Mike's 128i (HPDE & DD)

[edycol]

Originally Posted by Suprgnat

I think you were spot-on here:

I see an LSD in your future

If I can find used, maybe.
Mine is xDrive too. Will see how it behaves with new brake set up after I install it: front F30 Brembo, rear 135 Brembo, M3 MC.
Also, disabling ediff. disables torque split which is 20/80 on track. Disabling ediff. keeps it at 40/60.

[amg6975]

I've said it a million times and I'll keep saying it: E9x rear hubs, E9x 335i brakes all the way around. Bimmerworld brass bushing kit, PFC (11 or 12) pads. Cheap, fixes a ton of problems, and all a 128 will ever need.

[blnk-128]

March 2023 Update:

Alright, so the original offseason plans were the following...
- F30 front calipers + rotors
- E90 328i rear brake calipers
- 135i master cylinder
- 3-stage or N54 intake
- 3.64 or 3.73 diff (non-LSD)

What I ended up accomplishing were the F30 front calipers & rotors, stainless steel brake lines, N54 intake and throttle body, Roundel Werk headers, Stage FP tune, wheel studs, and sourcing a replacement fender and hood. All in this cost about $2300 doing the work with a buddy, excluding $400 for new DTC-60 track and Akenobo street pads.

I shook down the car at VIR this weekend and everything seemed to hold up other than developing an exhaust leak. My top speed on the back straight increased from 127mph to 132.7mph, and my personal best dropped by over 4 seconds. To me the mods seem well worth it, pending long term reliability.

Stage FP advertises a 7200rpm redline for their N52 tune, but I can assure you it goes well beyond that. Plugging in an OBD2 reader and revving it out showed that the redline is 7500rpm. On track I try to keep it below 7200 despite the power band temptation.

This may be specific to my car, but every day I lose a little more faith in the oil lever sensor. At the end of day 1 I did a fresh read and it showed that I was still at the max fill. I did a read in the middle of day 2, parked in the same spot, and it showed I was below min fill. This has happened at multiple events, and going forward I'll be adding a 1/2 quart every 200 track miles.

I tuck my catalyst camera cable in my glovebox while tracking to prevent it from flying around the cabin. Heading back to the hotel at the end of day 1, I found myself unable to open the trunk. It wouldn't respond to the key fob, driver side button, or trunk button. The valet switch was unlocked. Turns out if the glovebox isn't COMPLETELY latched, it won't allow you to open the trunk.

Over the next month or so I plan on knocking out the rear calipers, adding performance brakes to the VO, the 135i master cylinder if need be, raising the ride height, and getting a more aggressive alignment. On the maintenance side, it needs a new Guibo and it appears the transmission output shaft seal is leaking.

[spidertri]

That's really interesting about the increased top speed on the back straight at VIR. I have AA headers already (on a N51) but could only ever hit 128mph on the back straight there. Even with my headers and 3IM, the power just dies up top as I wind out 4th gear.

I've been on the fence about installing the N54 IM that I have because the dynos just don't seem to indicate that the trade-off in that little bit of power up top is worth losing all the power and torque below ~5500rpm. But it sounds like it really does work well at the track.


Also, I routinely lose 1/2qt of oil per 4x track sessions. The oil level sensor is extremely slow to respond, usually I have to drive the car on the street for ~20min before it shows the right oil level. I've tried castrol, liqui moly, and mobil 1, they all burn the same 1/2qt at the track, burns nothing during normal street driving.

[blnk-128]

It's good to hear a +1 on the oil habit.

I went back and forth on the intakes, and I think it'll take some time to have a clearer answer on N54 vs. 3stg for the track.

On the stock 3.23 diff, the extra redline and top end power are a definite advantage as I don't need to shift to 5th. Now is it worth the extra engine wear and torque tradeoff on the street? I'm not so sure the extra tenths justify it.

Another flaw with the 7500 redline is it's harder to lend the car to other people when I don't want them taking all the way up there!

[ornicar]

Did you fit Milvs? It seems to being a good way to retrieve the torque you loosed with the N54 IM.

[blnk-128]

No Milvs yet as they're out of stock and my valve cover gasket isn't leaking. Here is my fast lap from earlier this weekend.

[blnk-128]

April 2023 Update:

The exhaust leak ended up being between the headers and the mid pipe. I've attached a photo where you can see the gasket material blew out. I also replaced my front wheel bearings preventatively as a rushed diagnosis led me to believe the left one was failing. Turns out the play I was feeling is likely the spherical bearing in my TCKline camber plate.

On that note, I need to call them to see if I'm doing something wrong. With the small strut tower openings, I'm only able to get -2.8 degrees of front camber. It seems as though Ground Control and Vorschlag users are able to achieve -3.5 no problem. Hopefully I'm doing something stupid and it's inherent to the design.

The brake upgrade continues to be an excellent investment. I now have 600+ track miles and ~700 street miles on the front DTC-60s, and they still have a fair amount of life left. Even without coding and changing the rear calipers, I'm seeing a slightly reduced braking distance. This may be because of how soft my suspension setup currently is, but I'm thrilled.

