Moving on from M sport suspension
- Thread starter Z43.0Si
- Start date
Yes, about £350 for ARBs and you get less roll but same original ride height and ride comfort (almost). They are adjustable so you can tune under/oversteer characteristics. I also think the coupe has far too much body roll. Looking at the ARB sizes it's clear why, our 330 touring has a larger front bar...same size as the H&R before adjustment at 27mm.
The only other way to resist sustained body roll through longer corners is stiffer springs which compromises ride comfort all the time. Stiffer ARBs do mean slightly less independent wheel travel and if you go too stiff you can get wheels pawing the air so could result in a reduction in traction. It's all a balancing act.
I fitted Whiteline ARBs to my old Integra Type-R on standard suspension and it made it a lot nicer to drive as it took out the roll and allowed me make it more tail happy without having to redo all the suspension and lose ride height.
I fitted Whiteline ARBs to my old Integra Type-R on standard suspension and it made it a lot nicer to drive as it took out the roll and allowed me make it more tail happy without having to redo all the suspension and lose ride height.
pokeybritches
Member
Move to linear springs. They have less slop but less compliance as compared to the stock progressive rate springs. Linear springs are normally more predictable.
Most aftermarket spring-only kits are progressive, so you will likely need coilovers.
Most aftermarket spring-only kits are progressive, so you will likely need coilovers.
Both linear springs, stiffer arb's and also stiffer dampers will reduce body roll.
Stiffer arb's will have the least impact on comfort, but will also have the least impact on other aspects of roadholding.
The improvement of a decent set coilovers with linear springs is considerable when cornering, but also in the comfort zone
Pricewise the first thing you do is stiffer arb's. cheaper to buy, easier to fit. If you still want more performance and think you can still cope with some extra stiffness, you get coilovers with linear springs.
But with each step you're transforming the car to a car that is more fun when driven hard and less fun when driven slowly.
Stiffer arb's will have the least impact on comfort, but will also have the least impact on other aspects of roadholding.
The improvement of a decent set coilovers with linear springs is considerable when cornering, but also in the comfort zone
Pricewise the first thing you do is stiffer arb's. cheaper to buy, easier to fit. If you still want more performance and think you can still cope with some extra stiffness, you get coilovers with linear springs.
But with each step you're transforming the car to a car that is more fun when driven hard and less fun when driven slowly.
Depending on where you are in surrey/Hants you're welcome to have a bit of a go in mine provided you don't moan about how unbalanced the front alloys are currently :lol: Spec as per my sig below.
There is a little more harshness, but not that bad at all - I daily mine and have no issues whatsoever. It's an absolute joy to drive hard now too - I'm on the cusp of getting booked in for the next Goodwood trackday - just as soon as my wedding has been and gone... :roll:
There is a little more harshness, but not that bad at all - I daily mine and have no issues whatsoever. It's an absolute joy to drive hard now too - I'm on the cusp of getting booked in for the next Goodwood trackday - just as soon as my wedding has been and gone... :roll:
I got mine recently from carparts4less when they had 10% off performance parts. Normally performance parts are excluded from eurocarparts sales unfortunately.
I'm still playing with the settings but I started on hard front middle rear which was too much snap understeer. Then tried hard front and hard rear which felt a bit like it was on tea trays, definitely too stiff for the standard springs as it was picking up inside wheels too much under high load then snapping into oversteer. Now on soft front and middle rear but I'm going to change the rear to soft too as it's still a bit artificially slidy at the rear, particularly in the wet. In other words I recommend you use the softest settings front and back which are the holes at the end of the bars.
Much nicer than stock though which has an uncomfortable amount of roll. The front is easy to fit but the back is fiddly and I had to undo the chassis bracing. Not a big deal but much more time consuming.
