New 2009 2010 BMW Z4 - ZPOST
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read


Go Back   New 2009 2010 BMW Z4 - ZPOST > BMW Z4 Forum (E89) > E89 Z4 Photos / Video / Media Gallery

Post Reply
 
Thread Tools Search this Thread
      06-06-2021, 05:08 PM   #67
proboner
Private First Class
37
Rep
144
Posts

Drives: 2003 Z4 3.0 6-speed
Join Date: Feb 2017
Location: Mountain View, CA

iTrader: (0)

Little sneak peek at what FINALLY came in the mail this weekend...
Appreciate 0
      06-07-2021, 07:52 AM   #68
kaizzer
New Member
0
Rep
5
Posts

Drives: 2009 Z4 35i
Join Date: Jul 2018
Location: Up North

iTrader: (0)

Sick!
Appreciate 0
      06-08-2021, 12:32 PM   #69
proboner
Private First Class
37
Rep
144
Posts

Drives: 2003 Z4 3.0 6-speed
Join Date: Feb 2017
Location: Mountain View, CA

iTrader: (0)

Well I cheaped out today and paid the price. While I've been waiting and waiting for these wheels to come I began looking for stupid things to take up my time. Since I was fairly sure early on that I'd be getting PS4Ss installed, I searched Craigslist for a deal and ended up finding a pair of 235/40/19s (the exact size I was looking for in front) with 60% of their life left for $50 each. Considering that the rears will surely wear out faster than the front due to camber and slippage, this seemed to be the perfect plan! 60% used in the front, new in the rear, then they'll wear out at the same time!

Well today I went to Americas Tire to make this happen and sure enough they had issue with the fronts. They mounted but didn't have quite enough air pressure to get the bead to seat. They could have MADE them seat, but I was very specific up front that there would be hell to pay if any damage came to these rims. So after trying a number of tricks over the course of about 6 hours, I ended up just buying a new set for the front. Unfortunately they're not coming until Wednesday so now I have to wait 2 more days! Dang! Here's yet another teaser for now...
Appreciate 0
      06-10-2021, 01:10 PM   #70
proboner
Private First Class
37
Rep
144
Posts

Drives: 2003 Z4 3.0 6-speed
Join Date: Feb 2017
Location: Mountain View, CA

iTrader: (0)

Alright, time for a real update.

After driving a few weeks with H&R springs in the rear I decided to swap back to the Eibach's, primarily because of increased ride harshness but also because it was really a bit too low. This time however I removed the spring pads, which after measuring confirmed an extra .25" of lowering. This put her at and almost perfect 26" from ground to fender lip in the front and 26.25" in the rear. A little dark, but here's the profile shot of Eibach's all around with rear spring pads removed.


Then I got the idea to paint the two braces under the front bumper, red. Honestly it's a bit lame, but barely noticeable under normal conditions and in certain lighting helps tie the red accents into the front of the car, which has been noticeably missing. I opted to paint with plastidip for this rough draft so I can revert back to stock black if I don't like it. If I do like it however, I'll get them powder coated so they shine a bit more and match the calipers.






And for the update I've been waiting the last 6 months for- the Volks installed. As a reminder these are Volk TE37 Ultra M's in Blast Bronze in 19x8.5 +36 front and 19x10 +30 rear.










Ran a 15mm spacer in front to bring them out to flush and unfortunately the rear requires camber to fit under the fenders, but that camber was already there so it's kind of a moot point.


