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Big Willow recap! High highs and low lows. Set a time that I'm very proud of, got to test out the new aero mods which seem to have worked great, got comfortable with taking turn 8 at 135+ MPH and even handled oversteering through it a couple times, and nuked my 4th gear at the end of the day. Oh, right, yeah. I blew the trans I put in this thing just a month ago.
The morning of the event shaped up to be great. I got to the track at 11ish Friday night, got some great sleep, and woke up with time to spare as our class had no driver meeting and wasn't on until 9. I coincidentally parked next to a real nice guy, Scott, with a K24A2 NA8. Also across from me in the paddock was a younger dude named Carter, who was driving a K24A2 NB1. Both of these guys ripped, and instant companionship was made as we all geeked out over each others' cars haha.
My first session was at 9. It was 32* overnight and still pretty cool when I got out on track. Maybe high 40's. Near-perfect PB weather. I told myself I wouldn't go all out on the first session. It's been almost a year since I hit WSIR and it's both an intimidating and high consequence track. I got out and put in a few laps at 70%. To my pleasant surprise, I got into the flow of things much quicker than expected. By lap 4, I was almost fully confident I could rip the course at a proper pace. I ran laps 4-10 pretty much at full bore, only showing any hesitation coming into turn 8, which I was taking at ~133mph, already 5mph up from last year. On my final lap, I set what I thought was a pretty good heater, although I was aware that my tires were properly greasy at this point. I was running my lap timer even though I didn't think I'd be blazing fast first session. Might as well check it out, see if I was running close to my 1:31.5 PB from last season. I checked my timer. DAMN! 1:29.08 on the last lap! I was ecstatic. I was already going to be happy if I could take home a sub-1:30 for the day. Did a quick check over on the car and ate some grub before getting ready to go out for the second session.
Second session was a little less exciting. I gridded a little late and found myself stuck in traffic for most of the session. Still had fun with it though. I played around with the K Miatas and a couple S2k's which was fun. Running through the Omega was a good time but my car definitely had all the other little cars dead to rights in the straights and though turn 8. I was up to running turn 8 at 136mph now, no lifting. Holy hell what a feeling. WSIR got repaved late last year and the road surface is better, but still full of bumps. You can see it even with my camera's stabilization, those bumps are throwing you around in the cockpit. The aero did its job, though, and I was able to stay full inside through the corner without lifting or getting bounced to the outside. Last year, I was running this track with my buddy David in his K Miata with no aero and watched his car bounce what seemed like six inches to the outside of the corner on every bump we hit.
The aero balance with the 5.5" splitter and bigger wing endplates seems to be pretty good. Rear might be able to use a little more downforce. I had two instances in turn 8 where I began oversteering and a few in turn 9, which is still a 95-100mph corner. This might've been due to me pushing it too hard and/or the way I was taking the corners, though. Surprisingly, at no point was I scared when the rear end began to step out at high speed. Stoked that I'm feeling more confident with the car (or dumb, probably dumb).
Came back from session two and did a quick check over of the car. Everything was still running perfect aside from the chunks that were present on the inner edge of both my rear tires. F*ck, I must've literally boiled these things during the last session. Checked my inner fender wells and there were only a couple very small contact marks, and they didn't line up with where the chunks were taken out. Who knew that a tire known for lack of heat capacity wouldn't be happy if you pushed it hard on a high speed track with some decent oversteer for 10 laps straight. Oh well, it's not like they're totally torched at least. Drove on 'em for the rest of the day without issue.
Session three went about the same. Drove around in a little bit of traffic, made sure to take a couple cooldown laps. I got a few heaters in but it was getting warmer now and the dialed conditions of session 1 were gone. Ran a handful of 1:29's but couldn't get into the 1:28's. Then session four came and people had started to head home. I got to grid early, and was rewarded with an open track. Figured my RT660s weren't holding max grip for more than a couple laps here so I came out of turn 9 and decided this was gonna be my heater lap for the day.
1:28.96! I'll take that all day. I tracked out way narrow coming out of 8 and consequentially took 9 pretty narrow as well. Could've improved my time a little bit there but I'm not gonna complain. The car was ripping.
