howard coleman's FD Chassis/Setup
04-23-08, 08:34 AM
#251
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as mentioned a number of times this thread is about DUAL PUPOSING the FD. that means when heading up to Minneapolis to work on friend Frank's (150 mph 360 spin fame) 20b FD and carting a bunch of parts and tools not taking the winter car. so friday off i went on my 680 mile round trip... in my FD. 20+ mpg, thru some serious rain w newly shaved 6/32 Sumitomo HTR Z IIIs, no problems. our cars got to spend the night together. hmm, as i look at the RF tire... it looks like it is on backwards.
Frank runs Tein Flex and AP brakes. he will be upgrading to RacingBrakes in the rear shortly. we built a turbine heat shield and pulled alot of preseason maintainence.
in the "it seemed like a great idea" category... after doing some epoxy on the backside of one of his headlight covers and waiting for it to setup it was about cocktail time so we thought we'd just pop it in the microwave to hasten the cure. needless to say that didn't work (JB Weld to the rescue) but it did make for a stupid picture. of course i volunteered Frank for the notoriety. a bottle of '06 red should go well w the cover
pardon the above detour but i just wanted to make the point that you can have fun w your FD and enjoyably drive it almost anywhere properly modified. i marvel at my 8/6 springs. they are so perfect. i really like my Speedway Eng bar and don't currently yet know how it trims out longitudinally.
i am currently working on modding an AeroFiber Feed type 2 carbon fiber rear wing so it will be properly adjustable. as delivered it has way too much downforce rake even at it's lowest setting. i want to drive around town w zero drag and be able to adjust rear downforce from that point.
i am also waiting for an uprated FJO alcohol controller and FJO oil temp and pressure gauges which should shortly arrive.
then it is dyno and track.
stay tuned,
howard
Frank runs Tein Flex and AP brakes. he will be upgrading to RacingBrakes in the rear shortly. we built a turbine heat shield and pulled alot of preseason maintainence.
in the "it seemed like a great idea" category... after doing some epoxy on the backside of one of his headlight covers and waiting for it to setup it was about cocktail time so we thought we'd just pop it in the microwave to hasten the cure. needless to say that didn't work (JB Weld to the rescue) but it did make for a stupid picture. of course i volunteered Frank for the notoriety. a bottle of '06 red should go well w the cover
pardon the above detour but i just wanted to make the point that you can have fun w your FD and enjoyably drive it almost anywhere properly modified. i marvel at my 8/6 springs. they are so perfect. i really like my Speedway Eng bar and don't currently yet know how it trims out longitudinally.
i am currently working on modding an AeroFiber Feed type 2 carbon fiber rear wing so it will be properly adjustable. as delivered it has way too much downforce rake even at it's lowest setting. i want to drive around town w zero drag and be able to adjust rear downforce from that point.
i am also waiting for an uprated FJO alcohol controller and FJO oil temp and pressure gauges which should shortly arrive.
then it is dyno and track.
stay tuned,
howard
Last edited by Howard Coleman; 04-23-08 at 07:55 PM.
04-23-08, 08:07 PM
#253
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hi Kevin,
i'd rather that this specific thread not morph into a track only thread.
we are talking dual purpose only here. that said, i will shortly be at the track and will of course be tuning my setup for as fast as it will go.
track only cars primary difference is stickier rubber. 3/32 tires that can't run on the street unless you want a blowout after running over a marshmallow.
since track only cars pull more Gs you can run a bit more spring, bars, shocks and brakes. you determine how much by using tie wraps on the shock rods. you are looking for no more than 2 inches of bump travel at the wheel or 1.3 at the front shock rod and 1.4 in the rear.
use your pyrometer to set tire pressures and all suspension adjustments. if you want to go fast you will be making camber adjustments at the track on all four corners.
so there isn't much diff in the proceedure between what i will be doing w my dual purpose and a track car...
regards and kudos for building a super FD,
howard
i'd rather that this specific thread not morph into a track only thread.
we are talking dual purpose only here. that said, i will shortly be at the track and will of course be tuning my setup for as fast as it will go.
track only cars primary difference is stickier rubber. 3/32 tires that can't run on the street unless you want a blowout after running over a marshmallow.
since track only cars pull more Gs you can run a bit more spring, bars, shocks and brakes. you determine how much by using tie wraps on the shock rods. you are looking for no more than 2 inches of bump travel at the wheel or 1.3 at the front shock rod and 1.4 in the rear.
use your pyrometer to set tire pressures and all suspension adjustments. if you want to go fast you will be making camber adjustments at the track on all four corners.
so there isn't much diff in the proceedure between what i will be doing w my dual purpose and a track car...
regards and kudos for building a super FD,
howard
04-26-08, 02:35 PM
#255
Howard,
You've mentioned several times throughout the thread that you use the pyrometer to set camber as well as tire pressure. I've recently invested in a digital pyrometer with laser and have a question.
