Hello all, I have a 2008 NC PRHT; I have installed Bilstein B12 Pro kit suspension.
For some reason the back end is cocked up in the air, the front has settled nicely and a reduction in height by around 30mm as expected. The back end from ground to wheel arch is now higher than with the standard shocks, about 700mm.
I have had the wheels off again, undone all the relevant nuts and bolts; put it on the ground, done them all up again; even compressed the springs and tightened all nuts and bolts with it like that but it’s still jacked up.
All help very welcome.
I can empathise with your dilemma as I have recently removed, cleaned and refitted the std suspension and found it is riding 20mm higher than I expected.
Pictures of the car prior to my recent ownership appear to show the elevated ride height so its looks like it’s being like this for ever…
My solution was to install adjustables, I note the B12 are not adjustable! The only theory for your situation is that the springs are the wrong spring rate for your car, are they marked.
As stated talk to the supplier if they are new.
I did not have the confidence to install lowering springs as I did not understand why the car stood so high on what I believe are std springs hence could not guarantee a new spring would change much.
Hello, I made sure that they were the correct way round the longer ones were defo on the front, that end has sat just right at the height expected. As other have said I guess contacting the supplier is the way; possibly the wrong springs were included.
That’s very strange, I’ve just had the B12 kit fitted to my 2007 Icon and it sits beautifully. Going by some earlier posts on here I was worried that it would be too low, but it’s perfect and even rides speed bumps better than my standard NB.
For the guys n gals with lowering kits and coilovers, how far above the ground does the lowest part of your MX5 sit? I really want to lower mine but not if I’m going to scrape on every little bump etc. Cheers.
From a geometric point of view, the chassis bush ctr should be 10 to 15 mm higher than the centre of the outer ball joint ctr. This is the mechanical linkage arrangement, height can be affected by tyre wall and rim size
This is based on the theoretical and mathematically calculated weights and forced designed into the original link arrangement.
Based on that anything else is a compromise on handling.
How low do you want to go and what is your criteria other than handling?
Hello, I was wanting to improve the handling a little from the standard and after lots of reviewing and input from gurus on this forum the B12 kit was the way to go it would lower the car approx 30mm and give a more planted ride. Apparently the shocks should bolt straight in and Bob’s your uncle; but as you see half the car is as expected but the other half not??? I am no tech wizard I’m afraid.
I would suggest a wheel center to arch of no less than 320mm on 205/45/17 to avoid regular underbody contact. You will start introducing compromises at this height if you are just changing springs, 335 - 355 is a better range which should be around 25 - 45mm drop.
Hello all, thought I would update if anyone is interested; I took the advice given and checked once again it seems from a bit of Googling parts numbers that I might have been supplied with two sets of front springs (longer); or the wrong set for the car; I believe the springs are different depending on soft/hard top and wheel size?
I am in convo with the supplier at the moment and hopefully will get some resolve soon.
The front is sitting at 340mm from wheel centre to arch which is just as expected and the rear 400mm.
Cheers all.
Your fronts are more or less spot on for height, mine measure 335mm, same at the rear but I have MeisterR’s. They weren’t far off that measurement with lowering springs on Bilsteins, so definitely you have the wrong springs on the rear.
I remember jacking up the back of a MK 1 Escort back in the day; has that look about it. I am waiting on the suppliers to come back to me, I think the wrong springs were supplied.
Cheers
