monroepaul

What is the best bang for the buck in a suspension upgrade that will be the most noticable on the track. I don't want to turn my Z06 into a full blown race car I just want to eliminate some of the body lean on the track.

ErnieN85

See Joe or Curt at Phoenix and have your car setup.
That's the biggest bang for the buck

Silverton

Check with Gary at http://www.hardbarusa.com and order up those double-adjustable Penske coil-overs. Do a search on "hardbar coilovers" and read the review.

Jason

The two biggest payoffs to me were poly bushings and T1 swaybars.

jrz1

Put penske coilovers on mine and the difference blew me away. Too harsh for most people on road but I like it. Spring rates could be dialed back a bit. The car is amazingly flat with razor sharp turn in. Stiffer springs (even if replacing with modified leafs) and new shocks would be first thing I'd do to this car. They just design it for the lowest common denominator who is the guy that wants to cruise on Sunday in comfort. I laugh when people say stock ride is too harsh.

danswofford

I'll second big sway bars as #1

Bink

I'll third the T1s.

John Shiels

fourth it

vms4evr

Oh what the heck, I'll fifth it...

C6400hp

I'm not sure if anyone has already mentioned it or not but you might try a set of T1 sway bars.

AU N EGL

THE BIG BLUE sway bars





I just Though 1 would be different

JDIllon

From a cost and performance standpoint the Pfadt coilovers and Pfatty Comp sways are working great on my 07-Z06. The ride on the street at the #6 setting is fine and the car ran great at VIR. No side step and it felt really planted in the sweepers. There are 16 shock settings and 3 to 5 sway bar settings, and the quality and support from Aaron was great. Just my .02 JD

Independent1

If you have not switched over to using wider rims and racing rubber that is the first thing I would do.

If you do you own work the polybushing mod is also good but time consuming and hard work.

Next I would add coilovers and sway bars and then have the car's suspension set-up at a shop like Phoenix, including corner-weighting the car.

If you do all these things should have a noticeably faster and better handling car.

Wicked Weasel

T1 bars and good shocks. If you want more then coilovers. When I installed coilovers it was like driving a go-cart through the turns.

96CollectorSport

You can get a lot of improvement with a track alignment, bushings (to take full advantage of your alignment) and T1 bars. Having your car set-up by someone who knows what they are doing will help a bunch (Phoenix was already mentioned). I think you will notice a huge differeance with those mods.
Once you get to that point the differance won't be quite as large, and you will really have to be able to drive the car to see the differance between a well set-up car with the above mods and a car with a really good coil-over or VBP spring and shock combo.
However if you go through the expense of having the bushings installed you may as well install coil overs or a spring shock combo.
So for your first (and cheapest) mods the T1 bars, and getting the car set-up/aligned professionally would be the best "bang for the buck."

Aaron Pfadt

Both the C5 and C6 Z06's are very capable track performers even with stock suspension, however, as you've noticed, they are a little soft. Any sway bars are about $1000 and will control the lean you're getting in the corners and raise the grip level. The spring rates on your car are too soft as well and that compromises your braking and acceleration, so an increase in wheel rate can also be very helpful.

The nice thing about going first with coil overs instead of sway bars is that you pick up an increase in overall wheel rate which not only helps body roll, but also helps dive and squat. The car will feel more firm and planted all around. This will make the throttle and brake transitions more controlled.

For a stock C5 Z06 the sway bars have good balance and will work well paired with some coil overs. Stiffer sway bars will still provide more benefit, but the Z06 sway bars are a good start.

For a stock C6 Z06 the sway bars are poorly balanced. In my opinion the rear bar is way too stiff. Coupled with coil overs, I would at a minimum run the Z51 rear sway bar, or switch to Pfadt sway bars or another aftermarket sway.

While I prefer to see people switch to coil overs to increase the overall spring rate, just doing a sway bar upgrade can be a nice performance improver. Coupled with Z06 springs, I would recommend our Pfadt Competition sway package. Our competition package offers a lighter weight, fully adjustable bar set that offers better balance than a T1 set up.



Call me any time with questions.