Now I understand about the camber, since you want as even temperatures across the tire as possible (left middle right), but how do you use the temperatures to adjust your tire pressure?
Actually after I just typed that question, I just realized that you can use it to even out the temperatures of all of the 4 tires. Gotta love GranTurismo
But how do you get to what pressure is optimal?
Do you set tire pressure first, then camber? Other way around? Or it doesn't matter.
You've mentioned several times throughout the thread that you use the pyrometer to set camber as well as tire pressure. I've recently invested in a digital pyrometer with laser and have a question.
Now I understand about the camber, since you want as even temperatures across the tire as possible (left middle right), but how do you use the temperatures to adjust your tire pressure?
Actually after I just typed that question, I just realized that you can use it to even out the temperatures of all of the 4 tires. Gotta love GranTurismo
But how do you get to what pressure is optimal?Do you set tire pressure first, then camber? Other way around? Or it doesn't matter.
04-26-08, 03:27 PM
#256
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Howard,
You've mentioned several times throughout the thread that you use the pyrometer to set camber as well as tire pressure. I've recently invested in a digital pyrometer with laser and have a question.
Now I understand about the camber, since you want as even temperatures across the tire as possible (left middle right), but how do you use the temperatures to adjust your tire pressure?
Actually after I just typed that question, I just realized that you can use it to even out the temperatures of all of the 4 tires. Gotta love GranTurismo But how do you get to what pressure is optimal?
Do you set tire pressure first, then camber? Other way around? Or it doesn't matter.
You've mentioned several times throughout the thread that you use the pyrometer to set camber as well as tire pressure. I've recently invested in a digital pyrometer with laser and have a question.
Now I understand about the camber, since you want as even temperatures across the tire as possible (left middle right), but how do you use the temperatures to adjust your tire pressure?
Actually after I just typed that question, I just realized that you can use it to even out the temperatures of all of the 4 tires. Gotta love GranTurismo
But how do you get to what pressure is optimal?Do you set tire pressure first, then camber? Other way around? Or it doesn't matter.
camber is more fixed, it gets set and unless you change something it doesnt change.
04-26-08, 09:48 PM
#257
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" I understand about the camber, since you want as even temperatures across the tire as possible (left middle right), but how do you use the temperatures to adjust your tire pressure?"
you do not want even temperatures across the tire. at the track, you want the inside third of the tire to be approx 20+ degrees hotter than the outside. if you don't see this adjust the camber before going back ontrack.
overinflated tires are hotter in the middle. underinflated are cooler in the center.
i will go over setup and track tuning using real numbers when i get ontrack in the near future.
initial setup specs are found in post one.
hc
you do not want even temperatures across the tire. at the track, you want the inside third of the tire to be approx 20+ degrees hotter than the outside. if you don't see this adjust the camber before going back ontrack.
overinflated tires are hotter in the middle. underinflated are cooler in the center.
i will go over setup and track tuning using real numbers when i get ontrack in the near future.
initial setup specs are found in post one.
hc
04-27-08, 12:18 AM
#258
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I know that most of what has been discussed is for the track. What about autocross? I'm just running street tires, but I'm still trying to find optimal tire pressure. Will the use of a pyrometer still help set appropriate tire pressure for Autocross or is it best to just look for proper tire roll by examining the tire shoulders?
