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ccsouls
05-28-2009, 04:11 PM
What do y'all feel is the best setup for the Alltrac (hatchback) and Coupe for coilover rebound settings?

Should the front be slightly softer than the rears for the hatchback?

Should the rears be slightly softer than the fronts for the coupe?

What do y'all think?

Thanks.

k.beaty
05-28-2009, 04:48 PM
I have a GT-S. I've found that for the FWD platform, that having the rear slightly stiffer helps a lot with cornering, thats just me though. I'd like to hear what others are running.

METDeath
05-28-2009, 07:13 PM
KoreanJoey is sick right now, but he would be a good person to chime in. He knows suspension bits very well.

ccsouls
05-28-2009, 07:17 PM
Yes, I can't wait to hear what Joey has to say.

However, he is primarily a coupe driver like I used to be, so I am still hopeful some hatchback people chime in.

METDeath
05-28-2009, 11:20 PM
Well, he is building a GTS for the track... so I'm sure he's already done plenty of research on the matter...

KoreanJoey
05-29-2009, 03:57 AM
Ohla,

Yeah, sorry, been sick lying on the couch trying not to die.

Ok, as to the settings don't think it'll make too much difference on a hatch VS coupe, although you might be able to get away with being a bit softer on the coupe as there is probably less weight back there.

Remember you want to have your shocks and springs matched together BUT, you can do some fine tuning with your setup. There's no way for me to tell you how stiff or soft to set your car as it's going to have to work in conjunction with the rest of your setup (alignment, tires, tire pressures, ride height, etc). Remember the handling of your car is based on everything working together, not one part vs another.

For example, if you run a stiff rear bar you can probably back down your bound and rebound settings in the rear. If you don't you'll probably have to up them a bit.

Also it depends on how effective your shocks are at adjusting from soft to stiff. The Tein coilovers I've driven in the past showed no real handling changes from stiff to soft whereas my Konis make a huge difference as do Motons, Bilsteins and Ohlins.

Basically your best bet is to find the right spring/shock combo (I think I remember you already bought Megans) and go from there.

Set your camber using a pyrometer and chalk to check your wear.
Adjust toe as to the degree of turn in vs stability you want.

And then make your adjustments within the range of your shocks. Remember you want the compression adjustment to where it's slowing down your weight transfers from side to side so that you're not making a violent transition loading one side to the other while allowing the suspension to work to absorb bumps and imperfections in the racing surface. I found the best way to adjust for compression settings is by doing a figure 8 skid pad as they allow you to concentrate loading one side of the car VS the other. You generally set your compression settings and forget them.

Rebound is usually the setting adjusted per course/course conditions. Usually you'll increase rebound stiffness on the end of the car that you'd like to lose traction first. If you're oversteering you can increase the rebound stiffness on the front or reduce rebound stiffness in the back.

One thing to beware of while adjusting for rebound is to avoid going too stiff as you can cause the car to start to jack down (where compression strokes outpace the rebound strokes causing to car to fall to the bumpstops) which will not make for very good traction at all.

You can also try setting a camera on the side of the car looking at the wheel to ensure that your wheels aren't going airborne over small bumps unnecessarily. If you can't get the settings to feel good while still making traction you might have to make some adjustments, instead, to your alignment or to your spring setup.

k.beaty
05-29-2009, 01:36 PM
:bowdown:

KoreanJoey
05-31-2009, 05:31 AM
:)

Waffles!
05-31-2009, 01:23 PM
:bowdown:
x2

Dan_Q
05-31-2009, 09:55 PM
nice read joey :)

i only have single adjustables on my car and i only ever adjust the fronts, depending on conditions- the rears are always set to maximum (most firm)

joe's gt
05-31-2009, 10:20 PM
I vote Joey needs to make a suspension adjustment tutorial sticky!!!

Please :yes: :bowdown:

ccsouls
06-01-2009, 03:31 PM
This weekend was my first SCCA testing of the All-Trac setup at the Evolution Driving School at the Eastern States Championships. (Preparing for Pro Solo this weekend.)

Megan Coilovers, Whiteline 20mm rear sway, poly bushings, solid diff mounts, Dunlop Dizzaras.

Started out with factory camber, 35psi front, 32 psi rear, front struts at 8 clicks, rears at 4 clicks.

Car understeered pretty badly. Had to tap breaks to get it to turn in. Schredded front Dizzaras.

At break, went to 12 clicks front, 2 degrees camber front, increased air to 40 psi front.

Car turned better, but still a little more understeer than I would like. Front tires melting.

Moved to 45 psi front, 40 psi rear.

