SLC: 1989 Zinno coupe. Superlight, Super Functional *6spd swap inside*

[jeenyus]

i did them myself. i didn't shorten them though. if i would have needed to i probably would have found someone with a bandsaw i could use for that. i just chopped off the stock/shit spring perches with my peanut grinder and welded the gc perches on.

when you say peanut grinder are you talking about a Dremel? cause that's impressive. Good work man. hopefully i'll get to see this when it's running, or if you need a hand on something.

[mitchlikesbikes]

when you say peanut grinder are you talking about a Dremel? cause that's impressive. Good work man. hopefully i'll get to see this when it's running, or if you need a hand on something.

oh jesus no, i could have spent my whole life on those things with a dremel. i call my 4.5" angle grinder a peanut grinder because that's what my grandpa always called them haha


in other news, i just sent garagistic my payment for the completed custom dssr so hopefully that will be here in the next few days!

[mitchlikesbikes]

my custom DSSR from garagistic arrived yesterday. based on the shit prototype i built and sent them they did a great job on it. i did some test fitting outside the car and had to do some minor clearance grinding on the bottom of the shift carrier to clear the dssr. i may have to do some minor shaving on the dssr itself once i get it in the car but i was able to get into all 6 gears and reverse outside the car so i feel pretty good about it. i forgot to take pics of test fitting because i'm a failure but heres a couple photos of the DSSR:





lately i've been thinking about my options for my differential. i decided my best bet was to reseal my known working and solid 3.73 lsd and just swap the gears inside to a ratio better suited to this trans. my friend steve had an extra medium case 3.25 from an e28 laying around and was nice enough to give it to me so i will be stealing the ring and pinion from that for my diff. i was also planning on a clutch rebuild but i did the breakaway test on the diff and it held to about 50 ft/lbs (factory spec is 40-60 with 60 being the best) so i don't think i'm even going to bother busting open the clutch packs or anything right now since those components are so expensive and i would be wasting money to rebuild a diff that's still well within spec.

i have more parts on the way and will be getting after it more in the next few weeks, hopefully will have the car ready to go this spring.

[mitchlikesbikes]

way too much going on with the car right now. i dropped off all of my components for powdercoat, that should be done by this weekendish.

also fitting the oil pan a 12an turbo drain fitting since turbo plans are in the near future so i won't have to pull the pan with the engine in the car. i will just cap the fitting for now.

i am waiting on an order of random bits from FCP euro as well. front sway bushings and endlinks, oil level sensor block off plate, o ring, and some other knick knacks.

my diff reseal kit is on the way from ECS as well.

main project right now is the differential. based on lots of research i did i determined that i would swap the 3.25 ring gear on to my limited slip carrier, then install that into the case of the open 3.25. that way i don't have to remove the pinion for the 3.25 gearset and deal with resetting preload and pinion depth. with this setup i will just need to shim for gear pattern/preload/backlash. i am hoping that i can use the shims i have and get it set up properly so i don't have to buy a shim kit.

i also couldn't help myself and ordered another clutch disk and dog ear from thayer motorsports. i will be adding this with my 2 current clutch packs that are in good condition. i was actually amazed on the condition of the clutches as this diff has well over 200,000 miles on it as far as i know. to be fair the car has never had much more than stock power and i've also been running fat sticky tires since i've owned it that are very hard to break loose with 140ish HP haha. anyway, here's some photos of the diff after disassembly:









the diff build has felt very familiar so far, as this clutch setup is very similar to the wet brakes that are used on german forklift axles (which i have rebuilt before at work a couple times).

i also found this great DIY if anyone is considering an LSD rebuild/upgrade:

http://buildraceparty.com/diy-tech-how-to-rebuild-a-bmw-e30-differential/

my clutch components should be here tomorrow or wednesday so i can put it all back together. i ordered gear marking compound to verify the gear lash and got a dial indicator to check backlash when i'm done. luckily my coworkers used to build absurd racecars and will hopefully be able to help me verify the diff setup when i'm done so it doesn't make a bunch of noise or blow up.

once the diff is done my next priority will be some minor engine bay prep and touch up painting the bare metal where i remove the insulation attachment studs, ABS module brackets, etc.

i need to get the removable core support wrapped up and paint that whole shit show soon too.

