first350
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| posted on 21/5/11 at 03:14 PM |
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ride height adjustments...coilover questions
I'm trying to dial in my suspension, and all of the coilovers I've worked with have been on cars....and these are fairly different.
specs:
-Inboard front
-Miata donor
-195/50/15 tires (R888's)
-goal: front lower control arms level w/ ground and Rear about 10mm higher than front.
Questions:
1) The lower spring perches only have 1 collar...does the weight of the car keep that in place? (I've always had 2 collars, that can be
tightened to each other to lock in the height)
2) To get my rear low enough, the spring collar is threaded so far down that when the car is on jack stands, the springs are loose. Is this ok?
(I've seen other car coilovers that use "spring helpers"...basically a 2nd thin spring that doesn't add any force, but takes
up the slack when the car is on jack stands)
coilover w/ spring helper:
here's a pic of the front coils...this is how my rear look to get the right height (the spring is loose)
Cheers!
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bassett
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| posted on 21/5/11 at 04:02 PM |
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I remember mine feeling a bit loose but the weight soon takes care of that and all of them only have one spring i guess due to the short length
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tomgregory2000
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| posted on 21/5/11 at 04:18 PM |
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mine have a grub screw in them to keep them in place
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Davey D
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| posted on 21/5/11 at 05:00 PM |
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on the back of mine if i have it on axle stands the springs drop from the top cup. once it is dropped to ground though they always relocate with an
un-nerving twang noise :-)
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first350
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| posted on 23/5/11 at 01:43 PM |
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quote:
Originally posted by Davey D
on the back of mine if i have it on axle stands the springs drop from the top cup. once it is dropped to ground though they always relocate with an
un-nerving twang noise :-)
mine did that too - freaked me out the first few times!!
Once I get the ride height right, I'll make some marks on the shocks bodies so that I can see if the spring collars/perches move over time.
It'll be a good excuse to put as many miles on it as possible 
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BigLee
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| posted on 23/5/11 at 08:31 PM |
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Thank god its not just me!! I had planned to get to the bottom of this problem tomorrow by removing most of the suspension and checking I hadn't
got all the springs/shocks the wrong way around. Thats saved a job, but doesn't answer why this happens? Surely a shorter damper body should be
used. Seems a little half arsed. Unless someone can explain the benefit of your wheels dropping in this manner when in the air?
Lee
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Agriv8
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| posted on 24/5/11 at 06:40 AM |
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its normal - never known a colar move and as the do not rotate ( as the are bolterd into the mounting bracket) there is little roational force on
them. They locate them selves very well when dropped to the ground though the first few times you get a big "Twang" as the seat will make
you Jump
Ps the dampers are the length they are due to availability and cost a better I belive also sring strength and length is a factor. though the main
reason is to save weight as the same basic chassis are used for the EC boys where shaving every Ounce is important.
hope that helps ATB
Agriv8
[Edited on 24/5/11 by Agriv8]
Taller than your average Guy !
Management is like a tree of monkeys. - Those at the top look down and see a tree full of smiling faces. BUT Those at the bottom look up and see a
tree full of a*seholes .............
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BigLee
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| posted on 24/5/11 at 11:53 AM |
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Thanks for the info. Still sounds a bit iffy though. So when the car is "light" ie over a bump or hump back bridge ( in the extreme) then
you have no suspension provided by the spring, it looks like the damper is too long or the spring too short.
Lee
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Frosty
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| posted on 24/5/11 at 02:18 PM |
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If the spring is slack then definitely get some helper springs in there, or a shorter spring.
Windscreen Wipers
Need windscreen wipers for your car? Order from a friendly kit car owner.
Don't pay a garage to do them. You built a car for God's sake - I'm sure you can fit your own wipers! 
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procomp
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| posted on 24/5/11 at 08:13 PM |
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Hi
The spring length on that first pic can't possibly be right. The spring is wound up towards the top end of its height adjustment. When the car
is sat at static ride height the damper would only have 25 ish mm before siting on the bump stops. There is absolutely no room for movement in droop
before the spring is unloaded.
It's quite common for the spring to become unloaded at full droop of the damper IE when the car is on a jack out of normal working range. But to
have no load in the slightest of droop travel is ridiculous. Something is wrong with that setup.