Car still had a little understeer, but posted best times of the day with final setup. Front tires gone. Waves or rubber at 1.5 inch intervals across the front from the outside in.

I need help getting rid of this understeer. All suggestions welcome.

Also, any ideas on what is causing the tire ribs, please let me know.

The rear feels fine and I think it would come around if the front would hold better. I have a rear strut tower on order from 935 for over a month now. Hopeful it will help the rear come around. I am also waiting on a front strut tower bar on same order. If it ever gets here, I will update.

If anyone could offer suggestions, I would REALLY appreciate it. Need it for this weekend. Tell me anything you think. I am open.

Thanks Joey. Glad you are feeling better.

METDeath
06-01-2009, 05:14 PM
935 isn't exactly the quickest company. I had an order for an in stock part that took around two months.

88st165
06-01-2009, 05:41 PM
When I autox my 165 I usually start with 33psi front and 38psi rear (RS2's cold). The rest on my suspension is intrax springs with agx's on full stiff all 4 corners along with the whiteline rear swaybar in the middle setting. For me this gives me just enough oversteer for my liking. I found that the higher psi in the rear helps promote oversteer and if too much ill lower the rear a couple psi. The 165 is alittle lighter so it might vary for you.

ccsouls
06-01-2009, 11:20 PM
Hey Joey,

How would a rear spacer affect things?

This car has what looks to be a 25mm rear spacer on it. The last owner did it for looks like GT4RCDUDE does.

Suggestions?

KoreanJoey
06-02-2009, 06:58 AM
This weekend was my first SCCA testing of the All-Trac setup at the Evolution Driving School at the Eastern States Championships. (Preparing for Pro Solo this weekend.)

Megan Coilovers, Whiteline 20mm rear sway, poly bushings, solid diff mounts, Dunlop Dizzaras.

Started out with factory camber, 35psi front, 32 psi rear, front struts at 8 clicks, rears at 4 clicks.

Car understeered pretty badly. Had to tap breaks to get it to turn in. Schredded front Dizzaras.

At break, went to 12 clicks front, 2 degrees camber front, increased air to 40 psi front.

Car turned better, but still a little more understeer than I would like. Front tires melting.

Moved to 45 psi front, 40 psi rear.

Car still had a little understeer, but posted best times of the day with final setup. Front tires gone. Waves or rubber at 1.5 inch intervals across the front from the outside in.

I need help getting rid of this understeer. All suggestions welcome.

Also, any ideas on what is causing the tire ribs, please let me know.

The rear feels fine and I think it would come around if the front would hold better. I have a rear strut tower on order from 935 for over a month now. Hopeful it will help the rear come around. I am also waiting on a front strut tower bar on same order. If it ever gets here, I will update.

If anyone could offer suggestions, I would REALLY appreciate it. Need it for this weekend. Tell me anything you think. I am open.

Thanks Joey. Glad you are feeling better.

Sounds like you're overworking the front tires... turn sooner and less.

KoreanJoey
06-02-2009, 07:15 AM
Hey Joey,

How would a rear spacer affect things?

This car has what looks to be a 25mm rear spacer on it. The last owner did it for looks like GT4RCDUDE does.

Suggestions?

Well, I run a 25mm spacer as well... Honestly I'm not sure how much it affected the handling but I needed the spacer in order to clear the wheels and tires.

ccsouls
06-08-2009, 11:26 PM
OK. An update.

Took it to our best alignment guy locally and he said most of the problem was caused by the toe-in getting messed up when I went to negative camber.

So....

1. He set the camber to -1.5 front with a 3/32 toe-out.
2. He set the camber to -1.0 rear with 0 toe.
3. Put Rear Sway on full stiff (whiteline)
4. He also did some adjusting to the rear end to "unbind" some things (whatever that meant).
5. Told me to run the Megan's full stiff (but I didn't, I set them to 12 clicks front and 2 clicks rear)
6. I set the front psi to 35 and the rear to 40 psi (Dunlop Dizzara Star Spec)
7. I removed the rear 25mm spacer.
8. Ordered 245/40R17 Dizarra's on OZ Crono HT 8 inch rims {On sale at Tire Rack for $160} (But they won't get here until Wednesday)

Then I left for the Pro Solo. Keep in mind, I have only had this car 3 weeks now and still learning AWD.

Well... All I can tell you is the damn thing turns great now! Subtracting the 60 foot times because I am still learning the new stage 3 clutch, my times were less than 2 seconds off the national champions. This thing handles now like it should, and I still do not have the larger rubber on it. Alignment guy says we still have some tweaking to do and it will get even better, but he wanted to wait until I play on the new rubber first.

