The Suspension Mod Thread

[MangoNo5 55]

56 minutes ago, Tareim said:

did you specifically ask for 7/7 or is that the new standard rate?

Must be 6/6 then and Fensport just thought all rates were still the 7/7 rate standard. Either way a great setup. 😊

[Varelco 211]

6 hours ago, S18 RSG said:

You realise that springs have different "spring rates" right? That is, a stiffer spring requires more weight (or load) before it will be compressed a certain amount. Thinking about this logically, a stiffer spring helps "support" that load, and keep the car flat and level through a corner, meaning more even distribution of load between left and right wheels, and therefore more grip overall.

The stock springs that come on this car are 3kg/mm (I believe), whereas a stiffer spring could be something like 6kg/mm, meaning that twice the load is required to compress the spring the same amount, resulting in flatter cornering.

I think it's up for debate whether a fixed damper/spring combination is better value than a similarly priced set of coilovers, as we really don't have enough evidence to support either opinion, but we can at least agree on the facts here.

I think my point has been missed. Ultimately if you spend £500 on suspension then more of that investment is going to be into the damper and spring combo than if it was a coilover. There is alot more involved, that 500 quid has to cover a more complicated design (thread shock bodies, collars etc) pillow ball camber plates etc etc.

 

But yeah ultimately still up for debate. This platform is still young and most people go straight for the coilovers option. So who knows.

[Ade 517]

I'd put money on a Bilstein B8 / Spring combo (which costs ~£1k) being as good if not better than most of the sub £1.5k coilovers. You cant have your cake and eat it. Top mounts cost money. Adjustable bleed stafts (damping adjustment) cost money. All of this takes away from the money spend on the shock internals which is what gives you the quality damping.

 

[Nicebiscuit 655]

And B6/stock springs should be good also - but more biased to comfort/rough Tarmac.

Valving identical to B8 in this application. Only stroke differs. And nothing wrong with stock springs (unless you want stiffer/lower ones!)

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[S18 RSG 429]

17 minutes ago, GT86Owner said:

I'd put money on a Bilstein B8 / Spring combo (which costs ~£1k) being as good if not better than most of the sub £1.5k coilovers. You cant have your cake and eat it. Top mounts cost money. Adjustable bleed stafts (damping adjustment) cost money. All of this takes away from the money spend on the shock internals which is what gives you the quality damping.

 

This was never really the debate. The debate was whether spending £500 on shocks alone would give more or less benefit than spending £500 on coilovers.

I agree, with no further information you could make the argument about "cheap coilovers not being worth the money", but we're talking about Tein coilovers, a brand which is used by a huge percentage of owners on this site, and is proven to be great value for money, not some £200 set of Chinese made eBay coilovers.

I have no doubt that Bilstein make great products, and also have no doubt that a Bilstein shock absorber is "better quality" than the Tein shock absorber used in their coilover applications. However, in this scenario (Bilstein B8 vs Tein Coilovers) the Teins have adjustable damping, adjustable ride height and stiffer (although still very compliant) springs. As a package, they offer greater adjustability and greater handling performance.

The trade off is better "quality" damping performance for the Bilsteins, which is absolutely fine if the damping profile suits your needs and your driving style, but of course, if not, you have no adjustment, so you're stuck with them how they are.

As I've said, I don't think anyone can say for sure whether one is better than the other, as nobody here seems to have experience of both, and therefore all our opinions here are based on just that, our opinions. My opinion is simply that, as a package, Tein coilovers offer more than fixed height and fixed rate dampers at the same price point. Everybody seems to be willing to make assumptions that the Bilstein option will be better, but nobody has any reason to make that assumption other than believing that because they cost more money, they must be better.

 

[Ade 517]

 The B8 has a shorter bumpstop too.

[S18 RSG 429]

As do the coilovers.

