Mike's 128i autox/track

[mkeiser]

Wanted to make a thread to keep my spam in one place. I'll post some updates and videos on my journey with the 128i. As it stands now, the car is my DD (~60 miles a day) as well as my autox/track/fun car. I'll try and keep this first post updated with current mods.


Suspension

• M3/1M Front and Rear Control Arms
• Koni Yellows
• H&R Sport Springs
• Dinan Fixed Camber Plates
• TMS Solid Aluminum/Delrin Race rear differential mounts
• Bimmerworld Aluminum Rear Subframe Bushings
• M3 Strut Brace

Wheels and Tires

• Style 157 wheels (forged 17x8 et34 20lbs)
• Continental Extreme Contact Force (245/40r17)

Brakes

• F30 front calipers
• E90 328i rear calipers
• E90 335i master cylinder
• Hawk HPS 5.0 pads
• Zimmerman Formula F front rotors (340x30mm)
• Zimmerman Z Coat rear rotors (300x20mm)
• Bimmerworld Stainless Steel lines
• ATE Typ 200 fluid

Engine/Drivetrain

• Euro Intake w/ K&N filter
• N54 Intake Manifold
• MILVs
• Aliexpress catless headers
• Custom 3" Exhaust w/ Vibrant resonator & muffler
• 22RPD tune
• BMW Performance short shifter (128i)
• BMW Motorsport Golf Ball Shift Knob (the best, 25008322191)
• 3.73 diff w/ Team MFactory Metal Plate 1.5 Way LSD
• 19-row oil cooler

Miscellaneous

• placeholder

Future Wants

• 22RPD Velocity Stacks **pre-ordered
• RedShift Motorsports Competition 1W Coilovers w/ Swift Springs (8K F / 14K R) **ordered
• M3 strut tower brace **ordered
• 17x9 wheels and wider tires, not sure what I could fit under stock fenders
• some sort of wangggg
• Custom front splitter

[mkeiser]

autocross yesterday. fun course! I wasn't happy with my own driving but I think if I had another run or two I would have been able to improve. I'm looking into a headrest mount for the GoPro for future events.

[mkeiser]

My RacingDiffs LSD conversion kit went bye bye after that autocross event a couple weeks ago. This past weekend I installed a MFactory Metal Plate 1.5way LSD into my 3.73 pumpkin and put her to the test at an autocross event yesterday. It feels great! I definitely need to get used to the new handling dynamics of the car, especially mid corner on/off throttle.

I also replaced my valve cover as the valvetronic gasket on the old one was always leaking and I stripped out the bolts for it.

No vids as I forgot my gopro



EDIT; OH! almost forgot... I also installed TMS solid diff mounts. I've got Bimmerworld solid subframe mounts ready to install as well but didn't get around to it. I might wait to install those along with some new sway bars...

[spidertri]

Nice 128! When you did the MFactory plate diff, did you stack the plates in any particular order or just go with what they had it set to?

[mkeiser]

Originally Posted by spidertri

Nice 128! When you did the MFactory plate diff, did you stack the plates in any particular order or just go with what they had it set to?

Thank you! I left it to what they had set for now. It's a bit aggressive for the street as it stands but it felt really good during autox so I'm gonna roll with it for a while.

Admittedly, the documentation they provided (attached) to adjust the preload and lock capacity went a bit over my head. I'd definitely need to do some more research before attempting to adjust anything on my own.

[mkeiser]

did my first 'trackcross' event today. this was my first time driving this track layout and it can be pretty sketchy without much run off. there's another trackcross event next weekend and i think i can improve my time by a second or two with some better driving.

[mkeiser]

Originally Posted by mkeiser

Thank you! I left it to what they had set for now. It's a bit aggressive for the street as it stands but it felt really good during autox so I'm gonna roll with it for a while.

Admittedly, the documentation they provided (attached) to adjust the preload and lock capacity went a bit over my head. I'd definitely need to do some more research before attempting to adjust anything on my own.

Well that didn't last long! I wasn't quite happy with the amount of lockup the diff had in daily driving scenarios. Parking lots were brutal and even slight curves in the road I could feel the diff lock and unlock with throttle application. This caused a lot of pushing which isn't what I wanted to deal with.

So I did a lot of reading on how the clutch diffs actually work, tore it apart, and adjusted it to 0 pre load and 100% lockup. This should give me more open diff characteristics when at low/no throttle but progressively lockup as I apply more throttle. Felt good on a test drive...

[cerealwars]

Originally Posted by mkeiser

Well that didn't last long! I wasn't quite happy with the amount of lockup the diff had in daily driving scenarios. Parking lots were brutal and even slight curves in the road I could feel the diff lock and unlock with throttle application. This caused a lot of pushing which isn't what I wanted to deal with.

So I did a lot of reading on how the clutch diffs actually work, tore it apart, and adjusted it to 0 pre load and 100% lockup. This should give me more open diff characteristics when at low/no throttle but progressively lockup as I apply more throttle. Felt good on a test drive...

I've been going through this on my s13 240sx track car project. I've taken apart my Kaaz five different times trying to get it right, but after emailing the manufacturer, they essentially told me that it's supposed to be terrible. My output shafts have a slop-fit to the carrier. If you grab the flanges, you can wiggle them 1/4" in a circle. Apparently this is so the clutch packs can be lubed/cooled. This causes insane clunking noises.

I'm sure your mFactory diff is better than that though.