04-27-08, 10:04 AM
#259
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i have no autocross experience but i did sleep at a Holiday Inn last night...
autocross is a bit different as to setup V road racing. the same physics/dynamics of course is present. i would guess that if you want to run upfront there is a tradeoff for more roll stiffness. quicker transient response V advance communication.
each tire at each corner of your car will optimally require a slightly different air pressure and camber. as mentioned, a pyrometer is essential to set pressure and camber.
i do use a laser dot heat gun for checking temperatures but don't use it for tires. i use and recommend the pin/insert type pyrometer. there is no comparison as to info gained by using a pyrometer V looking at sidewall roll.
as previously mentioned, a pyrometer is essential if you are looking to tune properly.
i hope to make this all clear when i get ontrack.
howard
autocross is a bit different as to setup V road racing. the same physics/dynamics of course is present. i would guess that if you want to run upfront there is a tradeoff for more roll stiffness. quicker transient response V advance communication.
each tire at each corner of your car will optimally require a slightly different air pressure and camber. as mentioned, a pyrometer is essential to set pressure and camber.
i do use a laser dot heat gun for checking temperatures but don't use it for tires. i use and recommend the pin/insert type pyrometer. there is no comparison as to info gained by using a pyrometer V looking at sidewall roll.
as previously mentioned, a pyrometer is essential if you are looking to tune properly.
i hope to make this all clear when i get ontrack.
howard
04-29-08, 07:13 PM
#260
Regarding using the Tein Flex coilovers.
A couple of years ago I changed fron the 10/8 springs to the 8/6 springs. Since the springs on the Flex are straight wound all I had to do was to buy a set of 6's to put on the rear and move the 8's to the front, as they are the same size of springs front and rear for this model. I like the softer springs and do not notice any particular noise or harshness as a result of the solid upper mounts. FWIW
Ken
A couple of years ago I changed fron the 10/8 springs to the 8/6 springs. Since the springs on the Flex are straight wound all I had to do was to buy a set of 6's to put on the rear and move the 8's to the front, as they are the same size of springs front and rear for this model. I like the softer springs and do not notice any particular noise or harshness as a result of the solid upper mounts. FWIW
Ken
04-30-08, 07:47 PM
#261
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What was your total? I just got off the phone w/ Ryan and if you dont revalve due 2KG> or < the warranty on the shocks will be VOIDED! He quoted my a fee of $100 per to revalve ($400!) plus $150 for the spring change. That's $550 extra! Sounds like type Flex and using oem upper mounts might be the way to go. By the way thanks to Howard and contributers to this thread. G
04-30-08, 08:32 PM
#262
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according to my shock dyno it is laughable that Tein is telling you they need a revalve. the shocks adjust from rockhard to almost no resistance at all.
skip the warranty (my '99 Teins work perfectly) , swap the springs and enjoy.
hc
skip the warranty (my '99 Teins work perfectly) , swap the springs and enjoy.
hc
05-01-08, 08:56 AM
#264
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as often stated in this thread developing the full (awesome) potential of the FD on a road course requires especial focus on the rear half of the chassis. front engine rear drive cars are all about rear grip. they are not about 50-50. they are not about equal corner weights. i run close to 54% rear weight. the more rear weight the faster you go.
given that reality i decided to let aero help me a bit in the rear.... i examined my wing options.
the first requirement:
adjustability.
specific setup at the track in all areas makes for speed. i have stated that tire pressure, camber and toe should be trimmed using a pyrometer at the track.
rear aero downforce, the results of which cannot be overestimated, needs to be adjustable. so skip all non adj wings.
secondly, remember that this thread is NOT about building a track only FD. it is about building an FD that will outrun 80% of the track only FDs but will be a pleasure to drive on the street. on the street we want no drag.
that means after doing your track stuff you flat out the wing for the street. given the price of gas what would be the point of burning more than necessary with no positive trade-off.
the 99 Mazda wing looks good... zero to 17 degrees.
here we get in to a bit of personal preference where we will all differ a bit. while i like the looks it is just a little to wing-y for me. i prefer the stealth look if possible so as not to draw too much attention from the local police who have too much time on their hands around my area.
after looking around i settled on the Aerofiber (a vendor on our board) version of the Feed Type 2 wing.
while i liked the potential of it i realized i'd have to do some re-engineering. as shipped, the wing was not able to be flatted out. i built new aluminum endplates w an additional (neutral) angle setting. (the car was uphill a tad in this pic)
endplates
sits fairly low compared to the 99 wing. you can go faster in reverse w less obscured rear window vision. i hadn't reinstalled the rear hatch plastic in this picture. BTW, you don't need to remove it to install the wing as it mounts outside of the plastic area. please don't tell anyone i did this...
w the carbon fiber wing option the setup is quite light. i was happy to see my hatch stands up.
i look forward to messing w the wing ontrack. i paid market price for the wing from Aerofiber and found the carbon fiber work to be A+. the wing comes in CF or fiberglass. priced right too.
i do qualify my suggestion re the wing since i would not run it unless i made new endplates so you don't have to run around w so much rake.