Cheers Matt
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BigLee
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| posted on 24/5/11 at 09:06 PM |
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Rear shocks on mine. I presume the same as first350's as our chassis's were about 2 weeks apart. When the shock is fully extended by
winding out the preload (no actual preload on the spring - just the slack taken up) the back end was sky high. Now wound down to get the ride height
correct, but blows through half the damper travel. I can't believe this is how they are 'meant' to be considering they are supplied
by MNR.
 
Description
 
Shock
I know the brake line is in the way - it is getting shortened next week.
Cheers
Lee
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first350
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| posted on 25/5/11 at 04:50 PM |
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quote:
Originally posted by BigLee
Rear shocks on mine. I presume the same as first350's as our chassis's were about 2 weeks apart. When the shock is fully extended by
winding out the preload (no actual preload on the spring - just the slack taken up) the back end was sky high. Now wound down to get the ride height
correct, but blows through half the damper travel. I can't believe this is how they are 'meant' to be considering they are supplied
by MNR.
Mine look very similar in the rear...while driving hard around corners (~0.9 G's), it doesn't seem to bottom out. However when I've
hit descent bumps at speed, I'm pretty sure it's on the bump stops.
*My fronts are the opposite...when the car is on jack stands, the springs are not loose (the spring perch is all the way up so that the springs are
firm, but no pre-load). When the car is on the ground, my front ride height is a bit too low (LCA is not parallel with the ground). I assume this is
normal b/c my push-rods are at the minimum length...I planned to raise the front by extended the push-rods. Is it possible that the Front and Rear
should be swapped??
-Peter
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BigLee
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| posted on 25/5/11 at 05:07 PM |
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Swapping the front and rear were my 1st thoughts but doesnt work. The rears are 2 inches longer and simply won't fit with the front rockers. I
have extended the push rods by about an inch so far. Now the engine and fluids are in, it is almost there. Maybe another quarter inch.
I'll probably end up buying new shocks for the rear. Something that is correct for the job rather than driving on the bump stops!
Lee
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lucy
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| posted on 28/5/11 at 10:59 PM |
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Springs
Springs should not be loose on full droop for any situation and shouldn't be any need for helper springs with pushrod setup.
Adjust pushrods to achieve correct height.
One of the advantages of the pushrod setup is that you don't have to preload the spring to get the correct ride height unlike lesser
manufactures.
Wind the single collar up until the spring is not loose and then adjust the pushrod.
Don't tell MNR but I've put softer springs front and rear for a more compliant ride on the road. Not all road surfaces are like race
tracks. Much more compliant with 'normal' road conditions.
Lucy
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spiderman
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| posted on 29/5/11 at 12:22 AM |
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Shocks too long or springs too short, they should not drop away from the collar on full droop and twang when weight is reapplied, not a problem when
jacked up, just surprising when reseating, however not good when on full droop when driving i.e. hump back bridge, and possibly dangerous!
Spider
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bassett
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| posted on 29/5/11 at 11:07 AM |
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Lucy what springs did you opt for and if you dont mind me asking how much and where from, thank.
Adam
My MNR Blog Updated Jan 2010 - Track Day Prep Begins!
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BigLee
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| posted on 29/5/11 at 11:26 AM |
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Lucy - thanks for the info. The front shocks on the push rods are fine. All adjusted and sitting firm. The problem lies with the rears. I wonder
whether it is a recent thing or whether all MNR's have a dodgy rear setup.
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Krismc
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| posted on 30/5/11 at 08:08 AM |
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My Rears are set so Spring wound up around 15mm after spring contacts collar under droop to get desired ride height. it leaves me with 2-3inches of
travel in rear suspension, doesnt hit bump stops, and never ride your bump stops even once or twice, it will cause damage!
My fronts can fit the larger shockers in, all apeared fine but after settling that left very little suspension travel (so dont do it!)
Ive got the shorter ones in now with heavier 250lb springs and im still concerned that under droop the rockers can hit chassis rails.
[Edited on 30/5/11 by Krismc]
Built, Ivaed, Drove and now Sold - 2011 MNR VORTX RT+ 2000cc Zetec on R1 Throttle boddies.
