Are Z51 springs good enough for a iron block?

[DaTruth]

I am putting my old 408ci FMS SuperStroker in my 99 FRC within the next couple of months. I wanted to know if I needed to upgrade to Z06 springs or something stiffer in the front to offset the weight? Now I do not autocross or road race right now, but I might play a little in the future..

http://65.35.32.173/JAY/OnHwy-Small.wmv

[DaTruth]

Tttfm

[Dope]

Z51 front spring is the same as Z06 front spring anyway, so I wouldn't sweat it. It may cause the front end to drop a little bit, just raise it back up with the adjusting bolts if you deem it necessary.

There's plenty of people with superchargers and no suspension mods - the weight added is about the same I'd say (75-100lbs overall).

Dope

[DJWorm]

I would recommend considering the T1 Suspension Kit with engineered and tuned stiffer front and rear Springs, Shocks & Bars.
This will not only take the increased weight but handle the increased power

[DaTruth]

Good advice guys.. Any links to the T1 suspension with prices?

[DJWorm]

From your Chevy Dealer, GM Parts Direct or Pace Parts:

PN 12480062 T1 Suspension Kit (incudes):

12480063 Front Spring
12480064 Rear Spring
12480065 Front Sway Bar
12480066 Rear Sway Bar
12480067 End Link (4)
12480068 F Sway Bar Bushing (2)
12480069 R Sway bar Bushing (2)
12480072 F Upper LH A-Arm
12480073 F Upper RH A-Arm
12480077 F Lower LH A-Arm
12480078 F Lower RH A-Arm

You will also need

1248oo94 T1 F Shock (2)
12480095 T1 R Shock (2)

Around $3,000

Note: the T1 A-Arms are the same as the Z06 A-Arms but have better poly graphite bushings. You can save money if you have a press by using the old Z06 A-Arms and installing new bushings instead of a whole new A-Arm assembly. However I do not know if a C5 A-Arm is the same, although I think it might be.

Poly Graphite Bushings can be obtained from Vette Brake & Products

[No Doubt]

The T1 A-arms have rubber bushings but are a higher durometer rubber.

You have to get aftermarket bushings to get poly bushings.

[xsiveone]

You have to get aftermarket bushings to get poly bushings.

I don't like poly bushings for the street. They are too stiff and squeak. At least in my experiences.

X

[No Doubt]

Mine are polygraphite and don't squeak or if they do I can't hear em anyway. As far as stiffer I can't tell that either.

[DJWorm]

Poly ureathane bushings squeak; Poly Graphite do not.

Poly graphite are not that stiff when compared to a Delrin or all metal bushings....those are stiff. Poly graphite still has enough softness to dampen harshness but has better memory and faster rebound to ensure more precise handling and less suspension setting wander. He's dropping in a big bore iron block for C____sake....you think that's not going to be harsh? Those big cubes, torque and weights will crush rubber bushings. Then Metal on Metal , Baby.....That's Harsh!!

Correct on the T1 A-Arm bushing material, so.....Using aftermarket poly graphite bushings would not only be cheaper but better still.....If you have access to a press.

[No Doubt]

A press is almost a necessity. It's a PITA job. Not at the top of the "This is fun." list.

Mono Balls are in another league.

[DaTruth]

Wow!!! $3k for the T1 suspension setup. It must be a complete road race suspension. I will have to talk to my buddy. He has the hookup from GM Parts.. I am a previous Camaro owner and all of these high prices I have to get use too. My buddy Jay call it the $400 Corvette tax..

[DJWorm]

That's correct the Chevy bean counters figured out it was a lot easier to change the bushing by just swapping out the whole A-Arm unit.

They sold a lot more A-Arms that way and netted 10X the profit.

Most T1 guys just do the swap however and use the OEM Z06 A-Arms as back up....a sensible thing to do if your racing.

[DJWorm]

Yes it is a road race suspension that is engineered and tuned to upgrade a C5 for SCCA T1 racing. It is commonly called a "trunk kit" in that it comes from or can be ordered as a kit from the factory and can be Dealer installed.

Of note it will improve a Z06 about 2 seconds a lap and will improve a C5 6 seconds a lap. It will be harsher but you will need the spring rates to handle the extra weight and power

Be aware that even though it comes as a kit you can buy the componants seperately. However this is not advisable as it will probably be more expensive that way and the T1 Springs and T1 Shocks must be used with the other T1 componants and will not work correctly with other componants

[DJWorm]

I just checked our Supporting Vendor, GM Parts Direct
<--------OVER THERE

The Kit Lists for $3.410.33 and the shocks are $185.27 each

GM Parts Direct sells the Kit for $2,387.23 and the shocks for $130 each. Total will cost you $2,907.23 + Shipping and Installation