[Ade 517]

2 minutes ago, S18 RSG said:

This was never really the debate. The debate was whether spending £500 on shocks alone would give more or less benefit than spending £500 on coilovers.

I agree, with no further information you could make the argument about "cheap coilovers not being worth the money", but we're talking about Tein coilovers, a brand which is used by a huge percentage of owners on this site, and is proven to be great value for money, not some £200 set of Chinese made eBay coilovers.

I have no doubt that Bilstein make great products, and also have no doubt that a Bilstein shock absorber is "better quality" than the Tein shock absorber used in their coilover applications. However, in this scenario (Bilstein B8 vs Tein Coilovers) the Teins have adjustable damping, adjustable ride height and stiffer (although still very compliant) springs. As a package, they offer greater adjustability and greater handling performance.

The trade off is better "quality" damping performance for the Bilsteins, which is absolutely fine if the damping profile suits your needs and your driving style, but of course, if not, you have no adjustment, so you're stuck with them how they are.

As I've said, I don't think anyone can say for sure whether one is better than the other, as nobody here seems to have experience of both, and therefore all our opinions here are based on just that, our opinions. My opinion is simply that, as a package, Tein coilovers offer more than fixed height and fixed rate dampers at the same price point. Everybody seems to be willing to make assumptions that the Bilstein option will be better, but nobody has any reason to make that assumption other than believing that because they cost more money, they must be better.

 

Its worth noting that the adjustment on these teins is single way, mostly rebound adjustment. It not like you can really tailor the damping profile without a having them custom valved - even then you are limited by the technology inside the damper.

What really matters is how digressive the valving is and that's what will gets you lap times. Here's a philfered shock dyno of Koni Yellows vs Tein Flex. Look how the Koni has firmer rebound damping at lowspeed which gives to better control and handling, but at high speed it has less damping than the teins. What this means is when you drive over a pot hole the wheel will move quicker to stay on the ground because it has less rebound at high speed, but when turning into a corner the firmer low speed damping will give more control on turn in than the Teins.

Very high end dampers are very flat after the "knee" point on both rebound and compression. $10k Penske damper actually have less damping at high speed compared to low speed.

[Kodename47 446]

1 hour ago, GT86Owner said:

I'd put money on a Bilstein B8 / Spring combo (which costs ~£1k) being as good if not better than most of the sub £1.5k coilovers. You cant have your cake and eat it. Top mounts cost money. Adjustable bleed stafts (damping adjustment) cost money. All of this takes away from the money spend on the shock internals which is what gives you the quality damping.

 

Based on what I've read, if you use <30mm drop springs then the B6 is preferable. It's what I'll move to when my OEM shocks die. I would think that OEM springs on these would also be a good solution. If you don't want lower then there's no need for a "coilover". 

[S18 RSG 429]

I don't mean to be rude, but all that graph does is show the difference between a Koni damper (which has not been mentioned) and an unspecified Flex damper (of which there are many to choose from) on a car that isn't a GT86.

I remind you, the discussion was initially comparing the benefits of a proven coilover kit with the theoretical performance of a well respected shock absorber upgrade by itself. That graph compares two dampers, neither of which are part of this discussion and neither of which are for this car.

I'm sure if there was a test similar to the one you showed, but comparing a Bilstein shock to a Tein coilover on a GT86, then this conversation would have taken a slightly different path, but because no such thing exists as far as I'm aware, all we can do is speculate and compare opinions.

I had a quick browse through some google search results comparing these two options, and most people seem to suggest the Tein coilovers over Bilstein shocks/spring combo, but as these results vary across BMW, MX5 and Honda owners clubs (among others), I didn't really feel it relevant enough to mention until now, but I guess when in Rome.

[Nicebiscuit 655]

I'm just going to have to buy a set aren't I so we can try it :-D

I personally have no doubt the Teins will be better value if the adjustability is needed, which I think it probably would be with most of the users on here.

Of course there's always the B14/B16 coilovers too...

