Tein springs & bump stops.

turbnics · January 7, 2020, 19:22

Hi everyone,
I will be fitting Tein S tech springs this weekend to my 2.Do i need to shorten the bump stops?.

Thanks.

s12vea · January 7, 2020, 20:23

No you won't need to shorten them

bilodeaujeremy · January 7, 2020, 20:32

i cut per the instructions removing about an inch

househead · January 7, 2020, 20:57

I was wondering about this ... Can someone give the ELI5 explanation as to why bump stops get trimmed when installing lowering springs and what it achieves?

I've got the Teins on my car currently but I'm going to switch to Eibachs as it's just a little too low. Not sure if the previous owner who installed them has trimmed the bump stops. I'll know when I install the Eibachs.

Beachbum957 · January 7, 2020, 22:05

Quote from: turbnics on January 7, 2020, 19:22Hi everyone,
I will be fitting Tein S tech springs this weekend to my 2.Do i need to shorten the bump stops?.

Thanks.

I run Tein S springs and initially did not cut the bump stops. The front suspension seemed a bit harsh, and later investigation showed why. I measured the front wheel position sitting on the ground, and then removed the springs and set the suspension height to the same measurement. The strut was just touching the OEM bump stop. That means the front suspension was using the bump stop nearly all the time, which explains why it seemed so harsh. I cut the bump stop about 1" to just under the boot groove, and the suspension works much better. There is at least an inch of travel before the bump stop comes into play.

The rear did not have the same problem, and the rear bump stops were never cut

househead · January 7, 2020, 23:16

Thanks to the reply above, I think I understand this now

thetyrant · January 8, 2020, 12:56

As above if you want good ride cquality then trimming bumpstop with the Tein springs is essential especially on stock damper, the intstruction supplied with Springs used to show this but now dont for some reason (ive seen both) and i can only presume people complained springs were too soft so Tein took the info about trimming the bumps off the instructions as using untrimmed ride is much firmer, all depends what you want but i trimmed mine and ride quality is very good couple with Koni Sport dampers.

turbnics · January 8, 2020, 21:06

Thanks for the replies.

cptspaulding · January 9, 2020, 09:03

Quote from: Beachbum957 on January 7, 2020, 22:05The front suspension seemed a bit harsh, and later investigation showed why. I measured the front wheel position sitting on the ground, and then removed the springs and set the suspension height to the same measurement. The strut was just touching the OEM bump stop. That means the front suspension was using the bump stop nearly all the time, which explains why it seemed so harsh. I cut the bump stop about 1" to just under the boot groove, and the suspension works much better. There is at least an inch of travel before the bump stop comes into play.

Could this be the reason I didn't care for the Eibach springs? i.e. needing the same treatment to the bumpstops or are the Tein a different shape to the Eibach?

thetyrant · January 9, 2020, 09:13

Quote from: cptspaulding on January 9, 2020, 09:03
Quote from: Beachbum957 on January 7, 2020, 22:05The front suspension seemed a bit harsh, and later investigation showed why. I measured the front wheel position sitting on the ground, and then removed the springs and set the suspension height to the same measurement. The strut was just touching the OEM bump stop. That means the front suspension was using the bump stop nearly all the time, which explains why it seemed so harsh. I cut the bump stop about 1" to just under the boot groove, and the suspension works much better. There is at least an inch of travel before the bump stop comes into play.

Could this be the reason I didn't care for the Eibach springs? i.e. needing the same treatment to the bumpstops or are the Tein a different shape to the Eibach?

Most likely as the Eibach (and most other spring kit) all pretty much have the same amount of drop so all will be affected in the same way, as in once fitted there is very little damper free travel left before it starts to ride on bumpstop giving a jarring ride on rougher roads, coil spring rate isnt much different either on these kits which is the other factor keeping car supported.

Many cars these days use the bumpstop as more than just a extreme travel lmit like the old days and they are usually coil spring assist so when lowering this needs to be taken into account if you want good ride quality.

Beachbum957 · January 10, 2020, 11:34

The specifications for Eibach springs show they didn't lower quite as much as the Tein (Front Eibach 1.1 inch, Tein 1.4 inch), and H&R is about the same as Tein, so all would need the bump stops cut to some extent.

Even with the front bump stops cut, a larger bump could get well in to the stops, so we added a thicker spring isolator setup at the top of the spring to add about 3/8 inch (10mm), which raised the front about the same and gave a bit more travel. It made a noticeable difference

steve447 · January 18, 2020, 00:48

If you add a small ty-rap to the shock shaft you can see how close it is to hitting the bump stop. Depending on your set up you may need to poke the dust boot out the way. People use this technique on mountain bike suspension to see how much travel is being used..

tricky1138 · June 22, 2020, 16:41

Sorry to drag up this thread, but has anyone got the definitive answer as to whether you need to cut the bump stops when installing Tein Springs?

I had the Teins installed on my old shocks and have just swapped them into new KYB shocks but still haven't cut my bump stops down.