I'm still in processing mode for how I feel about them, and I may need to make some changes before I'm really happy. First of all the tires on them are 1.5" taller than stock (235/40/19 front and 265/35/19 rear). The 513M's were .6" taller than stock (245/40/18 front and 275/35/18 rear) and these are almost a full inch taller than those. Right now the thicker sidewalls really seem to stand out, but I think some tire shine will go a ways towards fixing some of that. I made this tire sizing choice for a few reasons:
  • Comfort- Trying to keep the same sidewall thickness as the 18's- this was a bigger deal when I was running harsher coil overs and planned to run R888R's for tires, but now that I've settled for PS4S in the tire department (R888R's were on a 6 week backorder!) and stock shocks, these things are buttery smooth
  • Wheel gap filling- A 1" taller tire will fill 0.5" of wheel gap, which has the car sitting pretty much exactly where I want it
  • Gear ratio- Even with the 1.5" taller tires, the LSD and it's 3.46 ratio will result in lower than stock ratios overall

I also wanted as much concavity as I could fit, which is why I opted for the 10" width in the rear. Unfortunately Ultra M's don't come in 9" width for the front wheels and 9.5" is simply too wide to fit (my current 9" wide fronts are very close to the spring perches. Would definitely hit with a wheel that's 0.5" inward and a tire that's 0.5" taller), so I had to settle for 8.5". Looking at the Volk website, the 8.5" wheels have a concavity rating of "Face 2" and the 10" are "Face 4". I figured this wouldn't be a huge difference but it really is. The rear wheels are MUCH more concave than the front, which the below picture does a pretty good job of demonstrating


This may grow on me over time, but for the moment it's a little bothersome. Wishing I'd gone with a 9.5" tire in the rear and then could have tried to dial out some of that excessive camber.

Lastly, I'm still very iffy on the front lip and side skirt extensions. By far my favorite picture of this car is the down low 1/4 view:


But IMO the lip and extensions absolutely ruin this perspective:


It just looks too chunky and less sleek. I'll probably remove the side skirt extensions for a couple weeks to see how I like just the front lip, and then remove the front lip for a couple weeks as well, and decide how I want to run it.

So anyways, that's where we are. Now that I've laid out my grievances I'm considering trying out another set of wheels to see which I like better. I am such a glutton for punishment and bad financial decisions! Think I want to try ESR SR07's (same wheel just knockoff) with R888R's in 235/35/19 front and 265/30/19 rear to bring the overall height back down closer to stock, and opt for a 9.5" width rear rim this time and see if I can't find a way to take some of the camber out of the rear suspension. I think the key though will be finding a way to justify this to the GF, after I just spent all this money on this setup! I doubt she'd actually say anything, but I'll have a number of extra sets of wheels (including those for the e30 which are sitting in the garage) and it's certainly excessive.

In terms of next actual steps, I've finally got all the parts together to swap in the LSD diff this weekend. Ended up getting new Meyle HD diff bushings, a new driveshaft center support bushing, and a new giubo. I'm very hopeful that these will eliminate that 6th gear heavy acceleration vibration I've been getting. Plus I might as well replace them while I'm in there.

Feel free to let me know what you think about the wheels!

Last edited by proboner; 06-10-2021 at 01:43 PM..
Appreciate 0
      06-12-2021, 08:41 PM   #71
proboner
Private First Class
37
Rep
144
Posts

Drives: 2003 Z4 3.0 6-speed
Join Date: Feb 2017
Location: Mountain View, CA

iTrader: (0)

Well... I have had quite an interesting day!

This afternoon I set out on the task to swap in the LSD diff. Got the car up on stands and began removing all the braces and shields that are the first line of defense.


With those out of the way I could clearly see our target, but there was still much to do before she was accessible.


As mentioned in my previous post, I had purchased replacements for the wear items in the drivetrain as "while-you're-in-there's", so this wouldn't be one of those jobs where you try to find the shortcut to get the diff out... everything had to go. While unbolting the exhaust from the downpipes, I noticed one of the bolts was missing. Surely causing some sort of exhaust leak, which I'd actually kind of been suspecting recently. Sure enough, with the exhaust removed it's clear there had been exhaust gasses slipping across the flange


I would also like to point out, I know everyone says there's no power to be gained by the mid-pipes, but that squeezed down section seriously drives me nuts. I just do not see how that doesn't cause a huge restriction and destroy HP.


