British vs. Yankee’s in Spring Weights - Alfa Romeo Bulletin Board & Forums
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post #1 of 188 (permalink) Old 11-14-2005, 01:15 PM Thread Starter
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British vs. Yankee’s in Spring Weights

I was talking to Richard at Alfaholic's today about how the British set their Alfa's up for the track. When I told him I had 1,300 lb front springs he just about died. He said over there they never go over 800 lbs springs in the front and 600 lb was the norm. He said the typical set up was 600 front and 180 rear and they run with Koni Yellows not Reds.

He also said that the trick with the Spider was to have the tail just a hair lower than the front. With that stance it made a hugh difference in the way it handled. In stock form the rear end is a lot higher than the front I think he said it help get ride of the oversteer problems.

It was very interesting to hear this........ he said that with my set up of 1,300 lb springs in the front that the Koni Red shock was the wronge shock for that heavy spring rate and that I would be much better off...... if I stay with that spring rate to go up to the Koni Yellows. He said the Koni Red's were fine with the 180 lb rear spring rate in the rear.

It does make sense that 180 lbs springs in the rear work well with the lighter weight Koni Red Shocks but with 1,300 lbs springs up front that the heavy duty Koni Yellows would be better. Richard said there is no way the Koni Red's could keep up with a 1,300 lb spring

I am goig to ask Richard if he wants to talk about the British point of view in how they set their Alfa's here on the BB.

Murray

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post #2 of 188 (permalink) Old 11-14-2005, 07:23 PM
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Murray, while I haven't raced on the British tracks, a softer spring rate would be superior on a rougher surface. When I bought my car from Mike Besic, it had 625 pound front springs and a 1750 engine. Mike was very competitive against 2L cars that were set up much stiffer. And in the rain, the soft set up was very much in his favor. I have since stiffened the car a lot to suit my tastes. But clearly there is more than one way to skin a cat. Also don't forget, most of the race cars Richard is talking about are 2000 pounds or lower. You have a lot more weight on the front end, so your rate should probably be a little heavier.

As to your Koni Reds, everything I have heard agrees with Richard. The Koni representative would recommend the Yellow Sport shock for your application. If I were you, I wouldn't replace your Reds. Set them on full stiff for rebound and they will probably do an okay job for you.

Erik
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post #3 of 188 (permalink) Old 11-14-2005, 08:38 PM
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Murray, lots of people run Yellows on front and Red on the rear. Just to make your head spin, the following text is copied from another board and was written by a guy who works for Koni.

Erik



In a nutshell, adjustable shocks are about tuning. Tuning your suspension to work together as one instead of an amalgam of different parts (bigger spring rates require more rebound within reason, etc.), tuning the understeer/oversteer balance of the car when cornering (rebound valving), and tuning to maximize the grip potential between your tires and the surface (compression or bump valving). Rebound controls the sprung weight of the car and is used to control the transitioning weight and body motion when the car is in motion. Bump controls the unsprung weight and is basically the tire's ability to be held to the ground. Shocks are typically a relatively fine tuning tool so if your springs, tires, etc. are too far out of the ballpark then shocks probably aren't going to save you.

