Ride height adjustment

[Roy Blyth]

Some simple advice, please!

Our car is a standard 2015 SuperSport, with a de-dion and anti-roll bar at the rear.  We're trying to lower the rear ride height and I assumed that we could do this by winding the Bilstein spring platforms down.  However, they are already wound right down as that is how they were supplied in the kit?

Springs 'n things are the work of the devil to me, so I would appreciate any simple explanation as to how I can achieve a lower ride height.  I know I need to check the ground clearance front and rear (with or without a pile of bricks onboard and a couple of Coke cans or beer bottles underneath!), but I would like to understand the theory a bit better.

Roy

[nickh7]

Talk to Dave at Gemzoe motorsport , he’s a guru on such things 

http://www.gemzoe.com/contact 

 

 

[SM25T]

See if there are more circlip grooves on the damper bodies. If not, you can machine new ones. Are you checking heights with your weight(s) in the seats ?

[russjones]

Greetings

You will have an extra groove on your damper to move the very small circlip that you can hardly believe holds the platform up

You do not need to machine new ones I know as I have the exact (virtually) same 7

Once moved all will become clear

If you are near Nottinghamshire happy to assist meet or talk you through it

 

 

[Geoff Brown]

There is something seriously wrong with the rake of the car if the rear platforms are wound right down!! Doesn't the car handle like a brick?

There is a basic set up:

Driver weight in the drivers seat + at least half a tank of fuel.

Adjust front dampers to a minimum of 150mm between the ground & the bottom of the chassis rail where the rear leg of the front lower wishbone exits the side of the car. The maximum height is 190mm.

Adjust the rear dampers to achieve a height of 15mm higher than the front measured from the ground to the underside of the chassis rail immediately in front of the A frame mounting point.

After adjustment roll the car forward & back then check the ride height as you may have to go round & adjust again.

You should find that after adjustment & if the drivers weight is 'average' that the offside rear platform should have approximately 12 - 14 threads showing & the near side approximately 4 - 6 threads.

Best way to measure the ground to chassis measurement is to cut two metal strip go/no gauges to your desired heights.

 

 

 

[Roy Blyth]

Thanks for all the advice.  The strange thing is that it does not 'handle like a brick'.  It's not perfect and the two drivers have done two sprints now and are not complaining of anything drastic.

Anyway, we're going to take some measurements first before we do anything and then follow Geoff's advice, if possible.

Watch this space...   

[Roy Blyth]

Okay, it's wet 'n windy out there, so we've been playing in the garage and whipped one of the rear dampers off.  We've wound the platform adjuster and lock ring up and now have the black collar sitting on it's own at the bottom, with what looks like a circlip set into it, as per the photo (damper upside down).  The question is, how do I get the circlip out without destroying it?  I've tried winding the collar up to expose it, but it just turns the whole threaded column.

Suggestions please, before someone finds me jobs to do in the house...!  

[John Alston]

Screw the spring platform back onto the black collar and then gently tap both away from the circlip with a mallet.  Once the circlip is on its own you can attempt to open it and work it toward the groove you want to use.  Beware though that the circlip can be a real pig to open up enough to move it out of the groove.  You may finish up just freeing one end and working your way round to the other.  Take care though, as although they're quite tough you don't want to stretch it and make it loose in the groove.  Good luck 

[Bricol]

Use a pair of circlip pliers to open it out, lift it out and keep it open just enough to slide along- tricky to keep balanced on the pliers ends, but doable.

Before you slide the platform down, liberally coat the shock body with anti-seize grease - I've used a loctite one and a PTFE based one in the past.   Otherwise, despite the shock being powder coated, and the collar anodised, in a few years you may well find the only way to shift the collar is with a BIG hammer and lots of heat - or indeed, the collar has cracked from the swelling corrosion between collar and shock.

Mine own have been pretty good by doing this, but I bought a second hand set that were bad!

[Bricol]

Slight update - swopping shocks this week from leaking 50.000 mile originals to a refurbed set.   Looks like I used copperease on one shock . . . and that one needed some pursuading with heat and a lump hammer to shift the sleeve from the shock. 

Have to be carefull with heat - enough to warm the aluminium (which expands nicely and rapidly) before the shock gets too hot and starts to catch up.

[Roy Blyth]

Update:

We measured the car first with roughly half a tank of fuel and driver onboard, front shocks already set with adjustment available up or down, rears at the very bottom of adjustment.

Front - 159 & 153

Rear - 173 & 163

As we were trying to lower the rear, we decided to aim for Front - 150 and Rear - 160 which meant moving the circlip down on the rears.  Once we realised that the black platform collar was not fixed to the shock  it all became a lot easier!  A quick calculation on the new position for the platforms, slap them back on and we ended up with the following:

Front - 154 & 154

Rear - 163 & 160

Not perfect, but close enough for now as we have two different drivers of 'similar' weights and we'd rather do small adjustments and see how it goes.  Their next sprint is at Curborough again in September, so we'll see what they think then  

Thanks again for all your help!  