i ordered a 12 X 12 piece of mirror polished T6061 aluminum 1/8 inch thick, used the original endplates as an outline and redrilled 7 new holes. (McMaster Carr, $51)
BTW, since this thread has become quite long anyone joining it is asked to please read post one as it is fairly comprehensive. i plan to re-read the thread and add an index by specific subject shortly.
more to come... brakes and ontrack tuning.
howard
given that reality i decided to let aero help me a bit in the rear.... i examined my wing options.
the first requirement:
adjustability.
specific setup at the track in all areas makes for speed. i have stated that tire pressure, camber and toe should be trimmed using a pyrometer at the track.
rear aero downforce, the results of which cannot be overestimated, needs to be adjustable. so skip all non adj wings.
secondly, remember that this thread is NOT about building a track only FD. it is about building an FD that will outrun 80% of the track only FDs but will be a pleasure to drive on the street. on the street we want no drag.
that means after doing your track stuff you flat out the wing for the street. given the price of gas what would be the point of burning more than necessary with no positive trade-off.
the 99 Mazda wing looks good... zero to 17 degrees.
here we get in to a bit of personal preference where we will all differ a bit. while i like the looks it is just a little to wing-y for me. i prefer the stealth look if possible so as not to draw too much attention from the local police who have too much time on their hands around my area.
after looking around i settled on the Aerofiber (a vendor on our board) version of the Feed Type 2 wing.
while i liked the potential of it i realized i'd have to do some re-engineering. as shipped, the wing was not able to be flatted out. i built new aluminum endplates w an additional (neutral) angle setting. (the car was uphill a tad in this pic)
endplates
sits fairly low compared to the 99 wing. you can go faster in reverse w less obscured rear window vision. i hadn't reinstalled the rear hatch plastic in this picture. BTW, you don't need to remove it to install the wing as it mounts outside of the plastic area. please don't tell anyone i did this...
w the carbon fiber wing option the setup is quite light. i was happy to see my hatch stands up.
i look forward to messing w the wing ontrack. i paid market price for the wing from Aerofiber and found the carbon fiber work to be A+. the wing comes in CF or fiberglass. priced right too.
i do qualify my suggestion re the wing since i would not run it unless i made new endplates so you don't have to run around w so much rake.
i ordered a 12 X 12 piece of mirror polished T6061 aluminum 1/8 inch thick, used the original endplates as an outline and redrilled 7 new holes. (McMaster Carr, $51)
BTW, since this thread has become quite long anyone joining it is asked to please read post one as it is fairly comprehensive. i plan to re-read the thread and add an index by specific subject shortly.
more to come... brakes and ontrack tuning.
howard
Last edited by Howard Coleman; 05-09-08 at 03:05 PM.
05-01-08, 10:36 AM
#265
Howard,
What's your sense that the wing will actually do anything? I've always thought the FEED wing was the nicest looking, but since the R1 wing doesn't have any affect, I've my doubts that the FEED is high enough, or in clean enough airflow to have an effect.
The '99 is higher at the outsides where it's likely to be in cleaner air... though I'm not a fan of it asthetically.
What's your sense that the wing will actually do anything? I've always thought the FEED wing was the nicest looking, but since the R1 wing doesn't have any affect, I've my doubts that the FEED is high enough, or in clean enough airflow to have an effect.
The '99 is higher at the outsides where it's likely to be in cleaner air... though I'm not a fan of it asthetically.
05-01-08, 10:55 AM
#266
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Peter raises the key question. no doubt i could put the equivalent of a DC3 wing on the rear trunk and probably run the rear springs to coilbind but this is all about dual purpose.
as posted earlier i recounted an experience at the Runoffs where on the last day of qualifying i removed, for the first (and only) time, my rear wing to get a little more top end. if you look at the pic of my RX3 you can't even see the factory rear deck spoiler. it was pop riveted on and weighed all of 3 pounds. it was out of the airstream.
and it's absence made the car undrivable.
i couldn't flatfoot the slight bend at the end of the long Road Atlanta back straight and on the other side of the track, 3rd gear esses, the car wouldn't stick.
so it remains to be seen what my FD spoiler will do. my guess is that on a car that is way out of balance it won't make everything perfect. for a car that is close to right it will add rear grip (for sure) and allow additional front grip to be dialed in thereby upping the G bar.
