RusherRacing

I have a stock c5 Z06 that I am Autocrossing now and will be running in track days and open road racing. I want an aggresive alignment but can't invest a ton of cash right now for non safety related or car protection. (buying harness bar, harnesses, fire extinguisher and mount etc, clear bra, mud flaps you get the point). The car is daily driven, even on gravel (so can't go TO low). I can deal with the aggressive alignment I prefer to drive a "setup" car on the street makes it more fun

Just want to verify my research has been correct.

Front to Rear 3/4" Rack?
Toe
1/16-1/8th toe out up front (currently at 1/16th)
1/16th to 1/8th toe in at the rear (currently at 0)
Camber
-2.5 deg up front (remove washers?)
-1.5 deg rear

What is the ideal castor angle? what do people settle with cause of max camber?

whats the recommended drop? I cut 1/3rd of the front bushing already should I go 2/3rds?


Is there a must change component on the suspension that causes slop etc? If the pfadt or hardbar alignment kits are a big difference on the track i could possibly swing it now instead of later. What about the hardbar stud kit?

I am planning bushings, T1 bars, coilovers (not sure which ones) over the winter or next year.

davidfarmer

Everything sounds good except for ride height. You probably should get some new adjusters and put them back in.

You have an aggressive alignment in mind, more than you need for track, but probably good for Autocross.

Castor isn't a big deal. Get as much as you can on both sides, and don't get too hung up on it. Usually 7.5deg is very do-able, maybe not with your high camber setting.

The concentrics are fine, just mark them with a sharpee to make sure they don't move. If you are really concerned, either set of camber plates is great. However, you need to either do it with concentrics first, then order the camber plates with the correct offset (in mm, 44mm wide....hardbar measure from the narrow side to the center of hole....12mm 14mm etc to 22mm dead center). If you just try and guess at the right plates, you'll end up bouncing all around the ideal setup.

I find the upper control arm thread finicky, and easy to strip. I'd remove the washers if you need to, then leave them alone. Loosening and re-torquing is asking to strip one.

RusherRacing

What would you recommend for the ride height? Measured from the ground to what point on the car? Stock ride height the best for autoX? and track day? Does lowering it affect the bumpsteer roll centers etc negatively? Thanks for warning me about the upper control arm thread.

davidfarmer

The control arm angles just get too steep (obviously dropping roll centers) if you lower much beyond the OEM adjustments. You may be OK now, but more is just asking for a downgrade in performance.

If you insist on going lower, buy some drop spindles from LG, as that's the only way to go lower without sacrificing ride and handling. They are only about $1000 each or so.

acrace

You may want to consider more rear toe-in. Not sure about track days, but for the serious autocross crowd, with stock control arm bushing, folks are running at least twice as much rear toe as you listed.

Agree about being careful about lowering the car too much.

Solofast

Toe the front in about 1/8 of an inch on the street and then mark the front toe links. Rotate 1 full turn on each link (towards toe out) for the track.

Leaving the toe out in there for the street, along with the large negative camber will eat front tires, and it only takes about a minute to change each front toe link when you are changing to sticky tires for an autocross.

Davinss

So 1/8" toe in in the rear for track days and 1/4" toe in in the rear for autocross? You are talking toe per side not total toe right?

1/8" toe in for the front on the street? Why not zero toe for the street?

I was planning on getting my car aligned this week. I'm going to readjust the toe for track/autocross. What do you guys think:

Front
2 degrees negative
0 toe for the street
1/8 toe out for the track/autox
Rear
1.5 degrees negative
0 toe for the street
1/8 toe in for the track (more for autox?)

Should I go with more aggressive toe setting for autocross rather than a road course? Also I don't want to go past 2 degrees negative camber on the front. What would be complimentary for the rear? 1 degree? 1.25? 1.5?

acrace

I've run as much as 1/2" total toe-in in the rear for autocross. I'm running less than that now (about 0.3" or so). I don't do too many track days (just an occasional autocross on a track), so I haven't played with rear toe-in to optimize it for track days.

