D.I.Y Griffy suspension and geo set-up?
Discussion
Have any of you good men (or women) ever attempted to have a stab at optimising your Griffy suspension and geo set up?
I've paid to have it done on expensive equipment on more than a couple of occasions and each time the car has felt perceptibly different, despite supposedly being set up to the same parameters.
I've got some new springs on the way and thought I might have a look at where my geo is currently at with the thought to make changes to suit my numb-bum driving stylee.
I have a flat level surface, access to a lift, levery things to check for play, time; what else might I need apart from a bit of a read-up? A rule, string, a device for measuring angles? There are some clever guys within this forum; wotya reckon? Ever done it? Input and results?
I've paid to have it done on expensive equipment on more than a couple of occasions and each time the car has felt perceptibly different, despite supposedly being set up to the same parameters.
I've got some new springs on the way and thought I might have a look at where my geo is currently at with the thought to make changes to suit my numb-bum driving stylee.
I have a flat level surface, access to a lift, levery things to check for play, time; what else might I need apart from a bit of a read-up? A rule, string, a device for measuring angles? There are some clever guys within this forum; wotya reckon? Ever done it? Input and results?
All the equipment you need is a plumb line, and a few rulers and bits of string. You can get equipment that makes it easier and quicker, but you don't need any of that if you're willing to take the time. The hard part is understanding the theory of vehicle dynamics so you can work out what adjustment you need to make to get the handling effects you want. There are various good books around, but none of them are light reading.
It might sound made. But i fitting them yourself, Spending X amount of money upgrading suspention. why guess the cars right, That is what computors are for..I recommend Wheel power in brockley london but might no be near you.
Any good racing tyre fitter can set your car for your driving style, if you like over steer & arse out im sure they can sort it. Wrong settings car ruin ride & tyres,,, Im not a tyre fitter But own a body shop & i wouldnt do my own car,, Horses for courses & all that stuff. I pay around 75.00 for full 4 wheel set up with print out so as if not as you require. you know were youve gone wrong,, Cheers GOLDIE
Any good racing tyre fitter can set your car for your driving style, if you like over steer & arse out im sure they can sort it. Wrong settings car ruin ride & tyres,,, Im not a tyre fitter But own a body shop & i wouldnt do my own car,, Horses for courses & all that stuff. I pay around 75.00 for full 4 wheel set up with print out so as if not as you require. you know were youve gone wrong,, Cheers GOLDIE
I think the point some are missing, and that Bruce is asking for is the capability to change settings so he can evaluate them in use?
If you want to evaluate for your own setup it is a long and hard process - set up , test drive, re-set, test drive.... For this reason I'm a great fan of adjustable wishbones. Just as you can note X turns on the TRE make Y toe, you can also have X turns on the wishbone give Y camber.. For me its easier to blag access to a laser alignment rig, and not only set the car up, but anally make notes of turns on adjusters to get other settings I wanted to evaluate. Having been through the process, you still need to go back & verify the settings on the laser at some stage.
For me string & protractor is just too fiddly and prone to error, the added benefit of using laser 4 wheel is also that you see instantly the impact that a single change makes to the other settings. That really helps clarify the 3d relationship between all the pivot points IMHO, you can also quickly see what weight changes do to the geo by sitting on boots / wings / bonnets. The extra information that can be gleaned from the real time displays on a laser system is well worth the cost of the session IMO
If you want to evaluate for your own setup it is a long and hard process - set up , test drive, re-set, test drive.... For this reason I'm a great fan of adjustable wishbones. Just as you can note X turns on the TRE make Y toe, you can also have X turns on the wishbone give Y camber.. For me its easier to blag access to a laser alignment rig, and not only set the car up, but anally make notes of turns on adjusters to get other settings I wanted to evaluate. Having been through the process, you still need to go back & verify the settings on the laser at some stage.
For me string & protractor is just too fiddly and prone to error, the added benefit of using laser 4 wheel is also that you see instantly the impact that a single change makes to the other settings. That really helps clarify the 3d relationship between all the pivot points IMHO, you can also quickly see what weight changes do to the geo by sitting on boots / wings / bonnets. The extra information that can be gleaned from the real time displays on a laser system is well worth the cost of the session IMO
I have made an adjustable 4 point system with metal bars and fishing twine and its very accurate, certainly to within 1mm on toe in or out and It cost about £40 with all new bits from B&Q. As for camber a good digital spirit level up against the wheel rim is a good place to start, followed by tyre temperture tests, but from what Ive seen of the Griff it simply has elongated holes to allow camber adjustment, which makes acurate setting difficult, unlike using say threaded rose joint suspension. It does take a very long time to get things spot on, (I need about 4 hours from scratch) and you must at least have your wheels on glossy magazines to allow them to slide as you make adjustments. You will always find things are never quite the same after a run, as everything settles.