If I were going down the coilovers route though I'd personally be sorely tempted by the Ohlins for sale elsewhere on the forum (OK, I AM sorely tempted...)

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[Kodename47 446]

JDM suspension has always been historically harder dampened, during my time in the Honda camp Tein were seen as track only suspension as it was too firm on the road. It seems that they have addressed this of late. You do still need to spend more money for the decent kits, I wouldn't go for less than the Flex As, which means that if you don't desire/require adjustability a good spring and damper combination is likely to be competitive in both senses.

[Ade 517]

1 hour ago, S18 RSG said:

As do the coilovers.

I missed this. The tein have far, far less damper travel than stock. Its compromise they have to make to be able to offer 50mm lowering. Cant have your cake and eat it.

 

[S18 RSG 429]

20 minutes ago, knightryder said:

JDM suspension has always been historically harder dampened, during my time in the Honda camp Tein were seen as track only suspension as it was too firm on the road. It seems that they have addressed this of late. You do still need to spend more money for the decent kits, I wouldn't go for less than the Flex As, which means that if you don't desire/require adjustability a good spring and damper combination is likely to be competitive in both senses.

I had chance to test the Street Advance coilovers at some length when my car had it's suspension issues. They felt every bit as comfortable as my Flex A's, with 95% of the performance on the road.

In terms of price, there's a few hundred pounds difference between the Flex A's and Street Advance units. In terms of difference of features, the Street advance have fixed upper mounts (no camber adjustment) and slightly different rear dampers, other than that, I think they're pretty similar, and given the price difference, I wouldn't be surprised if they were VERY similar, as those features would reasonably fill that price gap.

I certainly wouldn't dismiss them as not being "decent", they're at very least decent.

 

[S18 RSG 429]

17 minutes ago, GT86Owner said:

I missed this. The tein have far, far less damper travel than stock. Its compromise they have to make to be able to offer 50mm lowering. Cant have your cake and eat it.

 

Do they? I'm sure I remember seeing something about Tein coilovers being height adjustable without adjusting damper stroke length. Was something I noticed when buying the Flex A's.

[Kodename47 446]

2 minutes ago, S18 RSG said:

In terms of price, there's a few hundred pounds difference between the Flex A's and Street Advance units. In terms of difference of features, the Street advance have fixed upper mounts (no camber adjustment) and slightly different rear dampers, other than that, I think they're pretty similar, and given the price difference, I wouldn't be surprised if they were VERY similar, as those features would reasonably fill that price gap.

 

The As have HBS, which IMO makes them attractive for a street driven car given my prejudice for Japanese suspension.

[S18 RSG 429]

1 minute ago, knightryder said:

The As have HBS, which IMO makes them attractive for a street driven car given my prejudice for Japanese suspension.

Yeah, I can see what you mean. From experience of using the Street Advance compared to the Flex A, over normal street driving there's very little difference, although I do have mine set up quite hard, and to be honest, I avoid potholes and/or large bumps in the road wherever possible, so maybe I just never got to test the difference properly.

[Rich 378]

2 hours ago, S18 RSG said:

Do they? I'm sure I remember seeing something about Tein coilovers being height adjustable without adjusting damper stroke length. Was something I noticed when buying the Flex A's.

They are, which means the damper travel is set so that it works when they are fully lowered, i.e. it's short. This means even if you have less lowering, you still get the shorter travel.

[Ade 517]

 

1 hour ago, S18 RSG said:

Do they? I'm sure I remember seeing something about Tein coilovers being height adjustable without adjusting damper stroke length. Was something I noticed when buying the Flex A's.

Just looking at the front:

Tein Flex A's have 25mm bump + 12mm bumpstop and the HBS. Assume half the stop is compressible, you've got 31mm.

Stock has 33mm travel and a large progressive 60mm bumpstop. If we assume half the bumpstop is active you have 63mm bump travel.

