[alvitdk]

Originally Posted by Bimmerfun82

Here's the JA video I was referring to - go to 14:20 mark

Thank you, exactly what I was looking for. Saw the video a while back before ordering the car but totally missed that part.

[ebirotedu]

Interesting. I watched this vid when it originally dropped some time ago, but I didn't make the connection between him talking about the coilovers (at 0:54) and his later comment at 15:10 or so where he mentions that for his Sport Individual mode he has the suspension setting set at Comfort and compares it to an Alpina quality ride.

I wasn't aware that anyone made coilovers that work with the OEM adaptive suspension.

Looking at the product link, it seems a little ambiguous: https://www.acschnitzer-us.com/ac-sc...m40i-g29/p4158

Does anyone happen to know whether the AC Schnitzer coilovers, or anyone else's for that matter, allow for integration with the Z4's electronically managed adaptive suspension?

Originally Posted by Bimmerfun82

Here's the JA video I was referring to - go to 14:20 mark

[Bimmerfun82]

Originally Posted by ebirotedu

Interesting. I watched this vid when it originally dropped some time ago, but I didn't make the connection between him talking about the coilovers (at 0:54) and his later comment at 15:10 or so where he mentions that for his Sport Individual mode he has the suspension setting set at Comfort and compares it to an Alpina quality ride.

I wasn't aware that anyone made coilovers that work with the OEM adaptive suspension.

Looking at the product link, it seems a little ambiguous: https://www.acschnitzer-us.com/ac-sc...m40i-g29/p4158

Does anyone happen to know whether the AC Schnitzer coilovers, or anyone else's for that matter, allow for integration with the Z4's electronically managed adaptive suspension?

I'll call my local ACS dealer and find out

[alvitdk]

Originally Posted by ebirotedu

Interesting. I watched this vid when it originally dropped some time ago, but I didn't make the connection between him talking about the coilovers (at 0:54) and his later comment at 15:10 or so where he mentions that for his Sport Individual mode he has the suspension setting set at Comfort and compares it to an Alpina quality ride.

I wasn't aware that anyone made coilovers that work with the OEM adaptive suspension.

Looking at the product link, it seems a little ambiguous: https://www.acschnitzer-us.com/ac-sc...m40i-g29/p4158


Does anyone happen to know whether the AC Schnitzer coilovers, or anyone else's for that matter, allow for integration with the Z4's electronically managed adaptive suspension?

It does say it comes with an electronic kit...whatever that means but I'm very intrigued by the kit and will do some more research. The price is a bit steep but if it transforms the car's suspension as he describes in the video, it will be well worth it.

[ebirotedu]

Yeah, pricing is significantly higher than, say, the Ohlins coilover kit for Z4. But if it allows for electronic adjustment of compression & rebound damping on the fly via BMW Adaptive suspension integration, that might be worth it.

AFAIK, the BMW OEM adaptive suspension does not provide any sort of spring preload adjustment. Curious to know if anyone knows differently?

Originally Posted by alvitdk

It does say it comes with an electronic kit...whatever that means but I'm very intrigued by the kit and will do some more research. The price is a bit steep but if it transforms the car's suspension as he describes in the video, it will be well worth it.

[Bimmerfun82]

Originally Posted by ebirotedu

Yeah, pricing is significantly higher than, say, the Ohlins coilover kit for Z4. But if it allows for electronic adjustment of compression & rebound damping on the fly via BMW Adaptive suspension integration, that might be worth it.

AFAIK, the BMW OEM adaptive suspension does not provide any sort of spring preload adjustment. Curious to know if anyone knows differently?

Just talked to AC Schnitzer sales rep, and they said it's engineered by the same guy who's been doing this since the E30 M3 and is designed specifically for the Z4. Tuned in with testing on Nurburgring.

