about a yr. down the rd. its a bitch when you have a problem and you go to check the car and you have all black wires. that dont make no dif. though, i can still fix it. **) :cool:
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about a yr. down the rd. its a bitch when you have a problem and you go to check the car and you have all black wires. that dont make no dif. though, i can still fix it. **) :cool:
Thanks guys, I was at a one day conference today but it looks like you were working hard on the circuit. By the time I check this all out I should get something to work. It's going to be very cold here for a day or two (after two days in the 60 F range last week) so I plan on hunkering down and studying the TPI circuit, Sweeden's book and your diagrams till I am sure I got it figured out. Lt1s10 has it right though as to the difference between theft protection and NHRA requirements. Maybe I can get the theft protection mainly but also make the motor cutoff built in too. Thanks again. Any other comments are welcome while I figure this out.
Don Shillady
Retired Scientist/teen rodder
Quote:
Originally posted by Don Shillady
Thanks guys, I was at a one day conference today but it looks like you were working hard on the circuit. By the time I check this all out I should get something to work. It's going to be very cold here for a day or two (after two days in the 60 F range last week) so I plan on hunkering down and studying the TPI circuit, Sweeden's book and your diagrams till I am sure I got it figured out. Lt1s10 has it right though as to the difference between theft protection and NHRA requirements. Maybe I can get the theft protection mainly but also make the motor cutoff built in too. Thanks again. Any other comments are welcome while I figure this out.
Don Shillady
Retired Scientist/teen rodder
just keep in mind Don, if you're gonna be cutting the motor off with the ign. sw. then it dont make no dif. how you hook the bat. cut off sw. up. the only thing you have to be sure of it having the alt. wire hooked to the bat. side of the ign. sw.
I have an objection to section D:
Hydrogen gas is lighter than air, hence it RISES. Venting the box through the floor will prevent a hydrogen gas buildup in the car interior, but it will actually facilitate the battery box to become saturated with hydrogen. Anyone truly worried about hydrogen gas buildup in the battery box, should vent it to the top and the bottom. That will allow hydrogen gas to rise through the top vent, and atmosphere will rise up from the bottom to replace it.
if ya REALLY want to split hairs, that is.
BTW.. is sulfuric gas heavier or lighter than air?
Also.. if ya really want to fuse it, then check GRAINGER for some industrial fuses and fuseblocks.
Denny, glad you finally came around to seeing it my way :3dSMILE: :LOL: Just jokin....Quote:
Originally posted by DennyW
3. Correct way. :)
Chris
I've been through a lot of tech. lines at the drags, with bat. in the rear, and the best I can remember, no one never ask me if my alt. had a cut off on it, so I'm saying as long as you disconnect the bat. it don't make no dif. what your alt does. some people cut them off for more power, but for nothing else. what safety factor would it be anyway with the bat. cut off at the back of the car and the alt. cut off on the dash. safety people wouldn't know that.??????????
Mike, they always test my cutoff switch at tech inspection at least here at Bandimere speedway, usually right after testing the neutral safety switch. That's how I found out it originally was not wired correctly because the motor kept running, albeit pretty rough.
Perhaps some tracks are less stringent than others....
Denny, I was considering installing a relay to cut off the alternator to battery connection so as to cut the load to the engine when racing, this can be significant load with electric water pump and fan etc. Are there some specific NHRA rules that would make this more complicated than a simple relay?
Chris
The positive cable does not need protection, but a disconnect switch is a good idea, even if your are not drag racing. It should be run directly to starter positive post. Make sure cable run is protected from heat sources, sharp edges, etc.
Power distribution for fuse panel can be from disconnect switch. This wire should be atleast 8 AWG with a fusible link. The fusible link is always 2 sizes smaller (12AWG) and should be 5-3/4" long.
