Shock Setup (from gsum thread)
10-14-2005, 02:47 PM
#16
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hrk - many thanks for that insight!
10-14-2005, 03:01 PM
#17
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Mark: Do you mean to tell me most of the people, including yourself, understand and embrace the power of a g-sum analysis? I know some of the better drivers on this board do but it certainly appears to me that most don’t. If someone doesn’t understand it and refuses to use it, then to point out their ignorance is not an insult, it is a statement of fact.
The g-sum is a fairly simple analysis. Looking at suspension data and the related Fast Fourier Transform – frequency analysis and dampening functions is quite advanced analysis. Further tuning this to shock velocity with spring rates and bars, … is really advanced. Have I applied this analysis to my car yet … no. I’m not good enough driving yet to have it be very beneficial – see below.
I was primarily commenting about myself and most drivers that the general progression for going fast should be basic car set-up, high g-sum, high g-sum consistency, then line optimization and detailed car set-up.
Now if you would like to show us your data, we could all see how far along that learning curve you are.
I’m not very far as my data shows. I am concentrating on g-sum consistency.
The g-sum is a fairly simple analysis. Looking at suspension data and the related Fast Fourier Transform – frequency analysis and dampening functions is quite advanced analysis. Further tuning this to shock velocity with spring rates and bars, … is really advanced. Have I applied this analysis to my car yet … no. I’m not good enough driving yet to have it be very beneficial – see below.
I was primarily commenting about myself and most drivers that the general progression for going fast should be basic car set-up, high g-sum, high g-sum consistency, then line optimization and detailed car set-up.
Now if you would like to show us your data, we could all see how far along that learning curve you are.
I’m not very far as my data shows. I am concentrating on g-sum consistency.
10-14-2005, 03:08 PM
#18
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Originally Posted by ColorChange
I was primarily commenting about myself and most drivers that the general progression for going fast should be basic car set-up, high g-sum, high g-sum consistency, then line optimization and detailed car set-up.
10-14-2005, 03:17 PM
#19
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SJanes, until you can sometimes take turns at the limit you have no hope of taking all the turns at the limit. I think what you are saying is work at consistency away from the limit before trying the limit. This is what most people do but I did not. I think my way is better but that is only my opinion.
10-14-2005, 03:33 PM
#21
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Originally Posted by Geo
I feel a haiku coming on.......
Consistency is the way
How does the wall taste?
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Larry Herman
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Larry Herman
2016 Ford Transit Connect Titanium LWB
2018 Tesla Model 3 - Electricity can be fun!
Retired Club Racer & National PCA Instructor
Past Flames:
1994 RS America Club Racer
2004 GT3 Track Car
1984 911 Carrera Club Racer
1974 914/4 2.0 Track Car
CLICK HERE to see some of my ancient racing videos.
10-14-2005, 03:46 PM
#22
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Originally Posted by ColorChange
SJanes, until you can sometimes take turns at the limit you have no hope of taking all the turns at the limit. I think what you are saying is work at consistency away from the limit before trying the limit. This is what most people do but I did not. I think my way is better but that is only my opinion.
Also, you may change your tune if you ever have the chance to sit in the right seat of a high HP car charging into a corner where the inconsistant driver is trying to drive at their limit, and you're thinking "geee, I wonder how this is going to turn out."
I want to know that the driver can put the car where they want it consistently before they start exploring their limit.
Sorry to drag this further off topic
As for some on topic discussion. About a year ago, I was going to buy Fox adjustable shocks, but then figured that I'd accomplish nothing more than screwing up my car, so I looked into getting my shocks custom valved. A buddy of mine had it done (Bilstien shocks) and they increased his rebound and decreased his compression. I figured the idea behind that setting was so the spring could absorb the bump (instead of the shock), but the shock gets the wheel back down quickly.
Last edited by sjanes; 10-14-2005 at 03:58 PM. Reason: Add shock stuff
10-14-2005, 04:00 PM
#24
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Originally Posted by 924RACR
Distractions in the thread aside, this part interests me greatly! Is that consideration of very stiff - is your reference relevant only for sports racers and formulae cars, or would that by any chance carry over to our door-slammers?
10-14-2005, 04:02 PM
#25
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Originally Posted by Larry Herman
Mark, I have found that too much rebound will tend to mimic bumpsteer in undulating corners. The steering is loading and then unloading because the wheel cannot return to the road fast enough. I would keep softening the rebound until the car can smoothly track over the undulations. Any thoughts on this?