Should I be cutting them?

shnazzle · June 22, 2020, 16:43

Quote from: tricky1138 on June 22, 2020, 16:41Sorry to drag up this thread, but has anyone got the definitive answer as to whether you need to cut the bump stops when installing Tein Springs?

I had the Twins installed on my old shocks and have just swapped them into new KYB shocks but still haven't cut my bump stops down.

Should I be cutting them?

The twins? Teehee

Sounds painful

Ardent · June 22, 2020, 16:59

Quote from: tricky1138 on June 22, 2020, 16:41Sorry to drag up this thread, but has anyone got the definitive answer as to whether you need to cut the bump stops when installing Tein Springs?

I had the Twins installed on my old shocks and have just swapped them into new KYB shocks but still haven't cut my bump stops down.

Should I be cutting them?

Are you happy with the ride?
Could be wrong. But I always viewed the teins as the same as the tte springs.
Were the bumps cut for those?
On gut feeling alone. I suspect not.
I had teins and kyb fitted same time.
No cut.

tricky1138 · June 22, 2020, 17:50

Quote from: shnazzle on June 22, 2020, 16:43The twins? Teehee

Sounds painful

Bl00dy auto correct!

tricky1138 · June 22, 2020, 17:54

Quote from: Ardent on June 22, 2020, 16:59
Quote from: tricky1138 on June 22, 2020, 16:41Sorry to drag up this thread, but has anyone got the definitive answer as to whether you need to cut the bump stops when installing Tein Springs?

I had the Twins installed on my old shocks and have just swapped them into new KYB shocks but still haven't cut my bump stops down.

Should I be cutting them?
Are you happy with the ride?
Could be wrong. But I always viewed the teins as the same as the tte springs.
Were the bumps cut for those?
On gut feeling alone. I suspect not.
I had teins and kyb fitted same time.
No cut.

Yes Jase I was ok with the ride, but that was old shocks with the Teins, although I'm pretty sure I have felt it hit the bump stops a few times.

As I'm replacing with new KYB, I just though I'd do it right this time!

Topdownman · June 22, 2020, 18:34

I am interested in this too and having been doing all the research I can.

I found references to cutting the original front bumpstops by 0.8" (20mm) and leaving the rear alone.

I found my previous teins/ kybs surprisingly stiff but I had not cut the front bumpstops and now think I know why!

You will want to cut anything you decide off the top, flat end so that you leave the progressive end of the bumpstop intact.

The teins are designed to lower the front in relation to the back and that 3mm more than other springs is a fair proportion of your available travel.

I will definitely be cutting down my front stops and feel tempted to go a bit more than the 20mm.

shnazzle · June 22, 2020, 18:52

http://teinusa-blog.com/bump-stop-trimming/

Tein definitely seem to suggest it's something that must be done

Ardent · June 22, 2020, 20:11

This is a case of would really be nice to compare cut vs un cut side by side same road etc etc.

Accutually, I'm now seeing this as, there is no "right" or "wrong" only personal preference.
I am happy with my setup. Could it be better if I cut the bumps, I don't know. But I am not going to cut them to find out.

Like wines and photographic equipment.
Our individual milage may vary.

shnazzle · June 22, 2020, 20:27

Quote from: Ardent on June 22, 2020, 20:11This is a case of would really be nice to compare cut vs un cut side by side same road etc etc.

Teeehheeeehheeehheee

tricky1138 · June 22, 2020, 20:35

Quote from: shnazzle on June 22, 2020, 18:52http://teinusa-blog.com/bump-stop-trimming/

Tein definitely seem to suggest it's something that must be done

They used to advise it but now they don't. That's whats confusing.

Think they are going back on uncut and see what happens.

It's only the rear I'm doing currently so can always cut the front when I come to do them.

thetyrant · June 23, 2020, 08:03

Shorten them for improved ride or leave them for a firmer ride, if your not sure leave them stock and see how you find the car rides it may be ok for you, if its too firm/bouncy after fitting springs its not a big job to remove damper and shorten the bumpstop which will help improve this.

I did a lot of research and came to conclusion shortening them approx 25mm at top/fat end was what i needed, my car rides really well with them and Koni Sport dampers and doesnt feel too soft on road, its only on track where i see quite a bit of roll which longer bumps might of helped with a touch but ultimately stiffer springs are need for hard track use.

Suspension is always a compromise somewhere and everyone is different in there opinion of what is nice ride and what is too firm etc.. im mega fussy and prefer a car a touch softer these days, i can live with a bit of body roll as long as car handles well and keeps its tyres pushed in the ground haha

Topdownman · June 23, 2020, 08:12

Would it be possible to jack the car up, take the wheel off and cut the bumpstops with them on the car?

tricky1138 · June 23, 2020, 08:19

Quote from: Topdownman on June 23, 2020, 08:12Would it be possible to jack the car up, take the wheel off and cut the bumpstops with them on the car?

I'd say they would be too far up the inner wheel well to do them on the car.

Think it would be possible to cut them without disassembling them, but would have to have it off the car.