Several rules of thumb:
-Add rebound to an end to free it up. Add rear rebound to loosen up an understeering car or front rebound to an oversteering car. Depending on balance and range, you can also subtract rebound damping to stick that end better too.
-If the issue is on corner entry (understeer or oversteer), look more to the rear rebound. If it is on corner exit, look more to the front rebound but make sure that the issue is not induced earlier in the corner and carrying through. Make sure the issues are the chassis itself and not driver induced (like tossing it into a corner, overdriving, etc.)
-Shocks only work when they and the car are moving. Steady state corners and generally mid-corner situations when the car has "taken a set" are not shock issues so look more at sway bars, etc.
-If you have a compression adjustable shocks, adding rebound will help turn-in, work the tires better, and keep the platform generally more stable up to the point when you have too much then the car will begin to "overshoot" or skate on bumps and rough track surfaces because the tire is losing grip with the ground.
-Although a car with better tuned and more technical shocks can allow a car to work better with less spring than you might have with lesser capable shocks, do not try to hold the car up or force it to do things that it wouldn't otherwise with shocks. Stock class autocrossers can sometimes trick their very softly sprung cars into thinking they have more spring rate by increasing the compression damping but this is really not the best way to tune a car that allows real suspension tuning. Remember those guys only have air pressure, shocks, and maybe a front swaybar to do all of their tuning with. If you are allowed to change springs and otehr things, do it and let the shocks do their job.
-After good tires, shocks have the next single biggest impact on improving handling performance. If you have the ability to really tune with those shocks, it just makes them that much more valuable. Ask any serious autocrosser- likely one of the most focussed forms of motorsports on body and motion control.
-Don't expect that all shocks are the same internally. Some out there are not much more technical than a toilet plunger (okay, maybe a little more) and some do a very great deal. A shock dyno is one of the few ways to get real data from a shock and see what it can and does and what it can't and doesn't do.
-Don't get carried away by sexy reservoirs, pretty anodizing, and extra knobs. Just because it is flashy and expensive doesn't necessarily mean that it is good. Try to see a dyno sheet and have someone explain it to you. Look at the valving and see how much real effect a shocks adjustment has on the performance of a shock. An adjustment range should be quite wide (don't just count the clicks) and have real effect on performance, not just possibly change the feel (there is a difference). Just because it is expensive doesn't mean that it is the better.

Already mentioned in the thread are two very great extremes. Talking about very expensive shocks needing constant gas pressure changes (that is a whole 'nother lecture), regular rebuilds and revalves, etc. down to simple Carreras and even lever shocks. The answer is that there is a world of good dampers in between some of which are very good and some are not. Important internal things like wear and friction reducers should be considered, as well as how the adjusters work. Needle valves tend to wear quickly, be heat and viscosity sensative, etc. Reservoirs add much more weight, signal loss and lag, and mounting complications and don't really add the mythical extra cooling that everyone seems to think of. People ask me how often good shocks (and I don't necessarily mean expensive shocks) should be tested or rebuilt. My usual response is "How often do you crash?". If you have a shock that is wearing or failing in a short time and needing periodic service, revalving, etc., you might want to consider other options. Unless you have an incident, a performance problem, or you make major suspension changes, good shocks should last several seasons at least between testing and last for many years.
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post #4 of 188 (permalink) Old 11-15-2005, 01:07 PM
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Hi all! With a bit of input from everyone I think this could become an interesting thread!

At Alfaholics we have had a lot of experience with short and long distance racing, ranging from 1 lap sprints right through to 6hr Endurance races. For the minute I will only say a short piece....

With regard to racing cars (trackday/fast road cars a re a different kettle of fish!):-
We found that going very stiff on springs i.e. above 1000lb on the front and above 230lb on the rear can be as quick as staying below 1000 lb on a single given lap while the tyres are in good condition. However, the tyres deteriorate and go off much quicker and as a result lap times fall away much quicker than a softer sprung car. This effect is made even worse by shocks which aren't up to the job. In my personal experience if running a slick or non-slick racing tyre a Koni Sport/Bilstein shock is out of its depth if the springs are over 850lb on the front. The car starts wallowing about and you sit there twiddling your thumbs waiting for the car to settle itself.

I found the Bilsteins that were fitted on our race car 4 years ago inadequate as soon as we generated more grip by running a watts link, this was even when we were running 700lb front springs with cross ply CR65s.

I run road tyres on my trackday car which has front spring rates in this 800 lb region and I feel that the Bilsteins on it are on the very edge of their abilities, if I put a proper trackday or race tyre on the car and thus went up a little on spring rate (but not much), they would be out of their depth.

With regard to trackday/road cars compliance is the most important thing. The last thing you want is to rattle your eye balls out of your head driving the car on the roads or to the circuit. This makes softer springs even more important. I would never dream of putting a trackday car on the upward side of 800/200lb springs. Its just not necessary and the comprimises in ride quality far out weigh the minimal advantages in handling. Also bear in mind that road/trackday cars run road tyres, these have relatively low grip levels and soft side walls, as a result they cannot harness the advantages of stiffer springs like a slick or racing tyre, instead you just make mince meat of your nice road tyre!