Spectators said the car did not have any noticeable body roll more them the Nat. Champs, and it goes where I point it. If I do overdrive it into a corner and get some understeer; instead of left foot breaking; if I slightly lift the throttle; the rear will come around and I am back on the gas.

LOADS of fun. If I ever learn how to drive decently, I think I can compete well locally (I am not nat. quaility).

I had lots of drivers come over and loved the car. Some suggested I take it FSP, but I told them I wanted to try at least a year in STX before I would go that route. They said it would make a great FSP car though.

I will update again after the new rubber is on. Next event Father's Day.

Wish me luck.

KoreanJoey
06-09-2009, 04:33 AM
It would NOT be an FSP, it's a DSP car at least. And that means competing w/ the 325is which can fit WAY more rubber.

alwayzsidewayz
06-09-2009, 05:52 AM
Some good info here, will share my latest findings too from on track on the 28th, as changed a lot on the suspension.

With my Gt4, we got rid of the low speed understeer by seting the rear ARB to stiff, but, this really just masked the issues.

just as a indication of how different tyres are, I run my Toyo R888s at 24psi front, 26psi rear cold. this following advice from Time attack drivers and rally champions ( both of whom I race againist).

one thing we are looking at is a 6 point rear brace, in addition to the w/line rear strut bar, and an additional rear bar linking from the rear bumper surports.

These shells are not the stiffest, I have twisted my floor pan slightly, even before fitting decent tyres..

KoreanJoey
06-09-2009, 06:10 AM
No, definitely NOT the stiffest of chassis, and as you have a hatch it's even worse.

Definitely will get more predictable handling by stiffening up the chassis but do you have any idea what your g-force loadings are on your transitions? I found I hit about 1.8-1.9 on slaloms.

Hence why my car became flexy like gumby.

alwayzsidewayz
06-09-2009, 06:28 AM
not sure on loadings, one of the reasons I want to get a GPS data logger.

What condition sufaces to you race on? from all the pictures I have seen it always looks very good and un broken?

Part of the issue with my car set up, and infact everyones in my sprint series, is the varied nature of the surfaces.

Even at a official track such as Rockingham, we used both the smooth oval banking, and the mild gravel and poor tarmac of the escape roads for our track.

My car last year struggled on poor surfaces, such as gravel and wet mud due to the poor road tyres, and know with the R888s, I am gettin so much more grip, it was showing up the fast road nature of my set up, hence the spring drop, additional neg camber and fitment of the front ARB.

However, while I am confident that on good surfaces in the dry my new set up will work, the wet and poor surfaces of some tracks is a worry.

in a crazy world, I have beaten the lighter, more powerful cars such as MR2 turbos on the dry good track last year, but lost out when the trackks were wet or poor!

I had to compromise on tyre sizes, as to run 40 profille or lower is a gamble due to the rough nature of the tracks.

http://www.youtube.com/watch?v=WKLq2xlFuRw
Vid of round 4, look about 1.10sec in, 4 way from the line, the change in tarmac at the first corner gives you an idea of the bumps etc, I banged up one of my comp MOs on this track :-(

KoreanJoey
06-09-2009, 07:02 AM
Well, the main site that we use is actually a retired airport runway and taxiway. It's pretty beat up. AND the drag racers use the same site so we end up with a lot of VHT on the track which really screws with traction. We don't have to deal with gravel or mud, usually just rain w/ the occasional slush @ the beginning of the season.

ccsouls
06-09-2009, 02:40 PM
In the 2009 rule book, it has the All-Trac in the "G" stock class, so does that make it a GSP car?

If so, what are your thoughts Joey?

Correction: I just found it in the 2009 rule book and it is DSP. Dang!

Oh well, I guess I will stay in STX :)

alwayzsidewayz
06-09-2009, 05:23 PM
Well, the main site that we use is actually a retired airport runway and taxiway. It's pretty beat up. AND the drag racers use the same site so we end up with a lot of VHT on the track which really screws with traction. We don't have to deal with gravel or mud, usually just rain w/ the occasional slush @ the beginning of the season.

got you, excuse my daftness, whats VHT?

Do you have different course layouts each time?

ccsouls
06-09-2009, 07:42 PM
When we race on the old Air Force Bases we always have different tracks. FYI

alwayzsidewayz
06-09-2009, 08:13 PM
Cool, good to compare with the UK sprint Series I race in, whats you average track length?
We have to ensure that average speeds are below 100mph for the courses too.

Any links to vids of your series.

