[Z09B4U]

So I'd be aiming for a 10 inch installed height I guess since mines is already half an inch higher with the relocated spring perch. I'm thinking the 10.6 might cause it to be a bit too high,

With the relocated perch and axle I would suggest you use the "trim height diagnosis" chart (steering section).

Motortrend reported measuring 0.83g with a stock Impala and I thought I had seen a standard circle test reporting higher.

As I have said before my target was not autocross. If my back end was high it would be just about right with a full car of people or several hundred pounds of tongue weight.

What I find weird is my LS caprice which is supposed to be stock is also showing high in pictures. This is why I suggest you measure frame to ground (front and back) to get more data points. 91SS is clear his information is not perfect and is calculated, or colored by the fact he uses air bags and is a 1991 Caprice.

As the modifications stack up comparisons to stock become more challenging.

 

[toonwarrior]

True, just reading the older threads seems like the advertised heights was 27.8 inch in the front and 27.3 in the rear and can vary within an inch up/down based on conditions especially with how soft the rates are.

And with my rear reading at 27 and front at 28 right now it's pretty bang on I guess and the front is still fresh without having time to settle,

now the question is; is the rear bar/spring combo I have still too stiff to put the power down, we'll find out next saturday

 

[JJ96SS]

It's quite expensive, like 4 grand for the level 2 kit with the coilovers, you can't really just buy coilovers for these cars without the rest of the stuff if you want to dial it in, and that's in USD. Then when you add in the time to get it dialed in with the alignments and what not it's even higher.

you can’t just install these without anything else? my back sits a bit higher cause the tire is taller and my front left wheel rub sometimes if I hit a bump on a left turn. So I thought about going adjustable so I could have it set a bit higher in the front, what else would you need ?

 

[toonwarrior]

As far as I understand the stock arms aren't up to the task of handling it so it's recommended to get the matching tubulars along with it. I don't know if I've seen anyone also run coilovers on stock arms at this point either.

 

[1slow96]

Not sure what the attraction to "tall" rubber is about.
285/40-17 's are proven auto-x competitive if a performance tire

 

[91ss]

I'd say give it a couple weeks of driving, ideally with an autox session in there to get you heights more settled. But here are your choices. I'm running the 81479 in both the 91 and 95. I'd say for the 95, the sheet is pretty spot on. I measured 27 9/16 vs stock SS of 27.3 Which would be 10.6 vs 10.2 calculated. Within 38 thousands. New 9C1 bushings bumped it up to 27.75 initially. Haven't rechecked. I've have run the 6381 in the 91 prior and it sat pretty much same as the SS springs with empty bags. Sheet seems pretty accurate. So basically, 10" would give a 27.1" wheel opening height with a stock axle. But like you mentioned, your actual body height would be +0.5 since you raised the spring perches.

My 80090's are riding at around 28, the 80098 should sit lower. Did you clock them right, or seated correctly at the top? Some have inadvertently folded over some of the ears on the upside down crown on installation so the spring didn't sit correctly against the frame. Resulting in car sitting higher than it should. For the bottom, I like to see one hole covered and see the spring half way covering the other hole in the control arms. What kind of isolators did you use?
You should really be 1" lower than me.

Also if not mentioned, equal front and back wheel well heights does give the car downward rake compared to stock.

 

[91ss]

Oh, and for the 8000's up part numbers, I have not verified if they are a drop in. Things like pigtail diameter might be different. The 81479 are snug on the perch on the bottom where you can't run an isolator with a shoulder.

 

[toonwarrior]

Yea they were 28 on first install so I'd expect them to settle in soon enough.

So the flat end is the side I put the isolator on. I did try to line up the bottom by putting it between the two holes but it's possible it shifted a bit when I was lining up the control arm bolts. Isolators I should have replaced but didn't have any new one's with me but they are the moog part number, I think one of the might've been pushed out a bit. I'm also running the EB body bushings.

But yea I'll report back and give it some time before I do anything.

 

[madamorr]

On my 1995 Impala SS:
I have 275/40/17 tires mounted to the stock Impala SS rims.

Front Moog 7268 : Height measured perpendicular to the floor across the center of the rim to the bottom of the trim -> 26"
Rear Speedway Motors TrueCoil (200 lbs) :Height measured perpendicular to the floor across the center of the rim to the bottom of the trim -> 26 1/4"

Michael

 

[allen]

The number one thing you need for Autocroxss is seat time. The SCCA and other groups offer drivers schools for Auto X sign up and go. You will run all weekend and get dozens of runs in for your money. You do not need to spend a lot of money to have a fun car. My car sits with the bottom of the front fender 26.5 inches from the garage floor. The rear is slightly higher. Front springs are from a Dodge truck, Rears are stock with Air Lift air bags on individual valves. Shocks are currently Bilstein's, sway bars are from ADDCO. Find a class you like and build the car to the rules.