I'm still playing with the settings but I started on hard front middle rear which was too much snap understeer. Then tried hard front and hard rear which felt a bit like it was on tea trays, definitely too stiff for the standard springs as it was picking up inside wheels too much under high load then snapping into oversteer. Now on soft front and middle rear but I'm going to change the rear to soft too as it's still a bit artificially slidy at the rear, particularly in the wet. In other words I recommend you use the softest settings front and back which are the holes at the end of the bars.
Much nicer than stock though which has an uncomfortable amount of roll. The front is easy to fit but the back is fiddly and I had to undo the chassis bracing. Not a big deal but much more time consuming.
As mentioned above BMW use progressive rate springs, which if you have a look at them you will notice the coils on the ends are thinner gauge than the middle, so the first few inches of suspension movement is softer, the principle is sound for a road car you get a better ride (especially if your sticking with runflats) but it comes at a price, progressive rate springing means progressive rate roll, it goes hand in hand!
The excess body roll on the track is the first couple of inches of travel compressing, I note on my Z4 you have to turn in abruptly to transfer weight and load the spring to get her to bite, it's not a trait I like in a car, especially if your going through a chicane where you switch direction quickly leading to a horrible lurch off one spring to the other.
To control roll you can switch to linear springs, it brings with it a considerable improvement in response but at the expense of ride quality dependant on how stiff you go.
You can run stiffer dampers which slow the rate of roll but ultimately do not limit it as such, but can give a very good suspension control you can adapt to different conditions.
Or you can uprate the anti roll bars as mentioned above, BUT, anti roll bars also come with a penalty on the track, road tyres don't like too much weight dumped on them unlike race tyres, and A/R bars work by transferring weight from the unloaded to loaded wheel, they are useful if adjustable to tune handling but ultimately you want to reduce weight transfer as much as is practically possible with road tyres.
Ideally you do all three
This company advertise the ability to make springs for your car - http://www.coilsprings.co.uk/index.html , BUT, you have to know what springs you want, and believe it or not the coil rate is the last thing you calculate, a 300lb spring on a westfield is rock hard, same spring on a Bentley and it's soft as a sponge, the difference is not just the weight, it's the suspension leverage and the wheel to spring ratio.
You have to start with the required spring frequency, expressed imperially as CPM, cycles per minute, or it can be done in metric, but as I'm an old git I stick to CPM.
If your interested in doing this kind of thing, and it's not as complicated as it seems, it's not easy mind you, but there are several easily sourced books on the subject, Competition Car Suspension by Alan Staniforth is a very good text book written for laymen https://www.amazon.co.uk/Competition-Car-Suspension-Practical-Handbook/dp/1844253287 , it explains what's going on and is well worth the read!
I'm going to be weighing and measuring my own Z this winter and doing a set of figures which will give the CPM ratings of several spring rates, if you have a 3.0I it will be possible to just copy the figures, if you have a 2.0 or a lighter car you can use it as a guide.
The excess body roll on the track is the first couple of inches of travel compressing, I note on my Z4 you have to turn in abruptly to transfer weight and load the spring to get her to bite, it's not a trait I like in a car, especially if your going through a chicane where you switch direction quickly leading to a horrible lurch off one spring to the other.
To control roll you can switch to linear springs, it brings with it a considerable improvement in response but at the expense of ride quality dependant on how stiff you go.
You can run stiffer dampers which slow the rate of roll but ultimately do not limit it as such, but can give a very good suspension control you can adapt to different conditions.
Or you can uprate the anti roll bars as mentioned above, BUT, anti roll bars also come with a penalty on the track, road tyres don't like too much weight dumped on them unlike race tyres, and A/R bars work by transferring weight from the unloaded to loaded wheel, they are useful if adjustable to tune handling but ultimately you want to reduce weight transfer as much as is practically possible with road tyres.
Ideally you do all three
This company advertise the ability to make springs for your car - http://www.coilsprings.co.uk/index.html , BUT, you have to know what springs you want, and believe it or not the coil rate is the last thing you calculate, a 300lb spring on a westfield is rock hard, same spring on a Bentley and it's soft as a sponge, the difference is not just the weight, it's the suspension leverage and the wheel to spring ratio.