In car last two tracks I raced at.

http://www.youtube.com/watch?v=esHBnCq5_xI

http://www.youtube.com/watch?v=D_2cUOh1ASY

Sadly not my car, but going to get an in car set up done soon.

How does this compare to your tracks?

Cheers

Rich

ccsouls
06-09-2009, 10:10 PM
I can't speak for Joey, but your tracks are a bit more dangerous than the ones I run on.

We use very large open areas like large parking lots and old Air Force Base runways and the only obsticles we have are orange cones.

On your videos, if you made a mistake you were hitting old tires or walls. For me, if I error I only run over orange cones.

The track layout is very similar, just nothing harder than a cone to damage your car.

KoreanJoey
06-10-2009, 09:00 AM
Your sprint races are more like our club trials here in the states. We only have a few a year in my area and they're usually on the weekday so I haven't made it to one in a couple years. Mostly we do autoX which is lower speed and yes, the courses change everytime.

VHT is a traction additive they place on the drag strip for straight line launches. Unfortunately it migrates further up the runway and gets deposited usually where ever the brake zone after the 1/4. Great for straight line grip but the stuff migrates so easily it's hard to turn on it.

Here is a compilation video made by one of the other racers.

http://www.facebook.com/profile.php?id=533313800#/video/video.php?v=1097156821631&subj=533313800

The VHT is the very black parts of the runway near the last big turn.

I can't seem to find any of the other videos.





PS: Yes, tire walls are scary. Especially when your in someone elses Porsche GT3.

alwayzsidewayz
06-10-2009, 09:35 AM
Very interesting guys, I got to say that VHT stuff looks very tricky, as its all over the place. The only time I have experienced anything similar, is on one track which had a drift practice day, prior to us going out. It was terrible to drive on part of the circuit, as it rained, and the excess rubber down was in weird places for the racing line. I had a spinout thanks to the drift guys.

Your tracks look very technical and personally I think harder than some of ours, as I struggle with coned layouts. I prefer corners that have clearer Apex points etc. Must be a challenge to pick braking points?

We place poles and cones on corners etc to stop drivers cutting corners and to peanalise driver errors. If you hit a cone, you lose that run. I noticed that the Focus clipped a cone, would that result in a peanlty.

We have the following run plan during a day.

1 convoy recce lap
2 untimed practice laps ( to learn course and dial in car )
4 timed laps in the morning
4 timed laps in the afternoon.
1 hour free track time after timed runs, can be used for fast passenger rides, car set up stuff etc.

so far I have only rubber a tyre wall in a chicane, it left rubber all down the length of the car, but I got away with it, all the rubber polished off, no damage. but agree walls etc are scarey, esp when it rains.

How many runs will you get in the day and how is it scored?

The variation in cars is impressive.

Do you guys modify your handbrakes to help in slow corners?

ccsouls
06-10-2009, 02:48 PM
Dang Joey! Did you notice the body/door flex in your camera shots?

In my region the number of runs and scoring varies. Mostly you get 3 runs in the morning and 3 runs in the afternoon. Best combined time wins.

However, multi-region events can have more runs. For example, I was in a Pro Solo last weekend and we had 4 runs in the morning (2 runs each on mirrored courses) and 4 runs in the afternoon; then 4 more runs the following day. Fastest combined times from each side wins.

So, it varies and keeps it interesting.

And yes, the diveristy of cars is amazing and one of my favorite parts of this sport. Last weekend I saw a $260,000 Ferarri F430 get beaten by a $20,000 Honda Civic. Now where else would someone see such a thing? HA!

alwayzsidewayz
06-10-2009, 02:57 PM
Nice! the changing track must keep you on your toes.

Thats the one thing I miss about my sprint series, its great the variety of toyotas, but do miss racing other cars.

I could do other championships, but they have a higher cost normally and a lot less track time.

For instance an MSA sprint may only see you get 2 practice and 2 full runs, for 160.00, which for me is not great value.

Love the idea of a Fezza being beat up by a Civic.

KoreanJoey
06-11-2009, 07:11 AM
Generally we have 4 in the morning with 4 in the afternoon. We also have practice days which ends up being like 25-40 runs throughout the day (I avoid these as they're very, very hard on the slicks and the brakes).

I also end up with lots of free time during AM/PM transitions when I'm instructing. :)

KoreanJoey
06-11-2009, 07:17 AM
Yeah that's mostly just play in the door latch but there definitely is some chassis flex... car is tired...

The events are timed VS class. Different classes get different time modifiers (IE: A Modified (fastest class) = 1.00 VS F Street Prepared = 0.831

So that way, in the Pro class, we all compete against each other regardless of what car we run.

