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      04-13-2014, 04:38 PM   #1
VictorH
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What kind of ride? 600/900 springs

I currently have 425 front and 700 rear Hyperco springs with a JRZ RS-1 set up. Ride on the street is great, shocks set soft are as soft as stock, but a bit bouncy, 6 clicks front and rear is a bit firmer than stock but very acceptable and where I run on the street.

If I only drove on the street, this would be the ideal set up, and on the track if I only drove VIR I'd be fine and stick with this set up. Road Atlanta, which is probably my favorite track, has two turns where this set up bottoms out and not just a little bit. My options include some sort of custom bump stop or the proper route, I'm told is stiffer springs. Recommended set up is 600 Front, 900 Rear. 99% of my driving is freeway and this car is my daily driver. Track use is 3-6 times per year.

Questions:
1) Will I hate my car with these springs?
2) How much stiffer percentage wise will this feel? it's an almost 50% increase in spring rates, will it feel 50% stiffer?
3) What would you do? Live with it as is and go with some sort of custom bump stop or switch to the stiff springs?
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      04-13-2014, 07:02 PM   #2
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I'm running 600/800 lbf/in F/R on my JRZ RS1s and it's my primary street car. Rear suspension setup also uses BWs rear AL suspension arms with rod ends, and their F LCAB (thrust bearing). Personally, I find this a very comfortable setup on the street. I'm considering switching to MCS 2WNR dampers with higher spring rates and F suspension AL arms with rod ends, and I'm not at all concerned about the ride on the street.

So, at least for me, I'd have no trouble running 600/900 lbf/in F/R spring rates on an M3 used as a daily driver but, just like exhausts, everyone has their own tolerance level. It's not too difficult to swap springs so swap in the new rates, drive the car a few weeks, and then find out if you can tolerate the higher rates on the RS1s. Good luck!
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      04-13-2014, 11:39 PM   #3
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Running 690/900 here. Love it, street ride is better than stock with dampers set to 1 click above full soft. As long as your shock is set for it you should be fine.
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      01-27-2015, 12:48 PM   #4
Mvez
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Reviving an old thread as I prepare for things. My car would be track only, so I'm thinking 700/900 or 700/1000 for spring rates. It will be lighter too, think mildly stripped interior (all carpets, seats).

Still deciding on shocks, I want a single adjustable setup. I've been on revalved Ohlins R&T for high rates, and they are fantastic. Also had them on my GT3RS, and they are were awesome (they came with more track focused rates for that kit). Most people discount this setup because of low spring rates, but just have somebody like PSI revalve them for high rates and you have a great track setup, with long rebuild intervals.

Nitrons are supposed to be great, but rebuild intervals are supposedly much shorter.

JRZ and MCS are also options. Tough to decide.
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      01-27-2015, 01:08 PM   #5
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Quote:
Originally Posted by Mvez View Post
Nitrons are supposed to be great, but rebuild intervals are supposedly much shorter.

JRZ and MCS are also options. Tough to decide.
I have Nitrons on my daily E90 M3, albeit they are the NTR R3 version, three-way adjustable. Pics can be found in the Suspension Sticky under Coilover Upgrades for M3. I am also running the Bimmerworld rear spherical conversion, among other things. I want to eventually switch to a full coil over in the rear, but need to cage the towers before doing so, and this will allow me to run a softer spring (600lb) without giving up performance (The motion ration is different from the stock location, allowing a softer spring).

600F/800R and the ride is not bad. I have the shocks set slightly above rain settings for the rear (-12 is rain setting from Nitron), basically this:

Front
Comp High -12
Comp low -12
Rebound Low -12

Rear
Comp High -15
Comp Low -15
Rebound Low -12

I am still playing with the adjustability and every click can be felt. These things SHINE at the track and make the mountain twisties a breeze to drive on. Nitron recommends 2 years or something like 20k miles before a rebuild but if you look at some of the youtube video from Nitron USA, the shocks are made with quality parts and IMHO can be pushed further than the advised time frame.

Nitron offers a one-way shock as well, which has all the tech of the R3 setup without the piggy backs. I might be mistaken but I think the R1 can also be upgraded to R3 down the line, with a few modifications.

In all honesty, Motion Control, JRZ, Ohlins and Nitron are all a tough choice as they are all really really good shocks.

I got Nitron because no one runs them and wanted to be different...also the Top Gear episode where they run a set in that weird looking car they try to compete with the Lotus, helped a bit.

Last edited by italyix; 01-27-2015 at 01:15 PM.
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      01-27-2015, 02:03 PM   #6
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Not sure what JRZ suspension is
coilovers or stock shocks?
but 600/900 is soft as hell like mushy oem..
I have 14k/18k on fortune auto coilovers, and am upgrading to 32k for the rear of my E93 but that's a very slammed car so it's necessary..
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Last edited by GabeS; 01-27-2015 at 02:13 PM.
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      01-27-2015, 02:52 PM   #7
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Quote:
Originally Posted by GabeS View Post
Not sure what JRZ suspension is
coilovers or stock shocks?
but 600/900 is soft as hell like mushy oem..
I have 14k/18k on fortune auto coilovers, and am upgrading to 32k for the rear of my E93 but that's a very slammed car so it's necessary..
All BMWs have a rear divorced coil and shock and so do all aftermarket kits, as a true coil over would rupture the sheet metal on the towers if not reinforced.