To sumise a little:- People often think that a car that feels stiffer, feels more like a racing car, and thus must be quicker than one that feels softer. However, as they go stiffer and keep the same dampers (nothing off the shelf from Koni or Bilstein will ever control a 1000lb+ spring properly) the tyre ends up spending more time bouncing up and down, so as a result spends less time in contact with the ground, this increases its sliding which added to the work the sidewall and tyre surface is doing by being squashed more, causes the surface temperature to increase quicker than a softer car with the same dampers which is as a result better damped.

So much more to say on the subject, but don't want anyone falling asleep and want to see what other people have to say, i'll look closely at this thread and will do another reply when suitable!

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post #5 of 188 (permalink) Old 11-15-2005, 01:48 PM
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Quote:
Originally Posted by Max Banks
To sumise a little:- People often think that a car that feels stiffer, feels more like a racing car, and thus must be quicker than one that feels softer.
I'm sure I've said that before on this site somewhere ... what feels fast is not always what is fast ...

Max also brings up a great point about consistency. How many of us really test our car changes properly over a race long distance? ... heck I never did, I'd do 1 or 2 laps and using a couple of reference corners ... think hmmm that felt better and look it was quicker too.

BTW: Watch Aussie v8Supercars one day. While these cars are extremely heavy dinosaurs (at 1350kg's I think) they set these things up as soft as they can. Again TRACTION is everything ... and thus the drivers adapt and live with the car moving around. You cannot have perfect tyre traction with an over stiff spring/shock ... unless you have serious down force
Pete

[EDIT:]I've read somewhere that if you are still running the standard 'high' roll centre rear suspension that you will want to run harder front springs ... to try and compensate.

Also the other factor that definitely comes in to it, for us club racers anyway, is that trying different springs costs a lot of money and time ... thus we often end up with a small selection or just what we tried that was better.

In Australia and New Zealand they race Holden HQ's (large 70's family car) and somebody with the $'s found out that these things are extremely tuneable by playing with spring rates ... thus the original concept of a extremely cheap race series got blown out the window by somebody who had the cash to do the job properly. He even had one of NZ's best engine builders prepare the standard engine ...[/EDIT]

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post #6 of 188 (permalink) Old 11-16-2005, 04:32 AM
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I think Max brigs up one really important point- tires.

My GTV is set up with 1200lb front springs, and with the Kuhmos I run, the car does not deteriorate after 15-20min of track driving. Even over some rough surfaces on the local tracks, my car is quite content, and anything but jittery and hard to drive.

BUT, if I were to track the same Hoosiers that George autocrosses on, perhaps on the track, they would like softer springs, since they are so incredibly soft.

Erik- I know Mike was running the older Hoosier vintage track tires- are you still running those, or something more modern?

Oddly enough, my car also seems to like the Red Konis. Perhaps it's my driving style?

BTW, the primary purpose of our GTV is autocrossing, so it set up accordingly, but with stock geometry front and back.

It will be fun to play with the GT Jr I have in my back yard (I keep saying that, yet nothing happens to it...).

Oh, one more thing- based on the motion ratio, remember, the actual wheel rate with 1200lb springs isn't all that much.

Eric Storhok
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post #7 of 188 (permalink) Old 11-16-2005, 07:05 PM
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Eric, you are of course right about the wheel rate. I think my 1200 pound springs equate to a <400 pound wheel rate. And yes, I am still running the Hoosier Street TD's. I am not yet convinced that the radials that are vintage legal are any faster. Some day, I may have to do some testing.

Erik
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post #8 of 188 (permalink) Old 11-17-2005, 03:04 AM
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Murray, I'm sure they are talking spring rate, not wheel rate.
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post #9 of 188 (permalink) Old 11-17-2005, 09:44 AM
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Interesting info on spring rates and shocks on this thread. FWIW, the best dual purpose US spec Alfa Spider - belonging to my late friend Larry Vail - I have ever driven (both on road & track) had Ward & Deane spring with the bigger rear anti-roll bar and Bilsteins on it.

Now this same set-up on my Giulia Super which is considerably lighter was completely unpalatable on the road, either with the Bilsteins or red Konis.