[Jonathan Kay]

Well done.

What's the ground clearance under the sump, please?

Jonathan

[Geoff Brown]

So you are going to leave the rears with a difference of 9mm & 6mm to the front until the next sprint. These measurements are below the 15mm minimum recommended difference between front & back.

If you are OK that the car will handle well without a decent rake I look forward to reading how it drives.

[Roy Blyth]

Hmmm.. a "well done" from Deputy Headmaster Kay and a "you really don't know what you're doing, do you" from GB   

Listen chaps, as I said in the OP, we're trying to lower the rear ride height as that is what both the drivers say they would like to try.  Both of them have minimal experience of driving a Seven and are still exploring both their's and the car's potential on track.  But their feeling is that the car is 'sitting up' too high at the rear, an observation that was made a few months ago at Curborough by a couple of more experienced competitors.  Both drivers said the same at North Weald recently, however they only really had one dry lap to confirm that feeling.  But they may well get to the next event and find it didn't work, in which case we'll have a rethink.

The thing is, they want to experiment with anything on the car that's adjustable, in just the same way that they want to try different lines on the track.  Neither of them really have the opportunity to try things out on the road;  my son Chris who built the car is only 19 so insurance on a Seven is a no-no, my nephew Kevin is insured but it's not his car so he's reluctant to experiment on the public roads.  So we'll give this a go and we'll have a direct comparison as their next two events are both at Curborough next month.

Of course, I would love to give them the benefit of my experience and show them how it's done,   but I can't get in or out of a Seven at the moment, so I just keep waving my dusty old Curborough trophies at them and tell them to stop asking about Sigma upgrades...   

[StevehS3]

I have got two sets of wheels and it’s too high on the 14” set. The difference in handling and roll of the car is very noticeable. Setting up caster/camber etc made a difference too. I am less convinced by flat flooring/corner weighting but have never had it done so might be completely wrong.

[Geoff Brown]

Sorry if my comment appeared that way but as usual brain to fingers/key board does some times come out all wrong or appears to!

I applaud your 'suck it & see' for the youngsters. Just one caveat......if you cannot get a fist horizontally under the sump especially the leading edge then potentially it is goodbye sump.  Obviously this depends on the size of the fist! Or try a coke can on its' side.

 

[Roy Blyth]

No apology needed Geoff, these 'conversations' would be so much better stood at the bar with a pint in hand!   

The Coke can test works (just!) and we're all set for a return to Curborough this weekend.  Their first visit was the Club double-lapper, but this week it's a single lap event, so it's definitely a case of getting it right first time!

Watch this space...  

[Golf Juliet Tango]

Watch this space...

I'll do just that (but I'll still get Rob at Ratrace to set my cars up!)

[Jonathan Kay]

The Coke can test works (just!)...

Thanks

Jonathan

[Bricol]

Ah, but which coke can . . ?  There are differences between the makers . . . there'll be a name or symbol by the barcode area . . . 

(I design can making equipment :)  )

[Roy Blyth]

Doesn't matter which one, we had to squash it a bit to get it under the sump anyway...  

[Roy Blyth]

Well a great time was had by all at Curborough yesterday!  Fantastic weather and a wonderful mix of cars to enjoy; everything from hot hatches to a Mustang to single seaters.  Both Chris and Kevin were very happy with the changes to the damper settings, saying the car did not feel nervous any more and they were able to control the back end better.  We didn't make any more changes on the day, they both just kept trying to improve their times by finding a better line.

One area that they felt was definitely better was the start, with Chris getting down to a 2.28 at 64' and Kevin a 2.37 on his last run, a consistent improvement on their times back in May.  This kind of echoed their feelings that the car was now not squatting as much on the start.  All in all, a really good day with their best runs finishing up only 0.05 sec apart, with Chris the 'winner' on the day with a 37.45 sec run    There were only three runners in our class, the other being a well prepared W*******d with 175bhp, aeroscreen, etc.  He managed to beat us with a 37.35 so only a tenth in it and Chris could have come home with the silverware!  

However, while Kevin managed to keep it on the black stuff (apart from a brown trouser moment after Molehill!  ), Chris's final run then included his usual free lawn maintenance services, this time just after Flagpole!

So, they've done a double-lap and now a single lap event at Curborough and we're back there in two weeks time for a figure of eight event.  Not sure that we'll make any changes this time as that layout will give them something else to think about, so we'll probably play it safe and leave things alone for now.

One thing that did make me nervous though was when the drivers were called for an 'important' meeting and told to be aware of a hump that had appeared just after the finish line!  Thoughts of sump, Coke can and a frowning Geoff Brown came rapidly to mind... but thankfully it didn't cause anyone any problems  

Meanwhile, I cannot fail to be impressed by the Mustang driver.  The car looks like it only just fits on the narrow track, yet he drove up, slapped some numbers on, threw out the carpets and wrestled five litres of muscle round that track like he was driving a single seater!  Respect, as they say   

[Geoff Brown]

Me frown...never! But I would have felt sorry about the busted sump. If it happened.