25-30 mm lower in the front
20-30 mm lower in the rear

firmer but also more compliant - more comfortable than the factory setup.

the settings utilize the same adjustment on the strut/shock - same options as the car comes with.

tighter suspension, lower center of gravity, more performance tuned suspension but not losing any of the adaptive settings

no warranty impact, authorized by BMW

regular spring kit is recommendation for mine $690 plus labor ($600 or so) for install. he said order through the website and then call to get an appt for install from a dealer.

https://www.acschnitzer-us.com/ac-sc...g29-m40i/p2440

[ebirotedu]

The springs are pretty attractive cost wise. It would be nice to know how those compare to the OEM spring rates, but that's probably considered proprietary info.

Interesting that the drop is 15-25mm - I guess that's adjustable with the user of spacers?

I'd really like to drop my Z4 as much as an inch, but I'm dreading that I'd scrape on my driveway which has a fairly steep incline. I should probably go out and attempt to measure my existing clearance to see.

Originally Posted by Bimmerfun82

Just talked to AC Schnitzer sales rep, and they said it's engineered by the same guy who's been doing this since the E30 M3 and is designed specifically for the Z4. Tuned in with testing on Nurburgring.

25-30 mm lower in the front
20-30 mm lower in the rear

firmer but also more compliant - more comfortable than the factory setup.

the settings utilize the same adjustment on the strut/shock - same options as the car comes with.

tighter suspension, lower center of gravity, more performance tuned suspension but not losing any of the adaptive settings

no warranty impact, authorized by BMW

regular spring kit is recommendation for mine $690 plus labor ($600 or so) for install. he said order through the website and then call to get an appt for install from a dealer.

https://www.acschnitzer-us.com/ac-sc...g29-m40i/p2440

[Bimmerfun82]

Originally Posted by ebirotedu

The springs are pretty attractive cost wise. It would be nice to know how those compare to the OEM spring rates, but that's probably considered proprietary info.

Interesting that the drop is 15-25mm - I guess that's adjustable with the user of spacers?

I'd really like to drop my Z4 as much as an inch, but I'm dreading that I'd scrape on my driveway which has a fairly steep incline. I should probably go out and attempt to measure my existing clearance to see.

Good point. I should have mentioned that the full suspension kit is completely adjustable but he said it was more of a track setup and not what I was looking for. Plus I didn't want to spend $6k+.

[stlcdr]

Originally Posted by Bimmerfun82

Good point. I should have mentioned that the full suspension kit is completely adjustable but he said it was more of a track setup and not what I was looking for. Plus I didn't want to spend $6k+.

I've seen them, before, and thought it's a lot to spend on getting just a small amount of lowering. Good to know that it's more of a 'track' option.

[Pprior]

Lol I saw the 690 plus labor and was like yah I’m gonna check that out. Then I see 6k+ and like NOPE

[Bimmerfun82]

Originally Posted by Pprior

Lol I saw the 690 plus labor and was like yah I’m gonna check that out. Then I see 6k+ and like NOPE

I’ll let you know how the springs work out

[tracer bullet]

Originally Posted by ebirotedu

It would be nice to know how those compare to the OEM spring rates, but that's probably considered proprietary info.

Springs are pretty much always chrome vanadium. The formula basically involves how long the spring wire is, and the diameter. Compressing the spring isn't unlike grabbing the wire at each and twisting it. For the wire length it's basically the spring diameter and # of coils as another way to work it out, if it's constant anyhow. Things get screwy when it's a large diameter body and tapered at the ends (goes from linear to progressive).

In the end, if you have the springs side by side, you could take some measurements and get at a rough idea of the rate, and compare them. Easier said than done, but can be done, at least in the ballpark.

[ebirotedu]

Right, I just wish it was the info was published so I didn’t have to buy them to figure out the spring rate, assuming I’d go through the trouble to have them measured by someone with the right tooling vs just installing them straightaway and deciding based on actual driving time!

Within a few months of buying my 2004 STI, I installed the so-called ‘pink’ springs, which were shorter and stiffer. Besides the drop, there was no spring rate info published for these either, IIRC. Nonetheless, I was mostly happy with them excepting a wish for more drop in the front. But by the time I sold the car several years later, I was pretty tired with the go-kart ride quality. The buyer was a friend and the first thing he did was put the stock springs back on.

