which alternator should I buy?

[Chabs]

Mine is weak so I found a guy with 2 alternators, one is 80 amp and one is 90amp, he wants $35 for the 80amp and $55 for the 90amp. Which one should I get for my 318i turbo? Is it necessary to have better ignition or is 80amp sufficient?

Thanks

[Adrian_Visser]

You got a big sound system? If not the 80amp is fine. Doesn't hurt to have the extra capacity though.

[REVHARD05]

would the 90 amp be more efficient than the other? ie pull less torque at speed?

[Naplm00]

the 80 amp is fine

[dlmpsy]

You may be able to get your old one "rebuilt" for about the same price.

[Chabs]

I have coils from a 350 chev.... and its boosting 12psi... that change anything?