Please inform of us what suspension setups you have experience with, what kind of car they were on, what the intended purpose of the car was, and an overall evaluation of the pros and cons (ie. Oversteer, understeer, balance, harshness, body control, etc)
Please include all the specifications possible about things such as coils cut, spring dimensions if possible, tires, shock settings, etc.
Bryan,
From my notes when I ordered Alan's street springs and rear sway bar, (11/15/01) Front springs = 1200 lbs/in, Rears = 200 lbs/in. His rear sway bar = 5/8" vs stock = 9/16". Leave front bar stock
Ed
i have a vintage AR Ricambi book. here's the specs that they quote :
Stock :
F springs 392 lbs/in
R springs 97 lbs/in
F swaybar 24mm (measured 115 gtv)
R swaybar 13mm (measured 115 gtv), (N/A on early cars)
Sport :
F springs 466 lbs/in
R springs 114 lbs/in
F swaybar 27mm
R swaybar 16mm
koni reds
Super Sport :
F springs 580 lbs/in
R springs 134 lbs/in
F swaybar 27mm
R swaybar 16mm
koni red or yellow
they did not quote figures for their race setup. note that AR Ricambi went with softer springs than the "sport" springs from Centerline and IAP, but used stiffer sway bars. Centerline and IAP suggest to use stock sway bars with their springs for "sport" use.
from my notes : W&D race springs :
F 1250 lbs/in
R 250 lbs/in
The problem, as I see it, with the “British vs. Yankee’s in Spring Weights” thread (British vs. Yankee’s in Spring Weights) is that everybody is arguing about “what works best", and there is little attention paid to the much more relevant question, “What works best for a specific purpose?” It’s no wonder that there is minimal consensus between gentlemen who set up race cars and those who set up street cars.
Bryan,
There is no one right answer, even for the same race track 2 cars might have completely different setups due to driver preferences or style, or the tyres they run. And a real race car will have different setups for different tracks ... if funds permit.
Thus you are not going to end up with 2 settings, one for track and one for street.
The biggest thing is that too many people get hung up on having a overly stiff car, forgetting that suspension MUST work/move to be of any benefit.
I won't say too much on this thread, but i'll add a couple of points:-
There are several ways to skin a cat. Some better than others, but a couple of things are for sure -
1. Don't mix peoples suspension ideas and expect it to work - you will end up more confused than you started and probably with a slower/less comfortable car. Go down 1 route, and if you don't like it try another (even if it means borrowing another BBer's car!)
2. The old ways of setting up cars with very stiff springs and softer sway bars is out, especially when married to soft dampers to try to regain some ride quality (see Brit vs. Yankee thread for full details on this).
3. Following this, the idea of setting a 105 up very stiff to prevent the poor geometry doing its deed, is mad - cars have suspension for a reason - you just have to maximise the geometry of what you have. It obvious why a car with standard geometry needs to run one attitude, and that a car with modified geometry can run a completely different stance. (attached is a photo of our fully modifed Sprint GT (watts link & tubular wishbones) leading my GTA Replica (std. geometry) - the difference in stance is plain to see
4. There is far more to setting up a car than bolting springs/sway bars on a car. Vast knowledge is needed (or needs to be able to be supplied with the suspension bought) to ensure you get the most out of your car. Experience counts for a huge amount.
5. One kit cannot be used for all similar applications (esp race cars): individual weights of cars, tyres used, circuits run on, suspension linkages fitted and driving style are amongst a handful of a large number of factors that require different spring rates to be used. This is most important for the front end of the cars. Hence 2 1/4" conversion kits are important due to the ability to cheaply set spring rate to the nearest 20lbs.
6. One of the reasons why those of us talking on the Brit vs. Yank thread did not get too tied up in specific situations is that we aren't going to give all our secrets away. The other is that its the general theory that is far more important to discuss, we could argue about the odd 50 lbs until we are blue in the face, but where the big differences lies is in the general setup theory!
7. It takes a very experienced driver to tell a difference of 50lbs on the front, or 20lbs on the rear!
On the side (for race cars):- You need to take photographs of your car mid corner from several angles to see if your dampers/rollbars are actually doing anything! I once went to test and setup a race car and the owner would not believe that his springs were too stiff. I photographed his car coming down the straight and then mid corner (a hard corner). I showed him that the suspension had not moved at all on the outside front loaded tyre. I asked him what the rollbar was doing at this point.... its no longer a rollbar.... it requires suspension travel to be a rollbar, without it, its a transverse leaf spring, adding even more spring rate! He got he point and we fixed his car very easily!
Will watch this thread with much interest, good work Bryan!
I'm shure this thread will become very interesting.