With the exhaust fully removed, I could now scratch an itch that had been bugging me since I purchased the car. A rattle. I remember hearing it the first time I drove the car when out in Washington to buy it. I was 99% sure it was the valve rattling in the passenger muffler, which was actually part of the reason I ended up going aftermarket. But after moving to new mufflers the errant noise persisted. In one of my videos someone suggested they thought it was wastegate rattle, which scared me for a moment, but it just didn't sound right and the turbos are too new. Finally, several weeks ago I got under the car to inspect and find the source. I couldnt see anything that could be the culprit, but upon hitting the passenger most secondary cat, I could hear something in there rattling. With the exhaust now off, this was my time to see if my theory was right. I lifted it up from the muffler until fully vertical when a small black something came falling out the pipe inlets


I was right! The PO, who notably did a TON of performance work to this car before I got it, must have accidentally dropped a bolt down in there and either didn't realize or didn't want to deal with dropping the exhaust again to fix it. I am SO HAPPY that this was the actual reason.

It was now as easy as removing the last heat shield to have access to the driveshaft tunnel and the secrets it held. And what a secret it was! Back when I was deciding what replacement parts to buy, I was doing research to find pieces that would be upgrades from stock but wouldnt increase NVH. One of the items I did a good little bit of searching on was a metal giubo that sits between the transmission and driveshaft. I coulnd't help but think that with my now basically doubled hp/tq, that thing had taken a beating. I'd read about a metal giubo that was an upgrade for certain e90 335is', which started in about 2010 but was discontinued a few years later. There seemed to be a lot of uncertainty about this piece, but I happened upon a thread on *********** that convinced me to just buy a stock rubber replacement. Well wouldn't you know, upon pulling the heatshield, it turns out I have a metal giubo!


Now I'm not sure if this is stock, and honestly I kind of doubt it is, but it's so curious to me! I know the PO installed a 335is clutch, so maybe he went ahead and bought one of these unicorn giubo's as well?

Anyways, I decided to stop there for now, as I'm at a bit of a crossroads. I had theories that despite only having 50k miles, all the bushings were perhaps shot due to the massive increase in power. But upon close up inspection they all look totally fine. The giubo appears to be in great shape and I'm not sure if I want to replace it with a potentially less durable version. The drive shaft center support bearing rubber looks pristine, and if the giubo isn't coming off, it seems like a lot of work to replace a part that still looks new. As well, the diff bushings don't seem to be too bad either. I'll certainly replace the rear bushing, as it's easiest to get to and I had an upgraded Meyle HD version, but the 2 front bushings look fine and I believe will be noticeable harder to get access to. Choices choices. Tonight will be one of contemplation.

edit: you know what? Now that I think about it I'm willing to bet the PO already went through the drivetrain a few thousand miles ago when he did the clutch. Along with all the performance mods he performed, he was also way on top of preventative maintenance and had pretty much every possible wear item in the engine bay replaced. Seems pretty par for the course that he would have upgrade the giubo and replaced the center support bearing when the trans was out. I almost wouldn't be surprised to pull the diff and find that it was LSD already, haha!

Last edited by proboner; 06-12-2021 at 08:52 PM..
Appreciate 0
      06-14-2021, 10:42 AM   #72
proboner
Private First Class
37
Rep
144
Posts

Drives: 2003 Z4 3.0 6-speed
Join Date: Feb 2017
Location: Mountain View, CA

iTrader: (0)

And yesterday the work continued. Started off by cleaning the mating surfaces for the LSD diff/cover and sealing that bad boy up to prep for the fluid/install.


Also wire brushed the exhaust flanges to make sure they get a nice seal when I reinstall. You can see the gasket material that has come off on this one.


And all downpipes all cleaned up


Then it was time to get into the meat of the work. Unbolted axles and driveshaft from the diff and managed to slip it out by unbolting and turning the swaybar. For anyone wondering, I have not removed the wheels or axles during this removal. I would also note, I would HIGHLY suggest getting a Harbor Freight transmission jack or equivalent if you plan to do this job. It's just so helpful in so many places and I believe I got mine for $50 used.




