[Molarz]

Hi
'm relatively new to this forum but wanted to ask a question for all the experts out there who have done more extensive research on our Xdrive suspensions.
Ive tried to search other forums and even called Dinan for information but just cannot seem to get an answer that makes sense about the desired drop height.

I have a 2010 E92 335i M sport Coupe Xdrive

Of course, I have noticed that the suspension sits quite high compared to all of the other BMW's ive owned (standard suspension) and not even an M suspension. I'm trying to achieve something with a bit more aggressive drop like the standard sport suspension or Mtech, is suspensions while still maintaining a relatively civilized quality ride around the city.

This is what lured me to the Dinan suspensions since they are often quite conservative.

The Dinan stage 1 suspension is supposed to only replace the springs, rear shocks and bump stops.

However, the information on the site is confusing since the drop is only supposed to be half an inch in the front and 0 drop in the rear. However, the spring kit part number is the same regardless of whether one owns a 335i, 335i with sport suspension, 335is, 335 M tech and Xdrive. Therefore my question is if Dinan claims that there is a perceptable drop of 0.5 inch up front with the all the suspension options for the 335.... would my 335 Xdrive drop much more than the claimed 0.5 inch compared to the other 335 models that are already are starting off with a lower stance? This is based off the fact that the same part number Dinan springs are sold for all 335 models.

My understanding was that springs determined ride height and dampers controlled oscillation and rebound of the vehicle. All things considered, how could the springs drop an 335 sport suspension .5 inch in the front and my Xdrive which is probably already 1.5 inch higher than the sport suspension, only 0.5 inch..... they are both replaced by the same springs???? Unless the strut assembly and other suspension components determine ride height?

On another note, Dinan for my Xdrive does not offer the front strut replacement with Koni options just the rear shocks. It is interesting how you would leave the front strut and change the rears only? Having said that, if I were to do the suspension, would it be acceptable for me to change the springs and bumpstop kit and leave the rear shocks or should I be purchasing the rear shocks as well?

Thank you for all your input. I don't particularly like how high the xdrive sits and if I can get it back to something like a standard OEM sport suspension with a bit more road control, it is something I would be happy with.

[thegrinchboy]

There are quite a few threads re: suspension drop.

Here are my pics with different springs including Dinan springs on E90.

http://www.e90post.com/forums/showthread.php?t=981254

[Molarz]

Thanks grinchboy
Although Im not sure whether the e90 drop and e92 differ?
Your drop seems pretty low to me compared to what they advertised.... if mine turns out that way I may think it would be a bit more than Id like consider I do drive mine in the winter as well.... I basically want to get to where a stock sport suspension drop is.

[Welterweight]

I installed Dinan spring on my 2009 xdrive. The ride height in the front was only slightly dropped. The rear sits very nice however. I plan to remove front Dinan springs and replace with 335i fronts which I have been told will drop maybe a half inch. That's all I want. As the car sits it's not awful just uneven looking.

[Molarz]

Welterwieght
Thanks for the reply
Do you have any pics of your car? Id love to see your drop.
So does it look like your car is sitting lower on the rear compared to your front?
Thanks

[thegrinchboy]

You're welcome. The ZSP (BMW OEM sport) springs will give you the least amount of drop. Check the pic in the thread above. Good luck!

[ajsalida]

Listen to Grinchboy.

Part of the problem with the XI and lowering in front is the lower spring perch on the strut is higher than the non-XI. So when you install a set of non-XI lowering springs, the front does not appear to drop as much vs rear.

The other thing, or another thing, is the XI springs form factor is identical to non-XI this is why we can swap them in and out. But they are stiffer by a lot over non XI sport springs. This is part of how they get the ride height so high. So by installing non XI sport or eibach pro-kit and some others, you are going to a softer spring. Because the car is also heavier you get quite a lot more drop then you'd expect. IOW none of the advertised drops on non=XI are accurate. Add it all up and overall drop is large but the front does not always go as low as expected and the rear goes down more, giving a funny rear rake look in some cases. There are many approaches to this, for example I have eibach pro-kit front and non-XI ZSP rear.

There are other issues, front since it drops a lot from stock and has less travel than you'd think due to lower spring perch being higher, will often bottom out frequently esp without good sport shocks and trimmed or shorter bump stops. You can get konis (yellows) with shortened bodies and extra travel from TC Kline , though I have konis without that mod and do not bottom out much at all any more.

Quite a lot of discussion on all of this here in the XI section, topic pops up every year.

The Dinan susp you refer to came out before anyone really understood this, and also before koni and others started making good front strut/coil over options. I am partial to not liking dinan solutions much.

[Molarz]

Originally Posted by ajsalida

Listen to Grinchboy.

Part of the problem with the XI and lowering in front is the lower spring perch on the strut is higher than the non-XI. So when you install a set of non-XI lowering springs, the front does not appear to drop as much vs rear.