Having the car aligned at zero toe up front and marking the tie rod ends is probably a good way to go. You can then just "adjust to suit" prior to events, and also save your daily driver tires.

yakisoba

I don't notice lots of tire wear running toe out on the street. I run -2 front camber, -1.5 rear camber, toed out in front, in in back. I'm running Nitto 555 tires on the street, and they've lasted a couple years now with no complaints. They have also, in that time, been to road atlanta and are my rain tires for HPDE.

RusherRacing

Thanks for the info guys. When I get the car all finished up. I will post final specs with wheel weights etc.
Now a new post must have of tools for a corvette suspension...

jordan@pfadtracing

Here is a link to our suggested Camber settings http://www.pfadtracing.com/docs/camb...t-settings.pdf

You'll spend a lot of money getting a performance alignment done on your car - don't let that setting change just because you hit a pot hole, drop two wheels off the track or bang into some FIA curbing!

It's a known issue that the factory eccentrics are prone to slipping. Our camber kit allows you to achieve the maximum negative camber and eliminates the eccentrics so that the the settings don't slip. You'll be able to get more negative camber with our kit than is possible with the stock set up.

Our kit replaces the bolts on the front upper a-arms with stainless steel studs and we provide stainless steel shims to set your desired camber and caster. The lower eccentrics are eliminated and the bolts are locked into their maximum position using a set of off-set plates. For the rear we provide a set of shims for the eccentric to dial in your alignment and make it stick.

Don't risk tearing up a $1300 set of tires because of an alignment eccentric that has slipped! Install our camber kit and keep your hard-earned performance alignment in place!

This kit is a must for any C5 that is auto crossed or driven at the track.


The product that would give you a tighter feel would be the poly bushing kit, it would eliminate about 80% of the deflection found in the rubber bushings. Of course our coil overs and Pfatty sway bars would help as well!

yakisoba

Have to chime in and say that the Pfadt bushing kit is top notch. It's on my car. Just remember that alignment settings that work well with stock bushings might not be optimal with harder material.

Solofast

The Pfadt kit takes you out of stock class and sends you to at the very least to ASP.

The reason I say at least is that I am not sure that the alignment method with that kit is legal for ASP either. You are allowed offset bushings in ASP, but I am not sure that you can add shims to an area that wasn't designed by the factory to have shims. You would have to get a ruling that it was legal. The factory put in a couple of washers on the upper control arm mounts, but that is a far cry from shimming it like is done in the Pfadt kit.

Just a caveat....

I would do a set of good shocks first, then go to bushings and see if that gets you where you want to go. There are plenty of cars that have huge amounts of grip that aren't using coil overs. If you can get the spring rates that you want (for a dual purpose car) then coil overs are just a waste of money.

ghoffman

The Hardbar kit is the best on the market bar none. We use custom 17-4 PH stainless steel studs (not off the shelf plain low grade steel that is not even plated)with extra thread engagement in the frame, thicker camber plates for less "oil can" deflection with laser etched offset markings and grade 10.9 (not 8.8) M14 plated bolts with nyloc nuts and extra thick washers. We developed this kit originally in 2001 and it has evolved over time. This kit has been to victory lane in every series that Corvettes run in, from SCCA Club Racing, SOLO Nationals to professional series such as World Challenge to Rolex Cup. On at least 2 occasions, the car has been hit hard enough to break a first class BBS wheel and the alignment did not change. From design, to execution, every part of the Hardbar kit is the best. It is available for C5, C6, C6ZO6.
Gary Hoffman
Hardbarusa.com
603-682-8073

Fastener grades explained:
http://hardbarusa.com/Fastener%20Grades.xls


http://hardbarusa.com/hardbar/produc...products_id=56

gkmccready

I agree with the shocks and bushings, but not sure I agree with the coilover argument... the dual-rate spring set up I have on my car is amazingly docile on the street, feeling a lot like my car did stock until I lean on it. And I certainly don't need big swaybars with this set up! Plenty of spring rate once I get to it!