10-14-2005, 04:04 PM
#26
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Originally Posted by Bob Rouleau
For CC's benefit, having a better suspension set up on a Ferrari Challenge car took more than 2 seconds off a "best" lap time. Changes on the F car are limited by the rules, so it' spring packers and changes to the ride height (no aero tricks like Mark has). And yes, the driver is absolutely great.
Mark if I may, you set compression very hard and rebound soft to maintain contact. How is the ratio of compression to spring rate? I think you hinted at it, but I'm not sure I understand it. Rebound has to be firm enough to prevent oscillation. Are you using realtively soft springs and using the shocks to manage compression? Note the GT3 set up seems to do something similar. The shocks are way stiff and the spring rates are low. Rebound on the bilsteins is fairly stiff and I think there is room for improvement there .. or, my shocks are shot , which is possible after 12,000 odd track miles.
Mark if I may, you set compression very hard and rebound soft to maintain contact. How is the ratio of compression to spring rate? I think you hinted at it, but I'm not sure I understand it. Rebound has to be firm enough to prevent oscillation. Are you using realtively soft springs and using the shocks to manage compression? Note the GT3 set up seems to do something similar. The shocks are way stiff and the spring rates are low. Rebound on the bilsteins is fairly stiff and I think there is room for improvement there .. or, my shocks are shot , which is possible after 12,000 odd track miles.
10-14-2005, 04:08 PM
#27
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Sjanes, not as applicable I agree. What I used to do was not track out on exit as a "safety margin" while I was learning to handle my car at the limit. I think this worked for me but I am not recommending it for others.
10-14-2005, 04:12 PM
#28
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Originally Posted by ColorChange
Mark: Do you mean to tell me most of the people, including yourself, understand and embrace the power of a g-sum analysis? I know some of the better drivers on this board do but it certainly appears to me that most don’t. If someone doesn’t understand it and refuses to use it, then to point out their ignorance is not an insult, it is a statement of fact.
The g-sum is a fairly simple analysis. Looking at suspension data and the related Fast Fourier Transform – frequency analysis and dampening functions is quite advanced analysis. Further tuning this to shock velocity with spring rates and bars, … is really advanced. Have I applied this analysis to my car yet … no. I’m not good enough driving yet to have it be very beneficial – see below.
I was primarily commenting about myself and most drivers that the general progression for going fast should be basic car set-up, high g-sum, high g-sum consistency, then line optimization and detailed car set-up.
Now if you would like to show us your data, we could all see how far along that learning curve you are. I’m not very far as my data shows. I am concentrating on g-sum consistency.
The g-sum is a fairly simple analysis. Looking at suspension data and the related Fast Fourier Transform – frequency analysis and dampening functions is quite advanced analysis. Further tuning this to shock velocity with spring rates and bars, … is really advanced. Have I applied this analysis to my car yet … no. I’m not good enough driving yet to have it be very beneficial – see below.
I was primarily commenting about myself and most drivers that the general progression for going fast should be basic car set-up, high g-sum, high g-sum consistency, then line optimization and detailed car set-up.
Now if you would like to show us your data, we could all see how far along that learning curve you are.
I’m not very far as my data shows. I am concentrating on g-sum consistency.2. Knock yourself out with the math. I have done it, and I have used a professional data engineer who tells me it really can't help much compared to seat of the pants. A big part of that reason, that you seem to constantly ignore, is that nothing is constant. G capabilities are all over the map. Grip levels change with track temp, surface, wind, etc, etc, etc. Your car can NOT do 1.2 g's on the track. I can do 1.2 in one part of one corner and 1.15 somewhere else, etc. Shock data will show the same. It looks great in one place and sucks somewhere else. You can not set the car up to be perfect everywhere. Only an experienced driver (unless you have the depth of data and engineers that a F1 team has) can make the decisions about how the car should be.
3. Further, you seem to completely ignore the human side of driving. It is an ART, not a SCIENCE. You have to have confidence in the car. A fast setup for me in not necessarily a fast set up for you. Shock data will not show that.
4. I am not giong to play your data challenge game. I posted data some time ago and you had all sorts of excuses why you could not analyze it. Data helps me develop as a driver and understand what the car does. I have a case full of trophies and certificates of lap records. They are a whole lot more satisfying to look at than silly data charts.
10-14-2005, 04:29 PM
#30
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OK, I'm not jumping in to the data debate, I just want to say thanks to Sunday for coming back. I've picked up more usable, practical tips in the last few days than I can count (or use, probably).