Run a second wire from disconnect switch (same size) to a remote terminal block in engine compartment. The ouput of alternator will also go to this terminal block. Use at least an 8 AWG wire for this with a fusible link. This second run is your major load side, headlights, electric fan, pump, etc. All loads should have relays to handle that function. The fuse panel side is only for control function. Use a 3 wire alternator (one wire alternators were designed by GM for tractors only, as they run at one constant speed. They also require atleast 1600-1800 RPM initially to cause the field to self-excite. But when your RPM drops back to idle, the field can fall off and alternator output stops. The 2 small wires on side plug are as follows; one is for system voltage sensing and the other provides field from ignition. This wire you install a diode to prevent backfeeding when you turn off ignition. For MSD ignitions this is a must.
Hope this helps.
Skids72, do you mind saying where you placed the cutoff switch? For a long time I thought a "kill switch" should be in the cockpit as DennyW shows but then Tech1 is trying to tell us the specs for a 300 mph dragster with an outside rear cutoff. I can at least understand your circuit as the easiest with just a longer 8 gauge wire from the alternator to the battery. I note your method only needs a single pole switch of high amp rating but for a few bucks more the Moroso switch Tech2 suggested would allow cutting off both the battery wire and the alternator wire and give 300 amp continuous flow. The '29 cockpit is pretty tight with radio speakers in the kick panels, so I'm not trying to keep this thread going uneccessarily but I'm still learning. I need to go back to Arcet and get some more 2/0 black ground cable to run from the battery forward to a bolt on the trans at the back of the engine because I don't see any good connection for a ground on the engine except the trans mount. The Painless relay DennyW shows is more like what I had expected for a kill switch but at this point I am just trying to figure out one good way to do it. The TPI kit gives a nice total circuit diagram but does not include a cutoff or kill switch which I would like to add.
Catsasswiring, I bought a 100 amp one-wire alternator that is supposed to start charging at about 1000 rpm but I have also heard stories about a lot of alternators not working so I will just have to keep trying till I get one that works and charges at low rpm.
Don Shillady
Retired Scientist/teen rodder
To Don Shillady
Your alternator should have a plastic plug on the side, near the cooling blade. Remove it and install a plug available at any parts house to make it a 3-wire alternator. The importance of the field wire when ignition is on, is that your alternator will always have a field on it regardless of RPM. GM alternators power curve starts at about 2600 RPM. Your pulley ratio of crank to alternator needs to be 2-1/2 - 3 to one. This ensures enough RPM on alternator.
More info. available at "madelectrical.com"
Don, my cutoff switch is mounted behind the rear license plate. It is hidden by the license plate and I remove the license plate at the strip. I've seen others that mount the switch just below the deck lid of the trunk or even through a taillight. One fellow I met last year drilled a hole through the center of his license plate and had the switch there...... pretty slick but I think I'll keep what I have because I didn't want the switch visible when on the road.
catsasswiring: sounds to me like you know what you're talking about when it comes to wiring. :) Can you comment on my previous idea of using a relay to cut alternator out to reduce load for racing? Would this idea be worth pursuing?
Denny, I like your drawing just fine but I think you were targeting a different application. I know HOW I would install a relay to do it.... what I'm looking for is whether it's a good thing to do and whether it's legal. I guess I can check with NHRA on that latter part. Intuitively, it seems like it would be a good idea to run the motor/fan/water pump off the battery for a 1/4 mile (save a few HP?) then switch the alternator back in after the traps.
Agreed, except for one point: total load is on the whole system not just the battery. With lots of goodies running on electrical, the alternator needs to work harder making it more difficult to spin mechanically. Take the electrical load off the alt and it spins more freely and robs less from the crank at least that's my understanding of how it all works ;)
Okay... perhaps I could have chosen better wording :LOL: Point is there is an electrical load on the alternator which becomes a mechanical load on the crank if the alt is electrically hooked in to the system. Cutting this electrical load should result in reduced mechanical load on the engine(?) :confused:
Cables routed through appropriately sized grouments should provide the needed protection.
jc:toocool:
To Skids72 and DennyW
You need to run to separate systems (Load) & (Control). Reasons are for your fuse panel does not need the load, most aftermarkets are not sufficiently rated (Painless). Enos Components does make a 300A solid state mother board for his fuse panel. Second, drag race applications, tech will have you run engine, then open kill switch. On a system not separated, your voltage regulator will see volt drop when engine dies, this can cause a voltage spike and fry your MSD electronics box. TRUST ME! I have been wiring street rods, drag racing of all classes for 10 years. Larry Dixon Sr. (1970 Winter Nationals Winner) sends me his customers. I have been working in power plant for 32 years in operations as a senior control operator and shift supervisor (we make electricity).
