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On adjustments to the Tokico shocks

PeteInCT

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In one of our other threads we discussed settings for the Tokico shocks. I mentioned that I have my rears set for 4.5, inbetween the detents of the 4 and 5 settings. SInce there is no detent at the halfway points between the numbered detents, I posed two questions to Mark Wilson of Ford Racing performance:

1) Is setting at halfway points on the shock detents a legitimate practice (in other words, is the valveing truly progressive so that there is a difference between settings such as 4, 4.5 and 5) and will the shocks stay at a halfpoint setting or will they slip to an adjacent detent position?
2) Can one expect to feel a difference in the cars handling between settings that are only a 1/2 detent apart (i.e. 4.5 vs. 5) ?

Marks answer in a PM was a follows:
"Theres really no reason that the valving would change after you adjust it so I wouldn't worry about it. As far as telling the difference between .5 increments it really depends on how calibrated you are. My vehicle dynamics Engineer can tell the diffference but I can't....... really depends on the person....."

As for the shocks staying at settings at halfway points, my 4.5 rear settings have survived 3 tracks days as well as some street driving with no change in the settings due to vibration, etc.
 
Good info, thanks for sharing. That's how all of my dirt bikes worked. The numbers and detents are there for consistency in adjustment but in between the detents is infinite.
 

PeteInCT

#LS-378 - So many Porsche's, so little time....
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That's really dependent on the streets you are on, how you drive it and what you consider acceptable. Start off with the default setting of 3 for front and rear and see how increasing works for you. If you are on very rough roads even 3 may be too high. In my area the streets are very well paved so I keep it at the same as the track setting which is currently 5 up front and 4.5 in the rear. Pretty stiff, but no issues so far.
 
PeteInCT said:
That's really dependent on the streets you are on, how you drive it and what you consider acceptable. Start off with the default setting of 3 for front and rear and see how increasing works for you. If you are on very rough roads even 3 may be too high. In my area the streets are very well paved so I keep it at the same as the track setting which is currently 5 up front and 4.5 in the rear. Pretty stiff, but no issues so far.

Pete,

What is the effect of having a stiffer setting up front and softer setting in the rear? Does this setting allow for more oversteer?
 

PeteInCT

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Nice2BEtheBOSS said:
PeteInCT said:
That's really dependent on the streets you are on, how you drive it and what you consider acceptable. Start off with the default setting of 3 for front and rear and see how increasing works for you. If you are on very rough roads even 3 may be too high. In my area the streets are very well paved so I keep it at the same as the track setting which is currently 5 up front and 4.5 in the rear. Pretty stiff, but no issues so far.

Pete,

What is the effect of having a stiffer setting up front and softer setting in the rear? Does this setting allow for more oversteer?

This is the way it was taught to me - Keep in mind there are guys on this forum with many more years experience than I, some of it professional, on the subject:

The stiffer the shock setting (higher number) the quicker the load transfer to the tires when the car is in transition (i.e. going into a turn). A higher damper setting up front vs. the rear means that the load on outside front tire will be increased on turn in. More load up front means less in the rear, hence your rear will have more rotation (oversteer) through the turn. As Rocketman mentioned in a different thread here on the forum, reducing the rear damper setting can be used to address understeer issues.

There are many great books that outline the effects of suspension tuning on handling in performance driving. One that I found very informative when I first started driving in HPDE's is "Going Faster! - Mastering the Art of Race Driving" by Skip Barber of The SKip Barber Racing School fame (Bentley Publishers). It is a great all-around book, and in there Chapter 14 is devoted to Chassis Adjustments and the effects of load transfer. I've read the book cover to cover twice and still refer back to it from time to time because there's so much good info in it.
 
Interesting info, thanks Pete (and Mark). I'm not sure I am at the point of being able to feel or drive the difference but as time goes on it is something I will be looking into. I started at 5-5, then went to 5-4. Now I just set up 5-3 for my next event to see what happens.
 

PeteInCT

#LS-378 - So many Porsche's, so little time....
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How neutral did the car feel at 5 & 5 settings? You will probably feel the tail getting loose faster at a 5 and 3 setting. Watch it! ;-)
 
Tell me if I'm thinking correctly, I've always understood you soften the end that's loose to get it to stick better.

For instance, the LS Boss has a bigger sway bar (stiffer) out back, that helps the car turn in better for all out track use as the LS is designed for.

The regular Boss's smaller bar tends to add a little more push up front for the "normal" design input the factory designs in to their street cars.

The GT has an even smaller bar out back giving it even more tendency to push.

With that, if you want it to have less oversteer, you would want to soften the shock settings in the rear.

As simple as a Kart Chassis is, some of them have a sway bar out back. You would actually take the bar off on the short tracks so it would turn in, on the big enduro track you'd put the bar back on.

