. As it warmed up I actually spotted something.

    https://www.instagram.com/p/CQ53XF6DoVN/

    Looks like I found an exhaust leak.



    I'll get that sealed up and see what my AFRs look like going forward.

    Also threw some thrust bearings under the front springs. The driver's side upper mount had some wear on it like the spring was binding or rubbing or something. We'll see what these do. I may end up doing helper springs so that the springs don't pop out in droop.


  11. #561
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    Excellent detective work...

  12. #562
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    Had some time this weekend to work on the car. Wanted to avoid pulling the header, so I tried to tack on just enough weld to plug the hole. Obviously it immediately blew threw the extremely thin metal.

    So I pulled the header. This side isn't bad, I just have to pull the lower x-brace and the steering shaft and it wiggles out the bottom.

    Took the angle grinder to the tube to cut off my boogers and clean the area up.



    Then went about filling everything back in.



    Obviously I ran out of 0.023 wire right in the middle of this, so I had to revert to the 0.030 wire that's hell for thin walls. But I made do.

    Ground and painted to hide my shame.



    Ready to go back in.



    A lot of the wrap was degrading and falling apart, so I cut off anything that was loose. I'm also wondering if the wrap holding moisture against the tube had something to do with the corrosion. The headers were coated on the inside with Eastman's internal exhaust coating, so I don't think it rusted from the inside out. The outside was painted with a VHT high heat spray, but everywhere under the wrap had a lot of rust scale on it. And every time I get within 6" of the wrap, I end up with super itchy arms for a day or two. I think this experience has turned me off of wrapping exhaust in the future.

    I got the header bolted back in. It was a bit frustrating as the rearmost bolt kept wanting to crossthread, but eventually I got it all in place. Of course, once everything was bolted up tightly I remembered that it's a huge pain to get the steering shaft on with the header in place. Too late to do anything about that, I'll have to have that fight tonight.

    Then I need to clearance the areas in the rear where my tires were rubbing. After that the car will be back on the ground and hopefully good to go for the next event at the end of this month.

  13. #563
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    my steering shaft goes through my header and my #5 cylinder plug boot burned and started causing issues. so I wrapped my header, but mine looks like crud so I've been considering taking it off and using gold reflective heat tape and ceramic plug boots to try and combat the heat. I've heard or wrap holding moisture and rotting downpipes out so maybe I'll consider changing mine up sooner than I planned.

  14. #564
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    Quote Originally Posted by seriniboy View Post
    my steering shaft goes through my header and my #5 cylinder plug boot burned and started causing issues. so I wrapped my header, but mine looks like crud so I've been considering taking it off and using gold reflective heat tape and ceramic plug boots to try and combat the heat.
    My passenger side header was burning plug wires even through the wrap, so I got some of that heat-resistant sleeve stuff and ran the plug wire through it. No problems now.

  15. #565
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    Got the steering shaft reinstalled last night. Looks like I have an oil leak from the upper intake PCV fitting. Not sure if that was existing or if I caused that when I took the upper intake off, but I'm going to have to pull the intake again and seal it up better. Also my dipstick is flopping around and needs to be better secured, so I'll have to make a little bracket for that.

  16. #566
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    are you using the stock mustang dip stick? I ended up using a flexible lokar one. it's nice but isn't the most accurate.

  17. #567
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    I'm on the stock Explorer dipstick. Actually, when I pulled it out to check it, I found that the lowest part of the dipstick, below the little low-level hole, had snapped off, probably in the pan somewhere. So that's a little terrifying.

  18. #568
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    lol yeah, it is. idk if I'd drop the pan for it but it makes me cringe thinking it's swimming around in there. maybe try to drag it from outside of the pan with a magnet or run a pan magnet/ magnetic drain plug. the plug might catch it if it moves close by and come out with an oil change.

    this is all assuming it's not a non ferrous stainless steel...

  19. #569
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    I have two drain plugs and they're both magnetic. I've been meaning to change the oil anyway, it's probably worth a shot to see if it's been grabbed yet.

    Had a minute last night, so I took the opportunity to clearance the muffler and inner fenderwells where the tires rubbed.


  20. #570
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    Pulled the upper intake back off to take care of the PCV filter. It goes under the PCV valve, and as far as I know I never had one? It's just a bunch of wire mesh but it should help give the oil vapor some place to condense before it reaches the intake.



    Of course, when I was trying to take the intake off, I snapped the plastic vacuum tee between the plenum, FPR, and ECU. I couldn't find a similar one at the parts store, so I ended up at Menards getting brass fittings.



    And lastly I finally fixed the dipstick in place. I made a small tab, slotted the end to fit on the header stud, and welded it to the dipstick tube.



    I put the car back on the ground and fired it up. AFRs balanced nicely bank to bank. Got up to temp, held idle very nicely. Didn't have a chance to road test so I'll have to do that later. The real test will be if it still misfires at light load, hopefully not!

  21. #571
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    Tried to test drive the car last night. Got a few blocks away and saw the driver's side bank was pegged lean. With a little throttle it was clearly running on 7. Turned around and went back home. Even at idle the bank was sitting at 19.9, so I started disconnecting coils one by one. 5, 6, and 8 all caused the idle to get worse. No change when I pulled #7. That is the new plug wire that I made, so I pulled it off of the spark plug and hooked it to a tester - big strong spark from the coil. That's the plug that's right next to the dipstick that I just fixed, though I don't think I damaged the plug when I was working on it, I guess it's possible. I'll pull the plug out and make sure it's not cracked or anything, then check to see if it's wet or dry. That's also the cylinder that got the suspect fuel injector swapped to it. So it could be a bad fuel injector, or I could have mucked up something on the plug or installation. Looks like the UIM is coming off again.