Hope this helps. catsasswiring@yahoo.com
Forgot to mention, alternator cut out not needed with my set up.
As far as horse power loss for drag racing, the pulley ratio should be a 2 to 1. Alternator speed should not exceed 26,000 RPM. HP loss for drag racing is minimal. We run a '72 all pontiac, alcohol injected, run 8.60's. I have an GM 10SI series on it.
catasswiring
Thanks, catsasswiring. I never doubted your credentials... I could tell you know your stuff. As for voltage spikes killing MSD box... how are you saying this will be prevented? Separate control and load systems.... does this mean run everything with relays? I understand the benefit but I don't understand where the voltage spike risk is from and how specifically to prevent it. I have not installed MSD (...yet.... I do have all the parts) The only precaution I was aware of was to install the diode in the exciter wire to the alt.... what am I missing? I certainly don't want to fry this new toy.
Also, it sounds to me the HP gain cutting alternator while running is not worth the hassle?
Many thanks,
Chris
Let's assume you are generating 100 amps at 14.5 V dc and 95% efficiency. Then you are drawing about 2 hp from your engine.
Only on paper do I believe will this factor alone cost you a race.
Unless you are running a self-generating ignition (magneto) then the waning 12V may not be a great idea in general, albeit drag races are very quick, no?! Your MSD-coil will like 14.5 V much better!
One wire alternators are self-excited. You have to kick them up initially (at start-up or whenever) to kick them on. Once on I am not aware that they do not perfrom as well as 3 wire alternators. I would certainly like to see some performance curves ...............
The diode alone will not smooth voltage spikes, but then again I am not aware of MSD killing voltage spikes in a 12 V dc automotive charging system.
Kitz
How do you get to 7 HP from 14.5 V and 100 A?
Alternator load = V I = 14.5 * 100 = 1450 watts.
1 HP = 746 watts. ~ 2 HP
Kitz
Hey Guys...
Just thought that some of you may want to see this for your trunk mounted batteries... ps I would think of putting a dry cell in it ie. optima...
http://www.steeda.com/store/-catalog...relocation.jpg
That is the Battery relocation kit from Steeda Autosports
MSRP is $199 For the kit...
MSRP $129.95 For the box only
skids72, Thanks for the picture. That is really a neat way to both hide the cutoff and satisfy track rules.
Don Shillady
Retired Scientist/teen rodder
DennyW, this thread is developing so fast that his picture is one or two pages back. It is the rear view of his Pontiac with the cutoff in the license plate bracket. I like his method but may have to use a rod through a hole in the base of the rumble/trunk if I want to satisfy the rear rule. I could plug up the hole and then add a cotter pin attachment for a push-off cutoff if I ever want to get a timed 1/4 mile. I'm thinking it over, but at least I under stand some of the diagrams now.
Don Shillady
Retired Scientist/teen rodder
Well it looks like Spring is trying to bust out somehow but not quite. Today was pretty sunny and I should have worked on the car but I had other things to do. However along the way I stopped to buy a nice remnant 15' of RED garden hose to slip over my 1/0 red positive cable from the battery to the starter. That should provide a reasonable extra insulation between the cable and the frame rail, but I still need to find some plastic clips to avoid using metal which might cut through the insulation. Just a tiny step but I am starting to think I can do this!
Don Shillady
Retired Scientist/teen rodder
so much for spring up here in these Va. mountains this morning. its snowing, and sleeting. :CRY:Quote:
Originally posted by Don Shillady
Well it looks like Spring is trying to bust out somehow but not quite. Today was pretty sunny and I should have worked on the car but I had other things to do. However along the way I stopped to buy a nice remnant 15' of RED garden hose to slip over my 1/0 red positive cable from the battery to the starter. That should provide a reasonable extra insullation between the cable and the frame rail, but I still need to find some plastic clips to avoid using metal which might cut through the insulation. Just a tiny step but I am starting to think I can do this!