-Aaron

bowmanized

I have to agree with Aaron. Sway bars address one facet of handling, lateral weight transfer. However there are 5 areas that need to be addressed during HPDE. Corner Entry, mid corner, corner exit, accelerating, and braking. With coilovers(or better leafs and shocks) you eliminate some of the brake dive and squat. Keeping the weight more centered you'll have more mechanical grip and stop faster. This is true only to a certain point though, once the car becomes "skitterish" the compression needs to be backed off. The rebound you want to avoid "jacking down" where the shock will not extend completely after compression. There is much more details to shock tuning but there is plenty of info to help you and it's really not that hard. Penske has a really nice manual that I'm sure most of you have read. The shocks allow you to control the rate at which the transfer happens. Stiffer springs also achieve less body roll. The trick is to control the body while still offering soft enough springs to absorb all of the bumps to keep maximum contact patches to the road when going over imprefections at the track. Most tracks are 100% smoother than roads you encounter so race teams can get away with higher spring rates. While cars pulling double duty will benefit from a slightly higher spring rate than C6Z or T1 rates.

If you use more spring rate for body roll, dive, squat, entry and exit, you will not need to run such a huge sway bar. There are many theories on suspension but I believe that sway bars should be used as a tuning device and not the basis for wheel rate.

Corner entry and corner exit can be fine tuned with an independently adjustable shock package. You can control the compression and rebound independently. For example if you want to slow the weight transfer under braking you increase the front compression and increase the rear rebound. The 4 way adjustables offer low speed and high speed adjustment. High speed adjustment would really be nice if you are clobbering curbs like the F1 cars do at Monza. The average HPDE enthusiast will not really benefit from high speed adjustment. It's the low speed compression and rebound that's so critical to car setup. My personal choice would be the Motons. However they are $3995 and not really designed for daily use. The Callway/Eibach coilovers have trick remote resevoirs for compression and they are nitrogen charged just like the Motons. Then on the top of the coilover under the spherical upper bushing mount is the rebound adjustment. The shocks alone are worth $2000.

The advantage of the coilover is the adjustability of the springs. When I get the CEs I can swap the spring in 10 minutes. So if you add downforce later or want to dedicate your car to the track you can swap the springs. The shocks are completely rebuildable to if you want to change the shock rates/valving.

I spoke with the Director of the project between Callaway and Eibach at length before purchasing. These are unlike any of the other shocks they have designed. This was over a year long project and they weren't brought to market until Callway was completey satisfied. I have the shock dynos and the window for adjustment is fairly wide. I asked him about putting different springs on the coilovers since they use the leaf spring too and he said, "You can put a 3000lb spring in there if you want but it won't do anything". LOL The only thing that would make these better was if the shock was inverted. Callway and Eibach have taken all of the guesswork out of it for you and designed these specifically for your car. All suspension options such as base, Z51, and Z06 have different springs on them from Eibach so that you end up in the same place when utilizing the spring and leaf.

The reason they use the leaf spring setup is because you can. Leaf springs are very light and provide some additional roll control similar to a sway bar. However a lot of people like the coilover setup understandably so I can swap out the springs to the same rate they would be otherwise with leafs and coils. Plus Callway thinks they are more durable since the shock towers were designed for shocks not springs. However it's been proven time and again that the stock towers are more than adequate. Do you really think Callway would put a crappy coilover on a $300,000 C16 with Magnesium wheels and Carbon brakes?

I would be happy to do one set of these at cost to anyone who time trials or is a track rat who is willing to take pics and give feedback. I'll even absorb some of the cost for the opportunity if you go with the full coilover. By the time you do $1000 sway bars, $400 corner weight, and $150 race alignment you'd be 3/4 of the way to a fully independently adjustable coilover, aluminum shock body, and spherical bearings and remote resevoir. Then you can save some money on the sway bars by going with the Hotchkis or Pfadt Street setup. I can also adjust the spring rates based on the existing sways you have to acheive similar wheel rates such as T1s

If you read the racing instructional book speed secrets he talks about Michael Schumacher. I am paraphrasing but Schumacher wasn't the best because his car was faster down the straight or had more grip at the limit mid corner, he was the best because during corner entry and corner exit he could achieve a better slip angle on the tires during those two phases of the corner. He would pick up only 1/100ths of a second in a corner. But when there are 10 corners on a track that's 1/10 of a second per lap. After 10 laps he'd have a 1 second margin.

If you bolt on T1s to a C5Z your car will be faster than almost anything else out there in HPDE no question. However that doesn't mean your suspension is dialed. If anyone wants to see pics of the coilovers with new spring rates please PM me and I can send it to you. I'm telling you these are amazing. A fellow corvette owner with T1s only took a ride in my car with the C/Es and was sold immediately. His set is going in this weekend. T1s and C/Es

Thanks

RS WRC

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Gray Ghost GS

T1 springs, T1 sway bars, track alignment and corner weight = Best Bang for the Buck and IMHO its not too much suspension for the street (but that's subjective)

Vette Ed

ask "RAFTRACER"