Right now I'm not running one. I'm running a fuel pump, electric water pump, electric fan, and ignition off the battery. Never had a problem having enough battery power. But, I've never made it deep into the rounds where I'd have to be running back-to-back rounds and trying to keep the car cooled off. I'm thinking about installing an alternator, but I'm thinking that since the engine is only running during the run and the return lane it might not have enough time to do much recharging of the battery. Am I right or do I need to install an alternator?
Most racers have a small generator they run between rounds to recharge battery... Thing with a alternator is depending on amount of charge in battery how much load it puts on engine, as you probably well know .01 sec can be difference between winning or losing...
I'm not really concerned with the car running a bit slower, I'm running bracket. A small generator will cost me more than an alternator. But, that may be a better option, and I've considered that.
So you go to next round and then while you're putting car on trailer, wonder where the .042 sec went vs last three runs... My point was if battery is somewhat discharged, load from alt will slow the car down vs a full charged battery... I dunno about up your way but guys around here are good enough that I've run .011 from a perfect package(dial & reaction time) and still lost... Yeah usually that'll win but not always...
Krazy, I understand what you are saying. I haven't had that problem because I haven't made it past the third round. But, that's why I'm asking about an alternator. At some point I may lose power due to a weak battery..... if I can manage to go a few rounds.
I run an alternator on my drag car. Doesn't affect consistency to me. It is the way to go in a bracket car in my opinion. If your looking for all out performance as you would need in a heads up class, you would not want it, but in brackets, who cares if you lose a couple hundredths. The convieninece of not having to charge your battery between rounds is well worth it to me.
David Taylor who runs at Dinwiddie(blue 69 Fairlane) uses a 100 amp 1 wire alt. & never charges his batt. at the trk.He even has a switch where he can cut it off but he said he never does,has no issues what so ever.I plan on doing the same thing to my car,but also I`m sure a lot of it will depend on how many electrical devises you are using.
I run 2 Yellow top batteries with a 200 amp alternator. Electric water pump , fuel pump, radiator fan,. I 2 amp charge the batteries the day before racing and I can hot lap this car ALL DAY LONG without ever thinking of charging the batteries. I can sit in the staging lanes with the water pump and fan on and never run them down. There are plenty of ways to lose and a dead battery isn't one of them for me. Why the 200 amp alternator, It's what I had when I put it together.
airford1, explain the two battery setup for me. Do you switch back and forth between them or are they both providing power all the time?
The 2 batteries are mounted over the read passenger tire to help with weight on that tire. I have them connected in parallel for 12volts and double the amps.
I have switches and relays to turn on and off each device like water pump, fan, fuel pump, that way I can cool down a 210 engine in the staging lanes in August down to 150 in no time.
My car is ready to race right off the trailer. I try to make it fun to race and some like to work on their car at the track. Gas, Check tire pressure and I'm ready to go. (10.35 et no electronics foot brake) Pop up tent with 2 chairs and a cooler. We are good to go.
I guess I never realized that you were on batter only with this combo. 12 - 12.5 voltage supplies(such as battery only systems will provide) can cause high end misses or just plain snuff out some power in such consistent manners that some guys never know or fully realize what they are missing. If you talk to other racers as well as other ignition mfgrs and MSD themselves.. they will tell you that those ignition systems run even better with more voltage. The guys who run 16V setups will also tell you the same as well. And if your tune runs a hair lean while simultaneously combined with too much spark lead.. bad things related to insufficient spark energy become even more amplified at the top portion of the powerband. Not saying this combo won't like the new short travel lifters, but could also be part of the reason that this motor layes over like it does in that last few hundred rpm up top. I'd highly recommend installing an alternator and don't go crazy with the belt tension. 55-65 amp unit will be more than sufficient for your combo as the bigger ones just load the motor a bit more. If you're really worried about losing a couple horsepower.. install an old school style field cut switch. Eventually my road race motor will have a full throttle activated switch to do the same. There are also manifold vacuum actuated options for field cut switches too. Many OEM's use something similar for use in cutting A/C system induced power losses under heavy throttle. Which turns it into a engine vacuum related(essentially a load based system) so I may even end up going that route too.
That's essentially how I race. I don't like to work on my car at the track. If I have a problem I load it on the trailer and fix it at the shop.