While I had it all out I decided to replace the metal giubo. I've had some weird vibration issues and there have been suggestions that the metal giubos may cause issues, so I figure it couldnt hurt to just reinstall a rubber unit.


Then I moved on to the most dreaded part of the install... bushing R&R. Ended up renting a ball joint press from O'reilly but still had to go buy some all-thread, nuts, and spacers to make it work. Long story short it all worked out. To note the Z4 bushing sat different than the e46 that I ended up installing. And to be clear in case anyone else has the same question and can't find an answer (basically me for the past few weeks), E46 DIFF MOUNTS FIT. This really opens up your upgrade options, as basically nothing is available but the stock units for the Z4, but there are TONS of upgrades for the non-M e46. I was resistant to go too firm, but you've got options all the way up to solid with the e46 stuff, and there's no indication of them being cross-referenceable. Unfortunately I forgot to take a picture of the new bushing installed, but if you refer to the upcoming "installed" picture you can see how the fitment is slightly different. Same net effect, just bushing sticks out a bit farther on one side, which doesn't effect alignment, function, or install at all.


There was a moment there where I got lazy and thought about not doing the mount replacement, but I'm SUPER glad I did. Once I got that thing out I realized how much flimsier it is than the Meyle unit.






Finally the final step of the big work, moving that gigantic beast into place. Once again, I simply do not see how I would have gotten this done without the trans jack, but after about 30 minutes of struggling she was bolted into place. Thankfully I'd just done all this work on my e30 about a year ago, so it was very similar and I'd already had quite a bit of experience.




Managed to bolt up axles, driveshaft, and the sway bar before finally calling it quits for the day. To give an idea of time spent on this so far, I spent about 4 hours on Saturday and maybe 7 hours of Sunday. At this point it's mainly just buttoning things up to be completed. Final torquing of all the drivetrain bolts, reinstall heat shields, exhaust, and braces/covers... that's about it. Figure I've got another hour or two left in her. Super excited for the outcome of this! The benefits of course being:
  • No more exhaust rattle
  • Firmed up drivetrain with the stronger rear diff mount
  • Eliminated vibration witht the giubo replacement?
  • Better acceleration with the shorter final drive
  • More grip and predictability with the LSD!

Will have updates on these very soon.

Last edited by proboner; 06-14-2021 at 10:49 AM..
Appreciate 0
      06-14-2021, 11:20 PM   #73
proboner
Private First Class
37
Rep
144
Posts

Drives: 2003 Z4 3.0 6-speed
Join Date: Feb 2017
Location: Mountain View, CA

iTrader: (0)

And I finished her up today.

First thing I noticed, much more abrupt engagement when reversing. Honestly I was initially worried that maybe the lash on the diff was set wrong or something was loose, as the clutch engagement in reverse was so abrupt that it felt more like an on off switch. After backing her into the street and putting the car in 1st, I was able to feather the clutch and drive without an harsh engagement, so that was a relief! Definitely the engagement through the drivetrain is much more direct. My guess would be solid rubber diff bushing is causing this, which I would say isn't something I dislike, but more of a worry initially that something was wrong.

Second thing I noticed, no more exhaust rattle! Great success! So happy to be rid of that damn thing! Although now that I've had the exhaust all the way out and seen that horrendous necking down to like 1" ID in the mid-pipe, I may have convinced myself to go aftermarket with the whole thing.

After driving around for a bit and getting her up to temp, I decided to get on it. Did a WOT pull through part of 2nd and shifted early to 3rd and went WOT a bit more. I was really surprised with how different it felt. It feels... well... planted. The rear end just hunkered down and went. It was very different from the old diff, which almost felt like it skated and searched for grip. This rear end just grabs hold and takes the traction for it's own. It also feels surprisingly smoother. Under power there's no vibration at all, just smooth power delivery.