Now, the suspension kit from Alfaholics has a 29mm bar. I am curious with regard to the reinforcements on the chassis needed with that set-up. Having run a Shankle front bar that is 27mm (1 1/16) in combination with both Shankle sport and super sport springs I found that I tore up my front chassis legs on the Super, so that I had to reinforce and seamweld them. That is, the bigger bar put a lot of torsional load on the front of the chassis - I guess that's why Steve Ruiz and Jack Beck mount their front bar backwards in the steering box area.

Furthermore, the Shankle blade type bars actually made the car uncomfortable and unpleasant to drive on bad roads. That is, road unevenness, rather than being absorbed by the spring and shock on one side was now transmitted to the whole car making the ride choppy. This was a non-issue with an original Alfa conventional 26mm (GTA junior) front bar. So in this case, the bars rather than heavier spring rates had more of an effect on ride - contrary to conventional wisdom.

So I am curious how the Harvey Bailey set-up from Alfaholics deals with all that torsional load of the 29mm bar and how that suspension feel on rough roads. Also how would a 27mm bar work with the Harvey Bailey set-up? Too much oversteer?
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post #10 of 188 (permalink) Old 11-17-2005, 12:39 PM
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Quote:
Originally Posted by turbolarespider
I think Max brigs up one really important point- tires.


BUT, if I were to track the same Hoosiers that George autocrosses on, perhaps on the track, they would like softer springs, since they are so incredibly soft.



Oh, one more thing- based on the motion ratio, remember, the actual wheel rate with 1200lb springs isn't all that much.

Eric Storhok
Eric

Thats weird? I thought the softer the tire (grippier), the harder the spring rates should be? dosent softer tire= more grip=more loading of suspension?

Im guessing 1200lbs spirngs are nearly double the stock spring rates...which is significant. 1200 fronts on street tire....the car just skips and hops around. u really need sticky rubber to make them work especially on bumpy surfaces.

So far I've got W&D, IAP, David Rugh, Shankle Sports, with 3 different types of shocks, stock spicas, bilsteins and Koni yellows.

For dual purpose, I prefer the shankle sports when using street tires.

I have to agree with eric the 1200 pounders ride is quite acceptable when running with softer shock even at Waterford raceway (I've been on inner city alleys that are paved better lol).... or will rattle your eyeballs out with bilsteins. In my experience the shocks have a lot more to do with ride quality than the rates. weather if they are firm enough to control the wheel motion is another question. dosent Anthony run big willow on Koni Reds?

I would like to try the adjustable Alfaholics type some day... can anyone tell me what the there rates are?

my 2 cents

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post #11 of 188 (permalink) Old 11-18-2005, 02:03 AM
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Absolutely no chassis reinforcement is neccessary with fitting our 29mm antiroll bar!!!! We run this bar on all our cars and have literally sold hundreds of kits in Europe with none of these problems you talk about!!

In reply to davbert, it is surely not correct to improve the ride quality of an overly stiff spring by using dampers which are very soft, too soft for the springs. You confirm this by stating the car skips and hops around. It doesn't matter how stiff a spring is, if it is damped properly the car will always feel planted. If this makes the car too hard for use on the road, then you need to soften the whole car, springs and dampers by the same ratio. Skipping and hopping leads to the tyres not being in contact with the road, thus no grip - the car is either underdamped or oversprung.

TVR Tuscan race cars run 1000-1200lb front springs and they work very hard to get the shocks working properly with such strong spring rates, most of their testing time is spent dialing in shocks to particular circuits, set up properly they are devastatingly planted - they need to be to put down 600bhp!

Koni reds are what are used with standard springs, i cannot see how it can be possible to triple the spring rate and not increase the damping rate?! (standard springs are just over 400lb btw)

One of you guys needs to try one of our handling kits.... we aren't aliens in Europe!

We tried a 27mm bar on our race car and it caused the car to have too much oversteer after turn in, it was driveable but not as fast as with a 29mm bar.

p.s. the spring to wheel rate is 2:1 - i.e. a 1200lb spring gives a 600lb wheel rate.

We used to race against a Giulia with 1200lb springs and Koni Sports (yellows) - when you came past to lap it you could see the wheel shimmying up and down though bends.... not exactly a planted tyre.... he had to run softer compound tyres to get the grip. This actually made the car worse as after a few laps the softer compound made the tyre go off even quicker... reducing grip even further!