There is a reason the car sits so high in stock form. Again you cant have your cake and eat it with suspension. Everything is a compromise. My Ohlins only have about 28mm free travel and 25mm bumpstop. Giving around 41mm bump travel.

Of course bump travel isn't everything, but it does play a part on rough bumpy British B roads.

The reason high end dampers have external oil reservoirs is because it allows the shock to have more travel. The ohlins TTX on the TMG Cup GT86 has about 30mm more bump travel than the ohlins Road and Track which means you can really take on the curbs aggressively without the car bouncing all over the place.

 

 

[S18 RSG 429]

Well, today I learned something.

Taking all that into consideration, goes to show how little bump travel actually matters in comparison to everything else, when you think that even the cheapest Tein coilovers have more than 20mm less bump travel, and are still more compliant over bumps than stock. Makes me wonder why we even discussed it 

The funny thing is, we've spent the entire day discussing suspension options in a £25,000 sports car, and thanks to continually missing the original point, we're still no closer to a conclusion 

[Ade 517]

13 minutes ago, S18 RSG said:

Taking all that into consideration, goes to show how little bump travel actually matters in comparison to everything else, when you think that even the cheapest Tein coilovers have more than 20mm less bump travel, and are still more compliant over bumps than stock. Makes me wonder why we even discussed it 

This is simply not true.

Find some bumps that are more than 50mm and hit them at speed. You'll find stock is much more comfortable due to not bouncing off the bumpstops.

I'll put my hand up. I've spent 2.5k on coilovers that are supposed to be "Rolls Royce" of coilovers and I will tell you the same is true. They are great as long as you don't hit the bumpstops hard. However, in terms of handling, especially on a smooth track they shine. Its all a compromise. You simply cant have your cake and eat it. The cheaper you go the more compromise you make.

Spending £500 on fixed purch dampers, without top mounts, without all the height adjustments will absolutely give better performance than a £500 coilover with all the bells and whistles.. The koni shocks are £130 per corner for the GT86. The  new Teins have the same technology as the type flex, but the newer ones have the reworked valving. You can see from the dyno graph they are a more digressive shock = better.

 

[S18 RSG 429]

I don't hit bumps at speed, I care more about looking after my car than proving how good my suspension is.

However, I'm not going to bother structuring a reasonable reply to the rest of your post, for three reasons:

1. You spent 5 times more than me on suspension, so of course not only is your setup is 5 times better than mine, but your opinion is 5 times more valid. My apologies.

2. Judging by your last paragraph, you've obviously tried both options, so I can't really argue with that, as I haven't (I was just giving my opinion, like everyone else).

3. If you reply again, you're going to have to type " You cant have your cake and eat it" again, and I just can't hear more stories about cake today.

Let's do this again sometime 

[Tareim 343]

15 minutes ago, S18 RSG said:

3. If you reply again, you're going to have to type " You cant have your cake and eat it" again, and I just can't hear more stories about cake today.

Let's do this again sometime  

he might just want cake he can eat? 

[Ade 517]

A 50mm bump is not that big. Plenty of crappy UK roads have bumps like that. I've bottem out front and back on mine during quick B road driving.

I wasn't trying to rub In the fact I have the Ohlins and therefore my opinion is more valid, because its not. Sorry if it came across that way. Just trying to explain the fact that they are also compromised in terms of bump travel even at that price. Obviously valving plays a part too, but if its close to critical damping, the compression damping wont save the jolt from hitting a bumpstop hard. Thankfully the Ohlins are setup with more rear travel so the front bottoms out first which means you are less likely to lose the backend first.

Cake is good when you can eat it though  The Ohlins TTX stuff is stunning.

[Nicebiscuit 655]

I don't care that there's no conclusion. That'd be too easy, and in any case we'd all then say 'buy X' - job done

The point of starting this thread was to gather both experience and opinion in one place. That seems to be working out rather well.

And we can talk about cake too if you like...

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