The other thing, or another thing, is the XI springs form factor is identical to non-XI this is why we can swap them in and out. But they are stiffer by a lot over non XI sport springs. This is part of how they get the ride height so high. So by installing non XI sport or eibach pro-kit and some others, you are going to a softer spring. Because the car is also heavier you get quite a lot more drop then you'd expect. IOW none of the advertised drops on non=XI are accurate. Add it all up and overall drop is large but the front does not always go as low as expected and the rear goes down more, giving a funny rear rake look in some cases. There are many approaches to this, for example I have eibach pro-kit front and non-XI ZSP rear.

There are other issues, front since it drops a lot from stock and has less travel than you'd think due to lower spring perch being higher, will often bottom out frequently esp without good sport shocks and trimmed or shorter bump stops. You can get konis (yellows) with shortened bodies and extra travel from TC Kline , though I have konis without that mod and do not bottom out much at all any more.

Quite a lot of discussion on all of this here in the XI section, topic pops up every year.

The Dinan susp you refer to came out before anyone really understood this, and also before koni and others started making good front strut/coil over options. I am partial to not liking dinan solutions much.

Thanks alot ajsalida
This post is by far the most descriptive I have seen and really does help explain the concerns I have had.
I have read that people running the dinan suspension on xi or xdrive models have the kind of odd look where the rear looks more dropped....My question is I would like to see an Xdrive model with the Dinan springs to see what the drop realy looks like. Im not too concerned about dropping the car that much, just a little and hopefully get a bit better cornering because it feels very floaty now. How do you know that the springs are stiffer on an xdrive.... parts guy at BMW ran the vin on my car against the etk and he said the xdrive is the same suspension as the stock 335?? Can someone clarify?

Welterweight please post a pic haha of your suspension.
Thanks guys

[thegrinchboy]

Molarz - Ajsalida has done a lot research on this topic, so he can definitely provide solid sage advice, even though he is anti-Dinan ;-)

Hey Ajsalida - Glad to see you chime in. How was your summer? Any bear sightings recently? Hope all is well with you!

[ajsalida]

Hey Grinch, good to hear form you! Hope all is well up in NH.

Not so many bears this summer but a few. No big wildfires like we had last two years to disturb their habitat. Lots of rain, no drought, so their natural food source was in good shape and they did not need to come to my house to forage. E9x-wise I have been spending most of my time on tuning and not suspensions lately. Switched over to a JB4 G5 iso from Cobb, and then recently added meth. Debugging all that at high altitude has been fun, getting ready for a turbo upgrade possibly next season

Molarz, the reason I say XI springs are stiffer is I happened to have a set of stock, ZSP, and Eibach sitting around, and I measured them. Without getting into details in front they all look the same as far as number of coils, height etc. but the XI have thicker wire, which means they are stiffer. You will find this out yourself empirically if you R&R front springs, very hard to compress in fact I broke a spring compressor on one. Which is what got me to measure them and compare stiffness to the Eibachs and sports. This is for the front. Same comments apply to rear and XI vs ZSP. Eibach rear we know from other sources is same rate as stock sport, but slightly different form factor.

Whoever you talked to at a dealer that said XI springs are the same as non XI is an idiot. There are letter codes on the springs, starting with a "C" means XI, with a "D" means non-XI sport, and an "I" means non-XI non-sport. The letter is followed by a number which refers to the options and therefore weight that the original car had. Higher number meant heavier car (328 vs 335, MT vs AT, sunroof or not, etc.) . So for example front D6 was for a lighter car than front D7 etc. However they all can be swapped into an XI, so they all "fit".

Finally, in case you don't know, since you mentioned it in your first post. There is no sport suspension for XI. It has its own suspension and is the same sport package or not. Sport package on XI is just seats and trim.

[Molarz]

AJ Salida
Thanks for the info.... very very informative..... amazing how i need to go on a forum to get accurate info that even the dealership cannot provide.

So you perhaps maybe I should ask you another question. How low do you think putting the DINAN springs on my car will lower the front and rear? They claim 1/2 inch all around.... all things considered and using the same Dinan springs they would put on all 335 with the exception of the bump stop kits, will my car look weird?

Also, what suspension set up would you recommend for my car to get the same ride height as a 335 with ZSP setup but still be a civilized stock ride?
Thanks alot

[ajsalida]

Originally Posted by Molarz

AJ Salida
Thanks for the info.... very very informative..... amazing how i need to go on a forum to get accurate info that even the dealership cannot provide.

So you perhaps maybe I should ask you another question. How low do you think putting the DINAN springs on my car will lower the front and rear? They claim 1/2 inch all around.... all things considered and using the same Dinan springs they would put on all 335 with the exception of the bump stop kits, will my car look weird?

Also, what suspension set up would you recommend for my car to get the same ride height as a 335 with ZSP setup but still be a civilized stock ride?
Thanks alot

I can't help you with the Dinan, but I thought Grinchboy has dinan springs now, maybe ask him? Couple of others have dinan springs only on XI here, search.

The other choice would be properly chosen ZSP springs, ie non-XI sports. They give a nice drop, slightly more than ZSP on a non-XI, but not as much as the eibach pro kit or H&R sport, and are very civilized. One thing I would recommend is upgrading the shocks to either koni sports or bilstein sports. With lowering and all the other issues the XI really needs better dampers.

Also find a thread titled "i springs on xi" or similar, here in the XI section. Lot of discussion there about this.