At the moment, I’m only using my Z4 as a weekend toy and not for any sort of extended trips. I don’t find the ride to be remotely stiff or harsh, and don’t think I’d mind if it were a little firmer as long as it didn’t transform into anything bouncy or harsh. If I can convince myself that body clearance won’t be a problem on my driveway, I could see myself installing the aforementioned spring kit. Worst case is I don’t like it and I revert back to the factory springs.

I’ve watched a bunch of Joe Achilles reviews and that he likes them suggests they’re not going to be too harsh.

Originally Posted by tracer bullet

Springs are pretty much always chrome vanadium. The formula basically involves how long the spring wire is, and the diameter. Compressing the spring isn't unlike grabbing the wire at each and twisting it. For the wire length it's basically the spring diameter and # of coils as another way to work it out, if it's constant anyhow. Things get screwy when it's a large diameter body and tapered at the ends (goes from linear to progressive).

In the end, if you have the springs side by side, you could take some measurements and get at a rough idea of the rate, and compare them. Easier said than done, but can be done, at least in the ballpark.

[alvitdk]

Originally Posted by ebirotedu

Right, I just wish it was the info was published so I didn’t have to buy them to figure out the spring rate, assuming I’d go through the trouble to have them measured by someone with the right tooling vs just installing them straightaway and deciding based on actual driving time!

Within a few months of buying my 2004 STI, I installed the so-called ‘pink’ springs, which were shorter and stiffer. Besides the drop, there was no spring rate info published for these either, IIRC. Nonetheless, I was mostly happy with them excepting a wish for more drop in the front. But by the time I sold the car several years later, I was pretty tired with the go-kart ride quality. The buyer was a friend and the first thing he did was put the stock springs back on.

At the moment, I’m only using my Z4 as a weekend toy and not for any sort of extended trips. I don’t find the ride to be remotely stiff or harsh, and don’t think I’d mind if it were a little firmer as long as it didn’t transform into anything bouncy or harsh. If I can convince myself that body clearance won’t be a problem on my driveway, I could see myself installing the aforementioned spring kit. Worst case is I don’t like it and I revert back to the factory springs.

I’ve watched a bunch of Joe Achilles reviews and that he likes them suggests they’re not going to be too harsh.

Same here, it's my weekend toy and even if it's a bit harsh, as long as it does what I need it to do for those weekend fun rides, I'm happy to make the change.

[ebirotedu]

Originally Posted by ebirotedu

If I can convince myself that body clearance won’t be a problem on my driveway….

Uh, NOPE!

[Bimmerfun82]

Originally Posted by ebirotedu

Uh, NOPE!

Front lift kit - problem solved! Just $5k

[SCBMW02]

Most folks will never approach the limit in a Z4 or anything else on the street. Not sure how much faster you want to go on a curvy road. The Z4 is quicker, brakes better and has over 1g of grip out of the box, more fun in the real world than my Shelby GT 350, which does turn in a little sharper with less roll, but until you hit 4000- 8000 rpm it’s fairly tame. Dinan got stock 443 hp at the crank, so as usual BMW is quite conservative on hp numbers.
I’ve had 3 generations of M3, lots of track time, this car is more fun, again in real world. Tired of the “ it does not have the razor sharpe moves of a boxster”. It looks way better than a boxster,in and out, and is much cheaper after you build a boxster, and I wonder how many folks have actually driven a boxster 10/10s to compare?
Check out Andy Pilgrims track test of the Z4 on you tube, lap times are damn close to the last gen M2. But, to each his own. I just don’t see the reason to spend boxster money moding the Z to death to get .5 g more grip on a backroad when u are already probably dangerously too fast. I think it’s a blast as is

[Bimmerfun82]