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post #12 of 188 (permalink) Old 11-18-2005, 03:01 AM
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Some very interesting info here on spring rates. Am particularly interested on front to rear balance.

I was running my 2000GTV with a standard FARB, no RARB, 1000lb front springs, 100lb rear springs, koni yellow all round. - it was pretty well balanced and very supple, but was rolling off its tyres (Yokohama A048 R compound road racing tyres) and abusing the sidewalls both front and rear in the tight corners.

I changed to a 27mm FARB, 1300lb front springs, 200lb rear springs. The car now rolls less and is keeping its tyres alive better (actually seem to be generating more heat - which could be problem for long runs, but I mostly do sprints which are only 3 to 4 laps), but probably has a bit too much rear spring (oversteer is now an issue - although I'm learning to live with it before making another change - I do have some 150lb springs on hand just in case).

So you're probably asking what the point of this - my quandry is how the hell are you getting 800lb fronts and 230lb rears to work?

That seems way too stiff in the back and too soft in the front. My car is a 74 model so is quite heavy (1000kg) compared to earlier chassis or GTA's, but surely that wouldn't explain the big difference in rates or front to rear balance (?) Maybe the answer is the bigger 29mm FARB (?)

I do have some 800lb front springs, so I could try it, but would like to be convinced it is worth the effort first (with or without a 29mm FARB).

Thoughts appreciated.
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post #13 of 188 (permalink) Old 11-18-2005, 04:44 AM
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Quote:
Originally Posted by davbert
Eric

Thats weird? I thought the softer the tire (grippier), the harder the spring rates should be? dosent softer tire= more grip=more loading of suspension?
I should think that, too.

But something keeps bugging me about the tires. I know there are some tires who don't need static camber, others that do.

And the Alfa suspension isn't exactly known for it's wonderful camber curves...

I wish I were a chassis dynamics guy sometimes, but powertrain systems pays the bills.

Max, I would consdier using your set up, but the problem is that I'm quite happy with my set up. So my next car will be much like it. I know you are conviced that the Red Konis are not up to snuff on the really stiff springs, but I can't seem to find that same problem. There are some occasions when autocrossing that the car wallows a little, but those tend also to be very tight 180's where I overdrive the corner, too.

On the track, even the very bumpy Waterford Hills, my car feels very stable. And the times are reasonably quick- my street car would have placed mid pack in it's run group at the last historic race I saw at the track. And at Gingerman, it would be similar- both about 3-4 seconds off of the pole time. (makes my chest fill out a lot, you know... )

Review of my set up- W&D all the way around for springs- (I think that's 1200 front, 150 rear), Koni Red Shocks, Shankle front sway bar (27mm front mount), stock rear sway bar, 15x7 Panasports, normally wrapped with Kuhmo Victoracers, and -2.5deg camber in the front. When I put the cheap priced Hoosier Autocrossers on this past spring, those things were ROCKETS, but I wore through the tread way too fast. Good if I ever wanted to join George in Topica, but bad for the racer who likes valued based fun.

For the race car I will be building (someday, I swear it's not a dream), I will adjust the car to drive like the car above. Except for the lifting of the right rear tire on hard right corners, but that is another story.

Eric
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post #14 of 188 (permalink) Old 11-18-2005, 08:14 AM
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Quote:
Originally Posted by gtv27
Some very interesting info here on spring rates. Am particularly interested on front to rear balance.

I was running my 2000GTV with a standard FARB, no RARB, 1000lb front springs, 100lb rear springs, koni yellow all round. - it was pretty well balanced and very supple, but was rolling off its tyres (Yokohama A048 R compound road racing tyres) and abusing the sidewalls both front and rear in the tight corners.

I changed to a 27mm FARB, 1300lb front springs, 200lb rear springs. The car now rolls less and is keeping its tyres alive better (actually seem to be generating more heat - which could be problem for long runs, but I mostly do sprints which are only 3 to 4 laps), but probably has a bit too much rear spring (oversteer is now an issue - although I'm learning to live with it before making another change - I do have some 150lb springs on hand just in case).

