X5M lowered on VTF HR springs with links

[StatenEye]

Originally Posted by musa

Correct, it can only be the above mentioned part #3 which sits between the struts and the strut mounts. It's called the Auxiliary damper and is inside the protective corrugated rubber boot - part number 33537850217. There's nothing else in the entire rear axel. It's not much different than the rear suspension of my X5 E53 in which I overhauled myself the entire suspension system of the vehicle, installing the E53 HR springs and links.

https://www.realoem.com/bmw/enUS/par...BMW-X5_M&mg=33

In any case, I'm planning to do the same mode with VTF HR springs on my F86. Your F85 looks amazing. But I think I will shorten this auxiliary damper rather than remove it entirely.

Here's a pic of it I found on the web.

Installed the VTFs today, couldn't finish up bc I need to pickup replacement bolts for the upper control arm to spindle connection. I snapped mine trying to tighten it up. Ill be doing the links tomorrow, I'm hoping i can cut that bump stop without removing the strut.

[musa]

Originally Posted by StatenEye

Installed the VTFs today, couldn't finish up bc I need to pickup replacement bolts for the upper control arm to spindle connection. I snapped mine trying to tighten it up. Ill be doing the links tomorrow, I'm hoping i can cut that bump stop without removing the strut.

If you're going to cut it without removing it, be very careful not to damage the piston rod. You don't want nicks on it that could compromise the seal. Someone mentioned the dinan auxiliary damper is shorter, but that remains to be verified.

[spacejamm_x5m]

Originally Posted by StatenEye

Great thanks and I'm assuming/hoping its in the boot on the strut. Hoping its not somehow in the airbag itself.

It's under the strut housing.

[musa]

Originally Posted by spacejamm_x5m

It's under the strut housing.

Yep, see post #34 and #44 for anyone wondering what that is.

[urcrazy]

Originally Posted by StatenEye

Installed the VTFs today, couldn't finish up bc I need to pickup replacement bolts for the upper control arm to spindle connection. I snapped mine trying to tighten it up. Ill be doing the links tomorrow, I'm hoping i can cut that bump stop without removing the strut.

Hey, I'm about to install my VTF kit too. Did you find the torque specs for all of the bolts? I have been looking and asking with no luck. Even asked the service department at the dealers and they just gave me a BS statement of the techs just follow what's on the screen.

[musa]

Originally Posted by urcrazy

Hey, I'm about to install my VTF kit too. Did you find the torque specs for all of the bolts? I have been looking and asking with no luck. Even asked the service department at the dealers and they just gave me a BS statement of the techs just follow what's on the screen.

Should be somewhere here under Suspension Tightening Torques. Take your time and you'll find them. I've seen them before, everyone of them:
https://www.newtis.info/tisv2/a/en/f...epair-manuals/

[musa]

Came across a post on E53 forum where an X5 (first generation X5) with front bump stop removed + sofware glitch caused the vehicle to bottom out resulting in locked front wheel and a clean blown apart front CV.

https://xoutpost.com/bmw-sav-forums/...ration-17.html

[urcrazy]

Originally Posted by musa

Should be somewhere here under Suspension Tightening Torques. Take your time and you'll find them. I've seen them before, everyone of them:
https://www.newtis.info/tisv2/a/en/f...epair-manuals/

Thank you! This is exactly what I have been looking for. I just received my new wheels this morning and have the new tires ready to be installed. So, I will start on the lowering today since you have provided the link I needed. Thanks again!

[Bigfishe]

Has anyone done the VTF HR's with Dinan BumpStops?

[r33_RGSport]

Originally Posted by Bigfishe

Has anyone done the VTF HR's with Dinan BumpStops?

I believe so, I don't think I ever done one yet.
But I've sold the set to out of state before.
It is the same thing as cutting the stock one.

Well, better a actually since it is still one piece.

[spacejamm_x5m]

Originally Posted by StatenEye

Installed the VTFs today, couldn't finish up bc I need to pickup replacement bolts for the upper control arm to spindle connection. I snapped mine trying to tighten it up. Ill be doing the links tomorrow, I'm hoping i can cut that bump stop without removing the strut.

I think we were able to shave down the bump stop it with out removing the strut

[spacejamm_x5m]

Originally Posted by musa

Came across a post on E53 forum where an X5 (first generation X5) with front bump stop removed + sofware glitch caused the vehicle to bottom out resulting in locked front wheel and a clean blown apart front CV.

https://xoutpost.com/bmw-sav-forums/...ration-17.html

Yea. We didn't touch the front. Only the rear for that exact reason.

[StatenEye]

Here's mine done and settled, rides like stock, bump stops untouched at this height. Also included a stock for a comparo.

[spacejamm_x5m]

Originally Posted by StatenEye

Here's mine done and settled, rides like stock, bump stops untouched at this height.

Looks good. You have taller tires too

[StatenEye]

Originally Posted by spacejamm_x5m

Looks good. You have taller tires too

Yea at first the rear was too low ans i was hopping. I raised it a few turns and its rides mint.

