Bracket racing
Thread Starter
Melting Slicks
Joined: Apr 2013
Posts: 3,483
Likes: 1,823
From: McCloud CA
C2 of Year Finalist (appearance mods) 2019
Bracket racing
Question now that I have my rear suspension out should I change the strut rod bracket to a c3 type. Or will it make any difference or should I say a noticeable difference? Oh not for bracket racing
Last edited by reno stallion; Jan 2, 2019 at 10:35 AM. Reason: what to add
Race Director
Joined: May 2000
Posts: 12,712
Likes: 2,270
The C3 exhaust pipes had to be squeezed down more than C2 pipes to provide adequate clearance to the strut rod bracket, so a C2 exhaust system may not have sufficient clearance. It's not worth the hassle unless you have very wide tires (wide enough to require fender work for clearance) and are doing some serious racing.
Duke
Duke
Team Owner
Joined: Nov 2005
Posts: 28,174
Likes: 2,872
From: Beach & High Desert Southern California
When Bracket Racing, consistency is the goal, and a repeatable consistent launch is a benefit. The means to achieve consistent launches is to keep the rear tires and drive shafts near level and in the same position on every launch, for repeatable traction and less driveline abuse.
This can be accomplished on a dedicated track car by lowering the rear bump stops to limit the rear squat and tire camber to a traction and driveshaft friendly position on launch (but it can result in a rougher than normal street ride with compromised suspension jounce travel). If you plan on swapping the rear tires to slicks or a dedicated DOT track tire before competing, adding a fabricated bump stop spacer at the frame is only a few extra bolts per side when the tires are removed in the pits for the swap (it can become part of the track preparation check list).
The next best rear suspension modification, without as much ride quality concern, is to keep the tire tread contact and camber as flat & consistent as possible as the rear suspension squats with the stock bumpstop limit, with the C3 bracket to improve this goal (the same goals that motivated GM to redesign the bracket, to improve wide tread tire traction in all conditions).
If you keep the narrow tread and tall sidewall stock size tires, camber change is not as detrimental as with wide low profile tires. Bumpstop location and minimizing the camber change as the suspension cycles on launch are not as important with tall sidewall tires with a compliant skinny tread width. Tire choice and use should dictate how much suspension modification is warranted to achieve consistent tread contact and weight transfer (and resulting traction). Every car and car owner is a little different with different goals and concern for non-stock modifications, so the choice to optimize the suspension for a given use is your call.
This can be accomplished on a dedicated track car by lowering the rear bump stops to limit the rear squat and tire camber to a traction and driveshaft friendly position on launch (but it can result in a rougher than normal street ride with compromised suspension jounce travel). If you plan on swapping the rear tires to slicks or a dedicated DOT track tire before competing, adding a fabricated bump stop spacer at the frame is only a few extra bolts per side when the tires are removed in the pits for the swap (it can become part of the track preparation check list).
The next best rear suspension modification, without as much ride quality concern, is to keep the tire tread contact and camber as flat & consistent as possible as the rear suspension squats with the stock bumpstop limit, with the C3 bracket to improve this goal (the same goals that motivated GM to redesign the bracket, to improve wide tread tire traction in all conditions).
If you keep the narrow tread and tall sidewall stock size tires, camber change is not as detrimental as with wide low profile tires. Bumpstop location and minimizing the camber change as the suspension cycles on launch are not as important with tall sidewall tires with a compliant skinny tread width. Tire choice and use should dictate how much suspension modification is warranted to achieve consistent tread contact and weight transfer (and resulting traction). Every car and car owner is a little different with different goals and concern for non-stock modifications, so the choice to optimize the suspension for a given use is your call.