I hope ur joking about the mushy feel...but I think valving on the shocks plays a huge part in feel. My 600/800 setup can be back breaking if on track setup or stiffer.
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      01-27-2015, 03:30 PM   #8
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Quote:
Originally Posted by italyix View Post
All BMWs have a rear divorced coil and shock and so do all aftermarket kits, as a true coil over would rupture the sheet metal on the towers if not reinforced.

I hope ur joking about the mushy feel...but I think valving on the shocks plays a huge part in feel. My 600/800 setup can be back breaking if on track setup or stiffer.
Yeah, I know how our suspensions have the separate spring from the shock. I just never heard the JRZ term.
so I assumed it's an aftermarket coilover?

Because if you are talking about aftermarket lowering springs, for oem suspension, then the rates I mentioned are gonna be different, I am talking about coilover springs.
I currently run 14k/18k, but it's too soft and bottoms out all the time and has way too much squat, I have a set of swift 32k springs I ordered but they are only made in 6" so I have to have a custom extension on the mounting point.
and yes, my coilovers are valved for much stiffer springs.

A ton of my friends run spring rates upwards of 12k, and they consider their rides smooth and comfortable.
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      01-27-2015, 03:44 PM   #9
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Quote:
Originally Posted by GabeS View Post
Yeah, I know how our suspensions have the separate spring from the shock. I just never heard the JRZ term.
so I assumed it's an aftermarket coilover?

Because if you are talking about aftermarket lowering springs, for oem suspension, then the rates I mentioned are gonna be different, I am talking about coilover springs.
I currently run 14k/18k, but it's too soft and bottoms out all the time and has way too much squat, I have a set of swift 32k springs I ordered but they are only made in 6" so I have to have a custom extension on the mounting point.
and yes, my coilovers are valved for much stiffer springs.

A ton of my friends run spring rates upwards of 12k, and they consider their rides smooth and comfortable.
Talking about coil over springs. I would be super careful about running 32k in the rear, as it would be a spring equivalent of around 1800lbs. At that rate, I am not sure the subframe would hold. Even a 1000lb spring would be pushing it, which is why Bimmers generally do not go over 800lbs in the rear.

Are you on linear or progressive?
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      01-27-2015, 04:15 PM   #10
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Quote:
Originally Posted by italyix View Post
I have Nitrons on my daily E90 M3, albeit they are the NTR R3 version, three-way adjustable. Pics can be found in the Suspension Sticky under Coilover Upgrades for M3. I am also running the Bimmerworld rear spherical conversion, among other things. I want to eventually switch to a full coil over in the rear, but need to cage the towers before doing so, and this will allow me to run a softer spring (600lb) without giving up performance (The motion ration is different from the stock location, allowing a softer spring).

600F/800R and the ride is not bad. I have the shocks set slightly above rain settings for the rear (-12 is rain setting from Nitron), basically this:

Front
Comp High -12
Comp low -12
Rebound Low -12

Rear
Comp High -15
Comp Low -15
Rebound Low -12

I am still playing with the adjustability and every click can be felt. These things SHINE at the track and make the mountain twisties a breeze to drive on. Nitron recommends 2 years or something like 20k miles before a rebuild but if you look at some of the youtube video from Nitron USA, the shocks are made with quality parts and IMHO can be pushed further than the advised time frame.

Nitron offers a one-way shock as well, which has all the tech of the R3 setup without the piggy backs. I might be mistaken but I think the R1 can also be upgraded to R3 down the line, with a few modifications.

In all honesty, Motion Control, JRZ, Ohlins and Nitron are all a tough choice as they are all really really good shocks.

I got Nitron because no one runs them and wanted to be different...also the Top Gear episode where they run a set in that weird looking car they try to compete with the Lotus, helped a bit.
That's good to know. I really like what I hear about the Nitrons, 1-way is what I was looking at. Ohlins have about the same rebuild "recommendation" but can also go longer too. Mine will not be a daily driver, and I previously used 700/800 rates on my E46, which was track only and much lighter too (about 3150 lbs). Those seemed to work well. Seems like 600-700 front, and 900 rear might be a good starting place.
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      01-27-2015, 05:30 PM   #11
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Quote:
Originally Posted by italyix View Post
Talking about coil over springs. I would be super careful about running 32k in the rear, as it would be a spring equivalent of around 1800lbs. At that rate, I am not sure the subframe would hold. Even a 1000lb spring would be pushing it, which is why Bimmers generally do not go over 800lbs in the rear.

Are you on linear or progressive?
Fortune auto advertises them as Digressive piston technology.


Oh, I know I am sort of overdoing it, My car is pretty slammed, and the E93's differential sits low to the ground already, it bopttoms out hitting the pavement at hi speed fwy bumps, in CA, shitty fwy's
I am a drift/stance guy, I guess, and to not damage fenders and not bottom out I need overly stiff springs(I am not recommending everyone go run 20k plus.. not if they don't need it at all.
but being a fat hog that my E93 M3 is, Ineed to go much stiffer then the E92.
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