Pfadt Racing

Just wanted to share a recent article from Corvette magazine written on the benefits of upgrading your C5/C6 suspension to coilovers. There are some great points in here that dispel the myth that coilovers are for race cars only. Johnny O'Connell has pointed out that "When we improve cars, it doesn't mean you have to be a racecar driver, it actually means the opposite. It makes the car easier to drive." This is precisely the objective when we sit down to engineer a product for the Corvette chassis.

rfn026

The fastest C6s in SCCA use leaf springs. Danny Kellermyer has always stayed with leaf springs and is usually faster than the cars with coil overs. They should have used an AIM data logger in this article. That way we could have real numbers. Magazines have gotten a bad reputation in the past few years for being very very kind to people who buy ads.

Richard Newton

Solofast

Agreed, a classic "puff piece" with no data to back it up. Sad to see that kind of thing in any magazine.

davidfarmer

scanning the article and posting on the web isn't doing the Magazine business any good either!

STEVEN13

This is going to get ugly...

rustyguns

but............ just getting rid of the Stock Corvette shocks with some decent aftermarket shocks pretty much solves this dilema. Even GM admits their shocks are low cost!

Try Koni FSD's or better and you will be pleasantly surprised

rustyguns

There is a ton of Engineering Data to support this too !

JimbeauZ06

And deservedly so since the lack of any objective before and after test data makes this article worthless. The author's statment in closing to the effect that coilovers make the car faster is baseless and completely subjective but I'll bet sales will go up.

varkwso

Ran both, set up both - prefer the leaf. Many others prefer the coils. Real data is always better.

Super Chevy has a coilover article coming on C5s. They are articles - rarely engineering reports.

naschmitz

Changing spring locations usually changes the car classification. The best drivers will figure out which classification gives them the best advantage for that car platform. So in spite of having data showing the fastest SCCA drivers use leaf springs, there are certainly other factors involved.

I changed from stock suspension to the Penske coil overs and that bumped me two classes with COMSCC. At first I thought that was pretty harsh, but the car handles so much better than stock that it is still competitive.

Is it from shocks alone? I don't know -- I don't have the data on all the combinations to say whether it was the springs or the shocks. But the rules say it's the springs that bumped me two classes, not the double adjustable shocks.

RX-Ben

Just as an aside, COMSCC rules are written in a completely different manner than NASA rules. I am not sure what drove the COMSCC rules (many are seemingly arbitrary) whereas the NASA rules seem to have parity (backed by real world testing) in mind.
There is only a +2pt penalty (pretty minor) for converting from leafs to coils in the NASA TT rules (along with the 5 other points for changing springs and shocks).

95jersey

You have to compare apples to apples. Sure an 800lb LG Bilstein coil-over is going to out perform a standard OEM spring and Sachs generic shock.

The question is would a leaf system with an equal quality shock and equal spring rate work better than the coil-over?

Bottom line on a race track, stiffer springs (stiffer than OEM) are going to work much better and that is where a lot of the improvement comes from.

For me, I didn't want to have to match up (trial and error) and custom valved shock with an aftermarket VBP race leaf spring and aftermarket sways to try and make the car work. I also personally think the T1 kit is WAY overpriced and can be hard to find (and actually the T1 kit is so close to the OEM C6Z suspension specs, I'd think it be a waste of money).

So, the real question is FOR THE MONEY and/or the time required to set up a custom leaf car, which is the better option? You can buy a set of $2000 coil-overs and vastly improve the handling of the car. So in a way the article is not wrong.

I can say my LG car handles WAAAAY better than the OEM C6Z leaf suspension. I would bottom out the OEM suspension constantly with Hoosiers. With the LG set up, I win TT regularly and car if flat as a pancake, inspiring confidence.

John Shiels

copyright infringement

I never felt out classed by coil-over cars.

John Shiels

Can't castrate your ad base! Now more than ever.

Wonder what Johnny O's signature cost?

96CollectorSport

Wow guys take it easy!

The coil-over vs leaf spring debate has been fought a few times here and most of us know it comes down to personal preferance. I have set up cars with both and they both work very well.

Aaron and crew have every right to post good press about there products - remember they sponsor the Autocrossing and Roadracing page that we all frequent - I have been very happy with the Pfadt coil-overs that have won us many NASA ST2/TTS races, heck every Corvette that was at NASA Nationals in 2010 had some sort of Pfadt products on there cars.

So instead of saying how bias this article is and talk about how aweful Pfadt is for informing us of some positive reviews, lets thank Pfadt for sponsoring this free page where we all meet and mingle. Heck we are all guilty of tooting our own horn every once and a while.

Thanks Pfadt crew.

DarkMastyr

Has anybody gone through the rigor of comparing the times between the two setups with a good, consistent driver? e.g. run a track with leafs one day, swap out with coils + realign, run the track again another day, then compare times. Obviously factors like weather and tirewear will matter, but I'm curious what kind of time coils are worth. We often talk about how certain tires are worth X seconds on Y track, but what about suspension bits? Are we talking about full seconds, tenths, etc.

rfn026

We need numbers. They're not hard to get. You can get an AIM data logger for less than $5,000. Traqmate is less than $2,000. How hard would it have been to use one?

Richard Newton

96CollectorSport

Here's a link to a coil-over battle royal a few years ago.

http://forums.corvetteforum.com/auto...oil-overs.html

You couldn't do a test on different days, you would have to take stock cars and have them all set-up and ready to go for back to back testing. With a real test driver, someone who can put in consistent laps over and over. If a magazine could talk to the tuners and set-up something like that it would be sweet. Kind of have our own version of set-up, have a rep from each of the companies on hand to fine tune the car for the test driver and see who comes out on top. Stock cars say C6 LS2's with spec tires, spec sway bars, spec alignments the only differance would be the shocks and springs.

Ah if only, I guess we'll have to stick to threads like this and the one above.

trackboss

The test would actually be pretty easy to do. Pick a set of VBP springs that are known to work well. Install a set of good quality dampers to match them that either have threaded bodies or allow for a threaded sleeve. Dial in the the ride height, alignment, etc. Once all that is set do a test day using sticker tires each of the two setups. Top off the car with fuel and rip off some laps with the leaf setups.(only tire pressures can be changed) Then bring the car in, swap out leafs for coils on the same dampers and use coils with rates that match the wheel rate of the leafs. Set ride height back to where it was. Alignment, corner weights, etc. should remain the same. Refill with fuel to match the previous setup's starting weight. Install sticker tires and rip off some more laps with only tire pressure adjustments. That is about as fair as a test as can be had.

Gering

Sir, thanks for the good read!!!