As I continue to get comfortable with this N54 intake, I'm noticing oil consumption is drastically increased at the top of my rev range. Driving 250 miles on track this weekend used almost 2 quarts. Top speed on VIR's back straight maxed out at 133.2, I'm blown away by the difference the intake and header combo makes on track.

On that note I PR'd again hitting a 2:18:00, improving by 2.2s thanks to some incredible coaching with the Tarheel BMW CCA. I've driven with several orgs now, and they are far and away the best instructor group I've experienced.

[amg6975]

I have the GC plates and M3 control arms [and M3 knuckle] and also could only get around -2.8* due to the tiny opening in the shock tower. I made some custom threaded spacers so I could push the top of the shock right up against the inside of the hole and still allow it to spin.

I tightened this down and then put a skinny jam nut on it and the adjustment knob still fit. This allowed to me to get -3.5* without having to use adjustable control arms.

I thiiink this is what I used: https://www.mcmaster.com/7815K34/ but I ordered three different sizes and can't remember which one ended up being the right one.

[blnk-128]

Originally Posted by amg6975

I have the CG plates and M3 control arms [and M3 knuckle] and also could only get around -2.8* due to the tiny opening in the shock tower. I made some custom threaded spacers so I could push the top of the shock right up against the inside of the hole and still allow it to spin.

I tightened this down and then put a skinny jam nut on it and the adjustment knob still fit. This allowed to me to get -3.5* without having to use adjustable control arms.

I thiiink this is what I used: https://www.mcmaster.com/7815K34/ but I ordered three different sizes and can't remember which one ended up being the right one.

Interesting solution, I'm assuming CG is the Ground Control plates. I'll have to go to my car and visualize how it'll help gain adjustment.

[spidertri]

I have vorshlag plates and M3 arms and I'm only at -3.0deg up front. I started working on a custom plate design to get more but haven't finished it yet.

Are you revving it out to 7500rpm? I'm guessing the N54 IM isn't the culprit of the oil consumption but rather winding it out further. Still, 2 qts seems like a lot, just all the extra crankcase pressure at that rpm pushing oil past seals?

[amg6975]

Originally Posted by blnk-128

Interesting solution, I'm assuming CG is the Ground Control plates. I'll have to go to my car and visualize how it'll help gain adjustment.

Yeah, sorry.. GC (Ground Control) plates. This spacer just allows some more adjustment since [on the JRZs] the limit was the nut hitting the inside of the hole. It may be different on your set up.

I've also seen a lot of people just take a hammer to the hole and make more room but I wasn't going to do that to my car, and if you ever end up in a race series that may not be allowed anyway.

[blnk-128]

Originally Posted by spidertri

I have vorshlag plates and M3 arms and I'm only at -3.0deg up front. I started working on a custom plate design to get more but haven't finished it yet.

Are you revving it out to 7500rpm? I'm guessing the N54 IM isn't the culprit of the oil consumption but rather winding it out further. Still, 2 qts seems like a lot, just all the extra crankcase pressure at that rpm pushing oil past seals?

I think your assessment is spot on, I've been revving it close to the redline but not all the way there. Bob at Stage FP sent me a revised tune with a lower redline as I'm concerned with longevity running the motor like this.

Good to know on those plates, interested to see how the custom setup turns out.

[blnk-128]

Before heading to upstate NY I replaced my Conti ECFs with some Falken 615k+s, and replaced a likely failing voltage regulator.

At the Glen I did a personal best of 2:21.65, fighting understeer the entire time. It seems that shifting the brake bias forward with the F30 brembo kit, upping the rear damping, and less grippy tires combine to make trail-braking insufficient to rotate the car. I'm hypothesizing this is because the rear tires aren't at their limit anymore. This is caused by less weight being shifted forward (tire change), and they're being asked to do less overall braking (F30 caliper swap).

I'm leaning towards using these tires this as my rain setup, and will be throwing some ECFs on 17x9 wheels for the dry. I'll be going with the same 245 width I had on my 18x8.5s which "should" help me experience less sidewall rollover. I'll also be throwing on the slightly larger 328i rear calipers I have to shift the brake bias rearward.

Happy to say I ticked over 150k miles this week, here's to 150k more.

[spidertri]

Yeah, install the 328 rear calipers and do the sport brake coding and it'll balance the brakes out nicely on track. I did one event with F30s up front and 328s in the rear without the coding and it was still very heavily front biased.

The magic of the Mk60 ABS is that it can cover up a good bit of the significant front bias shift that comes with installing F30 or 335i front brakes and still being stuck with the stock 128i rear rotor.

[amg6975]

Originally Posted by blnk-128

Before heading to upstate NY I replaced my Conti ECFs with some Falken 615k+s, and replaced a likely failing voltage regulator.

At the Glen I did a personal best of 2:21.65, fighting understeer the entire time. It seems that shifting the brake bias forward with the F30 brembo kit, upping the rear damping, and less grippy tires combine to make trail-braking insufficient to rotate the car. I'm hypothesizing this is because the rear tires aren't at their limit anymore. This is caused by less weight being shifted forward (tire change), and they're being asked to do less overall braking (F30 caliper swap).

