For anyone thats thinking about this install here you go.

The only thing to know is that the Pos + lead will not reach the Optima's Pos + post. this is because of the way mazda intergrated a fuse into the cable. The fix is very easy.

First off take out your old oem Battery and snap on the big spacer on the bottem of the red top. you need this spacer to bring the battery up to the right level so the oem battery hold down will work.

After snaping on the spacer, place the battrey in the tray.

Next you need to modify the battery cable. +pos

 

here you can see the problemb

 

heres the parts you will need

 

now.. take the battery cable and cut off the crimped on end so the new cable is about 2"s

 

then slip the cable in the copper 4 guage lug

 

now remove the oem battery post clamp

 

now take a 3/4 inch x 5/16 stainless bolt and attach your new cable to the old one.

 

next clamp the new cable to the + pos post on the red top .

 

before you close it all up tape up the new copper lug and cable.

enjoy your new 910 cranking amps

 

pic of the copper lug. you can also just crimp a new eyelet on the new battery cable, but i like the lug connection because i can add to it later and i know its always tight ..

 

finished

 

ohh i took pics with the cover back on the battery box but i deleated them by mistake. the cover does fit just like normal.

Engin spins a bit faster now.. instant start

 

Very nice... again! Great little DIY, thew! :D

 

thew,
Nice work!

For future buyers, it looks like the RedTop 34R would work better for the RX-8 by avoiding the need to extend the positive battery cable.

The 34R is also rated a little higher, but it length is 10" vs 9.4" for the 75/35 - so fit need to be verified.

rx8cited

 

Thanks alot...I can go out and buy my red top now, knowing that i can install it in my car...great DIY.

 

Very nice work…. I was thinking in doing something similar, but so far my OEM battery is doing its job. If you wish of not doing the mod, Optima is starting to offer a battery that meets the OEM Specs (Group 35). The model is SC35R, and you can get it from http://batteriesareus.com/shop/produ...6359a1637b1a65
Here is a picture of the battery.
Cheers!

 

yes.. but Costco and sears dont sell it.. I asked the sears rep and they wont be carrying it also Costco only sells the 75/35 i guess its the most popular one..

so dont shy away becasue of the + pos post.. its a very easy fix.. took me about 5 mins.. took longer to post the pics hehehe

also i dont think it will fit in the box.. the 75/35 is very tight in the oem box.


Hey Omicron thanks for the nice words.. again.

 

By no means I was saying that your mod is bad... It is really good! I agree, this particular model is harder to find from a local battery supplier. If someone can get this particular model without going to through a lot of hoops, great... if not, at least they have an alternative with a more readily available battery

 

aye i know no offense taken :D

 

Sorry being a stupid Brit, what is the benefit of doing this over the stock battery?

A

 

Here are the Optima reasons.

cheers,
rx8cited

PS: thew, how much was the battery and all the other required hardware please.

 

very nice

I had two optima's in my last car

nothing worst than a car dying on you

 

Why two?

rx8cited

 

in my case i have a video system that draws power off the battery and i have had to jump it twice now.. once because of the trunk being ajar..

the other becasue the video system draind it..

the red tops are better for starting when the battery has been drained like in my case. the sstock oem battery is a POS.. is just enough to get the car going. the best mod you can make if you dont do anything else is to replace the stock battery .. even with a Diehard 1.. would be better than the oem unit..

 

i spent 2.95 on the copper lug, and the battery cable cost 19.00


the Red top cost 99.00 at costco. I have seen it online for 79.00
but then there shipping.


so all in all i spent about $125.00 for a first class battery.