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View Full Version : What are your thoughts on relocating the battery to the trunk?



HwyStar
02-05-2017, 09:21 PM
The only reason I drive this car is to have fun, or its my back up car in case my other vehicles quit. So, trunk space isn't a issue. But, I don't want to be stuck not able to get through Tech at the track. What do I have to do to get through the inspection? What are the best parts to use?

This should level the car which would be a God send. Every since I did the solid bushing change over, the car sits about 3/4" higher in the rear and I know that is hurting my traction. This should help a lot with that and transferring that weight over the rear wheels. If it doesn't lower the rear of the car enough, I'll probably drop a 1/2" on the rear. I needs weight transfer! Those are my thoughts at least....

racecougar
02-05-2017, 10:59 PM
I'd advise picking up a current NHRA rule book. You'll need either a sealed battery box or rear firewall (specs are listed in the rule book), as well as a kill switch (again defined in the rule book).

I went the firewall route, using 0.040" aluminum. I swap out the passenger tail light for one with a hole through it and connect a pushrod and bellcrank to my kill switch when I head to the track (takes all of five minutes).

http://i6.photobucket.com/albums/y207/racecougar/90%20XR7/interior/th_312877_252833764752194_160010320701206_616244_2 21593170_n.jpg (http://s6.photobucket.com/user/racecougar/media/90%20XR7/interior/312877_252833764752194_160010320701206_616244_2215 93170_n.jpg.html)

davec73
02-06-2017, 12:09 AM
It's alot more expensive than it would seem. Probably 700 all said and done.

nickleman60
02-06-2017, 12:39 PM
Ditto to everything mentioned above, here's my set up.

HwyStar
02-06-2017, 10:51 PM
Man, that's a nice setup! Don't think I have much choice, I have to do it. Even if it costs a good amount.

Broncojohnny
02-07-2017, 11:11 AM
You either need the firewall or a sealed battery box with a vent. Moroso makes a pretty good sealed battery box that summit sells. It offers a nice alternative to installing a firewall in your car.

Alternatively and much simpler, you can go with a smaller battery in the current location. I use this 15 pound Odyssey AGM battery (below) in my junkyard track car and have had no problems with it charging or starting the car. I am not sure how well it would work while driving around on the street but the road course and autocross guys in my area, who are very sensitive to weight, swear by them.

https://www.amazon.com/gp/product/B0002ILK6I/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

scotty54
03-07-2017, 08:45 PM
This is not an expensive mod. Battery boxes are relatively cheap and can be vented with a few additional OTC parts. I had a welding shop make one from stainless steel scrap and it wasn't even more that $50.

My biggest problem with moving the battery has been getting enough juice to the starter. I use 00 welding cable and run both (+) and (-) wires to the starter. I ground the battery to the starter mount AND the rear frame. All wire to lug connections are soldered and insulated (black tape and a zip tie). My current setup has worked perfect for 17 years.:)

Also consider a gear reduction starter if one is available. And a Optima battery has no fluid so no spills in the trunk (plus more CCA).

Avoid the kits sold by Summit, Jegs, etc. Wire is too small and the kits overall are overpriced.

HwyStar
03-08-2017, 11:43 AM
Good point. I was thinking about the gage of wire too. Running 00 hot cable to the front from the back will be a pain in the.... Also, Im thinking that I will put the battery where the spare tire used to go. I would like to get the weight centered in the back of the car.

racecougar
03-08-2017, 08:59 PM
Good point. I was thinking about the gage of wire too. Running 00 hot cable to the front from the back will be a pain in the....

If it's good cable, it isn't difficult at all. My leads are 00 gauge.

davec73
03-08-2017, 11:17 PM
I used copper 00 welding cable for the ground and positive.

Broncojohnny
03-09-2017, 10:11 AM
Make sure and put a big circuit breaker near the battery if you run that hot wire the length of the car, if it shorts it will burn the car down. One of the resetable ones used by stereo guys is usually the best option.

HwyStar
03-11-2017, 03:21 PM
If I recall, typical current draw when starting is about 300A. Am I right on that?

nickleman60
03-11-2017, 05:56 PM
Here's my inline megafuse on the left, it's a 300 amp.

S4gunn
03-13-2017, 02:11 AM
Good point. I was thinking about the gage of wire too. Running 00 hot cable to the front from the back will be a pain in the.... Also, Im thinking that I will put the battery where the spare tire used to go. I would like to get the weight centered in the back of the car.

Q: Are you sure you want it centered? if you are going to get all analytical about it - consider that your weight will be in the driver's seat and more on the FL of the car. Putting the battery on the RR of the car would offset this imbalance.

I guess it all depends on what kind of racing you are doing but playing with your car on a set of corner weight scales might not be a bad idea if you have a friend with one.
You could then move the battery around and see what position works best for your needs.
-g

HwyStar
03-18-2017, 05:08 PM
I have re-thought that some. Since the car tends to lift up on the driver side over towards the passenger side, I think that I will put it on the driver side of the trunk. Then, I can keep my spare tire. This car runs straight track only. I've learned my lesson the hard way about taking corners hard in one of these.