asp04

I have got an 04 Z06. I have been considering some koni sports and some new sway bars. I had a c4 before this and installed shocks, bushings, bars, and springs. It certainly cornered flat and stable, but I never really new if it cornered faster, and sometimes wondered if it was too stiff for the slick, bumpy autox courses that are available in my area. Now with the Z, I kind of miss the quick, flat turning of "old red". I know there are alot of very serious track guys that check out this forum that probably know if shocks and bars really create faster times or if they just make car feel like it is faster. please consider that tires and alignment have already been upgraded. thanks, R. Ford

JiminVirginia

This is a really excellent question, and I'd also be interested in responses from guys on the board.

My guess is that it's hard to improve alot on the 2004 shock/OEM spring combination, but adding stiffer bars might help. I've been thinking about trying this myself with one of the Pfadt adjustable sets.

Anyone else have an idea?

Cobra4B

Here's what I've heard: For auto-x sway bar selection is all about how you want to rotate the car etc.

Big huge bars are of no benefit. However, in the HPDE setting larger bars like T1s or Pfaddty do indeed provide benefit from flatter cornering and being able to hold more speed.

There are folks in here that know far more than me...

elh0102

If everyone took the time to research this kind of thing, the car mod business would take a big hit I think. I had a C5 ZO6 that I used on road courses, not autox. For most road courses, it is the exceptionally good driver only who would benefit to any measurable degree from ZO6 suspension mods. If you have over 30K miles on your shocks, or, if you feel any instability or floatiness through transitions, you might benefit from a set of good shocks. From what I have seen of autox courses, a ZO6 might benefit from a very specialized suspension setup, but I don't think it would be pleasing on the street or more open road courses. And you are right, if you deal with rough surfaces, you have to be careful about getting it too stiff or overdamped.

wtknght1

Sway bars are HUGE improvements...whether Auto-xing or otherwise - PERIOD. I recommend to anyone who wants to track their car to get the T1 bars and end links...and have it properly set - ride height, cornerweight, alignment. Leave everything else alone until you get tons of seat time.

Shocks are a double edged sword. My crew chief likes to use the Bobby Bowden analogy when asked about the speedy Florida State defensive backs he had one year (Deon Sanders, etc). He said something to the effect: "It's a good thing...maybe...but if they run the wrong direction, they'll be twice as far away from the play!"

Shocks are the same way - if you hit it right, they're good...but if you go the wrong way, you'll be a soup sandwich. Unless you have years of experience under your belt, don't fool with adjustable shocks. You've got enough to concentrate on without that headache. Learn the car, rules of the track, car control, etc. When you max out the equipment you have, then consider shocks. Have an expert with you though when you start!!!!

Until then, improve the contact patches and just enjoy the car (tires, brakes, belts, seat, suit, gloves, etc).

Cobra4B

^ Listen to him... he knows a little bit Still looking for some T1 bars that don't break the bank.

0Randy@DRM

Shocks are very important to any track car. Yes the 04 shocks and springs are good, but still a street setup. On a 3000+ pound car shocks and swaybar minor adjustments are not too important at a club level. Once you get to the point were .01 matter then start looking for a engineer type person to help dial for the last little bit. Let someone like us or other Corvette speed shop help get you very close to your goals. It will help save you money in relearning everything.

Randy

cj68

So what I am hearing is that 04 Z06 shocks with T1 sways is the way to go for most HPDEers? Seems like that would be the best balance between performance and "ease of use" and eliminate the guess work?

cj

wtknght1

yea verily!

TommyBoy72

my C5 Z06 has a lot of body roll, especially with race tires. Pics of Tedebear's car looks just like mine and this is at autocross speeds (usually 70mph or less). On the track its much worse. I'm running Koni shocks and just about to put on T1 bars tonight. I suspect I'll be doing springs eventually as well.

Maineiac

Well said....I just added T1 bars to my Z06..HUGE improvement!....and that front bar is massive.....

TommyBoy72

my C5 Z06 has a lot of body roll, especially with race tires. Pics of Tedebear's car looks just like mine and this is at autocross speeds (usually 70mph or less). On the track its much worse. I'm running Koni shocks and just about to put on T1 bars tonight. I suspect I'll be doing springs eventually as well.

hisvett

I'm glad someone started this thread because I have been asking the same question. My track ride;
'01 Coupe
Z51
PFC 01's
sticky tires with track alignment
Very stock other than replaced front sway bar with Z06.
40K miles.

I too have "some" body roll as seen in photos at TWS, but is this completely bad? I tend to look at a bit softer ride allows the tire(s) to stay in contact with an uneven or changing surface better than a stiff setup.

I guess the question(s) I have for those who have changed to T1's (or?) and state a "Major Improvement", I would have to ask; is this statement from a "seat of the pants" feel or is it backed up with true, before and after track times? And not because of other changes such as tires.

My other question is; are we gaining 10ths or seconds? As Randy stated, racers are looking for that last .01 per lap and the $$$ spent is worth the payoff. As a weekend racer want-a-be, I would expect the money would be better spent on seat/instructor time on the track or cone maze.