For now I only ask a favour : if possible, please use also kg and mm, while reading a post, for me it's difficult to convert mentally, for example, spring rates from lbs/in into kg/mm .
On the side (for race cars):- You need to take photographs of your car mid corner from several angles to see if your dampers/rollbars are actually doing anything!
Using cable ties around your shock shafts is the old and cheap + simple method to work out how much suspension travel you are using.
The most important thing is to actually have movement, as I have said before AND to keep off your bump stops, because ofcourse then you have no movement again (and effective spring rates go through the roof).
I used to pick a representative corner and try different settings (yep with the cable tie) and work on corner exit speed, while measuring tyre temperature readings across the face, etc. One change at a time ... and that is why testing is so expensive but also without it you will never get the most out of your car. Note you need to putter through the other corners so as to not move that cable tie ... and ideally the corner should be close-ish to the pits so the tie temperatures are almost valid, and it needs to be a real 'loading' corner not a kink .
Ofcourse once you think you are happy you then need to string a few complete laps together.
For a road car IMO this sort of discussion is a waste of time ... but each to their own. I guess if you find that you are chewing out your tyres you could change the alignment and might need to stiffen the front a little ...
Pete
Using cable ties around your shock shafts is the old and cheap + simple method to work out how much suspension travel you are using.
The most important thing is to actually have movement, as I have said before AND to keep off your bump stops, because ofcourse then you have no movement again (and effective spring rates go through the roof).
I used to pick a representative corner and try different settings (yep with the cable tie) and work on corner exit speed, while measuring tyre temperature readings across the face, etc. One change at a time ... and that is why testing is so expensive but also without it you will never get the most out of your car. Note you need to putter through the other corners so as to not move that cable tie ... and ideally the corner should be close-ish to the pits so the tie temperatures are almost valid, and it needs to be a real 'loading' corner not a kink .
Ofcourse once you think you are happy you then need to string a few complete laps together.
For a road car IMO this sort of discussion is a waste of time ... but each to their own. I guess if you find that you are chewing out your tyres you could change the alignment and might need to stiffen the front a little ...
Pete
Yes cable ties are nice to see where your suspension has been to. But I don't use them to accurately measure where travel has been in a corner - In my experience, they can get pushed much lower under braking where all the weight is on the front and the rollbar has no effect, than in a corner where the weight transition has moved back and you have a rollbar acting as well. You really need your tyres up to full temperature to take suspension measurements, to do this requires 3-4 banzai laps, coaxing it round other corners to prevent cable ties moving just cools tyres off and then in the important turn you cannot generate the required g-force to show up any problems. Most cars handle well on cold tyres (unless they are bog aweful), its only when you get the car and tyres in the zone that you can pick up the minor handling defects where so much time is lost. This is why I find photographs a useful method to show other people whats going on with their cars - I can feel it and see it for myself in the car - just some people need a picture to believe it!
I use cable ties to see where the suspension has been to and as an indication as to wether we are using all the suspension travel and if its hitting the bumpstops, how much of the bumpstops we think we are using (hence really small cable ties are best as they can actually become buried in bumpstops if there is enough force). This then allows you to shorten/lengthen clevises (if using Koni 3012/2812 race dampers), to reset the shock travel to where you want it. With regard to bumpstops, certain types can be a useful aid, I like pregressive bumpstops and at certain circuit formats they can be very useful to help sort a particular corner out if you are using a wacky line to improve times. We are now experimenting with popoff valves in our shocks to stop the car getting upset over big kerbs in chicanes we hope to gain up to 0.1-0.2 secs a lap with these at most circuits (with chicanes).
I am driving 125 kg/cm (about 700 lbs/inch) springs with Bilstein damper at the front, at the rear slightly stiffer than original springs from OKP with red Konis (at middle setting). Original sway bars.
The car was quite comfortable when I had red Konis at the front too, but now the ride got a little harsh, since I have the Bilstein dampers at the front, but diving at breaking got much better.
Has anyone heard of Linea Rossa springs? I found a set that will lower the car 1.5 inches for $200, NIB. The guy says they are progressive rate springs. Are they worth picking up, or should I hold off and get a set of Centerlines like I'm planning. Here is the ad. http://sfbay.craigslist.org/eby/pts/275964942.html
Bryan: you certainly have put a lot of thought and work into this thread. I would have to say this will definetly be one of the most outstanding efforts on this bulleten board.
And those that have tried "it", and now know what works and doesn't work (and when) are sure adding to the quality of this thread.
I'll add to it when I can help. Thanks for your effort.
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George Willet
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Note: I prefer to offer parts to the AlfaBB members first, and eBay second.
THESE are the good old days!
There are no easy answers to complex problems.
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