I agree, though, that lots of cars are using VBP springs with great success! And I certainly thought about it very very seriously before going coilover...

ghoffman

Hyperco makes composite leaf springs as well. We can put together an excellent package for you with Hyperco leafs, Penske shocks in any flavor from non-adjustables to the very best shock on the market, the awesome 8700 3 way. The Penskes are totally rebuildable, made in USA and have fantastic resale value. There are alot of very quick T1 cars running leafs (GM T1 kit) and Penskes, including current and past SCCA National Champs. The Hyperco leafs are available in many rates, depending on your needs. Call us and we can put together a package that meets your needs and budget.

BTW, the only real way to decide what aglinment is correct is to try a setting, then change it as needed. Paying for some shop to do that is not only expensive, but ineffective. We came up with a aglinment tool system that is quick, easy and very accurate, and you can use it at the track or your garage. The instructions for the tool are here, see if this is something that you would use:
http://hardbarusa.com/uploads/image/...%20rev1(1).pdf


Cheers,
Gary
Hardbarusa.com
603-682-8073

0JoshS

There are plenty of great suspension options without changing to coilovers. We are currently putting together several suspension packages that utilize both coil overs and the factory leaf spring layout.

Here is one of those packages that utilizes leaf springs...

Threat Level 2

Pfadt Sport Shocks


The Pfadt Sport Shocks will rid the car of the infamous rough corner nervousness that seems to plague the Corvette. The Pfadt Sport Shocks are adjustable so you can tailor the balance between cornering performance and ride quality to suite your taste, even if your taste changes during the day. This single adjustment lets you also tailor the corner entry and exit behavior of your car. The adjustments are simple and can be changed in a matter of minutes, with no tools necessary.

Retail: $890


Pfadt Competition Sway Bars


If you are looking for the ultimate in sway bar technology then you need to look no further then the Pfadt Competition Sway Bars. These sway bars feature a hollow Chromoly bar that is splined on each end to accept our splined CNC machined sway bar arms. These arms are made of 7075-T6 aluminum a grade aluminum that is more commonly found on military aircraft then on street cars. Both the front and rear sway bars are adjustable so that you can perfectly tune in the balance of your car for your combination of tire size, suspension setup and driving style. Then endlinks that are featured in our Competition kit include custom made 3/8", Teflon lined rod ends for years of quite operation. The hardware for mounting the Competition kit is custom made to accept the light weight 3/8" endlinks.

Retail: $1025


Hyperco HPT Leaf Springs


The Hyperco HPT Leaf Springs will give you about a 17% increase in spring rate which will lead to faster transition times from corner to corner.


Retail: $1050


Package Price: $2840


This kit will provide an obvious improvement in road holding capability over stock and excellent track capability.

We are currently working on releasing a complete list of Pfadt Race Engineering packages. So keep your eyes peeled for the release.

Please do not hesitate to call us if you have any questions!

jrmotorsports55

This would be my worry as well, as those kits don't look like they will fit in to ASP rules.

Jason

Solofast

A little bit of toe rolls the contact patch toward the outside of the tire when you are going straight on the highway. It helps with tire wear (not as much on the inside where it would be if you just ran zero toe, and the car isn't as darty and doesn't "tramline" as much over ruts. Since you are going to change it anyway at the track might as well run a little bit of toe in on the street.

If you run zero toe or some toe out with a bunch of negative camber you won't fall asleep at the wheel on long trip at night, but it makes a lot of those drives seem longer cause you have to pay attention all the time....

jordan@pfadtracing

You could certainly use the lower plates to lock in your alignment settings and remove the factory eccentrics, it isn't changing the factory geometry. You could then adjust your camber by changing the lower plates to achieve your desired camber setting.