[spacejamm_x5m]

🏆

[F85MTuNED]

Originally Posted by StatenEye

Here's mine done and settled, rides like stock, bump stops untouched at this height. Also included a stock for a comparo.

What spec are these wheels?

[VETTEPRO]

I'm at 30 1/2" in the rear with no bump stops. I've tried it with full stops, cut halfway and removed completely.
It rides fine until it bottoms and it does bottom hard if you're not careful.
The lower you go the softer the air spring (bag) gets. There is no getting around that. It really needs a true coilover for the rear with the proper spring rate. The air bag is always going to be a problem no matter what shock you get. You can get a shorter shock that won't bottom but the vehicle won't handle as well as it should because the rear spring rate is way too soft. I definitely notice it in mine.
I'm really surprised nobody else has mentioned it.
Doesn't anyone else notice it?
I'd pay a lot of money to have a real coilover in the rear.

[spacejamm_x5m]

Originally Posted by VETTEPRO

I'm at 30 1/2" in the rear with no bump stops. I've tried it with full stops, cut halfway and removed completely.
It rides fine until it bottoms and it does bottom hard if you're not careful.
The lower you go the softer the air spring (bag) gets. There is no getting around that. It really needs a true coilover for the rear with the proper spring rate. The air bag is always going to be a problem no matter what shock you get. You can get a shorter shock that won't bottom but the vehicle won't handle as well as it should because the rear spring rate is way too soft. I definitely notice it in mine.
I'm really surprised nobody else has mentioned it.
Doesn't anyone else notice it?
I'd pay a lot of money to have a real coilover in the rear.

Mine doesn't bottom out at all. Obviously it's a little stiffer but over all it's not bad

[VETTEPRO]

Originally Posted by spacejamm_x5m

Mine doesn't bottom out at all. Obviously it's a little stiffer but over all it's not bad

It's definitely not bad. The front is stiffer, which is as it should be on a lowered vehicle.
The problem is that the rear is actually softer.
I've owned A&A Corvette Performance for over 15 years. We've installed hundreds of sets of coilovers on Corvettes. The Corvette is obviously different from the F85 BMW but the basic principles are the same The spring rate is always stiffer than stock on a properly designed set. As a matter of fact, the rear spring is stiffer than the front, even though the front is heavier.
On our cars (trucks) we end up with the spring rates inverted. For normal driving this isn't an issue. I drive 800 - 1000 HP Corvettes all the time. I like to go fast. Even though these cars are way heavier, they can be fun to push through the corners. I honestly think that they handle better, when pushing it, before we lower them. They are just better balanced that way.
My M5, on the other hand, handles better lowered because the spring rates are balanced front to rear.

[Ehloo]

This is why the kw is a better option. Full shock replacement. The stock shock is too long and if you are slammed it’s going to bottom out without a proper shock to accompany the height.

I had a similar issue when I first lowered with HR Spring setup. It was the worst and unsafe ride ever. The VTf rear setup is pretty much the same. I had the rear height level with the front which was pretty low. Never liked the rake look. But after experiencing unsafe ride quality I raised the rear which made things more tolerable

Ended going with KW and couldn’t be happier.

Originally Posted by VETTEPRO

It's definitely not bad. The front is stiffer, which is as it should be on a lowered vehicle.
The problem is that the rear is actually softer.
I've owned A&A Corvette Performance for over 15 years. We've installed hundreds of sets of coilovers on Corvettes. The Corvette is obviously different from the F85 BMW but the basic principles are the same The spring rate is always stiffer than stock on a properly designed set. As a matter of fact, the rear spring is stiffer than the front, even though the front is heavier.
On our cars (trucks) we end up with the spring rates inverted. For normal driving this isn't an issue. I drive 800 - 1000 HP Corvettes all the time. I like to go fast. Even though these cars are way heavier, they can be fun to push through the corners. I honestly think that they handle better, when pushing it, before we lower them. They are just better balanced that way.
My M5, on the other hand, handles better lowered because the spring rates are balanced front to rear.

[VETTEPRO]

Originally Posted by Ehloo

This is why the kw is a better option. Full shock replacement. The stock shock is too long and if you are slammed it’s going to bottom out without a proper shock to accompany the height.

I had a similar issue when I first lowered with HR Spring setup. It was the worst and unsafe ride ever. The VTf rear setup is pretty much the same. I had the rear height level with the front which was pretty low. Never liked the rake look. But after experiencing unsafe ride quality I raised the rear which made things more tolerable

Ended going with KW and couldn’t be happier.

I'm sure that's what I'll end up doing. I'm a KW dealer so I get a pretty good price on them. I just wish there was a way to bring the rear spring rate up to where it should be.
The car will never handle as well as it could with the rear spring rate being so much softer than the front.
It's the best we can do until someone designs a true coilover for the rear. Unfortunately that will never happen due the low demand.
If we could still utilize the air bag and have a light spring on the shock to make up the difference, that would also work.