Do you know rotors? Step inside.
Instructor
Joined: Sep 2004
Posts: 153
Likes: 0
Originally Posted by froggy47
Thanks for taking the time to post Lawrence, this is SPECIFICALLY what I was looking for. This forum ROCKS.
Let me ask you one more thing. The used rotors I took off are worn quite evenly, they just have a "lip" at the outermost circumference, no cracks. I actually just replaced them because I had gone thru 2 sets of comp. pads. So they no doubt are already lighter by some amount just because of the normal race wear.
Question, could I just keep using these rotors or is that "lip" going to interfere with something? I was going to get them turned just to get rid of the lip.
Let me ask you one more thing. The used rotors I took off are worn quite evenly, they just have a "lip" at the outermost circumference, no cracks. I actually just replaced them because I had gone thru 2 sets of comp. pads. So they no doubt are already lighter by some amount just because of the normal race wear.
Question, could I just keep using these rotors or is that "lip" going to interfere with something? I was going to get them turned just to get rid of the lip.
Also, if you are changing pad compounds, it is a good idea to try and remove the old pad compound from the rotor surface.
How did it go with your spring swap?
Cheers,
Lawrence
Racer
Joined: Apr 2004
Posts: 487
Likes: 0
From: Huntsville AL
What about soaking your tires before an event? Changing your battery for a lighter weight one from say a camaro...that saved 7lbs for me and it's not obvious looking at it. Removed jack already I imagine? Maybe some underdrive pulleys? Remove the maf screen, it weighs something. I'm not sure what the rules are, I've modded my vette to make it go faster....not to adhere to any rules. When I autox, I aim to beat everyone that's there. Maybe you could get a 52mm TB and make it look stock. Anything sounds better than screwing with the rotors like this. Hell, "downgrade" to stock LT-1 rotors (non Z-51) like is on mine....they are 6lbs lighter a piece up front and will work just as good for one lap at least.
Thread Starter
Race Director
Joined: Oct 2002
Posts: 10,864
Likes: 196
From: Southern CA
Originally Posted by TrackDayLT4
If the lip is more than 1mm I would turn them. The problem is that the position of the pad sintered on the backing plate will vary quite a bit from pad to pad and a lip larger than 1mm may cause interference problems when bedding the new pads.
Also, if you are changing pad compounds, it is a good idea to try and remove the old pad compound from the rotor surface.
How did it go with your spring swap?
Cheers,
Lawrence
Also, if you are changing pad compounds, it is a good idea to try and remove the old pad compound from the rotor surface.
How did it go with your spring swap?
Cheers,
Lawrence
Spring swap was fine, sits a little higher front than the original, maybe 1/4 to 3/8 inch which I'm not too pleased with, but the added spring rate is a plus & handling still pretty neutral. I'm first in points for the year by the skin of my teeth in SDR. Wish me luck.
I'm going into a z06 for next season, so I guess I'm done beating on the LT4 trying to get it better than the 89-91's.
It was/is a great fun car to race & you gotta love those 315's on the back.
Thread Starter
Race Director
Joined: Oct 2002
Posts: 10,864
Likes: 196
From: Southern CA
Originally Posted by Wildcat1
What about soaking your tires before an event? Changing your battery for a lighter weight one from say a camaro...that saved 7lbs for me and it's not obvious looking at it. Removed jack already I imagine? Maybe some underdrive pulleys? Remove the maf screen, it weighs something. I'm not sure what the rules are, I've modded my vette to make it go faster....not to adhere to any rules. When I autox, I aim to beat everyone that's there. Maybe you could get a 52mm TB and make it look stock. Anything sounds better than screwing with the rotors like this. Hell, "downgrade" to stock LT-1 rotors (non Z-51) like is on mine....they are 6lbs lighter a piece up front and will work just as good for one lap at least.
Thanks.
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Not worth it. Lugnuts are hardly a rotating mass since they're close to the axle.
If you remove 1 lb from the surface of your tire, your car effectively weighs 2 lb less in accelleration and braking. (1static + 1rotating)
Apply this to your driveshaft, you weigh 4 lb less for every 1 lb removed at a 13 inch radius from rotation. (1static + 1 x 3.XX)
Apply this to the motor in 2nd gear, you weigh 7 lb less for every 1 lb removed at a 13 inch radius from rotation. (1static + 1 x 3.XX x 1.9X)
It works proportionally as well. If that weight is only 6.5 inches from the axis of rotation, you save half as much rotating mass as you would if it were 13 inches. Seems like an aluminum flywheel would be a worthwhile advantage in auto-x.
If you remove 1 lb from the surface of your tire, your car effectively weighs 2 lb less in accelleration and braking. (1static + 1rotating)
Apply this to your driveshaft, you weigh 4 lb less for every 1 lb removed at a 13 inch radius from rotation. (1static + 1 x 3.XX)
Apply this to the motor in 2nd gear, you weigh 7 lb less for every 1 lb removed at a 13 inch radius from rotation. (1static + 1 x 3.XX x 1.9X)
It works proportionally as well. If that weight is only 6.5 inches from the axis of rotation, you save half as much rotating mass as you would if it were 13 inches. Seems like an aluminum flywheel would be a worthwhile advantage in auto-x.