Wish I could've said the same about session five but I only got two laps in. Carter and I were hanging out in the pits and I suggested he let me follow him for a few laps so I could give him whatever advice my amateur-*** might have. Most of the day, I'd only been downshifting from 5-4 in turn 3, then lugging the car to the top of the hill at ~4,500rpm in 4th gear. At the end of session four, I realized I could drop it into 3rd, just barely kissing redline at the top of the hill before turning in for turn 4. Sweet, that's an improvement. I figured I could use that bit of knowledge this session and maybe get through the section faster. We came in for our first lap and rounded 1, 2 and 3. I got to the top of the hill and shifted into 4th. The shifter hit a bunch of resistance, stopped short, and kicked back into neutral, followed by a bunch of clunking and banging noises. Rad. This is it. I put the car in 6th and cruised it back to the pits and straight onto my trailer. I'd managed to kill a 6 speed running 240wtq. Luckily, it was mostly unaffected aside from 4th gear. I was able to get it on the trailer no problem, although the trans is making all sorts of cool rattly sounds when the clutch isn't disengaged, and the shifter wants to get stuck if you attempt to put it in 4th. Additional bummer because I had stopped missing shifts with my silly modified eBay shifter.
I ordered the Kmiata BMW 6 speed ZF transmission swap kit and dropped the car off at my work this morning. I think I'll be the first person I've seen to run a ZF6 on a car with a measly 2560r, but now the car will be futureproofed for when I throw an EFR in it. And the transmission will be yawning at the current power I'm throwing at it. I won't be able to race the NASA TT at Willow Springs in two weeks (bummer, I think this time would've made for a good result in TT3) but the car should be ready for GridLife Willow Springs at the end of April, with plenty of time to spare.
Hopefully tomorrow I find out that the kit's in stock and will have more updates soon!
You want to go GS6-37BZ? I have one in a Z4 3.0i E85, these boxes are very strong and shift like a dream (with the right oil), especially the 4th to 5th is WAY better than the mazda 6 speed.
As I mentioned, these are picky about oil. Use Redline MTL and Redline D4ATF 50/50, thank me later.
People launch these @500wtq+ on the dragstip, should be the last transmission you ever buy
...but the car should be ready for GridLife Willow Springs at the end of April, with plenty of time to spare.
Sucks about the trans, hopefully the ZF will treat you better. I'll be down there for GLTC in April, our shop is prepping two N54 BMWs that'll hopefully not blow up. Watching your video, I know we have at least one driver that's going to be a little slow through those faster turns, 136mph through a turn is no joke in our little cars.
You want to go GS6-37BZ? I have one in a Z4 3.0i E85, these boxes are very strong and shift like a dream (with the right oil), especially the 4th to 5th is WAY better than the mazda 6 speed.
As I mentioned, these are picky about oil. Use Redline MTL and Redline D4ATF 50/50, thank me later.
People launch these @500wtq+ on the dragstip, should be the last transmission you ever buy
I’m not familiar with that designation, actually. Is that the same trans that’s out of the 04-06 330i/ci? I know the getrag 5 speeds can be sourced from a Z4 but haven’t heard anything about the 6 speeds.
I thought all the getrag manual transmissions just use ATF (which is nice because I have a ton of that sitting around at work lol). I trust you regarding the fluids though. The redline stuff worked better than anything else in my Miata trans.
Im looking forward to seeing how the new trans feels! A buddy of mine has a ZF5 in his E46 330i and said I’m gonna love how it feels on track!
Originally Posted by curly
Sucks about the trans, hopefully the ZF will treat you better. I'll be down there for GLTC in April, our shop is prepping two N54 BMWs that'll hopefully not blow up. Watching your video, I know we have at least one driver that's going to be a little slow through those faster turns, 136mph through a turn is no joke in our little cars.
Yo, nice dude! I’ll make a point to cruise over and match a face to the name. Have you or any of your guys run WSIR before? It’s not a super tough track to get down from a technical standpoint, but initially getting used to the speeds in some of the corners can be very uncomfortable haha. Thank god for aero, I think our little cars would be hovering through those high speed corners otherwise.
Nice driving man! Ya that's gotta take some cojones to full send into that turn at ~130mph. That really sucks the tranny ate it already. Were you running any tranny cooling or logging temps? It'll be interesting to hear your experiences with a ZF or whatever tranny swap you end up with. I've never been impressed with the feel of BMW manual trannies but maybe with some mods they'll feel a little better. With that said, at some point feel goes out the window if it can't be reliable and hold the power. On a high speed track like that I'm sure it puts a lot of heat in the tranny..
Dang, that sucks. I guess it's a bit of a "luck of the draw" with our transmission options. Someone I autocross with runs a 2560 around 17 PSI on a 5 speed and it's held up for years, even running on Hoosiers. I'm surprised the 6 speed gave up on you so quickly.
On the upside, I'll now follow along on the ZF swap and will inevitably follow in your footsteps.
Holy cow man, that 130+MPH corner looks insane. It's terrifying just going 130 in an a NA, let alone ripping a full traction corner at race pace. Love it.
I can't believe you didn't even get a full track day outta that 6 speed. Just nuts.
Thanks dudes! Yeah turn 8 is wild at 130+ but such a cool feeling at the same time. If you can keep the throttle wide open, you're pretty much guaranteed to make up time on all the faster cars in that corner.
