Coilovers or LSD first?

[devinfox]

So I have enough money to buy either an LSD or coilovers. I already have all of the M suspension parts, FSB and subframe bushings, my car is a 2012 so it already has linear springs.

I think I am leaning towards LSD but would like others advice.

[135TX]

Lsd all the way

[dcaron9999]

LSD before coils for sure. Did that early last year, with stock linear springs and dampers, with M3 bits on the car.

Made the car much safer on the track and on the street. DSC light and e-diff will intervene much less. Priot to the LSD, the 135i use to kick sideways on the street when accelerating hard in a straight line, and would be very prone to violent oversteer when existing turns at the track.

Just bought Bilstein B8 dampers and Swift Spec-R springs and finally getting them installed this week. Will see how that limited budget solution helps out on the track.

[135TX]

My swift and b8 combo was very good at my last track day. I can see how eventually one might need coils but this combo was a great solution for us low budget heros.

[Pyrat 2]

Originally Posted by 135TX

Lsd all the way

^^^

[klick]

+1 for the LSD. MFactory sells a high quality one at a very reasonable price. You might be able to squeeze in some Koni yellow shocks from the money you might have left from passing on coilovers.

As far as reasoning. An LSD drastically changes the mechanics and feel of the car, almost to the point that it will be like getting something different. Master that component first and then you will know what kind of suspension set up you will want to run.

Going the other way around will make this redundant.

[swagon]

Hmmm, I'd say proper struts and springs first and then LSD. Or both at the same time.

[andrey_gta]

Originally Posted by 135TX

My swift and b8 combo was very good at my last track day. I can see how eventually one might need coils but this combo was a great solution for us low budget heros.

Which B8's are you using? 1 series on F&R, 3 series F&R or a combo?
I see 1 series Fronts listed cheaper than 3 series

[135TX]

1 series F&R i think it was $553 shipped for the full set from tire rack.

[135TX]

The swifts could be stiffer in the front but compared to the msport it was night and day. I'm not a good enough driver to fully utilize coilovers yet so it was more important for me to spend the money on track time and consumables (tires and brakes).

[135TX]

Sorry for blowing up the thread but back to the OPs question the LSD will affect driving and handling when putting power down. However the coilovers will provide for a stiffer more supported ride at all times. There are compromises you can make suspension wise IE Swift springs and Bilstein Shocks, that will provide your average/ spirited driver all the spring and dampening you need to push the car to 8/10. The LSD is a no compromise solution and will be necessary to get all of your power utilized and thus be in a position to squeeze the last 2/10 necessary to really utilize the coilovers to their full potential.

Doing one before the other greatly depends on your priorities and uses of the car. If you want a lowered ride and a better stance then coilovers. If you are going to be pushing the car and driving like the stig then the LSD IMO should be the FIRST thing to do.

[BMW86]

I've done it all and I would go with coilovers first. The stock suspension in the 135i is ratshit. Some quality coilovers will stiffen things up and keep you flat in the corners. Then I would get an LSD

[dailowill]

I'd say LSD unless you're really unhappy with your current suspension setup. Like everyone said before, LSD will give you more traction and less e-diff intervention. Now that I've installed mine, I feel that the car tracks so much more better than before. Also, if you have an manual 135i, you can also opt for a higher final gear ratio.

[knightarmor]

A good quality set of coilovers. Power is nothing without control.

[HP Autosport]

Originally Posted by knightarmor

A good quality set of coilovers. Power is nothing without control.

Exactly why LSD should be first!

There is a reason why M cars all come with LSD.

[Kgolf31]

I ran one whole season with TCKline Dual Adjustables and no LSD.

I was fine for the time being until I got the money to buy a diff

[HP Autosport]

Originally Posted by klick

+1 for the LSD. MFactory sells a high quality one at a very reasonable price. You might be able to squeeze in some Koni yellow shocks from the money you might have left from passing on coilovers.

As far as reasoning. An LSD drastically changes the mechanics and feel of the car, almost to the point that it will be like getting something different. Master that component first and then you will know what kind of suspension set up you will want to run.

Going the other way around will make this redundant.

Have a closer look at their products and where they are made.

It's worth while to take a look at what Quaife does and which company you should choose to provide a very complex part like the LSD for your BMW:

http://quaife.co.uk/

[MightyMouseTech]

I am in nearly the same boat. Will be doing LSD (with the 3.48 FD) before springs/shocks. Once you have the M3 suspension bits, the car handles surprisingly well.

[klick]

Originally Posted by HP Autosport

Have a closer look at their products and where they are made.

It's worth while to take a look at what Quaife does and which company you should choose to provide a very complex part like the LSD for your BMW:

http://quaife.co.uk/

Yea, definitely looked at the Quaife first before I picked up my MFactory. I definitely trust their reliability and name. But I ended up with the MFactory since I was already familiar with them from my Honda days and they were running a sale in which the diff unit was literally half the price of a Quaife. Had to much stuff being done at once for me to reasonably squeeze in a diff into my budget from anywhere else.

[MFactory]

Originally Posted by HP Autosport

Have a closer look at their products and where they are made.

It's worth while to take a look at what Quaife does and which company you should choose to provide a very complex part like the LSD for your BMW:

http://quaife.co.uk/

Seriously? Country of manufacture does not dictate quality; it is who makes/controls the manufacturing of the product that dictates quality, not where it is made.

See, we can both play this game, so please stop before turning this thread off topic. The Quaife is a very good LSD, but you don't need to advertise it in this way.

P.S A Helical LSD is a very simple part, not complex at all (unless you know absolutely nothing about the products you are trying to sell)

[Ginger_Extract]

With the power of the 135i, diff first. I ran a season with the coils before the diff, at lower speeds, the car was more likely to break traction due to the stiffer suspension and lack of wheel travel, which made it harder to drive at autocross.
On the flip side, I will say that the TCK coilovers knocked nearly 4 seconds off my lap time at Buttonwillow Raceway, with no other modifications. YMMV.

[Pig Farmer]

Just want to point out one thing I noticed when installing my LSD... Prior to the LSD, my car had all the M3 suspension components (front and back) and TCK DA coilovers with Swift springs. Comparing this setup to the stock suspension is like comparing night and day. The handling was very predictable in all conditions and at all boost levels, aside from the occasional inside wheel spin on tight turns. When I installed the LSD, I dialed back the boost during the break-in period and to re-learn the car. The LSD definitely allows you to control the ass end much better than what is possible with the e-diff. Now here's the kicker... When I turned up the wick (i.e. changed to an aggressive tune) I experienced something I never felt before with the e-diff. If you give the car WOT in 2nd, 3rd and sometimes 4th gear, the ass end squats and immediately pulls to the right. The front end gets light and almost feels like the front left tire is going to lift. By the time you counter steer, you're half way into the lane to the right. If you ride it out, the ass end waggles all the way to the next gear change. Keep in mind that the tires are not spinning. With the additional "grip", it feels like the suspension geometry is changing under load (which it probably is). Maybe there's a simple fix like stiffer trailing arm bushings, but just thought I'd share my experience. And if someone has solved this issue, I'd be interested in the solution.