 

[toonwarrior]

The number one thing you need for Autocroxss is seat time. The SCCA and other groups offer drivers schools for Auto X sign up and go. You will run all weekend and get dozens of runs in for your money. You do not need to spend a lot of money to have a fun car. My car sits with the bottom of the front fender 26.5 inches from the garage floor. The rear is slightly higher. Front springs are from a Dodge truck, Rears are stock with Air Lift air bags on individual valves. Shocks are currently Bilstein's, sway bars are from ADDCO. Find a class you like and build the car to the rules.

For sure, the event I'm going to isn't like official SCCA rules but they have their classing and what not, turns outs my neighbor down the street has been running it for 35 years and I had no idea..... shame on me, though to be fair I wasn't going to be able to autocross until now anyways.

And yea essentially following that same setup, 750 linear rate springs in the front, stiff AK1503 shocks, rear is a bit messed up cause it's hotchkis springs right now and the moog 5387 which is closest to a stock replacement is out of stock but I'm not changing it till I get a better feel of what needs to be adjusted anyways. BMRs all around though I still think the rear bar is too big but we'll see how it goes this saturday.

For your 26.5 inch ride height what tire size are you running.

If I make the two hour trip to the other auto X club this beast runs there, would loveeeeee to see it in person and see the setup he's running.

 

[Marky Dissod]

That's the 5 dams brake cooling mod! Ain't seen it in over a decade ...

 

[allen]

275/40/17 Falkens

 

[toonwarrior]

Kk mines should settle to 27.5 based on all the posts since my tire is an inch taller running a 255/50

 

[madamorr]

I run Corvette C5 wagon wheels with Pirelli slicks 305/660/18 front and rear.

 

[toonwarrior]

Jeezus that's some heavy meat, seems like you got a beefy motor to back it up also.

So I just had my session, car felt wayyyyyyy better, it felt like I was able to rotate and hold the grip without it kicking the tail out and causing that snap back when it corrects.

The issue is it felt so good that I ran the exact sametime every session, problem was the time which was actually slow 😂 even though inside the car it felt like I was pushing it. Obviously there needs to be some serious driver mod and probably need an instructor now with more experience to show me were I can go faster.

I haven't gotten the car aligned with the new springs so now that I have those in I will go for a more autocross alignment spec.

Just gotta sift through the footage and images to see if I can see anything out of the ordinary, if not then we'll see how the next event goes after the alignment.

The alignment spec I'd be going for

As quoted by Chicagobmrx

-2.0 camber treats tires well enough for street duty to get 3-4 years out of em, especially if you can rotate front to back.

They’ll dry out before you cord them I bet.

6-8° positive caster tilts the wheels more as the steering angle increases too, which is helpful for autocross and not killing tires with too much camber on the street.

And then 0 toe I think it was?

 

[Marky Dissod]

Every Caprice I've owned used the following specs on the schidtiest NY / NJ / CT / PA roads.
Minimum +4.0 degrees of Caster, preferably +5.0
-0.5 to -1.0 degree of Camber
1/8" Toe IN

Believe these are Dave Scribner's specs. Don't think Ed Runnion would mind these …
Caster Left & Right at least +4.00°
Cross Caster …… N/A° +/- 0.50°
How much positive caster is 'too much'?

Camber ……………… -0.25 +/- 0.25°
Cross Camber …… N/A° +/- 0.25°
The more aggressive your cornering, the more negative camber.

Individual Toe …… 0.00° +/- 0.00°
Total Toe ………… 0.00° +/- 0.06°
For street driving, Toe IN. If AutoCrossing, maybe a hair or two of Toe OUT?

 

[allen]

Every Caprice I've owned used the following specs on the schidtiest NY / NJ / CT / PA roads.
Minimum +4.0 degrees of Caster, preferably +5.0
-0.5 to -1.0 degree of Camber
1/8" Toe IN

Believe these are Dave Scribner's specs. Don't think Ed Runnion would mind these …
Caster Left & Right at least +4.00°
Cross Caster …… N/A° +/- 0.50°
How much positive caster is 'too much'?

Camber ……………… -0.25 +/- 0.25°
Cross Camber …… N/A° +/- 0.25°
The more aggressive your cornering, the more negative camber.

Individual Toe …… 0.00° +/- 0.00°
Total Toe ………… 0.00° +/- 0.06°
For street driving, Toe IN. If AutoCrossing, maybe a hair or two of Toe OUT?

The front end on the Caprice/Impala are not precision work. A little toe in (1/8in or so) will leave the front wheels running straight on the highway.
Using Zero toe for the track will cause the front wheels to toe out a bit. This helps turn in when on track.

 

[1slow96]

A hair toe-in is reasonble.
Key is not allowing front hub bearings to be on the loose side.
Also helps brake pads to stay closer to rotor.

 

[toonwarrior]

The difference in the cars ability to rotate is pretty visible, sorry for the potato quality:

With the moog 80089s up front (no alignment)

With the hotchkis up front, particularly at 0:10, 0:13

Pretty sure the corner balance was quite messed up with the car raked so forward resulting in no grip to the rear wheels, but I don't have any data to back that claim up so take it with a grain of salt.