Trying to understand rear shock top mounts...
 

So I'm new to this whole suspension thing, but I'm very tempted by this combination being offered by Raceseng:

http://www.raceseng.com/kw-variant-3...ubaru-brz-2013

http://www.raceseng.com/media/raceseng-kw-features.jpg

So everything makes sense to me. This includes the rear shock top. I get that moving the mounting point 2" higher basically gives you 2" of additional shock travel to work with. What I don't understand is how you account for this with the V3 coils if you only intend to drop your car about 1".

So I have a mount that is 2" deeper than stock... and I only want to lower the car 1". Does that mean that I need to... extend the coilovers? There is something I'm not understanding about the mechanics of this setup? Are these only intended for people who plan on slamming their car to the ground while not running up against the strut's bump stops? Am I basically not in need of these replacement mounts on the rear at all?

Thanks for the help!

I would not recommend the 2 inch drop mounts if you only plan on lowering the car 1 inch.

- Andrew

That's what I thought. I know I can buy separately, but when I saw as a package deal, I was confused, as I figured people buying the V3s are not generally the ones dropping the car to the ground.

As a follow-up, for around the same price as what I posted above, I could go with this instead. Not too knowledgeable about such things. I know Ohlins is the "better" coilover company, but the camber plates don't look quite as sophisticated as the Raceseng ones. Which kit would be the better option? My original reason for the V3s was the softer spring rates, as while I do participate in autocross and will do a few track days, this is still my only car and mostly a DD that does many road trips and needs to survive Chicago roads year-round (I don't intend on removing the coilovers in the winter.) I want the car to still be somewhat comfortable in the environment in which it will mostly be used. I'm only dropping 1" to eliminate some of the fender gap.

https://www.rallysportdirect.com/par...rack-coilovers

https://res.cloudinary.com/rallyspor...ohl_sus_mi20_6

I ran nearly the same setup the Racesng is selling for about a year. Based on my experience I'd skip the rear upper mounts and stick with OEM ones. The front CASCAM plates from Raceseng are way better than the ones that come with the Ohlins.

If you are comparing the costs, you need to consider that the Raceseng CASCAMs and Shock Tops are an upgrade for the V3s. The price on the Ohlin set you linked does not include the upgraded upper mounts.

What kind of tires and what size do you plan on running?

- Andrew

Try contacting @Raceseng to see if you could have them swap the rear tops for the 1" vs the 2" ?

If you want to have the Raceseng Cascam front + Ohlins, take a look at what I ran before:

http://www.ft86club.com/forums/showthread.php?t=48679

Just keep in mind, the Cascam would be ideal if you want more caster or you want the fronts to be lower. Otherwise, it's a nice but expensive upgrade if your coilovers already have front pillowball adjustment.

As for rears, shock travel and ride height are not the same. Do not mix them up. Ride height is determined by your spring free height, spring rate, and adjustability of rear lower shock mount bracket.

-alex

For DD use, I've got a set of HRE FF15 18X9ET40 that I just put Michelin PSS 255/35R18 tires on. I eventually intend on getting a separate set of 17" wheels for track/autocross use with something more like RE71Rs.

Your thread is what had me looking at the Ohlins to begin with. Honestly, the problem is that I'm trying to scrounge up the money to get all these parts together by spring, but I had originally intended to spend $3k at most for coilovers/camber plates/LCAs. Now I'm looking at a bit over $3k for JUST the coilovers and camber plates (and more like $3500 for the Ohlins and Raceseng plates, which looks like an amazing setup.) I could always survive without rear LCAs for a bit. I want NICE parts on the car, so I don't necessarily have anything against spending that much, but I don't want to overspend unnecessarily on what will realistically be a 95% DD car that needs to be comfortable on long road trips too.

My tuner (Sharif at Forged Performance) was just telling me yesterday that Ohlins has a new version for our cars that uses OEM top hats and softer springs that is much cheaper, $2400 MSRP vs. $3100. He can get them for you and will price match anyone.

Okay, just thinking about how much camber would be useful for you. Nice wheels btw!

I agree with Bob...the rear mounts may not necessary for you. The front Raceseng plates are very high quality pieces that are an upgrade worth considering. You can get a decent amount of camber without plates with KWs, but the plates are still worthwhile.

The "old" Ohlins are very good coilovers as well. A little more money. I think either option would work for you. I'm not sure I recommend the "new" Ohlins for your uses.