[mitchlikesbikes]

parts are all here!

should have a decent update tomorrow with the diff build up

[mitchlikesbikes]

i got a little excited/zoned in assembling the diff so i didn't really get any pictures, whoops. i removed the spacer and added my new clutch pack from thayer motorsports (who happen to have their products on amazon with prime 2 day shipping, booyah). i replaced the clutch cap bolts with new and then installed the 3.25 ring gear on the diff. i used resbond 2100* Fahrenheit rated thread locker on all of the internal components to ensure everything stays nice and tight.

i decided to bring the diff inside where its warm overnight to let it acclimate since i used heating/cooling to fit the ring gear and speed sensor trigger wheel and i didn't want the stupid trigger wheel to fall off while installing the diff in the case.

my seal kit should be here next week so i will finish the diff up then.

here are the only two photos i took of the diff. first is the finished product and second is the spacer that is leftover after adding the extra clutch pack





after the diff assembly i shifted focus to my removable core support and got that all finished up. i still need to finish prepping and paint all of the bare metal when i get a little warmer weather. i used captive nuts inside the frame rail and welded tabs to attach there, then welded tabs up in the corners above the headlights and welded captive nuts there to attach to the fenderwell section. i added one last bolt/captive nut on each side on the bottom of the frame rail for good measure. here are some photos, don't mind my horrendous welds lol
















i also drilled and tapped my pan for 3/4npt, and installed a 3/4npt to 12an fitting. i am also going to have it welded because the very thin pan won't allow the npt to seal by itself.

[mitchlikesbikes]

i was able to do some test assembly on my differential. i initially had the shims backwards left to right and it caused my gearing to be very tight with no end play whatsoever. this was concerning but i had hope that swapping shims from left to right would take care of it. swapped shims and voila, good to go. pinion bearing and carrier bearing preload is slightly less than perfect but this diff is already used and "broken in" so hopefully this won't be an issue. backlash/freeplay is right at .005" which is dead on the tight end of spec. wear pattern on the drive and coast side is also dead on as pictured. this is a real testament to the tight tolerances that these diffs were manufactured with. i'm amazed to be honest...seal kit for the diff arrived this week so i am going to replace the seals and do the final reassembly in the next day or two, then pop it back in the car. will be very happy to have the diff done so i can get focused on some other things.

coast side of ring gear:



drive side:

[mitchlikesbikes]

finished up the seals on the diff and put it back together. just need to wait for the hondabond on the cover to dry so i can fill it up and stuff it back in the car. i converted it to studs as well because diff bolts are a pain in the ass.

after the diff stuff i installed my oil pressure adapter with my oil pressure and temp gauge senders. i started reconfiguring my wiring for the gauges too since it needs to run to the opposite side of the engine. i got a new pressure sender that has a low oil pressure warning circuit built in so i'm adding an led low pressure light to the dash as well.




the low oil pressure light is a little LED button marker that i mounted in my radio block off plate next to my 12v and USB ports. it is smoked but lights up red. when everything is all done it will light up if oil pressure drops below 11psi.

[mitchlikesbikes]

i filled the diff with oil and installed it in the car today. after that i started tinkering with intake/pcv/icv stuff. i still need radiator hoses, heater hoses, and some bits and pieces for the ICV and PCV systems.

[mitchlikesbikes]

here are some photos of some small stuff i did today

i am not going to be running the throttle body heater because i don't like extra hoses/failure points and this is a warm weather only car anyway. so i chopped the barb off of the feed fitting on the head and welded it shut. i also chopped the barbs off of the throttle body and filled the holes with jb weld. when the jb hardens completely ill sand it down so it looks nice and tidy.

[zwill23]

I really like the idea of a removable core support, definitely on my list of future projects.

I'm also very impressed with your diff rebuild, the extra locking from the additional plate paired with your new power plant should be a lot of fun.

Doin' werk!

[mitchlikesbikes]

I really like the idea of a removable core support, definitely on my list of future projects.

I'm also very impressed with your diff rebuild, the extra locking from the additional plate paired with your new power plant should be a lot of fun.

Doin' werk!

Thanks! The removable core support should help a lot in the future, this m50 I have has an unknown history and will probably explode with the way I'll be driving it haha

I'm excited to lay down some elevens

[zwill23]

this m50 I have has an unknown history and will probably explode with the way I'll be driving it haha

It might surprise you, those M50's are hard to kill ;)

[jeenyus]

The studs on the differential cover is a great idea. I hated installing a new gasket on mine because of this annoying ass bolts.

[mitchlikesbikes]

The studs on the differential cover is a great idea. I hated installing a new gasket on mine because of this annoying ass bolts.

It was still a pain in the ass to get it situated back in the car but it was definitely easier than it was with the bolts. For $10 worth of hardware I'll take it



little more progress. i decided i would strip my extra valve cover and paint it wrinkle black because the more i look at it the more i can't stand the ugly yellow/silver stock color. i got lucky and it turns out someone had already blasted and painted or powdered the cover poorly so it stripped right down to bare metal. paint stripper is scary but also really badass. i am hoping it's warm enough to paint it sometime in the next week or so.







i also picked up all of my parts from utah powder werks. i even liked the color so much i dropped my strut bar to have it done as well. the plan will be all of this plus the strut bar in this color, then a wrinkle black valve cover and oil filter cap. should look pretty good when its all done. my bay itself will still be ugly for now but it's not crucial.



i also picked up an AHP AC/DC tig welder today for a killer deal so i'm preparing to jump into that rabbit hole. excited to start tig welding, i've wanted to learn for years and it is finally materializing.