I'm leaning towards using these tires this as my rain setup, and will be throwing some ECFs on 17x9 wheels for the dry. I'll be going with the same 245 width I had on my 18x8.5s which "should" help me experience less sidewall rollover. I'll also be throwing on the slightly larger 328i rear calipers I have to shift the brake bias rearward.

Happy to say I ticked over 150k miles this week, here's to 150k more

I'm surprised you think the ECF is faster than the Falken, the ECF is not a fast tire at all. I had the RT660s on before the ECF and they were in a different league, but now looking at data on the RE71RS, those are a significant step faster than the 660s... If you have a rain set and a dry set I'd go as far as looking at the Supercar 3R or something really fast.

Edit: Just saw you're comparing the ECF to the 615 not the 660. Still, I would expect the 615s to hang with the ECF...

[blnk-128]

Originally Posted by amg6975

I'm surprised you think the ECF is faster than the Falken, the ECF is not a fast tire at all. I had the RT660s on before the ECF and they were in a different league, but now looking at data on the RE71RS, those are a significant step faster than the 660s... If you have a rain set and a dry set I'd go as far as looking at the Supercar 3R or something really fast.

Edit: Just saw you're comparing the ECF to the 615 not the 660. Still, I would expect the 615s to hang with the ECF...

All good points, at this stage I'm primarily optimizing for longevity so I can do as many events as possible. TireRack ran a test showing the ECF is a tier above the 615s, the 660s a tier above that, and the new 71rs as the overall fastest 200tw. Nice to see that our experiences seem to largely back that up

I've thought about moving to the 71rs or a semi-slick next season, but have some concerns with oil starve on sustained high-G corners (i.e. turn 7 at WG). I'm thinking I'll add the condor baffles similar to Phloozy the next time my oil gasket starts leaking.

I can't remember, what are you running for data collection?

[amg6975]

Originally Posted by blnk-128

All good points, at this stage I'm primarily optimizing for longevity so I can do as many events as possible. TireRack ran a test showing the ECF is a tier above the 615s, the 660s a tier above that, and the new 71rs as the overall fastest 200tw. Nice to see that our experiences seem to largely back that up

I've thought about moving to the 71rs or a semi-slick next season, but have some concerns with oil starve on sustained high-G corners (i.e. turn 7 at WG). I'm thinking I'll add the condor baffles similar to Phloozy the next time my oil gasket starts leaking.

I can't remember, what are you running for data collection?

Ah yeah that was my goal with the ECF as well. Get consistent seat time and make the wing nut faster. Now I’m running out of brakes in two laps… always something. I honestly think the RS4 is just as good as the ECF for a lot less money if budget is a consideration, and the Direzza is almost as consistent and faster than either.

I’ve been running an AIM. A bunch of us with similar weight/tire cars are running them so it’s fun to compare. Always happy to share data but I’m definitely not the best benchmark, I still probably have a second to find in various places at the Glen.

[blnk-128]

Originally Posted by amg6975

Ah yeah that was my goal with the ECF as well. Get consistent seat time and make the wing nut faster. Now I’m running out of brakes in two laps… always something. I honestly think the RS4 is just as good as the ECF for a lot less money if budget is a consideration, and the Direzza is almost as consistent and faster than either.

I’ve been running an AIM. A bunch of us with similar weight/tire cars are running them so it’s fun to compare. Always happy to share data but I’m definitely not the best benchmark, I still probably have a second to find in various places at the Glen.

I prefer the rs4s, somehow track day tire was running a buy 3 get 1 free on the ECFs. When I move up to AIM land I'll take you up on that offer, right now I'm using the Catalyst.

[blnk-128]

Ran back to back events at Pitt Race and Mid-Ohio over Memorial Day and it was nothing short of eventful. My buddy blew a Vanos oil line on his S54, his brother had a caliper bolt eject after backing out and contacting the wheel, my instructor's car caught fire in the paddock while he was in my car instructing me, my car rattled its positive terminal connection loose and died in the middle of an EZ pass, and I cracked a wheel I borrowed from a friend after my 615ks wore down to slicks. I've never gotten so little sleep and still had this much fun.

That being said, the beatings will continue until moral improves, and I'll be back on track for instructor training at VIR this Monday and Tuesday. As I wait for longer studs and a fender roller to arrive for my ECFs, I replaced my 615k+s with some Kumho v730s. Tire rack is currently running a sale and shipped some 235/40/18s for $536.

I'll post my laps at some point although they're nothing special. Pitt race was fun as you throw the car around and it has tons of run-off in case you send it a little too hard. It lives up to its reputation of eating tires, my open diff combined with the curbing destroyed my Falkens in about 4 hours on track.

Mid Ohio is fun thanks to a few high speed corners, significant elevation changes, and close barriers a la the Glen.

Going forward I need to seriously consider getting an LSD, and adding either a sway bar or stiffer springs to the rear. My concern is if I do the bar or springs first, the car will lift the inside wheel more and make my traction issue worse.

[amg6975]

Originally Posted by blnk-128

That being said, the beatings will continue until moral improves]

[joeo]

Good stuff!