I was keeping track of trans temps and had a cooler setup on it, although it was only dropping temps ~20*F even with a fan. Temps that day were higher due to the nature of the track, but not outrageous. I was running ~185*F at SOW and Chuckwalla with the cooler on, and was around 200*F at WSIR. I believe Emilio said the danger zone for these trannies is around 270*, and they start getting locked out of gear at that point. That being said, they said that the trans is fine and will shift after it cools down. I think lugging the car up the hill at full boost at 4,500rpm between turns 3 and 4 all day largely contribuited to my problem. I should've known better. Seems like dropping it into 3rd would've been faster anyways.
It seems like the Kmiata kit has a couple little mods that should contribute to a better shift feel on the ZF6. However, I'm with you Teg, at some point I'd take a crappy feeling transmission as long as I could find every gear easily and have peace of mind that it won't blow up haha.
Maybe I oughtta throw my old 5 speed in for the weekend and see how far I can push it until it pops. Nobody seems to want to buy it anyway, even for $200
Maybe I oughtta throw my old 5 speed in for the weekend and see how far I can push it until it pops. Nobody seems to want to buy it anyway, even for $200
I wanna see this, for science.
I say that not being the one who has to do the labor. But seeing how quickly you bust out big jobs I'm sure you'd knock it out in an afternoon.
Kpower just got back to me and said my order will ship in 2ish weeks. This is tough. I could probably slam the 5 speed back in this weekend and run it for a bit. However, two weeks and change isn't that long for the car to be down. If it were longer, I'd consider tossing the other trans in much more so.
Found the spherical info, I'll quote it here for posterity. I have verified none of this, other than the fact that the part exists.
Originally Posted by Chris Watson on Facebook
I've been running OEM MB 2203520027 sphericals for a couple of years now. I don't expect they'll wear out, considering the OE applications they're used in, which include the highly-loaded LCA-I on MB sport sedans. They improve the response of the car considerably, but pass more information to the driver that makes the experience different than driving on a car with bushings. I'd recommend them on a track car for an experienced driver. A light press and bearing retainer is all they need. I machined the joints to size and honed the arms. Stainless for spacers as-needed. There is a Ford OEM option as well:
Originally Posted by Chris Watson on Facebook
No pictures unfortunately. Just bearing retainer (loctite green something or another) from a safety standpoint, they're fully contained. Looks like a nominal (0.1mm - light hone) diameter interference was used. I calculated the press + retainer and it was a non issue IIRC. I regularly see ~1.8G Ay at 2800lb and they haven't moved yet. I don't really use the brakes (<1.2G), so don't know if that would do it. Looking back, I don't even think I had to machine the OD on most of them (40.1 into a 40+hone). The control arm bores aren't even slightly round, but it doesn't matter, they get round enough after the bearings are pressed in.
That's some serious digging! Thanks for the follow up man. I'm kinda tied up this week but will try to check with our parts department and see if we have them available/in stock.
Haha man you are always putting in the work. Did you decide what tranny you're going to go with? Not sure what the difference is between the getrag and ZF trannies but haven't done much research.
Also quick question for you, what pads are you running? Gloc?
But seriously man, mad props, I bet this one lasts longer than your last 6 speed, though that's not really saying much. Eagerly awaiting the impending destruction.
I also wanted to say, I'm very interested to see you progress on the ZF swap. My first thought was that your timeframe was ambitions, but you get **** done in record time so I think you can do it.. if you don't end up having to order and wait on a bunch of parts.
Hahaha thanks guys. Don't you ever underestimate my ability for impatience
Kmiata told me it'll be roughly two weeks until the kit ships, and the ZF6 trans I ordered should be here in a week or so. The current plan is to get the 5 speed in just so the car's running, and keep it on wastegate pressure until I have all the parts in my possession. At that point, I'll do a few pulls at 17psi and see if it survives lol. Last call if anyone wants to buy this thing for $200!
I ended up going with the Kmiata ZF 6 speed kit, as well as their PPF-less diff brace and a ZF6 ACT 6 puck sprung clutch good for 530wtq. God help us all if this car ever makes close to that amount of torque. The ZF6 gear ratios are close to that of a Miata 6 speed, but more importantly, it's the only Kmiata kit compatible with a Miata diff. As much as I'd like to, I can't pony up for a Getrag diff swap at the same time. Maybe down the road after the sixteen thousand other things I want to do to this car.
Originally Posted by SlowTeg
Also quick question for you, what pads are you running? Gloc?
