That alt light thread again.

[Olythekid]

I am running with no gauge cluster, I made my own. To excite the alternator I wire a light. I give it 12V and connected the other end to the blue wire of the C1 plug <blue plug of the instrument cluster>.

When I fire up the car the light stays ON and the batery is not charging. If I do the rev up past 4K, then the light goes off and the bat is charging.

What am I doing wrong? (Btw, D+ is that alt plug on the passenger side right?). Furthermore I sent 12V to an another light and tapped into the C1 plug brown/green wire (to the oil pressure switch) and this one does not work at all either. But that's an another deal.

[baders]

Are you sure that you are getting field excitation voltage to D+ on the alternator ?

[Olythekid]

Hum ... only 10.66V. What do you think ... too weak to excite till I get more RPM? But if I'm too weak to excite in the first place why more RPM would fix it?

[baders]

10.66 vdc should be enough for excitation. As the field coil is the rotor, there may be a problem with your voltage regulator or slip rings/brushes. Have you had the alternator apart for inspection ? The fact that the alternator excites at higher revs also indicates that the initial excitation is not effective.

[Olythekid]

I tried to remove the D+ washer and the whole post was spinning. I think it is corroded inside. New alternator on order. Thank you for the expertise.

She came a long way since P.O. reception:

[baders]

Nice !! Let us know how you get on.

[Brucey]

shame about the alternator. FWIW if you have the same fault again, check the slip rings/brushes; quite often these cause bad charging too. With the new alternator you might want to specify a 14.4V regulator rather than a 13.8V one as originally used; 14.4V is needed for fully charging most modern batteries. Replacement also gives you the chance to install a smaller, lighter alternator, and/or to gear it down for smaller parasitic losses. I have even seen an E24 race car with the alternator driven by a belt drive off the diff; this presumably helped with weight distribution too.

FWIW looking at your cockpit I can't help but feel that your steering column is could be set too high for a track car. Because there is a (good) flex disc in the steering column, you can normally lower the column slightly without any further modifications. This is most easily done by putting a few washers in the mounting bracket, as spacers. Even 1/4" at the bracket lowers the steering wheel noticeably in your hands.

cheers

[Olythekid]

It's the best I can do height wise. I'm 6ft tall and it's the setting where I can see the gauges the best (still missing the top of the top side ones) and still see the hood with the seat reasonably vertical. If I bring the seat all the way to the floor I can lower the wheel but I cant see a bit of the hood.

[Brucey]

seeing the hood is probably overrated in terms of raw lap times (in a lot -most- proper race cars you can't see the hood) but can be useful when you are running close to others, or just getting used to things. Lowering the seat a couple of inches can have a noticeable (beneficial) effect on the overall handling, and this is liable to have a lap time benefit, so there is a choice to be made there.

cheers

[Olythekid]

Yep, you always look far ahead. It feels better for me, in traffic as you mentioned and maneuvering the tight garage/paddock/trailer. It's such a boat as a race car compared to half of the field being Miatas and all you see is their roll cage when sitting all the way down (talking like maybe 2 inches before I sit all the way down). I drive standing pretty straight with the wheel fairly close too. Feels best for my 2 hours stints.

[billy bee]

It's such a boat as a race car compared to half of the field being Miatas and all you see is their roll cage when sitting all the way down (talking like maybe 2 inches before I sit all the way down). I drive standing pretty straight with the wheel fairly close too. Feels best for my 2 hours stints.

What series? Looks like Champ Car or Lucky Dog. We are doing our first Lucky Dog race next month at Buttonwillow.

--bb