PS: VHT = the suck...

PPS: Snow = really, really suck.

http://vimeo.com/923114
Yes, it really was snowing.

ccsouls
06-12-2009, 03:07 PM
Not a lot of course workers that day huh? HA! :)

Liked the spin on the other video.

KoreanJoey
06-12-2009, 04:00 PM
Yeah, water pwned me.

alwayzsidewayz
06-12-2009, 04:49 PM
Damn snow is pretty hardcore!!!! although can beat you on the water thing. could not get traction even in 3rd!! short shifting and arm twirling were the order of the day!!
http://i22.photobucket.com/albums/b319/leafy1380/IMG_0129.jpg


Night racing is fun too, hard to find any braking points at all!!
Great for the turbo though. Cold windy October day.
http://i22.photobucket.com/albums/b319/leafy1380/IMG_8408.jpg
http://i22.photobucket.com/albums/b319/leafy1380/IMG_8457.jpg

Invested in a surface temp gauge, but still really finding out how to get the best from the tyres.
http://i22.photobucket.com/albums/b319/leafy1380/P9200188.jpg
It looks like you guys have the same rules as we do re tyre and brake warming, ie non allowed at all. I always find it hard to get temps up for the first few stops and corners. We have a few drivers who share cars and they have a big advatage in that they have their cars running 2 or 3 times as much as mine, and so can benefit from tyres and brakes that are up to temp. any tricks you guys use??

Going to show the other sprint guys the snow vid, love that, fair play to the marshals etc, that musta been a long day standing out in the snow on a windy runway.

Dan_Q
06-13-2009, 02:26 AM
PPS: Snow = really, really suck.

http://vimeo.com/923114
Yes, it really was snowing.

thats awesome mate, thanks for posting that :)

feel sorry for the MX5 driver (or is it a miata over there?)

alwayzsidewayz
06-13-2009, 02:28 AM
thats awesome mate, thanks for posting that :)

feel sorry for the MX5 driver (or is it a miata over there?)

Can you imagine Colin letting us race in the snow?? he would have a health and safety heart attack!!

Dan_Q
06-13-2009, 02:38 AM
he prob would though, woodbridge lake last year was aquaplane central!!!

KoreanJoey
06-13-2009, 08:29 AM
It's an MX5 here as well... and yes, it must have been terrible... We even had to wait for some of the blizzard to pass as it kept tripping up the drag lights.

Yes, a pyrometer is super important to have. Best bet as to getting the best out of your tires is to know what's the best temp for them. Hankook says that my Z214s are best at between 160-220*F so we always dual drive with the race rubber on.

alwayzsidewayz
06-13-2009, 09:52 AM
Toyo R888 tyre info. copied from toyo info sheet. maybe some help to thers using them too?
The R888 has a semi race construction (very stiff) and a race tread compound. The optimum tread temperature range is between 85C and 95C measured using a probe type pyrometer, and ideally a maximum difference across the tread of 9C. The maximum hot pressure we recommend is 40psi. Camber angles up to 5 degrees are permissible but the final setting will depend on tread temperatures. It is advisable to have as much positive castor as practical as castor induces a beneficial camber change during cornering. I recommend that the tyres be put through 2 heat cycles before hard use.


The pressures you use will initially depend on the weight of the car, too little pressure on a heavy car can lead to over deflection of the tyre and subsequent failure.

Below are some basic settings:

VEHICLE WEIGHT COLD PRESSURE HOT PRESSURE
Very Light < 800kg 17 - 22 psi 22 - 29 psi
Light 800kg - 1000kg 20 - 26 psi 24 - 32 psi
Heavy 1000kg - 1400kg 23 - 27 psi 28 - 40 psi
Very Heavy > 1400kg 27 - 35 psi 37 - 40 psi


As a tyre gets hotter the pressure increases, this is due to the moisture in the air. The cold pressure you set to achieve a desired hot pressure will depend on the conditions on the day i.e. ambient and track temperature, wet or dry. If the day/track is cold you will need to start with a higher cold pressure as the tyre will not get as hot therefore the pressure increase will not be so great.
Hot pressures must be balanced side to side. Once the tyres have cooled you will find that you will have a difference in pressure side to side, if you have been racing on a right hand track you will find the offside pressures will usually be higher than the nearside.


Changing hot inflation pressures by small amounts can be used to fine tune handling.

Reduce Oversteer Reduce rear pressures or increase front pressures
Increase Oversteer Increase rear pressures or reduce front pressures
Reduce Understeer Reduce front pressures or increase rear pressures
Increase Understeer Increase front pressures or reduce rear pressures