I'm currently running Gloc R10's front and rear. I decided to go R10 in the front this time instead of R12 and regret it. The R12's were super loud on the street (although I usually would find the time to swap in my street pads between track days) and I felt like they were roaching my rotors pretty quick. With my current power level, the G10's fade after a few laps at full bore. They only lose stopping power to a certain degree. It's not awful, but it's noticeable. I'll go R12 up front again once these are toasted.
Originally Posted by Fireindc
I also wanted to say, I'm very interested to see you progress on the ZF swap. My first thought was that your timeframe was ambitions, but you get **** done in record time so I think you can do it.. if you don't end up having to order and wait on a bunch of parts.
I'm not gonna call it too quickly, but I think I should be able to knock out the swap in a couple Saturdays, assuming nothing goes horribly wrong. I'm gonna try to lay some of the groundwork during the week beforehand, notching the bellhousing for the starter, mounting the transmission driveshaft flange adapter, etc. Hopefully it all lines up. I'd like to make it up to Chuckwalla on 4/12, but drop dead I really want it to be ready by 4/26 for Gridlife. I think that's reasonable... at this point in time at least haha.
I'm currently running Gloc R10's front and rear. I decided to go R10 in the front this time instead of R12 and regret it. The R12's were super loud on the street (although I usually would find the time to swap in my street pads between track days) and I felt like they were roaching my rotors pretty quick. With my current power level, the G10's fade after a few laps at full bore. They only lose stopping power to a certain degree. It's not awful, but it's noticeable. I'll go R12 up front again once these are toasted.
Thanks Zak. I got the car back together and don't think the street pads are gonna cut it for the first track day next weekend so gotta order some pads. What street pads do you run? I read the Glocs are finicky with having a proper transfer layer? Some people said Glocs are similar to Carbotechs which I've heard people complain about not bedding properly when mixing diff pad compounds. I've run Hawk and PFC on my Honda and they didn't really care about what street pads I used. Hawks were good but I've gotten away from them as the dtc60 brake dust was a bit corrosive/harsh. Not sure if the transfer layer "issue" is overblown and you can just toss some 12/10's or 16/12's on, give it a few hard stops, and they're good to go..
I've been following the build thread, the car's looking good man! I've probably said it multiple times but you basically have a completely different Miata now haha.
I'm currently running the Gloc "GS-1" street pads on both ends for street use. They're super tame and have lasted LOOOOONG even with lots of canyon runs on them. I think i've worn them a couple mm since buying the brakes over a year ago. They faded bigtime on me when I ran 'em at the track last February at 210whp. Might be ok on a naturally aspirated car but I can't say for certain. For an N/A car, I'd probably run R8's all around, or R12/R10 if you want to futureproof it and think the car will be boosted before you kill a full set of brake pads. One thing worth mentioning with the R12s up front is that they bite HARD until they're brought up to operating temp. Like easily lock up the brakes in the first corner after your out lap type of bite. Ask me how I know I'm sure you could get em up to temp fine in an N/A car but it might take a bit.
Also worth noting is that I only have experience with the G-loc pads on the BBK. When I was N/A, I ran stock 1.8 brakes with EBC yellowstuff pads (seem to be regarded as garbage by many) for street and track and had no issue. Said pads almost literally melted on me during my first track day with the turbo lol.
As for the bed in process, only the R12's seemed to really be picky about it. My R10s, I just took for a regular track session and pulled off track after 4ish laps once I could smell them breaking in. Didn't feel any difference in stopping power or noise. The R12's however, had an insane amount of bite until I followed the break in procedure on them. Like a borderline undriveable amount of bite on the street. I ended up bedding those in by doing 4-5 hard accelerations to 80-90mph and aggressive stops down to 20mph on the highway by where I live. After that they mellowed out but still bit pretty hard before reaching operating temp.
On all of the G-loc's I've run, the rotors were either new or had already been run with a G-loc compound so I can't say how sensitive they are to having a fresh transfer layer or not. G-loc wasn't lying, however, when they said their dust isn't corrosive. I just cleaned my wheels with a proper degreaser for the first time in 6+ months and the anodizing below still looks basically new. Really good if you're lazy about deep cleaning your car like I am haha.
I'd consider picking up the 5 speed if it wouldn't cost a ton in shipping and my roommate didn't already have 2 spare transmissions in the garage. Space is at a premium these days.
I'm also going to bet that the 5 speed holds up longer than the 6 speed. Maybe not to track abuse at 17 PSI, but I bet you'll pull the 5 speed out in one piece.
Still seems weird that your 6 speed gave up so quickly.
On the coattails of my last post, I found the video of me locking up my front brakes in T1 during my first hot lap last April at WSIR. Not the brake pads' fault, but I figured you all might enjoy laughing at me lol.
03-11-2024, 12:30 AM
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I'm sure you could get em up to temp fine in an N/A car but it might take a bit.
