The M3 is a little SWIFTer now

[bimmer ///man]

If you have seen my other threads then you would have seen my Hotchkis sway bar install and that I am in pursuit of an even better handling e36.
I am currently on TEIN SS-P's and I love them. Now they aren't AST 4200's or TC Kline D/A's but they have been a great coilover to date.
One thing that had bothered me though was the spring rates. I am currently running 559F/532R. For a car that is only 3150lbs, 550+ is a pretty aggressive
rate for a car that is 95% street driven.

So, I started talking to my local shop, HP Autowerks to see what they suggested to increase handling and comfort (I realize this may sound like an oxy moron).
Harold, the owner, suggested that I change my spring rates and at the same time step up to a much better quality spring in the process. Also, he suggested running
a linear spring rate in the rear for more consistent handling. So, I went ahead and did it.

I chose to go with Swift springs as they have had terrific reviews in comparison to Vogtland and Hyperco (both respected brands but Swift outshined them in testing).

Basically, what is to follow is the first TEIN SS-P Swift Spring conversion. Description of picture is below picture.




Everything at the start. Swift 448F/616R Springs, Swift Thrust Sheets, AST Rear Height Adjusters and Vorshlag Nylon Seats.




Swift Front Springs




Thrust Sheets (Help to keep the spring free moving/prevent twisting which results in spring rate increases)






6" 11 Kilo 60mm Spring, quite light




6" 8 Kilo 65mm spring




Front Spring Tein weight 559LB 65mm 7"




Vogtland Weight 450Lb (8 Kilo) 60mm 6"



Rear Spring Weight TEIN, Progressive




Assembled




Assembled rear spring weight Tein




Assembled rear spring wieght AST




Rears Before




Comparison pic

[bimmer ///man]

Rear After





Front before





Fronts assembled





Very nicely designed camber plates. Monoball




Fronts installed


This change was definitely worth the cost of admission. It was a good way to upgrade and it didn't hurt that they are some of the best if not THE best
springs on the market right now. I did a lot of research and this mod was actually spurred by all the recent testing that has been done by a member on
e46fanatics.com.

I know it isn't a direct comparison because I switched up spring rates but the higher spring rate in the rear feels amazingly better and smoother than
the TEIN. I really hated the way my car used to act going into the corners and how high my front spring rates were (it probably decreased traction) but now
the springs suck up the bumps in the road. It feels much more athletic and responsive which is what the advantage is supposed to be of a light spring, a quick
reaction time. The member on E46 actually put the car on a shaker to measure response plus these spring don't sag like the Vogtlands and are worlds better than
Eibach's offering.

This is a great upgrade for all you KW owners as well since your whole system is progressive and has poor spring rates in my opinion and many others.

Special thanks to Leonard at SWIFT for answering my questions and HP Autowerks for getting everything sqaured around for me.

For those of you may think that I am talking out of my, you know. Here is some data that helped me make my decision.

Originally Posted by ninjlao

Now as for the testing I happen to have a spare volkland spring lying around because I had a friend that wanted me to test it out. I also have a set of lightly used Swift springs in almost the same dimensions. The Volkland spring that i have is a
2.5" ID 9" length 180lb/inch spring.
The swift on the other hand is
2.5" ID 9" length 4kg/mm spring which equals to 223lb/inch spring.

Now just a little background information on this little test that I did. The lower the spring rate the spring rate changes and spikes throughout its compression is much less affected than a heavy spring rate. The spring rate spikes are obviously much more noticeable but the percentage increased are about the same. The reason I tested out such low rates though is because these springs are the only springs comparable that I have lying around.



Now there is a lot more to a spring than the spring rate but that is by far the easiest to see the quality and accuracy of the spring itself. So that is exactly what I tested first.



There is nothing bad I can really say about this spring, it is really hard to tell the accuracy of the spring rate because it is not too hard to be off on a spring rate so low. But as a 180lb/inch spring it is pretty dead on its spring rate all the way through its compression.
1st inch- 181
2nd inch- 183
3rd inch- 186 (already starting to hike up)
4th inch-250 (it was nearing coilbind so its natural to increase this much so you can judge this spring at this amount of compression)


Now with the swift spring.

again this spring is also a low spring rate, it's a little stiffer than the Volkland but it is nowhere near high enough to accurately tell how precise this spring is. But this is the spring rate that was recorded throughout its stroke

1st inch- 220
2nd inch- 223
3rd inch- 222
4th inch- 224

Now I took a picture of every inch of compression, I tested it several times through the different strokes of the springs and the numbers for both really consistent throughout their compressions. The pictures and the recorded numbers I decided to post up are numbers starting with zero preload.
These pictures posted below is where the Swift started to outshine the Volkland. This is at 3 inch of compression.




You can clearly see that the swift spring has a much larger sweet spot than the Volkland spring. You can also see that the Swift spring is much closer to the desired spring rate.

But this is not the only advantage to the spring.
Right after being put on the spring checker I remeasured the springs to see if there were any difference in length.



The Volkland spring was brand spanking new. With just a few compressions on the spring checker it had already sagged 1/16 of an inch.

the used Swift on the other hand was dead on at its height.

This was just a few minutes of compression on the spring checker. Now you can imagine what the spring would do after a few months of use with the weight of the car and the vibrations exposed to the spring.

Well Volkland springs are known to sag after a few race events in the real time racing. This is why I decided to measure it before and after the checking of the rates. I already knew the results before going into the test.
Also to show the craftmanship of these springs

^This picture was also taken before the dyno testing. Now all springs do slant a slight amount. They usually are within whatever the manufacturer specs are. This spring though is almost like an S shape which is something I only thought came with Megan springs. This was kind of disappointing to me.

And some of the threads:
http://forum.e46fanatics.com/showthr...212&highlight=
http://forum.e46fanatics.com/showthr...203&highlight=

[Superfly_M3]

Awesome post, thanks for sharing