Shifter6

Looking for someone with a Z51 car that can give me a comparision between a stock Z51 setup and a Z51 with the JOC package.

Shifter6

Ttt

Pfadt Racing

There are a couple threads up on the forums here with some feedback, but we get a lot of praise for the JO package via Email. Here are some links to Z51 vs. JOC:

JMcDon1007 reviews JOC suspension package.

Z51 to Pfadt JOC Review

Here was my favorite review that I've seen come across in the last few days...

I've seen you've made a couple threads about the JOC package. Maybe it's time to jump on board?

Shifter6

Thanks for the info...

Yeah I've been thinking about this for awhile now. My original thought was to do a basic upgrade from my FE1 by using Z51 springs and sways with an off the shelf shock like a Bilstein sport. Now I am thinking about using the Z51 springs with your JOC setup. I think both setups will offer a substantial performance improvement, with the nod obviously going with the JOC package.

My two concerns with the JOC package are ride and cost. This setup has to work as a daily driver as well as a track day car. I have been in Z51 cars and the ride is completley tolerable to me, I wouldn't expect the Bilsteins sports to alter that too much. I am concerned the JOC package will be considerable stiffer, especially on a narrow body car.

My other concern being cost, a z51 swaybar upgrade and Bilstein shocks can be obtained for less than half of what the JOC package will cost. I understand the difference is only 400-500 dollars but money is money and it is tough to justify the cost considering both systems should be a significant improvment over what I have.

Pfadt Racing

The car is going to be a little stiffer with the JO package, mostly due to the changes in the dampers. We setup the package for increased performance without significant compromise to ride quality. In our opinion, and we've driven a lot of Corvettes out there, this is the perfect balance between a performance tuned suspension package while still being daily drivable.

The cost of the kit for the amount of performance increase really does make the JO package a bargain. You can always get OEM parts which will improve performance from where you're at now, but you're ultimately going to be limited to OEM performance.

With either package you're going to have more fun with the car! Give it a little more thought and we will be here if you would like to place an order.

Shifter6

One thing I wont get from GM parts is support from Pfadt! You guys have always been great with the info!

My car is going to be a 1-3 track day a year car, 98% of the time it will be driven on New England roads. So I need to be honest about how aggressive of a setup I need.

That being siad it will kill me to go the Z51 route and find it was "not enough", especially on more agrressive tires (I will probably go to RE11s). Right now the lack of body control with the FE1 is downright obnoxious, not becoming of a performance car.

RandelB

2007 Z51 Coupe. On my periodic track days there's a few corners that create excessive body roll, with the stock Z51 set-up. I've recently added the JOC sway bars and have yet to track the car on that same course. Ironically, that is coming up next Monday. I'll try and remember to update this reply at that time.

In the meantime, I can give you 2 anecdotal experiences...
1) on the street, feel, control and ride quality are now what I would expect in a performance vehicle. More stable in turns, a bit more "stiff" when one side hits an obstacle and the other doesn't. I will transfer these bars to my next Corvette, if that time comes. btw, the yellow bars appearing from the rear view is kinda cool on the Velocity Yellow car.
2) My wife is anything but a performance driver. She doesn't drive the car to it's limits. Even she has commented on the "feel" of the car. For example, there is that one favorite curve that we all have near our home. It's that one that we keep trying more and more. Well, the first time going through "that" curve with her in the right seat, she exclaimed "Wow, that was a lot better". Even she could feel the difference in reduced body roll.

Thank you Pfadt for the excellent product. I HIGHLY recommend all Corvettes upgrade to at least the JOC bars.

ZRCLONE

I didn't comment cause I have a Widebody, however it is an 09 with the Z51 package. The difference with the JOC-Pfadt package (shocks and bars) is night and day! Driving in today I thought to myself this is how a Corvette should ride and especially handle. You do feel the road though, it is a little harsher than stock. But well worth it!

Shifter6

So I ordered the JOC package today! I am super excited about trying this suspension setup.

I have one question the guys at Pfadt may be able to help with. I have some leaf springs I bought used and I would like to identify them before I install them.

The numbers on the springs are...

Front: Engraved 22171750, sticker 22178729
Rear: Engraved 22200944, sticker 10302917

Pfadt Racing

The front sticker number matches the part number we have for the C5Z front spring. That's confirmed with our own in house data.

The rear spring is trickier. I don't have that part number listed. Confirm that the spring is indeed for a C5 by looking for the C5 rear spring specific mounting hardware. A C5 rear spring will look like this: Rather than the C6 which will have a threaded hole for the spring adjuster pads to thread into...The C5 will have a hole at both ends like the picture above.

Either way if it's a C5Z or C5Z51 it's an increase in rate over the base spring.

