Z06 spring & Koni FSD install...

[Cobra4B]

Knocked out the rear tonight... easy work, but if you ever do this be very careful to not cross-thread the bolts that hold the spring to the cradle... almost had to bust out the tap/die set but got it to go in straight. For some reason the right side shock was a PITA to get the upper bolts started, left was a non-issue.

These are OEM C5 Z06 mono leafs and Koni FSD shocks. I have C6 front spring adjusters and the LGM rear kit which uses longer bolts than stock. I got the springs from Toque and used his suggestion of 8 threads showing for the rear... looks pretty damn low and the car looks ridiculous w/ the nose at stock ride height. Going to lower it to the max in the front w/t he C6 bolts and then set the rear off that to maintain the fatory recommended 5mm of negative rake.

C5Z monoleafs


OEM base rear shocks vs. a Koni FSD


FSDs installed... you can also see the C5Z swaybar here.


Stock rear spring out



Forgot to snap a picture of the Z06 spring installed, it looks like the base spring but with less arch and not dirty.

Took it around the block to allow the ride height to adjust.

Left Rear


Right Rear


Stylin

[Toque]

Looking sweet !
Glad you like my Leaf Springs...

Good luck with the rest of your project.

Toque

[Cobra4B]

Thanks again for such great condition parts. Going to take the front apart tonight and see how far I get.

[WKMCD]

NICE! I ran the Z springs and bars on my vert with Bilstien Sports. Great combination. Even better when I put the Z spec alignment on it. I didn't get any unusual tire wear with it.

[Cobra4B]

Yeah sometimes I wish I had kept the Pfadt coilovers, but freeing up $1600 was nice when buying this car. Plus everything I've heard says the coils are a bit on the stiff side for a nearly daily driven car. My goal here is to get good performance while maintaining ride quality.

Going to get it alligned a tinge more aggressive than Z06 specs once I get it all done and get new wheels/tires. Probably about 1.2 degree neg. camber front and 1 neg rear with zero toe all around... it's really the toe settings that kill tires. Should help the big streets be even more flush.

Do you ahve any clue what kind of rear camber setting your car had/has?

[WKMCD]

I run the 04 Z settings. Seems to work well without being "darty".

BTW: Yesterday's numbers with the new cam - 621-601.

[Cobra4B]

Originally Posted by WKMCD

I run the 04 Z settings. Seems to work well without being "darty".

BTW: Yesterday's numbers with the new cam - 621-601.

Ok... then you're probably around .3-.5 neg in the rear. Are those numbers still w/ the ported L76 manifold? Will be interesting to see what the worked over FAST gets you.

[WKMCD]

Originally Posted by Cobra4B

Ok... then you're probably around .3-.5 neg in the rear. Are those numbers still w/ the ported L76 manifold? Will be interesting to see what the worked over FAST gets you.

Still with the ported L76 intake but with the new cam. Shawn will be installing a stock FAST for some pulls and then working on it and doing some more pulls at which point the motor will go back in the car.

[Cobra4B]

I'm guessing 648 @ the motor when it's all done

[WKMCD]

Originally Posted by Cobra4B

I'm guessing 648 @ the motor when it's all done

That would be sweet but we'll see. Sorry for the hijack.

[Peter Pan]

Great setup you have for a daily driver. I used to run the Koni FSDs on my C5 before I went to the PFADTs with C6 Z51 bars. I really liked the Koni's so much they are on my C6 with the same bars and this is an awesome daily driver setup. Though my C6 is at stock ride heigth as the wifey drives it. Nice write up and you will be fine when you get the ride height settled out

[Cobra4B]

Finished it all up this evening. Ended up raising the rear up a bunch, about 7 full turns a side and it still needs to come up a smidge more, but thats easy to do. Front ended up 1/4 inch lower (ground to fender) than my Z06 lowered on the stock C5 adjusters, but the tire/fender gap is a smidge more b/c the 17 inch wheel/tire combo is shorter than the 18 incher; new wheels will be 18s.

The rear ended up 3/4 inch lower ground to quarter panel than my Z06 lowered w/ the stock bolts, will probably bring it up another 1/4 inch to get the rake set correctly. I expected the front to be a little lower, but frankly Im happy its not. I dont want a super slammed car. The car rode/handled like pure **** when I took it out w/ the rear super low from last night. Once adjusted properly everything fell into place... car feels awesome.

Local popo followed me around for a bit when he saw me slaloming the car on Damneck... he split off when I turned into my neighborhood... hopefully he would accepted a garage full of tools all over the place and I was testing my new suspension and setting ride height as a valid excuse

Stock front suspension




Disassembly to remove the spring complete



Here you can see how the ride height adjuster works in the front. The less pad/space you have between the lower A-arm and the spring the lower the car sits. Some people remove the adjuster completely and slip a piece of rubber in there to cushion the spring end on the A-arm, but that really slams the car and it rides/handles poorly


Stock C5 adjuster max lowered vs. stock C6 adjuster max lowered


Comparison of base front spring and C5Z front spring


Ready for the new spring to slip in



Slipped in place... time to put it all back together...


Main brackets in and toqued w/ blue loc-tite


All back together w/ Konis installed


Front height... 18s will fill up about 1/4 inch of wheel well more


Rear after raising it some... will probably go up a smidge more but want to see it in the daylight first


Gnight!

[Toque]

Nice work !

The new leaf's sure are clean ! Its like they never saw a drop of rain before....

Toque

[Cobra4B]

^ Any idea how much taller your front SP500 w/ tire is than a stock z06 wheel/tire? Looking at that pic on your website I expected the front of the car to be a little lower, but I think it's the fact that your 19s fill up the wheel well a bit more than the stock 17s.

[WKMCD]

BTW Brian,

I meant to tell you your car sounds GREAT with the Corsa Extremes.

[Cobra4B]

Originally Posted by WKMCD

BTW Brian,

I meant to tell you your car sounds GREAT with the Corsa Extremes.

When did you hear it? When I dogged it leaving Va Speed?

[Toque]

Originally Posted by Cobra4B

^ Any idea how much taller your front SP500 w/ tire is than a stock z06 wheel/tire? Looking at that pic on your website I expected the front of the car to be a little lower, but I think it's the fact that your 19s fill up the wheel well a bit more than the stock 17s.

Brian:

Yea the 19's fill my wheel wells a "little" more than the stock Z06 setup. Its not much though.

I posted all my specs here:
https://www.thevettebarn.com/forums/c....html#post7309

Front
Stock Z06 = 265/40/17 = (Circumference = 2022mm)(Diameter 644mm)
New CCW = 275/30/19 = (Circumference = 2038mm)(Diameter 649mm)

Rear
Stock Z06 = 295/35/18 = (Circumference = 2082mm)(Diameter 663mm)
New CCW = 305/30/19 = (Circumference = 2094mm)(Diameter 667mm)

So with my new CCW tire setup:
Front --> Increased the Circumference by only 16mm (Diameter 5mm)
Rear --> Increased the Circumference by only 12mm (Diameter 4mm)

[Cobra4B]

Gotcha... so it's just under 1/4"

[WKMCD]

Originally Posted by Cobra4B

When did you hear it? When I dogged it leaving Va Speed?

I heard you hit it hard while we were waiting at a light. You were going towards the restaurant.

[Cobra4B]

Snapped a couple quick shots while there was still light to show the resultant ride height.