KW Clubsport - Is there a true rear coilover option?

[slicer]

Originally Posted by aus

Can you tell us more about the new offerings?
I always felt Ohlins had a HUGE hole in their line up above the R&T and TTX.
Thanks!
.

I just ordered one of the first "Dedicated Track" kits to inspect and photo. I should have it by the end of this week or early next week. The kit comes with camber plates and rear upper mounts. My understanding is that the basis of the kit is the R&T damper revalved for the higher spring rates. They are using Swift springs. Note that the R&T doesn't come with camber plates or rear top mounts. I did source the spring rates. Below is a comparison of the rates of some common kits:

Ohlins R&T
Front - 60 nm
Rear - 120 nm

Ohlins Dedicated Track
Front - 120 nm
Rear - 180 nm

KW Club Sport - note that KW changed their rates a few years ago.
Front - 110 nm (used to be 90 nm)
Rear - 120 nm (used to be 140 nm)

Ohlins TTX
Front - custom made to order
Rear - custom made to order

[aus]

Originally Posted by slicer

I just ordered one of the first "Dedicated Track" kits to inspect and photo. I should have it by the end of this week or early next week. The kit comes with camber plates and rear upper mounts. My understanding is that the basis of the kit is the R&T damper revalved for the higher spring rates. They are using Swift springs. Note that the R&T doesn't come with camber plates or rear top mounts. I did source the spring rates. Below is a comparison of the rates of some common kits:

Ohlins R&T
Front - 60 nm
Rear - 120 nm

Ohlins Dedicated Track
Front - 120 nm
Rear - 180 nm

KW Club Sport - note that KW changed their rates a few years ago.
Front - 110 nm (used to be 90 nm)
Rear - 120 nm (used to be 140 nm)

Ohlins TTX
Front - custom made to order
Rear - custom made to order

Looking forward to your pics and any information on pricing.
As these 2 way or one way coils?
Thanks again!
.

[Mr_Reeves]

Originally Posted by Expressivedrives

True. E92 is not designed for rear coilover.

You do not need a welded in roll cage to run a true coilover at the rear of E9X.

Nor does the rear axle carrier panel or subframe require any reinforcement. The rear of these cars was over-engineered after the boot floor failures that occurred on the E46. This is particularly true on the E90 which has a stiffer body shell than the E92.

Of course, one should not turn down the benefits of a roll cage in terms of rigidity and safety for hard track use but it is not essential at all to run a true rear coilover on this platform.

[rhyary]

Originally Posted by Mr_Reeves

You do not need a welded in roll cage to run a true coilover at the rear of E9X.

Nor does the rear axle carrier panel or subframe require any reinforcement. The rear of these cars was over-engineered after the boot floor failures that occurred on the E46. This is particularly true on the E90 which has a stiffer body shell than the E92.

Of course, one should not turn down the benefits of a roll cage in terms of rigidity and safety for hard track use but it is not essential at all to run a true rear coilover on this platform.

@Mr_Reeves
Are you speaking from experience?
Can you provide more information on your statement?

[WhiteM3EMC]

Originally Posted by Mr_Reeves

You do not need a welded in roll cage to run a true coilover at the rear of E9X.

Nor does the rear axle carrier panel or subframe require any reinforcement. The rear of these cars was over-engineered after the boot floor failures that occurred on the E46. This is particularly true on the E90 which has a stiffer body shell than the E92.

Of course, one should not turn down the benefits of a roll cage in terms of rigidity and safety for hard track use but it is not essential at all to run a true rear coilover on this platform.

Also curious to see where this info comes from. In speaking with reps from a few companies, cars that are tracked hard are prone to punching out the rear shock mount when using a true rear coilover without reinforcement.

I personally have no experience to speak from, but in this case, I'm inclined to defer to the wisdom of the people who've been testing these cars for a decade.

I will agree, that if you aren't tracking the car crazy hard, you may not NEED reinforcement, but I'd rather know that I won't have any problems, than be hoping that I don't and dealing with an expensive repair bill should my gamble fail.

[SYT_Shadow]

I'd bet the E9X does not need any reinforcement to run a true coilover, however, I'm not willing to bet on my car which is why I run the divorced rear setup.

[Mr_Reeves]

Not personal experience, no.

But I know many who have run a true coilover with a bolt-in cage and/or no cage at all for many years with no issues whatsoever. Many of which having done dozens of Nurburgring trips which is a circuit that is particularly tough on suspension.

I have put this same question of the dangers of running a true coilover without reinforcement to the rear strut tower to the people who have been working on these cars for years and performed bare-shell builds, and they have assured me that the rear of these cars is very strong and does not require reinforcement. I know that is a bit of an appeal to authority fallacy but BMW over-engineered the rears of these cars.

If you want to add extra reinforcement, then by all means. However you do not need to reinforce the rear strut tower in these cars in order for them to safely accept a true coilover.

[WhiteM3EMC]

Originally Posted by Mr_Reeves

Not personal experience, no.

But I know many who have run a true coilover with a bolt-in cage and/or no cage at all for many years with no issues whatsoever. Many of which having done dozens of Nurburgring trips which is a circuit that is particularly tough on suspension.

I have put this same question of the dangers of running a true coilover without reinforcement to the rear strut tower to the people who have been working on these cars for years and performed bare-shell builds, and they have assured me that the rear of these cars is very strong and does not require reinforcement. I know that is a bit of an appeal to authority fallacy but BMW over-engineered the rears of these cars.

If you want to add extra reinforcement, then by all means. However you do not need to reinforce the rear strut tower in these cars in order for them to safely accept a true coilover.

Interesting. Thanks for the info!

[aus]

I was able to speak to AST guys and they run a true coilover for our car.
They said they've always used a true coilover for the E9x series and never had an issue, even in street cars and HPDE street cars.

.

[tsk94]

I think it's true you can somewhat safely run a rear coilover on this chassis without reinforcement. The caveat being, it depends on the rear spring rate you're running.

Obviously for these street cars, or dual purpose cars, they'll be using considerably lower spring rates than a true track or race car. As a result, the stress on the unreinforced chassis will be significantly lower.

The real question is, can I run a rear coilover with X spring rate without reinforcing the chassis. Depending on the spring rate you run will determine whether or not reinforcement is required. Frequency of hard track use is also a factor. Even with a lower spring rate a frequently tracked car will experience more stress and may lead to failure over time.

[Willem3]

I know that Intrax said it can be used without problems, they tested it on race cars.

[M3ANMACHINE]

Originally Posted by slicer

Yes, not an apples to apples comparison

Ohlins did just release a track kit slotted in the KW Clubsport price point. I haven't tested it but it looks promising.

Ohlins TTX is of course their true Motorsports level line. FWIW I have had 2 TTX kits on my personal car with zero issues and amazing results.

This interests me

[WhiteM3EMC]

Originally Posted by tsk94

I think it's true you can somewhat safely run a rear coilover on this chassis without reinforcement. The caveat being, it depends on the rear spring rate you're running.

Obviously for these street cars, or dual purpose cars, they'll be using considerably lower spring rates than a true track or race car. As a result, the stress on the unreinforced chassis will be significantly lower.

The real question is, can I run a rear coilover with X spring rate without reinforcing the chassis. Depending on the spring rate you run will determine whether or not reinforcement is required. Frequency of hard track use is also a factor. Even with a lower spring rate a frequently tracked car will experience more stress and may lead to failure over time.

That's why I copied your rear shock reinforcement! I don't wanna be limited on my spring rate options.