Effects on geometry of lowering springs

[Mr Lazy]

I've been pondering over this for a few days. Should I really get lowering springs (and new struts) or should I just be happy with what I've got? Anyway, whilst working on the car earlier, this dropped off the bottom of one of the springs. I guess that settles it then. A new set of Teins and struts will be ordered tomorrow.You cannot view this attachment.

[Mr Lazy]

@Ardent, @McMr2, @Beachbum957 , @Iain , @Topdownman I think you all said that you use/have used lowering springs (mostly Teins) with KYB shocks. How much have you trimmed the front and rear bump stops by, and did you trim from the top or the bottom? I have mine now, but haven't fitted them yet.

[Beachbum957]

The original Tein instructions I got with the US springs (apparently slightly different than Tein UK) listed cutting the fronts .8" (20mm) off the bottom, and not cutting the rear.  I cut our fronts 1" (25mm) to just below the groove for the boot.

[Topdownman]

I cut mine in the first groove down which was something like 20-25mm (cant remember exactly) but seen here on the left with the cut off bits;



I would have preferred to cut the bottom as the top probably has more flexibility to take up stress gradually but I didnt want to force them out of the gaiter to get to the bottom section.

[Beachbum957]

Here is a diagram from the Tein instructions to remove the portion marked as "A".  I can't find a picture of the OEM bump stops, but I think the boot goes in the top groove,and we cut ours just below that groove

[Iain]

@Ardent, @McMr2, @Beachbum957 , @Iain , @Topdownman I think you all said that you use/have used lowering springs (mostly Teins) with KYB shocks. How much have you trimmed the front and rear bump stops by, and did you trim from the top or the bottom? I have mine now, but haven't fitted them yet.

Im running Eibach springs. Not trimmed any bump stops and have no issues 👍

[Ardent]

@Ardent, @McMr2, @Beachbum957 , @Iain , @Topdownman I think you all said that you use/have used lowering springs (mostly Teins) with KYB shocks. How much have you trimmed the front and rear bump stops by, and did you trim from the top or the bottom? I have mine now, but haven't fitted them yet.

Did not cut mine. Nor recall seeing instructions to do so.

[Ardent]

@Mr Lazy

We are close enough to meet up.
Have a ride round in mine for reference.

[Mr Lazy]

Thanks everyone, especially Jason for the ride offer. I'd actually like to drive your car just to see what the turbo is like 😃.

On this occasion though, based on your feedback, I feel happy to go ahead without trimming anything. I actually bought some new front bump stops because they came with new (disappointingly cheap looking) gaiters that I had to buy because the old ones split as soon as I removed them. I've just compared the new and old ones, and the new bump stops are actually about 10mm shorter than the OEM ones, which seems like an ideal compromise.

My back is a bit dodgy at the moment, but I'll update here when the car is eventually back on the road.

[Beachbum957]

Did not cut mine. Nor recall seeing instructions to do so.

We bought our Teins 10 years ago, and they came with instructions to cut the front bump stops.  But many people have reported that springs purchased in the past few years did not have the same instructions.  It also seems the Teins sold in the UK don't lower the front as much as the ones sold in the US. Neither Eibach or H&R mentions anything about the bump stops, but they don't lower quite as much as the older Tein we had.

[Ardent]

Bought my tein's Feb 15.

[shnazzle]

I don't remember anyone ever reporting that Teins bottom out. So cutting should be unnecessary. Unless they're not aware it's bottoming out and just think it was a particularly harsh bump on the road
Let's be honest, most people likely would never realise they've bottomed out their strut

[Mr Lazy]

Tein's UK instructions are useless by the way. Just a page full of tiny diagrams with ambiguous meanings. Presumably it is their attempt to produce a single set of instructions for all markets without a need for translations as there is no text, but they've missed the mark.

[Ardent]

any diagrams suggesting cutting?

[tricky1138]

I remember this cropping up as I was putting my springs on with my new KYB struts and had mixed messages too so I emailed Tein.

They eventually returned my email:

Good afternoon

Thank you for your enquiry, my apologies for the delay in our reply

Please check the part number of the product
If its SKY24-AVB00, there is no need to cut the bump rubber

Please contact us if this is not the part number


If you have any questions please don't hesitate to contact us.

