Ha, thanks Kevin - hopefully I'll have it replaced by then (since it's now on my mind), but if not, sure I'll take it off your hands for you Can you measure it and/or take a photo of (or just tell me) whatever it says on it (CCA, size, p/n, etc). For a measurement, I'm most interested in the length half-way up the battery (ie not including the lip at either the bottom or top). Thanks!

 

Thanks. Looking on their site now, I see the listed one for a "2002, 911 Series, H6-3600 3.6L" is:

PepBoys:
Bosch Premium Performance Battery Part # 49-850B SKU:9073755
$108, -$20 MIR = $88

Notes
Bosch 36/96 Month Battery
850CCA/1000CA - RESERVE MIN = 120 OE CCA: 650 - OPTIONAL OE CCA: 740 BATTERY IS VENTED OUTSIDE OF VEHICLE

 

I have 740 and it's vented outside to stock hose.

 

I updated the body of my original thread with more info I searched out today. The one thing I realized with this PepBoys one that was a match on their site is that it is Group 49 which is 14" long. I don't know how that will fit and be secured down to the tray. It seems there's two tray settings for ~11" and ~12.5". See original post for more info on that. Their site won't let me look at all batteries without entering a vehicle so I'll have to go in store to see what other offerings they have. At this point, I'm leaning towards the Bosch if I can find something of similar performance/price to this one I found, but that will have a way to be secured down....

 

No problem Mark. I'll get the measurements for you tomorrow.

 

My Bosch is 12'' long and is secured down ..
At the bottom of the tray is another thread hole for the bracket to be attached to, to use the shorter type battery.

 

I recently replaced my stock (I think it was Mobil 1) battery, which was about 14" long and weighed 42 pounds when I removed it! I replaced it with the Interstate MTP-91, which you mention in your original post. Here are the specs on the Interstate:

Product ID: MTP-91
Amps: 875
Cranking Amps: 875
Cold Cranking Amps: 700
Voltage: 12
Termination: A
Weight: 36.7
Width: 6.88
Length: 11.38
Height: 6.88

It weighed about 35 pounds when I installed it (weight savings of 7 pounds using same scale) and is about 3" shorter. It fit perfectly in the stock tray by use of the threaded hole as you can see by the pictures (note the used stock size hole). It also came with a vent tube adapter (had to ask for it though). I just had to shorten the original vent tube a bit. It cost me $132.95 from an independent shop. Interstate customer service number is 888-772-3600. I'm sure they can find a retailer in your area.

I keep it on a trickle charger almost all the time, and so far I am very happy with it. I have had Interstate before on various vehicles and boats with zero issues. I hope that helps.

 

I just got this battery from Pepboys. Cant beat the price. I had to use the last hole as well as flip the metal clamp piece in order to tie it down. Battery is secure in the tray though.

 

Did you see post #22? Smaller, lighter, and no modification needed.

 

I really hate advertising my stuff BUT check out the rennlist threat I made recently.
Get my ebw battery mount w a oddesey battery. Weight is so crucial. I'm selling the battery bracket at near cost. It's not about € for me it's about helping members. Weight reduction is the biggest gain we can see gains on every aspect in dynamics of a car. My oddesey battery has been nothing but spectacular.

 

What he said.

Life is to short to chase the least common denominator.

No matter what you decide, invest in a tender and use it regularly.

 

Same one that is in my car too, works perfectly fine for cold starts but there is no battery in the Porsche line up that deals these cars when just sitting for more the 2 or three weeks...

 

Making threats are we...LOL. In any case your weight reduction editorial is not necessarily correct. The battery in these cars as we all know is up front. The front end is already lighter than the rear. For improving "dynamics", weight should be reduced from the rear or dropped in the car for a lower COG.

 

LOL I was at a bar waiting for a friend, and drinking some booze... typo
"thread" is the correct word i was looking for !

While I agree that we should remove weight from the back, i disagree that we should keep weight up front to balance the car. The car's engineering is already design with 1/3 front 2/3 rear weight. Coilover's with a corner balance, restores the balance. You did hit the nail in the hit with Lower center of gravity, that is crucial.

I believe one should be diligent in removing weight from whereever you can, that makes it cost efficient per dollar spend.

reducing the cog by 35lbs in the course of one lap that is huge.


Here is the example i just did in terms of force reduction at one lap at laguna seca. My car after 2 pc rotors will be at 3161 lbs w 1/3 tank of fuel. I have taken little bites everywhere until i have reduced the weight to that point. The car looks stock and drives like a gt2.....

"Im at a bar having a few drinks waiting for a friend so pls follow w caution
Cayenne rotors front 28 lbs
2pc ap racing rotors - 22 lbs

F=ma

Cayenne
F= 28 x ( 80 mph avg at track ) 35.763 m/s
F= 1001 x 95 seconds (1.35 sec lap time around laguna seca)

2 pc
F= 22x 35.763
787x 95 seconds

front

(1001-786)x 95 seconds = Total force reduced over a course of a 1.35 sec lap at laguna seca


Rear

Oem
F= 22x 35.763
787x 95 seconds

2pc

F=17x35.76
608x 95

(787-608)x 95 seconds = Total force reduced over a course of a 1.35 sec lap at laguna seca

That means I would reduce 74860 lbs of force in one lap at LS in a 1.35 second lap. "

 

There aren't too many modifications for our cars that allow you to take 35 pounds of weight off the car for about $300 total investment (short of pulling useful content out of the car). Just think that it would be like you losing 35 pounds of body weight, without having to lose the weight!

I definitely recommend keeping aftermarket (small) batteries on a tender, but I bought a terrific tender/charger from Target for under $20 that serves me very well year round. So, this doesn't have to be expensive whatsoever. Like Enrique, I'm obviously a big fan of weight reduction mods though!