hc
as posted earlier i recounted an experience at the Runoffs where on the last day of qualifying i removed, for the first (and only) time, my rear wing to get a little more top end. if you look at the pic of my RX3 you can't even see the factory rear deck spoiler. it was pop riveted on and weighed all of 3 pounds. it was out of the airstream.
and it's absence made the car undrivable.
i couldn't flatfoot the slight bend at the end of the long Road Atlanta back straight and on the other side of the track, 3rd gear esses, the car wouldn't stick.
so it remains to be seen what my FD spoiler will do. my guess is that on a car that is way out of balance it won't make everything perfect. for a car that is close to right it will add rear grip (for sure) and allow additional front grip to be dialed in thereby upping the G bar.
hc
05-07-08, 11:52 AM
#269
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Thanks Howard,
Here are my AutoX settings on a stock FD in SS class.
Let me know what you think
thanks
front:
-3 camber, 3/32 toe out, caster....hmmm.. I think its 3.5?
Rear:
-2.3 camber, 1/8 toe in
Tri point sway bar:
one setting back from full soft.
Koni double adjustable with stock springs. Settings ??? dont really know yet.
Hoosiers A6 245/45/16
Here are my AutoX settings on a stock FD in SS class.
Let me know what you think
thanks
front:
-3 camber, 3/32 toe out, caster....hmmm.. I think its 3.5?
Rear:
-2.3 camber, 1/8 toe in
Tri point sway bar:
one setting back from full soft.
Koni double adjustable with stock springs. Settings ??? dont really know yet.
Hoosiers A6 245/45/16
05-08-08, 10:21 AM
#270
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i have never autoX'd and did briefly comment in post 259.
swaybars, springs and tire pressure determines total roll. shocks effect the speed of the roll only.
you are running stock springs w slightly higher front roll stiffness from your swaybar. this will make the car tend to push. you may effect the push (longitudinal trim) by going down on front air pressure and up on rear a pound or two.
(NASCAR routinely adjusts tire pressures to the TENTH OF A POUND)
you want no more than two inches of wheel travel. use tie wraps on your shocks and you will need more spring rate if you see the tie wraps moved up more than 1.4 inches. if you see any more travel i recommend Eibach Pro Kit springs as the next step. you will love them.
as previously mentioned camber needs to be set for each course using tire temperatures. if you are serious about your results you need instruments (pyrometer, camber gauge, toe gauge, good tire pressure gauge) and you need to keep records on each run.
toe is VERY VERY critical. a 16th can change the car. toe will be very different for autoX than road racing etc. i do not have a toe number for you and i would like to keep the focus on road racing/aggressive street but i welcome brief accredited setup comments for autoX in the interest of all.
do fiddle w your shock settings too. autoX rewards setup.
good luck,
howard
swaybars, springs and tire pressure determines total roll. shocks effect the speed of the roll only.
you are running stock springs w slightly higher front roll stiffness from your swaybar. this will make the car tend to push. you may effect the push (longitudinal trim) by going down on front air pressure and up on rear a pound or two.
(NASCAR routinely adjusts tire pressures to the TENTH OF A POUND)
you want no more than two inches of wheel travel. use tie wraps on your shocks and you will need more spring rate if you see the tie wraps moved up more than 1.4 inches. if you see any more travel i recommend Eibach Pro Kit springs as the next step. you will love them.
as previously mentioned camber needs to be set for each course using tire temperatures. if you are serious about your results you need instruments (pyrometer, camber gauge, toe gauge, good tire pressure gauge) and you need to keep records on each run.
toe is VERY VERY critical. a 16th can change the car. toe will be very different for autoX than road racing etc. i do not have a toe number for you and i would like to keep the focus on road racing/aggressive street but i welcome brief accredited setup comments for autoX in the interest of all.
do fiddle w your shock settings too. autoX rewards setup.
good luck,
howard
05-08-08, 03:39 PM
#271
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just received word my delayed module should be in my hands wed-thurs next week so it won't be too much longer and we will switch the venue of this thread from my office to the track.
things are about to get interesting,
hc
things are about to get interesting,
hc
05-08-08, 09:42 PM
#272
G,
$835 for the coilovers $250 for the springs, with shipping I'm looking at a little over $1100.
$835 for the coilovers $250 for the springs, with shipping I'm looking at a little over $1100.