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marc n
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| posted on 31/5/11 at 07:53 AM |
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quote:
The problem lies with the rears. I wonder whether it is a recent thing or whether all MNR's have a dodgy rear setup.
hi lee
when car has settled, you will need to wind the springs back up to acheive your correct ride height, so will not have spring collar loose, ride height
/ travel when car is fully settled will be 1/3 travel in bump, 2/3rds travel in droop
cheers
marc
[Edited on 31/5/11 by marc n]
please email rather than u2u
direct workshop email ( manned 8am till 6pm )
www.mnrltd.co.uk enquireys to :-
chrismnrltd@btinternet.com
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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stevegough
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| posted on 31/5/11 at 08:07 AM |
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quote:
Originally posted by tomgregory2000
mine have a grub screw in them to keep them in place
Aye! +1 (Gaz shocks) allen key grub screw is in the single adjusting collar.
also +1 for the twang! on the rears as they regain their seating as they come off the jack.
Luego Locost C20XE.
Build start: October 6th 2008.
IVA passed Jan 28th 2011.
First drive Feb 10th 2011.
First show: Stoneleigh 1st/2nd May 2011.
'Used up' first engine may 3rd 2011!
Back on the road with 2nd engine may 24th
First PASA mad drive 26/7/11
Sold to Mike in Methyr Tydvil 19/03/14
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lucy
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| posted on 31/5/11 at 07:44 PM |
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springs and things
As marc n said; 1/3 travel in bump
2/3 travel in droop
Krismc - rockers hitting the chassis under droop! That can't be right. That isn't right. Would it help if the bolt on the top of the
shocker was turned round? My bolt on the offside has been cut short to miss the tube.
stevegough - isn't right to have twang under any circumstances I would have thought.
bassett - for my bec setup I changed from 250lb x 8in and 150lb x 7in to 175lb x 9in and 125lb x 7in. £20 each approx
first350 - winding out the pushrods is the way to adjust for height. For my protech shocks the springs should be 5ins shorter than fully open length
of the shock. ie 14in shock = 9in spring and 12in shock = 7in spring
Big Lee - as stated at the top, at the correct ride height the shocker pushrod should be 1/3 closed with 2/3 to go when hitting a bump ( without any
spring slack at any point in the suspension travel). Sounds like shorter shocks would help. Are your springs loose at full droop when ride height is
correct?
marc n - I'm struggling to see how the situation will be better when the suspension has settled. The shock length won't change and the
spring may shorten making things worse not better (if there is slack in the spring at the moment, that will get worse, or am I missing something?)
ps I visited Protech for some work to be done on my shock. They wouldn't charge me!
I also bought my springs from them and they explained about the correct length spring for the particular shocks I had. Brilliant service.
pps I love my vortx.
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daniel mason
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| posted on 31/5/11 at 07:53 PM |
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^^^ have you bought my old car?
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lucy
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| posted on 31/5/11 at 10:04 PM |
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quote:
Originally posted by daniel mason
^^^ have you bought my old car?
Not yours Dan. But I did see yours for sale some time ago( the blue one that is) I think.
Mines orange and a Busa. Built by ANother who did a cracking job. Left to me it would still be in kit form, waiting for more time than I've got.
Too many hobbies etc
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Krismc
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| posted on 1/6/11 at 05:29 AM |
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Nope it'd the bolt head that hits chassis ,so unavoidable, I've mention a few times but I keep getting told its my setup, but either way
it catches. Unless I preload the spring a lot more so that its more difficult, but still happens when I lift car up!!
Built, Ivaed, Drove and now Sold - 2011 MNR VORTX RT+ 2000cc Zetec on R1 Throttle boddies.
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lucy
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| posted on 1/6/11 at 09:51 AM |
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quote:
Originally posted by Krismc
Nope it'd the bolt head that hits chassis ,so unavoidable, I've mention a few times but I keep getting told its my setup, but either way
it catches. Unless I preload the spring a lot more so that its more difficult, but still happens when I lift car up!!
Can MNR give you a clue as to what is wrong with your setup?
Which part of the rocker is hitting the chassis?
If it's hitting on full droop I presume the only thing you can adjust is the pushrod. The damper is the correct length I assume? Mine is 12in on
the front for my bec. What length and poundage springs do you have?
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