You have to start with the required spring frequency, expressed imperially as CPM, cycles per minute, or it can be done in metric, but as I'm an old git I stick to CPM.
If your interested in doing this kind of thing, and it's not as complicated as it seems, it's not easy mind you, but there are several easily sourced books on the subject, Competition Car Suspension by Alan Staniforth is a very good text book written for laymen https://www.amazon.co.uk/Competition-Car-Suspension-Practical-Handbook/dp/1844253287 , it explains what's going on and is well worth the read!
I'm going to be weighing and measuring my own Z this winter and doing a set of figures which will give the CPM ratings of several spring rates, if you have a 3.0I it will be possible to just copy the figures, if you have a 2.0 or a lighter car you can use it as a guide.
Thanks for all your valuable info, what a wealth of knowledge this forum is!
Slightly worried that if I just go for the H&R roll bars now I won't necessarily achieve much due to the progressive rate M-Sport springs and Dampers. I was thinking of going for some Eibach springs but I guess apart from further lowering the car I won't see much of a gain either? I don't think at this stage I can warrant the cost or ride during normal use of coilovers. Help ............
Slightly worried that if I just go for the H&R roll bars now I won't necessarily achieve much due to the progressive rate M-Sport springs and Dampers. I was thinking of going for some Eibach springs but I guess apart from further lowering the car I won't see much of a gain either? I don't think at this stage I can warrant the cost or ride during normal use of coilovers. Help ............
Z43.0Si said:
If the car is a keeper, then I highly recommend a set of KW V3s. Expensive but awesome on the road and easily asjustable to harden them up to make it like glue on the track. I found the stock car to be not planted, comfortable and crashy for fast road runs, but then too soft and twitchy on the track for fast reliable laps. Sitting in the middle of both worlds.
Like a fair few on the forum I took my Z4MC from stock to well modded. The Eibachs were a worthy good value upgrade, I did them at the same time as getting a sturt brace, and changed the geo away from the stock understeery setup, adding some neg camber and reducing toe. I kept the stock ARBs. I found the car was nicely improved. Yes there is still some roll, and i am aware the MC has the 27mm ARB as standard so it resists rolling better than the non M thinner ARB. As you know it all depends on what result you want. If you are serious about improving the car beyond a 10-15% max improvement then you will have to spend a decent amount of cash. If you can't justify that then just change the springs next with the H&R ARBs, see how it feels and go from there. Oh and get the RTAB limiter kit if you haven't. Blinding upgrade for little money.
The ARBs are still worth it, I have stock M Sport suspension. Just don't bother with the harder settings. An ARB effectively compresses the unloaded wheel suspension due to equal and opposite forces so too stiff compared to the springs and it unloads the tyre. The car feels much more planted now I've backed it off and cornering speeds are up compared to stock.
I think I'll get the ARB's with the intention of upgrading the suspension at a later date. The car is most definitely going to be with me for a long time! One consideration is that I have a 2500 mile trip into Europe planned next year, coil overs would probably finish me off!
Twin Turbo
Active member
With suspension it can be bit of a bind date
You read the profile and hope you get it right - as to achieve your requirements there are three paths to go:-
But beautify is in the beholder - so personally I would try and get rides in peeps cars - and have a ride before you by.
I had the same issue - but ended up going for KW3's - but suspension is very personal preference. I know there is another forum member went for ARB -but now planning going for KW3's
I have no regrets - but since they are linear they don't soak up small imperfections in the road - however quick roads there are really and I mean really good.
You read the profile and hope you get it right - as to achieve your requirements there are three paths to go:-
But beautify is in the beholder - so personally I would try and get rides in peeps cars - and have a ride before you by.
I had the same issue - but ended up going for KW3's - but suspension is very personal preference. I know there is another forum member went for ARB -but now planning going for KW3's
I have no regrets - but since they are linear they don't soak up small imperfections in the road - however quick roads there are really and I mean really good.