Heres some basics Ive done, and Ill see If I can do some photos of the metal bars. Much better than the wooden set up shown on the web site, but the same principal. Obviously settings will not be the same as the Griff.
http://www.g33.co.uk/setting_up.htm
Heres some basics Ive done, and Ill see If I can do some photos of the metal bars. Much better than the wooden set up shown on the web site, but the same principal. Obviously settings will not be the same as the Griff.
http://www.g33.co.uk/setting_up.htm
For me part of owning and running the Griff is that you can do virtually everything your self and the valuable knowledge available from the guy’s on here make the learning curve less steep.
I made myself a wheel protractor, a long wooden thing to help measuring toe angles and a device for checking the vehicle is level. It all works fine and when I got lost, then I took it in to get set up correctly.
My point is you can do it either way, I know now I can tweak the ride height, change a top ball joint or replace a suspension bush and get the geometry back just as I like it.
Cheers,
Simon.
I made myself a wheel protractor, a long wooden thing to help measuring toe angles and a device for checking the vehicle is level. It all works fine and when I got lost, then I took it in to get set up correctly.
My point is you can do it either way, I know now I can tweak the ride height, change a top ball joint or replace a suspension bush and get the geometry back just as I like it.
Cheers,
Simon.
Next time anyone sees their car on a laser alignment rig, look out for the changes that occur when you roll the car back & forwards, bounce the suspension... This needs doing frequently - you can't just tweak things and expect the settings to stay the same, you have changed the loadings so you have to get the car to 'settle' each time...
Thanks for the replys guys; there are reasons I've not managed to get back sooner but appologies for the lateness anyway.
At the weekend I fitted new springs (325lb rear and 375lb front (down from 400lb)). The rears had sagged badly and I always found the fronts a little too hard. I set up the ride height as the damper outlet suggested but deviated from the recommendations for damper settings on the rear by quite a margin (from 12 clicks to 8) after a bit of seat of the pants experimenting.
With regards the geo set-up, one of my aims was to reduce that front end nervousness that Grifflers sometimes experience. My initial thought was that after getting the ride height and spring/damping right then a bit of front-end toe-out may be the way to go. What surprised me though was that reducing, what I considered to be rear-end over-damping, tamed down that nervousness; giving it consideration, that could make sense.
Thanks for the x-ref Simon; I've printed that out and will digest that one tonight.
GreenV8S: I bought Herb Adams 'Chassis Engineering' to get a grip of the fundamentals: it's a field of speciality unto itself and moreso than I'd given credit.
Yes, I could take the car back for another 4 wheel geo check and adjustment; it's about £60. But as I mentioned, three times the car has been on the same (very expensive) kit and each time I've experienced different results. I know the guys and have watched them do their stuff without reason for negative comment. For those of you that have rigged aircraft flying controls to a basic setting you'll know that if one man does the job, another (or even the same person) attempting the same task again would make further corrections despite using the same tools etc. Not the best analogy but a double wishbone suspension/geo set-up is no less an undertaking and both possessing room for interpretation.
With a little understanding I'm sure I can make changes and realise the results enabling me to taylor the handling to my satisfaction; hopefully without sending me off into a ditch. I may learn something along the way too. If I make note of how things are currently set then I can return to those but I'd like to know if there are any obvious anomalies first - tyre wear patterns would suggest not.
At the weekend I fitted new springs (325lb rear and 375lb front (down from 400lb)). The rears had sagged badly and I always found the fronts a little too hard. I set up the ride height as the damper outlet suggested but deviated from the recommendations for damper settings on the rear by quite a margin (from 12 clicks to 8) after a bit of seat of the pants experimenting.
With regards the geo set-up, one of my aims was to reduce that front end nervousness that Grifflers sometimes experience. My initial thought was that after getting the ride height and spring/damping right then a bit of front-end toe-out may be the way to go. What surprised me though was that reducing, what I considered to be rear-end over-damping, tamed down that nervousness; giving it consideration, that could make sense.
Thanks for the x-ref Simon; I've printed that out and will digest that one tonight.
GreenV8S: I bought Herb Adams 'Chassis Engineering' to get a grip of the fundamentals: it's a field of speciality unto itself and moreso than I'd given credit.
Yes, I could take the car back for another 4 wheel geo check and adjustment; it's about £60. But as I mentioned, three times the car has been on the same (very expensive) kit and each time I've experienced different results. I know the guys and have watched them do their stuff without reason for negative comment. For those of you that have rigged aircraft flying controls to a basic setting you'll know that if one man does the job, another (or even the same person) attempting the same task again would make further corrections despite using the same tools etc. Not the best analogy but a double wishbone suspension/geo set-up is no less an undertaking and both possessing room for interpretation.
With a little understanding I'm sure I can make changes and realise the results enabling me to taylor the handling to my satisfaction; hopefully without sending me off into a ditch. I may learn something along the way too. If I make note of how things are currently set then I can return to those but I'd like to know if there are any obvious anomalies first - tyre wear patterns would suggest not.
Gassing Station | Griffith | Top of Page | What's New | My Stuff