Originally Posted by SCBMW02

Most folks will never approach the limit in a Z4 or anything else on the street. Not sure how much faster you want to go on a curvy road. The Z4 is quicker, brakes better and has over 1g of grip out of the box, more fun in the real world than my Shelby GT 350, which does turn in a little sharper with less roll, but until you hit 4000- 8000 rpm it’s fairly tame. Dinan got stock 443 hp at the crank, so as usual BMW is quite conservative on hp numbers.
I’ve had 3 generations of M3, lots of track time, this car is more fun, again in real world. Tired of the “ it does not have the razor sharpe moves of a boxster”. It looks way better than a boxster,in and out, and is much cheaper after you build a boxster, and I wonder how many folks have actually driven a boxster 10/10s to compare?
Check out Andy Pilgrims track test of the Z4 on you tube, lap times are damn close to the last gen M2. But, to each his own. I just don’t see the reason to spend boxster money moding the Z to death to get .5 g more grip on a backroad when u are already probably dangerously too fast. I think it’s a blast as is

To each their own, as they say.

Getting the AC springs installed tomorrow and spacers. Should be fun to hit the canyons this weekend! Btw I added spacers to my e93 and that car was incredibly fun and tight without the chassis being so taut/punishing like the G8x.

The Z out of the box is def very capable but also more of a GT. Still far less expensive to buy the Z and mod it than buy a 718, and as you said get all the additional luxury and creature comforts.

Hope this lowering, stiffer springs and spacers combo vastly increases the “fun”!!

[Bimmerfun82]

ACS springs installed
Spacers 15 mm front , 12 mm rear.

By the way they first quoted me 5.9 hours of labor for 1150, but I pushed back and they lowered it to 750. Alignment is also required.

After
Before

Will let you know about ride quality after this weekend.

Edit- drove around for 25 miles. Initial impressions are very good. Less recoil, very flat in corners even in comfort mode with less body roll and load transfer. Feels like a proper sports car now. Over speed humps easier on my back but definitely feeling the g forces in sharper turns and the bumps are more noticeable with my sore back.

Kind of reminds me of my C5 corvette with the Z51 package although that was 24 years ago. More like the M3’s I’ve had for sure, similar to the E46 possibly rather than the G80 or E93.

Feels great. Confidence is up for sure in the corners! Got a little sideways on purpose without feeling that lurch - more controllable - but think I’ll be quicker in the twisties.

[Bimmerfun82]

Sorry forgot to mention the ground clearance is now 6.7” or 17 cm at the front lip and about 5.3” on rocker panels. Lower for the kick pad (4”?). By my imperfect calculations and measurements it dropped the car somewhere around 13-15mm.

[Bimmerfun82]

Originally Posted by SCBMW02

Most folks will never approach the limit in a Z4 or anything else on the street. Not sure how much faster you want to go on a curvy road. The Z4 is quicker, brakes better and has over 1g of grip out of the box, more fun in the real world than my Shelby GT 350, which does turn in a little sharper with less roll, but until you hit 4000- 8000 rpm it’s fairly tame. Dinan got stock 443 hp at the crank, so as usual BMW is quite conservative on hp numbers.
I’ve had 3 generations of M3, lots of track time, this car is more fun, again in real world. Tired of the “ it does not have the razor sharpe moves of a boxster”. It looks way better than a boxster,in and out, and is much cheaper after you build a boxster, and I wonder how many folks have actually driven a boxster 10/10s to compare?
Check out Andy Pilgrims track test of the Z4 on you tube, lap times are damn close to the last gen M2. But, to each his own. I just don’t see the reason to spend boxster money moding the Z to death to get .5 g more grip on a backroad when u are already probably dangerously too fast. I think it’s a blast as is

Watched the video you recommended from Andy Pilgrim - he says the car is a little bit softer than he expected and has to slow his hands down to prevent oversteer.

This spring upgrade has eliminated some of that problem for $1300. That's a small price to pay and puts the cost for a Z4M40i right around the base price of a 718.

[BMWGirlFL]

Originally Posted by Bimmerfun82

Sorry forgot to mention the ground clearance is now 6.7” or 17 cm at the front lip and about 5.3” on rocker panels. Lower for the kick pad (4”?). By my imperfect calculations and measurements it dropped the car somewhere around 13-15mm.

BMW tech spec is 119 mm.

https://www.press.bmwgroup.com/canad...23?language=en