Maybe if I were spending more than 3 or 4 DE weekends a year at at the track or had issues with pointing an occasional faster car around, I might consider taking a chance on the expense.

wtknght1

Sway bars distribute the load more evenly and reduce the body roll. The T1 bars are normally worth around 2 seconds per lap on a 'typical' road course. Other than tires and brakes, it's some of the "cheapest speed" you'll ever buy!!!!! You can both feel the difference and see it on the stopwatch.

Combine that with the adjustable end links and a proper suspension set up from Phoenix and you're looking at a total of 4 seconds per lap. All of this assumes that you can drive and benefit from the improvements. Poor drivers, no matter what you do, can't really benefit...but a decent driver, with a few DEs under his belt can certainly see and feel it.

If you're doing 4 DE events per year, then it would be worth $600 to buy them.

The springs and shocks have MUCH more of an affect on ride quality.

As you said though (and I've stated many times), the best investment for any driver is seat time!

asp04

Wtknight, 2 seconds is huge. I'm buying sway bars. Are the T1 the best bet? How about shocks? If adjustables are not the best for the regular guy would you say a Bilstien sport would be an upgrade over stock 04 z ? Thanks for the input.

wtknght1

The T1 kit (to include the bars) is race proven over years and years of running and were developed by Mr. Corvette himself, John Heinricy. That's tough to beat. They work!

I'd leave the shocks alone...they are good enough. If you want a touch of an upgrade, you could run the SACHS. That is also a sub-part of the T1 kit. 95% of the drivers out there though probably couldn't tell the difference between those and the shocks you now run. Save your money for more seat time!

hisvett

[QUOTE=wtknght1;1561648115]

If you're doing 4 DE events per year, then it would be worth $600 to buy them.

Perhaps I should reconsider. Right now I take great satisfaction in spanking the $150K "P" cars in the corners with a basicly stock C5! Maybe I should set my sights a bit higher

When the time does come to change, I will do it using some track tellementry to see the real differance, before and after.

Thanks for the input

TedDBere

It depends what you want to do with the car.

If you're going to track it then the stiffer springs and bars will help stabilize the car at higher speeds where the downforces generated will need to be countered with the stiffer set-up to maintain a good geometry for a good contact patch.

In autox your class rules dictate what you're allowed to do. If you stay stock SCCA then all you can change is your front bar and shocks, so you have to make do with that and find the best configuration that works for your driving style. In SS you learn to drive around the limitations, rather than correcting the problems, because the rules prevent you from changing anything.

In my sig picture I'm at 1.17Gs and accellerating hard at 41 mph. This was an offset move, not a slalom. My rear is squating down and my nose is lifted about as high as it goes. A stiffer front bar, ie T1, would probably have hurt me here by reducing front grip because I don't have a stiffer rear bar to compensate for it due to the rules. In SS autox very few people have been able to make the T1 bar work with the stock rear bar.



Here's a picture of the car at 1.24Gs at 31mph, the rear is twisted but the Gs were good (stock rear bar). I increased the rear rebound from that seen in this picture to help lower the rear but have only been able to achieve 1.17 Gs since then, albeit on older tires:



Here I am decellerating hard into a box off of a straight, from 70 mph to about 30 mph. Stiffer front springs would be of benefit, but to reduce the nose dive I'd have to stiffen the front bump and increase the rear rebound and use the shocks to do what the springs can't. This is not the best way to handle this, but given the rules it's all I'm left with:



So in summary: Springs and bars will help but do it with a purpose based on what the car is doing. Just diving into it and making changes because you think it'll improve your times will most likely hurt you because every car, driver and course may require a different setup to be faster. FWIW

Good luck.

hisvett

I hear what your saying Ted, I gave up the cone maze a year or so ago for track days (more bang for the $$$). Also it's the "Need for Speed" type thing! Running with a Z51 (not much different than Z06) suspension, I'm seeing the same nose dive under hard breaking and lean in the corners as you are. Running the tire combo I do, the car handling is so neutral and feels perfect for my current abilities, hence my hesitation on changing anything.

Earlier this month I ran the Roval at TMS. I had my buddies G3 (I think that's the name) telemetry system installed in the back. The car was bumping 1.37 max G's on the turn in (about 30 MPH or so) off the Oval onto the infield. Faster corners (50 to 70 MPH) were running about 1.1+. Not sure it this to good, average or for the car/track.

Before changing anything, I will get a good baseline reading with the system out at Motorsports Ranch where I spend most my time. Then another reading with new sway bars.

I'll keep my eye out for a set of T1's that I can maybe try before I buy , them maybe I will be a believer in a stiffer setup.

asp04

TedDBere, I hardly autox anymore. I got the hpde bug. I don't worry about class rules too much, even though I would not go past Street Prepared allowances. I am not much interested in changing springs, but shocks and bars are are quick on and offs. It certainly sounds like you are a fan of alternate shocks. What did you get and why? HISVETTE, I see you have telemetry capabilities, that would be the way to know if you are making progress or just changes. That telemetry stuff is probably out of my league, I have'nt even figured out all the buttons on my new phone yet! Still interested in opinions from any of the other hard core guys. How about some of the RAFT boys. Solofast, what do you say? THANKS