Don Shillady
Retired Scientist/teen rodder
This must be the old thread back again because it is now officially Spring and tomorrow we will have the snow flurries to prove it! We lost a few comments due to the old/new thread situation, but I have actually been working a fair amount on this problem on the warm days. I finally purchased a new Summit No. 830051 Remote Battery Cutoff Switch. It comes spring-loaded to the off position and has a click-set on position with an 18" steel handle to extend outside the back of the car. It is rated for 250 amps continuous current and several thousand amps surge so I think that will handle my nearly stock 350 with only 9:1 CR. I chose this unit mainly because of the spring-loaded setting and the external handle. I have mounted it in the right rear corner of the bottom of the Model-A floor behind the rumble seat tank because I plan to install a luggage rack on the roadster and I need to avoid the rack on the outside of the car. As suggested by Tech1 I used the rubber sleeved Adel clamps to fasten the 0-gauge red welding cable to the starter and to the switch at the back. The alternator wire will feed back to the + battery side of the switch as others have show on this thread and I ran a 00-gauge black welding cable from the - post of the battery to the frame and then to a transmission bolt on the engine. I got a 1/4" longer mounting bolt so I still have lots of thread into the engine even after adding the brass lug and two star washers under the head of the bolt. It took about 30 minutes of grunting and some grease but I was able to slip red garden hose over the 0-gauge hot + cable to further protect it from shorts through the Adel clamps. Now for my innovation, I think it is unlikely that I will ever use the race track cutoff more than a few times and I still want to have a security cutoff so I can park the car in a Va Beach parking lot without it being stolen (I have had other cars stolen!). Thus I threaded another stock piece of 1/2" steel rod just like the 18" "push-off" rod and flipped the heim end of the spring-loaded switch lever around to the front. This gives me an internal cutoff when the push-off track switch is not installed. If/when I take the car to a track for a time trial I will have to reverse the heim-end of the lever and insert the push-off rod through a hole in the body which will have a rubber grommet and a nice chemistry laboratory rubber plug in it most of the time. Viola! I have both a track cutoff switch if/when needed AND a hidden handle in the rumble seat area to disconnect the battery in a municipal parking lot. It is like Bob said, it is one slow step at a time just like eating an elephant but step by step maybe I will get the body on this summer after I finish with the floor-fenders on there now.
Don Shillady
Retired Scientist/teen rodder
Boy, this is an old thread! The weather is much better now and I am studying "Wire Your Hot Rod" by Dennis Overholzer. I have a wiring kit so this is going to be a mess and fun too, but I will probably be asking questions as I go; I have done a lot of wiring on low amp stuff in electronics, but we are talking about big sparks here!
Don Shillady
Retired Scientist/teen rodder
Hi Denny,
I used some of those to hang my welding cable ground wire but I need to get more. I am going bonkers with the nice weather and this book deal requiring 12 hours a day so at some point I am just going to put in some days on the car. I really have more on my plate than I can handle but I am waiting for my custom column drop and then the fun begins with the instruments and wiring so I am trying to get myself psyched up to figure out a way that I can type for a few hours a day and still get into the garage for a few hours, but I am basically an obsessive guy who prefers to stay with one thing until it is finished and I just got in over my head with this book deal. I pretty well finished up the chapter on the "twisted light" effect and sent some results to a colleage in Germany who uses large computers for that sort of calculation and she was amazed I could do similar stuff on my home PC and get good results so that chapter should be pretty good. Still, I like to be careful with the car and measure three times before cutting and now I have to worry about big sparks, so your suggestion of the rubberized hangers is a good reminder. I still have to hang the fuel line on the right frame rail too and I can use the smaller diameter rubber hangers for that, but I need a 40 hour day! Retirement means you can work at home but the hours are still long!
Don Shillady
Retired Scientist/teen rodder