Swapping some clutch plates around definitely helped and it's better, but it is still super obnoxious in tight turns, parking spaces, etc. I guess eventually I will pony up and buy an OSGiken unit, or swap to the cheaper helical found in later s-chassis. It locks up AWESOME, but it's hard to overlook the pushing of the front tires. Since the rear tires resist differential, the car only wants to track straight, and so the front resists turn-in, which is seriously disappointing.

Hope I'm not venting too much in your thread, but I definitely can relate to these struggles.

Sick car by the way, those wheels and alpineweiss are great choices!

[mkeiser]

Originally Posted by cerealwars

I've been going through this on my s13 240sx track car project. I've taken apart my Kaaz five different times trying to get it right, but after emailing the manufacturer, they essentially told me that it's supposed to be terrible. My output shafts have a slop-fit to the carrier. If you grab the flanges, you can wiggle them 1/4" in a circle. Apparently this is so the clutch packs can be lubed/cooled. This causes insane clunking noises.

I'm sure your mFactory diff is better than that though.

Swapping some clutch plates around definitely helped and it's better, but it is still super obnoxious in tight turns, parking spaces, etc. I guess eventually I will pony up and buy an OSGiken unit, or swap to the cheaper helical found in later s-chassis. It locks up AWESOME, but it's hard to overlook the pushing of the front tires. Since the rear tires resist differential, the car only wants to track straight, and so the front resists turn-in, which is seriously disappointing.

Hope I'm not venting too much in your thread, but I definitely can relate to these struggles.

Sick car by the way, those wheels and alpineweiss are great choices!

Thanks and definitely not venting too much! I've been reading a lot about diffs so I enjoy hearing other people's experiences.

Jeez that Kaaz unit sounds brutal! I definitely know what you mean about the front end pushing... After the changes I've made I'm a lot more happy with the day to day performance but I still need to go 9/10 or 10/10 to really see how it feels when being pushed. It was my first time messing around with a diff and I was more than nervous I was going to break something lol.

[cerealwars]

For sure! It's scary opening up these expensive units for the first time or two. But, turns out they're pretty simple and straightforward, as long as you don't have to mess with ring/pinion backlash.

The Kaaz didn't come with adjustable pre-load (gotta pay OSGiken dollars for that feature), but you can swap the clutch plates (8 on either side) around to adjust aggressiveness. It comes set to 100% (preferred for drifters), but I initially set it up at 80% (1 step down). Then I tried 65% (2 steps down) and went back up as it didn't lock quite enough, and also didn't help with the NVH issues.

That's sick that tuning it (and tuning the adjustable preload in particular) has been working out for you. It definitely helped with mine. I've also found that stickier tires seem to help, as did spicing up my alignment (more front camber, nothing too crazy, maybe 2.5 degrees). The car still pushes a little, but feels pretty good when you're really laying into it.

[mkeiser]

Little update. I purchased M3 rear suspension bits to prepare for coilovers in the future that need the M3 rear lower control arm clevis mount. I went ahead and swapped in the wishbone and guide rod.



The last autox event was last weekend. I am stoked on my progress both in the event and over the entire season. I'm learning the capabilities and limits of the car and becoming a better driver every event. I know the car has more time in it. I'll be bringing the car to some IceX events this winter

and now I am preparing and planning to install an oil cooler. I picked up a housing/thermostat from an S55 car, so I believe the thermostat opens a little later than N55 cars (240*F vs 230*F). We'll see how that performs. I was all set to install everything this weekend but I'm missing a few parts needed for mounting everything so I'll get to that later.

[mkeiser]

not much "progress" on the car recently. we're expecting our first child in May so i've been renovating the house a bit to prepare. but i went ice racing today! lots of fun.

[mkeiser]

another fun day on the ice!

[mkeiser]

Finally got around the mounting up the oil cooler. My handy dandy fabrication skills on full display here LOL! Some thick aluminum hand brackets, hand bent in a vice. M8 rivet nuts into the frame, thank you harbor freight. Some trimming of the fender vent. She's solid and fits pretty damn well!

I gotta figure out what I want to do for intake air flow, I was originally planning on modifying a fog light but there's no room. I'll probably end up working with some cardboard and sheet aluminum to whip something up.

[ZHPizza]

Nice install! One option would be to swap out for the 135i ducts as I did on my 128i to:
1. have the ducting ready for when I get around to installing an oil cooler on the passenger side like you did
2. pipe some extra cold air into the airbox via the unused driver's side duct
3. I never used the fog lights, so why not take the weight savings from deleting them too

Here's a pic of how the intake ducting ended up (I think I had to do some massaging of the horn location, but nothing crazy):

[mkeiser]

Originally Posted by ZHPizza

Nice install! One option would be to swap out for the 135i ducts as I did on my 128i to:
1. have the ducting ready for when I get around to installing an oil cooler on the passenger side like you did
2. pipe some extra cold air into the airbox via the unused driver's side duct
3. I never used the fog lights, so why not take the weight savings from deleting them too

Here's a pic of how the intake ducting ended up (I think I had to do some massaging of the horn location, but nothing crazy):

Thanks for that pic! I'll look into this option. I didn't realize the 135i ducts would work alongside the brake ducts. This is pretty much exactly what I was envisioning on the passenger side when I get around to doing the airbox mod.

I am a little more hesistant to try it on the oil cooler side... there is really not much space to work with between the opening and the cooler. Maybe I can use it and modify it a bit though
..

Thanks again, cheers.

[mkeiser]

m3 strut brace installed! now i can easily make adjustments to current koni's and future redshift coilovers