There is a bit of annoyance though. When maneuvering at slow speed, like when trying to creep up into my driveway or switching between 1st and reverse when changing directions, there's a bit of engagement weirdness. Almost like it's loaded up when it shouldn't be and pressing in the clutch releases the tension. I know that a lot of people talk about banging going into gear, and I'm definitely not getting that. But I do think that it could be the same potential culprit, which is driveshaft center support preload. I knew there needed to be some and I did push the center support towards the rear of the car to introduce that preload, but now I'm wondering if I should have maybe preloaded it in the opposite direction? I'll have to do some more driving and research to decide if it's worth digging back in there to change it.

Sorry no pictures this time around.

edit: How could I forget! The gearing change. It definitely feels quicker, especially at lower rpms off boost and especially compared to how it felt before the diff swap but with the new taller tires. Let's talk through the calculations really quickly shall we?

Stock rear tire- 255/35/18 aka 25" diameter- with the stock 3.07 final drive ratio this results in:
80mph cruise- 2880rpm
top speed- 194mph
2nd gear 7000rpm shift- 71mph
513M rear tire- 275/35/18 aka 25.6" diameter- with the stock 3.07 final drive ratio this results in:
80mph cruise- 2820rpm
top speed- 199mph
2nd gear 7000rpm shift- 72mph
Volk rear tire- 265/35/19 aka 26.3" diameter- with stock 3.07 final drive ratio this results in:
80mph cruise- 2750rpm
top speed- 204mph
2nd gear 7000rpm shift- 74mph

All in all not a huge difference, let's look at the 3.46 final drive

Stock rear tire- 255/35/18 aka 25" diameter- with the LSD 3.46 final drive ratio this results in:
80mph cruise- 3250rpm
top speed- 173mph
2nd gear 7000rpm shift- 63mph
513M rear tire- 275/35/18 aka 25.6" diameter- with the LSD 3.46 final drive ratio this results in:
80mph cruise- 3150rpm
top speed- 177mph
2nd gear 7000rpm shift- 64mph
Volk rear tire- 265/35/19 aka 26.3" diameter- with the LSD 3.46 final drive ratio this results in:
80mph cruise- 3090rpm
top speed- 182mph
2nd gear 7000rpm shift- 66mph

The 3.46 final drive obviously makes a much larger difference, which on the stock tire diameter really cuts the legs off. With the 1.3" taller tires on the Volks however, things start looking much closer to the stock tire diameter on stock diff, just a little bit quicker. We'll see how it actually works out in the real world, but I really like that it allows me to increase acceleration despite these much taller tires but not cut too much into my 80mph cruise rpm.

Last edited by proboner; 06-15-2021 at 12:07 AM..
Appreciate 0
      06-15-2021, 12:15 PM   #74
proboner
Private First Class
37
Rep
144
Posts

Drives: 2003 Z4 3.0 6-speed
Join Date: Feb 2017
Location: Mountain View, CA

iTrader: (0)

Did some quick searching and it seem the preload should be pushing the center support towards the front of the car, not the rear like I did. Looks like she'll be coming apart again (albiet just the bare minimum to reach the support) this weekend. Blast!!

Anyways, here she is sitting pretty (and dirty) after being pulled out of the garage yesterday. She doesn't look different at all, as the modification was obviously internal, but you can tell she feels more confident in herself, and what's sexier than confidence?
Appreciate 0
      06-20-2021, 02:43 AM   #75
proboner
Private First Class
37
Rep
144
Posts

Drives: 2003 Z4 3.0 6-speed
Join Date: Feb 2017
Location: Mountain View, CA

iTrader: (0)

Finally washed her for the first time since the new wheels and LSD
Appreciate 0
      Yesterday, 12:15 AM   #76
proboner
Private First Class
37
Rep
144
Posts

Drives: 2003 Z4 3.0 6-speed
Join Date: Feb 2017
Location: Mountain View, CA

iTrader: (0)

Couldn't resist taking a few at the grocery store today


Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 09:29 AM.




zpost
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST