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Weight reduction

OK, I know we have a 3600+ lb car so small weight savings take a while to add up. However, the relatively minor changes I've made (especially for track days) seem to have made an arguably significant dent.

Enkei PF01 wheels/Hoosier R6 295/315:
Front 60 street vs 45 - 15 lbs each x 2 = -30 lbs
Rear 58 street vs 49.2 - 9 lbs each x 2 = -18 lbs
Corsa Extreme axle backs (pair) 54 lbs stock vs 24 lbs = -30 lbs
Kooks Off-Road H-pipe 32 lbs stock vs 17 lbs = -15 lbs
Side pipe delete 5.5 lbs each = -11 lbs
Kooks LT headers vs stock manifolds = + 3lbs
Roll bar, mounts & harness bar +69 lbs.
Rear seat delete kit +12 lbs.
Remove rear seats and belts and factory mounts -54 lbs
Swap to the Tiger Hood -17 lbs
Remove washer bottle incl fluid -8 lbs
Remove flat repair kit -5 lbs
Sparco race seat 35lbs versus stock seat 46lbs = -11 lbs
302S tow hooks +2 lbs
FRPP air-to-oil cooler +8 lbs
1-pc DSS aluminum driveshaft vs stock -21 lbs
DS saftey loop +10 lbs
Trunk liner -7 lbs
Passenger seat -46 lbs (track only)
Watts link versus panhard bar +15 lbs
Rear axle weights -5 lbs
Battery relocation kit +25 lbs
Remove A/C condenser, compressor, lines and belt -21 lbs.

Total weight savings so far is 116 lbs with passenger seat and 162 without it.

With a curb weight of 3630, I'm at 3514 to 3468 with or without the passenger seat.
 

Grant 302

basic and well known psychic
ArizonaGT said:
KB hasn't been involved in Grand-Am with the S197, but they did win the SCCA World Challenge with it.

Also to whoever posted the BMR stuff, do yourself a favor and leave their drag-race oriented parts on the shelves. They don't understand what it takes to design proper road-racing parts.

;D Tell us how you really feel!
 

Sesshomurai

ArizonaGT said:
KB hasn't been involved in Grand-Am with the S197, but they did win the SCCA World Challenge with it.

Also to whoever posted the BMR stuff, do yourself a favor and leave their drag-race oriented parts on the shelves. They don't understand what it takes to design proper road-racing parts.

yeah, that's what I meant. lol. Was too lazy to go back and edit my remark.
 
Is anyone successfully using a Braille or other lightweight battery in their DD Boss? I'm ready to pull the trigger on one and ditch at least 20 lbs if there are no issues. Someone told me that there could be a problem on a DD but that might be if you run it in a cold environment.
 

ArizonaBOSS

Because racecar.
Moderator
8,552
2,392
Arizona, USA
cloud9 said:
Is anyone successfully using a Braille or other lightweight battery in their DD Boss? I'm ready to pull the trigger on one and ditch at least 20 lbs if there are no issues. Someone told me that there could be a problem on a DD but that might be if you run it in a cold environment.

The guys at Vorshlag are running an Odyssey battery on their S197 project car and haven't reported any issues:

fair;918460 said:
Project Update for Sept 12, 2011: Wow, haven't raced the Mustang in nearly 2 months. Took the last 60 days and got the new Vorshlag commercial space demolished and rebuilt, then we moved in. Very long hours and lots of work. During that time I only went to a karting event (Vorshlag Karting Challenge), the day after we did demo. The guys and I worked a little on the Mustang, installing the PC680 Odyssey Battery.

Lightweight Battery Install

DSC4200-S.jpgDSC4262-S.jpg

DSC4232-S.jpgDSC9768-S.jpg

As you can see, the OEM battery weighed 32.2 lbs (33.6 lbs with the OEM bracket), and our PC680 was 14.7 with the screw-on, SAE style brass top terminals. Our Hodge-podge of custom brackets came in at 1.5 lbs, which you can watch us put together in this gallery.

DSC4254-S.jpgDSC4250-S.jpg

Basically we took a piece of aluminum plate (see above, left), then bolted it to two existing battery tray holes in the chassis. Then we made a steel post that bolted to a 3rd hole, and then to our new lower bracket (see above, right). Then we bolted the West Coast Batteries CNC bracket (made for the PC680 but impossible to bolt to the S197 chassis without major surgery) to that, in the car, using counter-sunk bolts (below, left). Lastly the cylindrical stanchions screwed into their plate, the battery went in, and the the top bracket locked it all down (below, right). Took me a few hours to finish the custom brackets, one night after hours, like it sometimes does.

DSC4247-S.jpgDSC4259-S.jpg
 

pufferfish

Supporting Vendor
1,094
66
Maryland
weight loss is secondary to weight balance. lightening the battery by 18lbs up front doesn't effect the weight bias percentages by any measurable amount. by moving the weight to the rear (and adding a few pounds for the cables and box), i was able to shift 1% of the weight to the rear (on paper). i think it may have a greater impact though, so i am working on procuring a corner scale to verify. the reason i think it will have a greater impact is because the 32lb battery sits just behind the front axle, which means part of its weight is shared with the rear. i moved it to the back of the spare tire well, which moves that 32lbs to the rear axle only. another benefit is a lower CG from that weight sitting nearly 2ft closer to the ground.

its an expensive option though. to do it right (and to racing rules), you need to have a 2-pole disconnect and an alternator shut-off solenoid, so the alternator can't continue to power the engine if the disconnect is turned off while running. there is also a rumor that alternator current without being hooked to a battery, is dirty and can fry the copperhead PCM. definitely not willing to test that theory!
 
I ran the pc680 in my dd / track boxster for over 2 years without ever charging it and had zero problems. I've had really good luck with their batteries in other vehicles as well.
 

Sesshomurai

pufferfish said:
weight loss is secondary to weight balance. lightening the battery by 18lbs up front doesn't effect the weight bias percentages by any measurable amount. by moving the weight to the rear (and adding a few pounds for the cables and box), i was able to shift 1% of the weight to the rear (on paper). i think it may have a greater impact though, so i am working on procuring a corner scale to verify. the reason i think it will have a greater impact is because the 32lb battery sits just behind the front axle, which means part of its weight is shared with the rear. i moved it to the back of the spare tire well, which moves that 32lbs to the rear axle only. another benefit is a lower CG from that weight sitting nearly 2ft closer to the ground.

its an expensive option though. to do it right (and to racing rules), you need to have a 2-pole disconnect and an alternator shut-off solenoid, so the alternator can't continue to power the engine if the disconnect is turned off while running. there is also a rumor that alternator current without being hooked to a battery, is dirty and can fry the copperhead PCM. definitely not willing to test that theory!

I plan to relocate the my battery to the passenger side of my car to help with lateral balance. There won't be a passenger seat there for long and it will corner differently without lateral balance. Probably need to add weights to the passenger compartment as well to offset my own weight.
 
You better check with tech before putting a battery in the passenger compartment. I use a lithium 16v in my drag car and nhra says no to the mounting it in the passenger compartment and it has no acid. Weighs about 7lbs.
 
Maybe FRPP will make this battery relocation kit available.

boss302s25.jpg
 

JScheier

Too Hot for the Boss!
cloud9 said:
Very cool. Unfortunately I don't think I want to go through all that custom work to secure it though :'(

Don't worry about all that custom work. They have to make it look nice, it's a shop car which showcases their work.

In the M3, I ran the same odyssey PC680 battery. I went to Home Depot and bought 3 feet of aluminum L stock, a set of longer batter tray bolts and made a bracket that passed tech with SCCA, NASA and BMWCCA at many regional and national events. As long as the battery is safe and secure, it will work.

As for using a braille or odessey for daily work, no issues. One thing they don't like to do on modern cars is sit for extended periods of time without being charged. They also HATE cold weather. I kept mine on a trickle charger and never, ever had an issue (it's actually still in the M3 which I saw on the road yesterday). Take care of them, follow the instructions for trickle charging, and they will / can last as long as an OEM battery.

If I ever get the car back in my garage, that's on my list of weight loss items for the spring. Will most likely go with the PC680-MJ again (the one with the MJ has a steel jacket) as I've had very good luck with them.
 
JScheier said:
Don't worry about all that custom work. They have to make it look nice, it's a shop car which showcases their work.

In the M3, I ran the same odyssey PC680 battery. I went to Home Depot and bought 3 feet of aluminum L stock, a set of longer batter tray bolts and made a bracket that passed tech with SCCA, NASA and BMWCCA at many regional and national events. As long as the battery is safe and secure, it will work.

As for using a braille or odessey for daily work, no issues. One thing they don't like to do on modern cars is sit for extended periods of time without being charged. They also HATE cold weather. I kept mine on a trickle charger and never, ever had an issue (it's actually still in the M3 which I saw on the road yesterday). Take care of them, follow the instructions for trickle charging, and they will / can last as long as an OEM battery.

If I ever get the car back in my garage, that's on my list of weight loss items for the spring. Will most likely go with the PC680-MJ again (the one with the MJ has a steel jacket) as I've had very good luck with them.
In for the parts list and instructions when you're done :D
 
ArizonaGT said:
The guys at Vorshlag are running an Odyssey battery on their S197 project car and haven't reported any issues:

We are still running it and it's still issue free.

But, it was left in that location because autocross competition is more sensitive to total weight than balanced weight. It was also convenient to not have to fabricate long new battery cables that would be class legal and reach a relocated battery.

Now that the car has been retired from National level autocross, we will be tailoring it for NASA Time Trials. One of the items on the list is to install a larger battery and relocate it to the trunk. Larger? Yes, we need it to make minimum weight. We will most likely stick with an Odyssey. Most people tend to use them because they are small and light, package well and have good longevity. But their heavier batteries also have that same longevity. We will most likely do something like this mount we built for Brianne Corn's Pikes Peak car. Please excuse the finish quality, as the car was built on an extremely tight deadline (20+ hour days for multiple guys).

Here's the mount.
DSC_3126-S.jpg

And here it is mounted in the car. Ignore the massive cable. We used what we had on hand as Brianne doesn't have much of a budget.
DSC_3138-S.jpg
 

pufferfish

Supporting Vendor
1,094
66
Maryland
please help me understand how ^this^ is legal anywhere? its not enclosed. its not separated from the driver in any way. and its not externally vented. are oddyssey batteries legit for open air mounting in the cockpit?
 
pufferfish said:
please help me understand how ^this^ is legal anywhere? its not enclosed. its not separated from the driver in any way. and its not externally vented. are oddyssey batteries legit for open air mounting in the cockpit?

Pikes Peak Hillclimb Rules say this:

14.0 Electrical System-
 14.1 Batteries must be installed in a safe manner. The battery must be in a leak proof container or equipped with gel or dry type battery. The hot terminal must be insulated on all vehicles. All batteries shall be securely attached to the primary structure of the vehicle.

Don't shoot the messenger. :eek:
 

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