So you're probably asking what the point of this - my quandry is how the hell are you getting 800lb fronts and 230lb rears to work?

That seems way too stiff in the back and too soft in the front. My car is a 74 model so is quite heavy (1000kg) compared to earlier chassis or GTA's, but surely that wouldn't explain the big difference in rates or front to rear balance (?) Maybe the answer is the bigger 29mm FARB (?)

I do have some 800lb front springs, so I could try it, but would like to be convinced it is worth the effort first (with or without a 29mm FARB).

Thoughts appreciated.
You would need to run a 29mm bar with 800s on the front... keep your current 200s on the back... the car won't be far away like that....

1000lb on the front, 100 on the back with a standard front bar is a very Italian way to set up a car!... spends most of its time on 3 wheels, with the huge resultant body roll giving the outside front tyre a good few theoretical degrees of positive camber... thus chewing the outside edge of the tyre like a rabid dog!!!! Looks impressive... not fast! A perfect example of a set up like this in an extreme photo... he has bounced off the kerb to get it so high... but the principles are stil there, is attached!!

Murray.... on a billiard flat corner when the car is settled and powering through the corner the suspension is not moving, thus the dampers aren't really doing anything. The difference is getting the car into the corner, i.e. when there is huge weight transfer... its all about getting the car settled as quickly as possible.... this is much harder if the corner is bumpy too as the surface is always working against the suspension... Chicanes also show up dampers very well....

p.s. who said Eric would be leading anyway!!!
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post #15 of 188 (permalink) Old 11-18-2005, 02:19 PM
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Eric,

The SCCA National Solo Championship in Topeka was terrible for me this year. But... this discussion is really interesting and I may as well chime in with another set of spring rate data (even though it seems kind of strange).

My autocross Spider has 800 front and 300 rear springs. Front sway bar is a 31 mm rear mount style from Jack Beck, and the rear is a 19mm Shankle with new holes drilled in the end plates to shorten the moment arm.

Interestingly, the car doesn't oversteer and can actually be "driven" into understeer by charging into a corner and being too ham-handed with steering wheel input. It is fairly well-balanced for autocross, don't you agree?. For the time trials in Seattle, I used shaved, heat cycled Khumo V700 and felt these "went away" during the course of four 15 minute sessions. They used transponders, and my fastest timed lap was the third one of the first timed session. Rats...

Quote:
Originally Posted by turbolarespider
I should think that, too.

But something keeps bugging me about the tires. I know there are some tires who don't need static camber, others that do.

And the Alfa suspension isn't exactly known for it's wonderful camber curves...

I wish I were a chassis dynamics guy sometimes, but powertrain systems pays the bills.

Max, I would consdier using your set up, but the problem is that I'm quite happy with my set up. So my next car will be much like it. I know you are conviced that the Red Konis are not up to snuff on the really stiff springs, but I can't seem to find that same problem. There are some occasions when autocrossing that the car wallows a little, but those tend also to be very tight 180's where I overdrive the corner, too.

On the track, even the very bumpy Waterford Hills, my car feels very stable. And the times are reasonably quick- my street car would have placed mid pack in it's run group at the last historic race I saw at the track. And at Gingerman, it would be similar- both about 3-4 seconds off of the pole time. (makes my chest fill out a lot, you know... )

Review of my set up- W&D all the way around for springs- (I think that's 1200 front, 150 rear), Koni Red Shocks, Shankle front sway bar (27mm front mount), stock rear sway bar, 15x7 Panasports, normally wrapped with Kuhmo Victoracers, and -2.5deg camber in the front. When I put the cheap priced Hoosier Autocrossers on this past spring, those things were ROCKETS, but I wore through the tread way too fast. Good if I ever wanted to join George in Topica, but bad for the racer who likes valued based fun.

For the race car I will be building (someday, I swear it's not a dream), I will adjust the car to drive like the car above. Except for the lifting of the right rear tire on hard right corners, but that is another story.

Eric


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George Schweikle

1976 Spider (Dedicated Autocrosser, "SPICA, No Carbs")
1991 Spider Veloce (Retirement cruiser)
Scuderia Non Originale

Last edited by conedriver; 03-07-2006 at 07:43 AM.
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