What was your total? I just got off the phone w/ Ryan and if you dont revalve due 2KG> or < the warranty on the shocks will be VOIDED! He quoted my a fee of $100 per to revalve ($400!) plus $150 for the spring change. That's $550 extra! Sounds like type Flex and using oem upper mounts might be the way to go. By the way thanks to Howard and contributers to this thread. G
05-08-08, 10:45 PM
#273
Rapidly succeeding brute transitions happen in autox. Class ruling permitting, you want stiff suspensions to load the tires quickly upon lateral weight transfer and improve chassis stability (think of a tight slalom, with soft suspensions the chassis may still have yet to settle completely while you start turning the wheel in the opposite direction to negotiate the next cone; an extremely upsetting condition).
Since in stock class you are "stuck" with the OE springs and rear swaybar, a beefy front bar is a must to increase overall roll stiffness. The benefits largely outweigh the resulting front bias (understeer).
In order to appreciate why a stiff swaybar is such an effective upgrade in stock class, consider the following. As you enter a corner or a slalom, the swaybar will constrain the car to stay flat. This provides several benefits. First, the suspension settles quickly (as discussed earlier). Second, by keeping the car flat, the rear wheels are kept "pushed down" and throttle can now be applied much earlier on corner exit (this is big gain since you can now leave the corner at a higher speed). Third, if you loose control, it may still be possible to regain it with understeering, impossible with an oversteering car.
The main disadvantage is corner entry as the car will tend to go straight and resist rotation. This can be corrected simply by breaking early before the turn in, or by some more advanced techniques, such as trail braking together with a very aggressive rebound n the rear shocks or throttle lift off to help rotating the car. For the same reason, I prefer setting the rear loose, not much negative camber, 1.2-1.5 deg, and zero toe. But here is were individual preferences may vary, depending on your driving style.
In the front, you want to max out the negative camber, as you did - by the way it is remarkable that you could get 3 deg. In my car I can only get 2.2-2.3 deg. As for the toe, toe out should help turn in. Though, I prefer zero. I noticed that if the toe is set out then you will have to turn your steering wheel more to the next change of direction.
As for shock valving/settings, an interesting theory is that you should use very soft compression and super stiff rebound. That would cause the car to "jack-down" during the runs, compressing the springs and therefore stiffening the suspensions. Another stock class trick. Maybe, even though I tried it a few times but could never feel it. My favorite combination is full stiff rebound front and rear all the time (to keep the chassis in check). I always use full stiff compression in the front. I found this very effective to quickly settle the car and improve braking. I suspect because at their highest compression setting, the resulting force may override the stock OE springs. The higest settings provide a very noticeable positive feeling on braking and directionally changes. In the end, rear compression is the only setting I found worth adjusting in order to maximize tractions as conditions change. I use the softer settings if the tires are cold or used up and stiffer in more ideal conditions.
Have fun in finding out what other combinations may work for you better.
- Sandro
Since in stock class you are "stuck" with the OE springs and rear swaybar, a beefy front bar is a must to increase overall roll stiffness. The benefits largely outweigh the resulting front bias (understeer).
In order to appreciate why a stiff swaybar is such an effective upgrade in stock class, consider the following. As you enter a corner or a slalom, the swaybar will constrain the car to stay flat. This provides several benefits. First, the suspension settles quickly (as discussed earlier). Second, by keeping the car flat, the rear wheels are kept "pushed down" and throttle can now be applied much earlier on corner exit (this is big gain since you can now leave the corner at a higher speed). Third, if you loose control, it may still be possible to regain it with understeering, impossible with an oversteering car.
The main disadvantage is corner entry as the car will tend to go straight and resist rotation. This can be corrected simply by breaking early before the turn in, or by some more advanced techniques, such as trail braking together with a very aggressive rebound n the rear shocks or throttle lift off to help rotating the car. For the same reason, I prefer setting the rear loose, not much negative camber, 1.2-1.5 deg, and zero toe. But here is were individual preferences may vary, depending on your driving style.
In the front, you want to max out the negative camber, as you did - by the way it is remarkable that you could get 3 deg. In my car I can only get 2.2-2.3 deg. As for the toe, toe out should help turn in. Though, I prefer zero. I noticed that if the toe is set out then you will have to turn your steering wheel more to the next change of direction.
