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Under Drive Alternatir Pully On A Street Car: Bad Idea, Right?
Am I right in thinking it wouldn’t be advisable to put an under drive alternator pulley on a street car? Not enough juice for daily driver accessories like lights, AC, stereo, etc, and general difficulty charging the battery?
Do the underdrive pulleys really help that much? To me, it seemed like something I would get if I had already checked off literally everything else I could possibly do for more performance. On a street car, I would delete the balance shafts before I went to an underdrive pulley.
should be OK, but even better if you do the Nissan Quest alternator upgrade for more juice, period.
do know that pulleys do NOT make power...spinning up incrementally faster *might* show on some dynos but it's not "actual" power.
They don’t make power, but they do reduce the parasitic drain on the drive train. I’m ditching my PS rack and thought I might go for a smaller alternator pully to compliment it. The pully itself isn’t all that expensive - $200 or so. Between the manual rack and an under Drive alternator pully, it should be good for a few extra RW hp, and for an NA car (I have an S2), every bit counts - but not at the cost of an undercharging alternator.
Yeah, the LR pully was what I was looking at. You’re running both the LR pully and the OAP? How do you like the OAP? Do you run the AC a lot? Have an updated stereo (nothing crazy, just improved over stock?)
... Between the manual rack and an under Drive alternator pully, it should be good for a few extra RW hp...
If its hp you are after you could spend the money much better than a rack and a pulley, which will cost you north of $500 and probably a lot more when you are done. You are basically degrading the steering and charging and imo you need the best of both of those systems on a street car. Manual steering is really tough when trying to maneuver a car at slow speeds like when trying to parallel park and you will not notice the benefits of a manual rack unless you are on a racetrack. As for charging, why risk the chance that you will be left stranded from a flat battery or god forbid lose your lights at night and all for a couple of measly hp.
If its hp you are after you could spend the money much better than a rack and a pulley, which will cost you north of $500 and probably a lot more when you are done. You are basically degrading the steering and charging and imo you need the best of both of those systems on a street car. Manual steering is really tough when trying to maneuver a car at slow speeds like when trying to parallel park and you will not notice the benefits of a manual rack unless you are on a racetrack. As for charging, why risk the chance that you will be left stranded from a flat battery or god forbid lose your lights at night and all for a couple of measly hp.
i don’t own a car with ps - all my cars are manual, so I’m very use to it. Also, I like the feel of manual racks and their relative mechanical simplicity vis-a-vis PS. But your second point is the one I’m debating - I won’t sacrifice charging capacity, but a poster a few replies up says he hasn’t had any issues. I’ll give Lindsey a call and see what they’ve got to say about it.
i don’t own a car with ps - all my cars are manual, so I’m very use to it. Also, I like the feel of manual racks and their relative mechanical simplicity vis-a-vis PS. But your second point is the one I’m debating - I won’t sacrifice charging capacity, but a poster a few replies up says he hasn’t had any issues. I’ll give Lindsey a call and see what they’ve got to say about it.
Gotcha, did not know you had experience with a manual rack and I’d hate to not give you all the facts about living with one. Btw I have underdrive pulleys on my track car but it idles at 1100rpm and doesn’t have ac or headlights, I’ve never had issues. My concern on a street car would be how an underddive would perform: (1) while sitting idling at traffic lights with the ac and headlights on at night, and (2) after two or three short journeys at night while parked up in between.
Gotcha, did not know you had experience with a manual rack and I’d hate to not give you all the facts about living with one. Btw I have underdrive pulleys on my track car but it idles at 1100rpm and doesn’t have ac or headlights, I’ve never had issues. My concern on a street car would be how an underddive would perform: (1) while sitting idling at traffic lights with the ac and headlights on at night, and (2) after two or three short journeys at night while parked up in between.
I appreciate the warning, and you’re absolutely right about the potential charging issue. I’m mucking around that part of the engine at the moment, and I thought, “why not?,” then thought, “because...,” and finally decided to ask what other people’s opinions on it were. I’m definitely leaning towards not unless a few more people with first-hand experience chime in with positive, trouble-free experiences.
FWIW, pulleys don't affect parasitic loss either.
you don't get more HP with a lighter clutch setup or wheels...it's just a little bit less rotating mass that has to be accelerated with everything else.
PS itself does eat power, but only a little bit if you're going in a straight line (pumping loss and belt friction)...it only gets hungry when you are holding the steering wheel at a sharp angle and the pressure has to go up a lot.
damn, $200, i gave one of the blue alternator underdrive pulleys away at like $50 last year.
let me be clear, i'm not trying to steer you away from using the pulley, it does work in a certain way. just want to temper expectations.
...
Yeah, the LR pully was what I was looking at. You’re running both the LR pully and the OAP? How do you like the OAP? Do you run the AC a lot? Have an updated stereo (nothing crazy, just improved over stock?)
Basically in the 80s and 90s Porsche always did a bit of overengineering. As montioned I run the LR pulleys on my 944 and 968. My 944 is an early one without PS and AC. So there is just the alternator pulley and the OAP installed. The 944 /I alternator is the smaller one, with just 90A. But with the LR pulley it still works sufficiently. I must say I don't drive both of my 9xx in the winter. My 968 is a convertible. I drive both more or less only on sunny days. I don't run the AC on my 968 convertible a lot. So there is no rear window defogger and much current for heating and ventilation needed. The 968 alternator with 115A is of course better prepared for all eventualities.
As for the power steering pulley, I only installed the one on the engine side.
As for the OAP, I simply like the idea that you don't have to accelerate the alternator again after every upshift. The same is, when you downshift, the alternator runs free, which I think is always nice.
Thank you for the link on the Quest alternator !
I picked one up two years ago at a salvage yard and was wondering about the wiring and electrical part ... will be going
on my race car this season.
01-12-2019, 05:02 PM
Under Drive Alternatir Pully On A Street Car: Bad Idea, Right?