  22. #572
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    Aack!

  23. #573
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    Okay, lots to share. Pulled the #7 plug and found it was dry but all sooty like the #5 was before I swapped its injector over. The #5 plug was nice and clean, so looks like we have a suspect injector, but it's failing in a really weird way - lean at idle/low pulsewidth, but apparently rich enough elsewhere to make the plug all sooty? Doesn't make any sense.



    So I pulled the injector off and put it on my test bench. Hooked it to the Megasquirt and ran test mode and found the weirdest thing - under 3ms pulsewidth, it would lock up and not fire. Above 3ms it cycled just fine. Never heard of this before, but it matches my symptoms. I had ordered a four pack of new injectors Wednesday night to be delivered Friday, so then it was just a waiting game. In the mean time I started working on the new Megasquirt for the RX-8's new engine, so I stole the USB cable out of the M3's glove box. Injectors showed up late Friday and I got the replacement put on that night. Of course, I didn't notice that when I pulled the USB cable out of the glove box, I left the glove box (and light) open. Also, I let the 3 year old play in the race car while I was working in the garage, and as usual she left the dome light on. So come time to start the car up, the battery was 100% dead. I got my jump pack out and got it started up and it idled perfectly, but it was too late for a test drive. Had to jump it again Saturday, so I let it idle and charge for a half hour or so and then confirmed that it no longer pegged lean...success! Brought it back, swapped to the race tires, and got the car loaded up once I picked up the trailer.

    Sunday was back at the Eddyville drag strip once again. There was a fairly low turnout - about 24 racers. Seems not many people are interested in taking a long trip to race there in 95+ degree heat. Because of the number of people, instead of running two groups, we ran three. Two groups would work while the third would race. The racing group did 8 runs all at once, then swap over to working. The course itself was very short - fast times were in the mid-20 second range. It was actually kind of nice having a short, simple course to be able to work on perfecting just a few elements.

    Because of the short course and small driver groups, we were just about doing hot laps - I had just enough time to check tire pressures before it was my turn to go again. I took my tire sprayer and was grateful to have it. By about the fifth or sixth run I noticed the rear getting a little looser and I even saw some blistering on the driver's front tire, as that's the outside tire for the direction we were running.



    Between runs I'd check tire pressures, spray down all four tires, and hit the radiator with some water as well. By the time I was starting my next run, the car was able to cool down to under 200 degrees which was good. The brakes were getting very hot - I actually smelled pad, which I haven't yet done with these new BlueStuff pads. I also felt a little fade in the later runs on the first big braking zone, so I had to adjust my braking point to compensate.

    The finish was especially exciting, as it involved "exiting" the banked loop and going over a slightly rough patch through the finish line. The first two runs I did, it was enough of a jump that my tablet fell out of its holder and swung around at my feet. After that I shoved it in the glove box and just checked engine temps between runs. It was also fast enough that I needed third gear. I tried staying in 2nd, but as the rear tires got light over the bumps, the power in second was enough to spin the light tire and add to the instability. I started shifting to third a bit early and just accelerating over the bumps and through the finish.



    The fastest guys in the first heat were running around 25.3 seconds. Until an ND Miata managed a 24.8 on his very last run. I started at a 26.3 and then a 26.0, both dirty. It was kind of a relief to hit some cones, since I didn't hit any at all on the last event and knew I could get tighter on them. I think the video shows me hugging them pretty well. I cleaned up my cone act and figured out where I need to brake earlier to get a better line through the Chicago box and got a clean 25.3 and a couple of 25.1s. That felt good, so I cranked it up a notch and got a 24.9 but coned that one out. My last two runs were a 25.2 and a 25.0. You can hear my reaction to the 25.0 in the video. I wanted a clean 24! No one in the third heat could match that time so I ended up 2nd in raw for the day. We cleaned up, I loaded the car on the trailer, and I was out by 12:30. A great day!



    One thing I noticed - I still have minor lean spikes under 1700rpm. They used to be on the driver's side bank, but now they're on the other bank. When I was in the engine back at the beginning of this month, I swapped all of the coils side to side. This makes me think I still have a bad coil since the issue swapped banks. I need to buy a known good one and just swap them out one by one until I don't get those spikes. Should be simple enough, just need to make time to do it.

    Overall extremely pleased with how the car is handling. The balance is great - I don't plan to make any changes to the sway bars or coilovers. Power is good, too, and I think this current setup could take advantage of more power. I was on the throttle hard, early, and often and it took everything I could give it. Tires are great, I'm interested to see how long these stay fast.
    Last edited by Laminar; 07-26-2021 at 09:14 AM.

  24. #574
    Join Date
    Apr 2012
    Location
    Stuttgart, Germany
    Posts
    577
    My Cars
    1997 M3 / 5.3
    Great report and enjoy living vicariously thru it! Thanks.

  25. #575
    Join Date
    Dec 2014
    Location
    Des Moines, IA
    Posts
    1,051
    My Cars
    '97 M3/4/5.0
    So I bought a new ignition coil and swapped it with #1. Test drove, still misfired. Put #1 coil in place of #2. Still did it. Put #2 in place of #3, still did it. Put #3 in place of #4 still did it. Shit. So maybe I have two bad coils? After that last test drive I left the car idling and shut off the garage lights to look for any rouge sparks. AH HA! The #3 boot was arcing to the header flange.



    Luckily I was able to get some silicone WD-40 in there and just slip the old boot off and a new one on without having to cut and recrimp. I filed down the sharp edge of the header flange that the boot is right next to. Started back up and no arcing, but I didn't have a chance to test drive. Hooooopefully this is the end of my weird misfire woes.

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