We're working on getting Raceseng to carry our RCE T2 coilovers, which are custom KW Clubsports with unique spring rates, valving, and a warranty. They would be a little more aggressive than V3s and the Ohlins if that's the direction you'd like to go. Still pretty good ride quality.

- Andrew

Well, nobody really explained the top hats... Here's a pic from Raceseng's site, the spring will sit under the top hat plate and the damper body to the bottom of top hat distance will remain the same:

http://www.raceseng.com/media/strut-top-sidebyside.jpg


The advantage is that because it's recessed the bump stop shown on the right side will nestle inside the top hat meaning the damper (and entire suspension) can travel further in compression/bump without bottoming out. However this still leaves opportunity for other suspension components to bottom out (like upper wishbone) and reduces how far the damper and suspension can 'hang down' or 'droop travel'

For the V3's it will be different from the picture on the right as I don't think they come with rear top hats, they come with adapters to go into the OE top hats which look like the picture below (not very good, I can post a better one later tonight if I remember), the spring is pushed down away from the chassis by about one inch. So if you took off the shelf V3's (or any other coilover changing from OE top hat) and mated to the Raceseng's you'd have to move the spring perch up ~1" to get the same ride height which should not be a problem at all.

http://www.rallitek.com/13912-home_d...012-5-2014.jpg


Another pic stolen from Raceseng showing the threaded damper body which allows you to move the spring perch up and down:

http://www.raceseng.com/media/height-adjustment.jpg

Like mav said, travel and height are two different parameters.

I want to start out by stating that I appreciate everyone's input.

Is there anywhere for me to get more information about these?

Okay, that makes a lot more sense. It's the spring that I wasn't thinking about. I understand now. Thanks!

It sounds like I'll definitely want the Raceseng plates then. They look lovely, and they do seem functional. $500 is a lot, but they look like they're worth the price (I read through the development thread for them). I want the ability to adjust front camber for autocross, mainly, but it looks like I'm going to need it anyway for the DD wheels to look "right" on the car (as much as I'm all about form over function, I don't want my front wheels poking past the fenders too much.)

It also sounds like I don't need the 2" rear top hats, but perhaps I should look at the 1" rear hats. If I'm understanding everyone's descriptions properly, they don't affect the ride height, because they don't shift the SPRING mounting point (which is what the car really sits on.) They just allow the strut to stick out a little further, which means you stay away from the bump stops. In that case, it sounds beneficial, though I'm wondering if it's better to hit the bump stops on the strut, vs. bottoming out something else, or over-flexing some other suspension component. I'm wondering what you guys suggest, then? If I'm only lowering the car ~1", are they even worth it, or should I keep the OEM top hats, which I'm sure would be slightly better from an NVH standpoint anyway.

I had considered the Tarmac 2s, but I don't really track or autocross my car ENOUGH for the increased ride stiffness to be worth it, I think. As I said, this car is mostly a DD. So that left me bouncing between the Ohlins and the V3s. Though now I'm hearing there are "new" vs. "old" Ohlins, and I'm not really sure what the differences are (spring rates?) At this point, it seems to simply be a matter of whether you guys think the Ohlins are worth the price differential. I can get a set of V3s through ft86speedfactory for $1899 shipped! That's a HELL of a lot cheaper than the $3150 for a set of Ohlins, but if the Ohlins are really worth that much more...

...it's also worth noting that I intend on leaving these struts on the car year-round. That means salt, and lots of it, which is one of the main reasons why I want a better set of coilovers that will survive without rusting to hell. I will likely buy covers for them, and since I don't plan on changing the ride height once I lower it, I might paint the threads with a thick layer of plastidip or something too, and perhaps find some rubber end-caps to slide over the adjustment ends to protect them.

So, what do you guys thing, then? KW V3s or Ohlins? (new or old)

Killboy is referring to the "new" Ohlins I mentioned, the MP20 kit. There is some discussion on them towards the end of this thread:
http://www.ft86club.com/forums/showt...t=48679&page=8

They are cheaper and do not come with top mounts (which is great if you're considering adding your own plates). They are very soft though. The rear spring rates are actually softer than stock. I don't necessarily recommend those for most people.

Yes, strat61caster is right on with the rear mounts. Another way to think about them is that at a given ride height, the 2 inch drop mounts will have 2 inches more bump travel than the stock mount. The issue is you can only run the KWs so high...a 10mm drop is kind of the minimum. So with that in mind, a 1 inch drop mount does make more sense, although I'd probably stick with stock if you plan on just a 1 inch drop overall.

- Andrew