As for shock valving/settings, an interesting theory is that you should use very soft compression and super stiff rebound. That would cause the car to "jack-down" during the runs, compressing the springs and therefore stiffening the suspensions. Another stock class trick. Maybe, even though I tried it a few times but could never feel it. My favorite combination is full stiff rebound front and rear all the time (to keep the chassis in check). I always use full stiff compression in the front. I found this very effective to quickly settle the car and improve braking. I suspect because at their highest compression setting, the resulting force may override the stock OE springs. The higest settings provide a very noticeable positive feeling on braking and directionally changes. In the end, rear compression is the only setting I found worth adjusting in order to maximize tractions as conditions change. I use the softer settings if the tires are cold or used up and stiffer in more ideal conditions.
Have fun in finding out what other combinations may work for you better.
- Sandro
05-08-08, 11:47 PM
#274
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nice
thanks for that.
A lot of the old RX7 drives are telling me a lot of rea toe in
some are saying that you want snap oversteer
I have not AX on this new alignment yet. Before the car was pushing going in and loose coming out on thottle.
Any idea what pressures to start out with on the A6 hoosiers.
thanks a bunch
thanks for that.
A lot of the old RX7 drives are telling me a lot of rea toe in
some are saying that you want snap oversteer
I have not AX on this new alignment yet. Before the car was pushing going in and loose coming out on thottle.
Any idea what pressures to start out with on the A6 hoosiers.
thanks a bunch
05-09-08, 09:00 AM
#275
Different drivers have different setting preferences and driving styles. In Stock class, I prefer using a very stiff front bar and compensate the radical resulting understeer with looseness in the rear I can induce and control with the throttle.
Now that you have all this adjustable equipment, big part of the fun will be to play with it and find out what settings combination you will feel more comfortable driving with.
I suggest making separate large adjustment as you will be testing. E.g. disconnect the front sway bar completely, then use your thickest tubular bar and connect the links to the get the shortest arm leverage; with the shocks, use full soft or full stiff settings in different combinations compression and rebound. Be aware that any time you stiffen the shocks in one direction the faster the weight will transfer to/from the tires in that direction, and viceversa. E.g. full compression in the front and full rebound in the rear will load the front tires quickly under braking, at another extreme, low front rebound and low rear compression will load your rear tires more gradually under acceleration, etc. Try using the extreme combination in pairs to test and feel the results. Otherwise, you will get easily confused.
As for your problems, overcooking a corner entry, 95% chances are that you are entering it too fast. Just brake early to solve it - even though this will cost you time, it will be a small fraction of the time otherwise lost to recover from a bad corner entry. The other 5% might be that your tires are not enough sticky. If either of the two are true, no shock adjustment will help you solve the problem.
Coming loose on throttle on corner exit, most likely you apply too much throttle too early, before unwinding sufficiently the steering wheel. It's very typical of our cars. This is where the big front sway bar becomes essential in Stock class and allows you much earlier and decisive throttle application.
I haven't used the Hoosiers in the last several years. With the Khumos I generally use 30-32 in the F and 24-26 in the R. The old Hoosier required more pressure, in the 40 range. I don't know if that still is the case with the A6. You may want to ask them directly.
- Sandro
Now that you have all this adjustable equipment, big part of the fun will be to play with it and find out what settings combination you will feel more comfortable driving with.
I suggest making separate large adjustment as you will be testing. E.g. disconnect the front sway bar completely, then use your thickest tubular bar and connect the links to the get the shortest arm leverage; with the shocks, use full soft or full stiff settings in different combinations compression and rebound. Be aware that any time you stiffen the shocks in one direction the faster the weight will transfer to/from the tires in that direction, and viceversa. E.g. full compression in the front and full rebound in the rear will load the front tires quickly under braking, at another extreme, low front rebound and low rear compression will load your rear tires more gradually under acceleration, etc. Try using the extreme combination in pairs to test and feel the results. Otherwise, you will get easily confused.
As for your problems, overcooking a corner entry, 95% chances are that you are entering it too fast. Just brake early to solve it - even though this will cost you time, it will be a small fraction of the time otherwise lost to recover from a bad corner entry. The other 5% might be that your tires are not enough sticky. If either of the two are true, no shock adjustment will help you solve the problem.
Coming loose on throttle on corner exit, most likely you apply too much throttle too early, before unwinding sufficiently the steering wheel. It's very typical of our cars. This is where the big front sway bar becomes essential in Stock class and allows you much earlier and decisive throttle application.
I haven't used the Hoosiers in the last several years. With the Khumos I generally use 30-32 in the F and 24-26 in the R. The old Hoosier required more pressure, in the 40 range. I don't know if that still is the case with the A6. You may want to ask them directly.
- Sandro