Bee Jay's lightweight battery mod! 25lbs saved!
#42
Tech Contributor
Member Since: Jun 2004
Location: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Posts: 18,342
Received 766 Likes
on
548 Posts
I was able to take out 48# total (remember, all unsprung!). Seven pounds off the caliper, and five off the rotor. The rear parking brake is an issue in some applications. YMMV
#43
Instructor
69427 Thanks for correcting and educating me on that! Deff on my to do list as soon as my check book allows! 48 lbs is still a nice reduction especially since it is unsprung weight!
#44
Safety Car
Thread Starter
Member Since: Nov 2005
Location: Lompoc, CA. Santa Barbara County
Posts: 3,932
Received 543 Likes
on
198 Posts
Been there, done that. Wilwoods saved me 44lbs, 11lbs per wheel. Do a search on my username to see all of my tricks. Maybe I will do a weight loss thread. I need an aluminum Gen I block.
#45
Instructor
I will have to search that Bee Jay, a weight loss thread would be great! I for sure want mine under 3,000 lbs and i have a certified vehicle scale here at my work to check it. Thanks for all the info!
#46
Safety Car
Thread Starter
Member Since: Nov 2005
Location: Lompoc, CA. Santa Barbara County
Posts: 3,932
Received 543 Likes
on
198 Posts
A hundred pounds is about the total weight of the corner brakes (4 x 26#). Hard to take out all of that.
I was able to take out 48# total (remember, all unsprung!). Seven pounds off the caliper, and five off the rotor. The rear parking brake is an issue in some applications. YMMV
I was able to take out 48# total (remember, all unsprung!). Seven pounds off the caliper, and five off the rotor. The rear parking brake is an issue in some applications. YMMV
Bee Jay
#47
Tech Contributor
Member Since: Jun 2004
Location: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Posts: 18,342
Received 766 Likes
on
548 Posts
When I put the C4 suspension under my '69 I had to get different rotors to fit under the stock C3 wheels. In addition to the weight savings, it was just easier (for my application) to use Wilwood rotors and hats to get the necessary diameter and offset to be able to mount the calipers. The rotors are dirt cheap (about $30), but the aluminum hats are a bit more expensive. Wilwood has a bunch of different offset hats listed in their catalog (and I assume their website), and I would expect that you could find some to match the offset of the stock rotors.
These rotors are nice on track days. Part of the reason they're light is that they have a slightly thinner wear surface, but this also results in a reduced thermal impedance to the cooling vanes and air flow.
#48
Tech Contributor
Member Since: Jun 2004
Location: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Posts: 18,342
Received 766 Likes
on
548 Posts
Inexpensive rear rotor option?
I was thinking about something while I was working on the '69 the other day. I'm curious if early C4 rear rotors will work on the rear of a C3 (with the stock trailing arm setup). The C4 hat offset is nearly identical, and the hat diameter is a touch bigger than a C3 part so that the stock emergency brake shoes might still work in this different rotor. The C4 rotor is inexpensive, and certainly lighter than the C3 rotor. I believe the rotor diameter is also pretty similar. The rotor (if it fits) will also work just fine on track days, as the stock heavy C3 rear rotor is overkill in its application. Given how long pads live in the rear (compared to the front), it's obvious that the rears in a C3 aren't doing that much work.
Just a thought for those who are inclined to tinker.
Just a thought for those who are inclined to tinker.
#50
Safety Car
Thread Starter
Member Since: Nov 2005
Location: Lompoc, CA. Santa Barbara County
Posts: 3,932
Received 543 Likes
on
198 Posts
Ok, I got a good year out of this battery, and it won't get me thru the day anymore, even after an overnight trickle charge. It's not the battery's fault. I've been brutal to this battery. I bought a Porsche Boxster last year, and I haven't been driving the Vette much. I frequently start the Vette, move it, and shut it down. Brutal on even full size batteries. I'm replacing it with this Oddysey PC680. It is pretty well known as a suitable lightweight battery and has more CCA (220 CCA). It costs a little more though, $110 from Battery Mart. I also bought these terminal adapters for $12. I'll be more careful about charging and not shutting the car down right after starting it. This battery weighs 15lbs. I also finally did that weight Los thread, it's here:http://forums.corvetteforum.com/c3-t...loss-mods.html
Last edited by Bee Jay; 01-11-2013 at 07:54 PM.
#51
Tech Contributor
Member Since: Jun 2004
Location: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Posts: 18,342
Received 766 Likes
on
548 Posts
I've been running a lightweight battery in the '69 for a couple seasons. For personal amusement one day I hooked up the battery out of my lawn tractor onto the '69. Damn if it didn't crank right over. I ended up installing it in the right rear compartment to move weight away from the left side. The battery I had been using was 26# (about 540 CCA), and the present battery is an Interstate brand, 17#, 300 CCA, and $32 at the local Farm/Fleet store.
Because of the good luck I've had with this battery I've just put this same model in the '84. This removes the 32# battery off the left front corner, and puts the 17# on the right rear corner in the rear storage compartment. Picture during assembly:
I put a disconnect switch on the '84 to keep from draining the battery while in storage. There's so much electrical draw on this car that it was killing the previous 600 CCA battery if the car was stored for several weeks at a time, which it currently is over the winter.
These batteries aren't fancy, but they are doing the job well on my warm weather cars. I certainly wouldn't recommend these for a cold weather DD car for obvious reasons.
As these batteries are mounted in the right rear compartments I have the option of installing a full size battery in the original locations if I chose to for any reason.
Because of the good luck I've had with this battery I've just put this same model in the '84. This removes the 32# battery off the left front corner, and puts the 17# on the right rear corner in the rear storage compartment. Picture during assembly:
I put a disconnect switch on the '84 to keep from draining the battery while in storage. There's so much electrical draw on this car that it was killing the previous 600 CCA battery if the car was stored for several weeks at a time, which it currently is over the winter.
These batteries aren't fancy, but they are doing the job well on my warm weather cars. I certainly wouldn't recommend these for a cold weather DD car for obvious reasons.
As these batteries are mounted in the right rear compartments I have the option of installing a full size battery in the original locations if I chose to for any reason.
#52
Race Director
i saved 16# with a mini-starter, it draws 1/3 less amps, so i can use a lower capacity battery.
i've got my eyes on that $50 walmart size 26. 450CA feels like 20-25#.
good job beejay!
i've got my eyes on that $50 walmart size 26. 450CA feels like 20-25#.
good job beejay!