Kind Regards

Yukiko Koito
TEIN UK LIMITED

[Beachbum957]

The Tein-S sold in the US is different than sold in the UK. The US part number is SKL22-AUB00.  The amount of lowering is different (-36mm Front, -31 Rear in US) and I wouldn't be surprised they are completely different springs.

[McMr2]

@Ardent, @McMr2, @Beachbum957 , @Iain , @Topdownman I think you all said that you use/have used lowering springs (mostly Teins) with KYB shocks. How much have you trimmed the front and rear bump stops by, and did you trim from the top or the bottom? I have mine now, but haven't fitted them yet.

Sorry @Mr Lazy , been a busy week. I didn't trim mine as the paperwork that came with the springs seemed to suggest it wasn't necessary.

The car isn't sitting on the bump stops at rest, but I'm certain they come into play quite easily on the bumpy b roads I tend to drive. I've thought of experimenting by cutting the old bump stops (kept them when I replaced the springs/struts) but haven't got around to it.

[Mr Lazy]

any diagrams suggesting cutting?

No, nothing at all.

[Mr Lazy]

@tricky1138 thank you! That is the same part number as mine.

[Smithy]

Good morning. I have managed to get some nearly new KYB shocks recently and have noticed that the front and rear have the same bump stop and boots? is this right or has the previous owner made a mistake?

[Mr Lazy]

Good morning. I have managed to get some nearly new KYB shocks recently and have noticed that the front and rear have the same bump stop and boots? is this right or has the previous owner made a mistake?

I didn't buy KYB branded bump stops, but the OEM ones are definitely different front to rear.

[Dev]

 Most people don't realize that the OEM struts is not the same as the KYB replacements. 
Both are made by KYB but they are a different product. I was taken by surprise when I had a chance to compare them together side by side by pushing down on them. This could be a good thing for the KYB replacements as far as longevity but they might not be as good as a damper as the OEM.
 I would image that if there are bump stop differences it should be taken into consideration and compared to OEM for which the springs were designed for.

[Joesson]

Most people don't realize that the OEM struts is not the same as the KYB replacements. 
Both are made by KYB but they are a different product. I was taken by surprise when I had a chance to compare them together side by side by pushing down on them. This could be a good thing for the KYB replacements as far as longevity but they might not be as good as a damper as the OEM.
 I would image that if there are bump stop differences it should be taken into consideration and compared to OEM for which the springs were designed for.

So, what was your perception of difference Dev, the KYB firmer or not as firm as OE?

[Dev]

Most people don't realize that the OEM struts is not the same as the KYB replacements. 
Both are made by KYB but they are a different product. I was taken by surprise when I had a chance to compare them together side by side by pushing down on them. This could be a good thing for the KYB replacements as far as longevity but they might not be as good as a damper as the OEM.
 I would image that if there are bump stop differences it should be taken into consideration and compared to OEM for which the springs were designed for.

So, what was your perception of difference Dev, the KYB firmer or not as firm as OE?

 I cant say for sure since I haven't done a back to back comparison with it installed on the car. What I did notice from relatively new OEM suspension that was removed at around 20k miles from a garage queen compared to KYB aftermarket replacements was a different damping force when I compressed both.
 The OEM was a bit firmer to compress displacing the shock oil but it did not spring back like the KYB when you let go. I suspect that there was more of a gas charge in the KYB. 

At first I thought that more of the gas charge having the strut rod pop up is better but now I think its not very relevant. Its possible that the valving is different and so is the gas bladder.

 How it translates is hard to tell but they were certainly different.The OEM doesn't last very long and there are those that say  that say the KYB replacements have done many more miles from anecdotal reports. It is possible that the specification was given to KYB by Toyota and they are of that specific design where the KYB are a bit more generic for their aftermarket product line  but it meets the specs somewhat.

[Joesson]

Thank you @Dev. So similar but not identical. As is usually the case buyer be aware. It is, I suppose unlikely  that an aftermarket product at a lesser price is going to exactly replicate the OE, even if by the same manufacturer, otherwise there would be no point in the main player having replacement OE items manufactured to sell at a premium price.