Thanks for the order! Definitely keep us updated on how you like the JO package after it's installed!

CGGS

Does the JOC Stage 1 take all or just most of the rear-end twitchiness out of the C6 Z06?

Does it recover and stabilize right away after being upset in the rear?

Shifter6

I was told they were C6 Z51, I hope I didn't get swindled. Here are some picks of the springs:








What are the springs rates of a C5Z51 vs C5Z vs C6Z51?

Thanks, I will post up when I get the kit on my car!

0JDP Motorsports

You'll be very pleased with this set up! It is a great package that works excellent on the street and is track capable.

I'll check those part #'s against what I have here. I have a few Z51 take offs.

Please feel free to call, email or PM us anytime with questions.

Kind regards,

Jordan Priestley
888.308.6007

Nd4spd2

I put this suspension on my 2000 FRC that I run off and on at HPDE events. In track form the car is very neutral and well balanced. I love it. On the street it is a bit firm but it really helps the car with bumps in corners as it doesn't jump out like it used to. My buddy has this suspension on his C6 Z06 and he loves his too.

Shifter6

Ok, on another thread the rear spring I have has been identified as a C6 Z51 spring according to this website.

http://www.corvetterecycling.com/product_p/22200944.htm

The front however, has been identified as a C5Z front spring. So the question is...is that the same spring as an C6 Z51??

I know they both have a rate of 526lbs, but are they the same spring?

Pfadt Racing

Given they're both the same rate, and front springs are interchangeable between C5 and C6... install that thing and go have some fun!

Shifter6

OK I figured it out. Both numbers have been superceded by GM.

The front spring number is for FE3 sport suspension manual and automatic transmission from 1997-2012.

http://www.gmpartsdistributor.com/pa...ow=1&maxRow=10

The rear spring number is for FE3 sport suspension manual and automatic transmission from 2005-2012.

http://www.gmpartsdistributor.com/pa...ow=1&maxRow=10

Looks like I didn't get swindled!

MisterMidlifeCrisis

Do you sell the Z51 take-off springs? I'm looking for a front spring to try. Could you please PM me with a price?

Shifter6

As some of you know, I have done lots of research on what direction to take my suspension and now that I have gone the JOC route I am very satisfied. I have only had the chance to street drive the car, but even if I never brought the car to the track, I am very satisfied. For the record, I had a completely stock FE1 car and went with the JOC setup and Z51 springs. Also know that CT roads are some of the worst that I have experienced and I personally live on a dirt road with stutter bumps.

The ride is surprisingly compliant, there are times when I am driving it where I think it could actually be stiffer, and that is with stock GY RF tires. The worst thing about the ride is it exposes some of the interior and roof creaking that was not as apparent with the FE1 setup. After a roof lube (see roof primer post) the interior is very quiet. It’s been a while since I drove a Z51 car but IMO the JOC setup rides better than a stock Z51.

As far as performance all I can say is wow. The JOC package makes the car much more enjoyable to drive at the limit. Exploring the limit of grip with the FE1 is a white knuckle experience. With the JOC you feel confident pushing the car right to the limit of the tires and when you go over, it is very controllable. I have some common corners that I have always driven hard, and here are a few things I have noticed right away.

The high speed body control is worlds better. No matter how hard I push the car, it seems buckled down and much more connected to the road. I find myself coming into every corner (where safe) carrying more speed. And the best part is if I do overcook it, it lets me know with a more gradual and recoverable breakaway.

On one corner, I came into it a little hot (new found confidence), so I lifted a little coming into it. It’s a downhill corner so I got a lot of transfer to the front. The car actually power-off over steered, which it has never really done before. The best part was how it behaved. It was a very soft breakaway, it just rotated the car a little, I dialed out some steering and it stayed perfectly on line, what a great feeling.

The car will actually take some power on corner exit (low speed) now. With the FE1, the car would always power on over steer on a particular corner, with the tires loaded it would not tolerate any throttle on exit. Now I can actually feed out the power earlier, I was shocked! The pavement was not perfect so I think I was losing tire contact, but not with the new setup, this is a huge improvement.

I think the best thing about the whole package is the ride/handling balance tuning. There are some times I wish it was a little softer, and other where I actually wish the tuning was more aggressive, this is how I know it’s perfect. Feels firm and responsive without being harsh. The phrase "should have come this was from GM" is over used IMO, but in this case it applies. This should have been the Z51 setup from GM.

Hats off to the guys at Pfadt for making a great product and JDP motorsports for the sale. I can't wait to get this thing on the track!

Pfadt Racing

Thanks so much for this great review. We knew you were going to love the new setup!

Let us know if we can do anything else for you, and definitely report back once you've hit your first track day!