I had an old Formula Ford (Saracen) that had no rear bar at all, that car tended to push a lot, I would put stiffer springs out back to bring it back to being more netural.
 
Softening up the rear has taken out oversteer for me. When I started I had more understeer, mostly from going into turns too fast. As I progressed I started getting much more oversteer and changed to 5-4, that helped a lot. I have left it there to learn to drive the car instead of adjusting the car to my bad habits. It has been working very well but still has a little oversteer tendency even with the staggered tires. This is where the .5 change may work, a 3.5 setting may work out better then going to 5-3.

I am going down to three since I will be testing a square setup for the first time. I may have to make some additional changes to the car but want to get a feel for it and see how manageable it is. I have plenty of slicks but will still be switching back to the street tires sometimes. I took a ride with a friend with the same square tire setup and the car did not feel out of control.
 
It all depends what your base setting is, from my experience. There are bell curves to suspension changes, adding stiffness can either lose grip (if already really stiff) or gain grip (if it wasn't stiff enough). As an example, adding a thicker front or rear sway on a CT9A Evo (what I had) would help turn in and fight understeer, as the front one was soft enough a thicker one would add grip, and the rear one was thick enough that a thicker one would reduce rear grip. Net affect of either was a shift forward of the grip and less understeer. If you watch video of a CT9A on the track, they like to raise the inside rear tire because most people went the rear sway way since it is a lot easier to install.
 

PeteInCT

#LS-378 - So many Porsche's, so little time....
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Very good point, it's logical that any suspension tuning has a 'sweet spot' and too much or too little of any one tunable parameter will put you at the front or end of those curves. Also, need to keep in mind that adjusting the shocks doesn't change the ultimate load on any corner of the car, it just changes the instantaneous load at inertial change events (brake, accelerate, turn). Eventually you get the compression on the springs independent of the shock settings. I think that's part of the answer also, although I personally still need Mr. Wizard (aging myself there ;-) to fill in the details.
 
CaliMR said:
It all depends what your base setting is, from my experience. There are bell curves to suspension changes, adding stiffness can either lose grip (if already really stiff) or gain grip (if it wasn't stiff enough). As an example, adding a thicker front or rear sway on a CT9A Evo (what I had) would help turn in and fight understeer, as the front one was soft enough a thicker one would add grip, and the rear one was thick enough that a thicker one would reduce rear grip. Net affect of either was a shift forward of the grip and less understeer. If you watch video of a CT9A on the track, they like to raise the inside rear tire because most people went the rear sway way since it is a lot easier to install.

very complex..... :p
 
Nice2BEtheBOSS said:
CaliMR said:
It all depends what your base setting is, from my experience. There are bell curves to suspension changes, adding stiffness can either lose grip (if already really stiff) or gain grip (if it wasn't stiff enough). As an example, adding a thicker front or rear sway on a CT9A Evo (what I had) would help turn in and fight understeer, as the front one was soft enough a thicker one would add grip, and the rear one was thick enough that a thicker one would reduce rear grip. Net affect of either was a shift forward of the grip and less understeer. If you watch video of a CT9A on the track, they like to raise the inside rear tire because most people went the rear sway way since it is a lot easier to install.

very complex..... :p

Yes, so true, thankfully the Ford Engineers worked out the complexity in the Boss and now we just tweak it to our liking. ;D
 

PeteInCT

#LS-378 - So many Porsche's, so little time....
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FYI - I found this while snooping around the 'net today. Some of it is specific to oval track driving but I still thought it had some good pertinent info in it. They also assume that you have fully adjustable shocks with separate adjustments for compression and decompression, but it's more than just info on shocks. I can't attest to it's validity, so Caveat emptor (Let the buyer beware) ;D

http://www.racelinecentral.com/RacingSetupGuide.html
 
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"Going Faster! - Mastering the Art of Race Driving" by Skip Barber of The SKip Barber Racing School fame (Bentley Publishers). It is a great all-around book,

+ 1 on that book. It really breaks down how and why things work on the suspension!
I'm starting on my second time through
 
I'm a fan of the British tuning school: soft springs and heavy sways, with soft high speed and hard low speed damping. But again, every car and every driver is different. I like a little weight transfer to tell me what the car is doing.

Anyone know of a shop that revalves the stock shocks? Not sure it is worth the cost, when you can just go aftermarket, but maybe if you want to keep it a sleeper. Or as much a sleeper as can be done. I've seen some incredible results when having shocks mucked with on the insides on bikes.
 
So may be a dumb questions, but the adjustment is on rebound, compression, or both?

Been reading a bit and supposedly rebound for weight transfer, compression for grip. So curious which it is.
 

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