legacycentral bbs

I was thinking of swapping a lightweight pulley set from my 98 into my new 91 turbo sedan.

Would this be a bad move for a turbo car. Right now the SS likes to buck when coasting in gear...if I remember correctly the pulleys helped this bucking crap on my 98.....please give my your opinions and experiences

I have switched from the under-driven lt. wt. crank pulley
to the Cobb lt. wt. crank pulley and found that the lights
don't dim and the a/c blows colder than before. In addition,
I've gota lt. wt. Exedy flywheel too. No adverse affects and
many miles with this combination on my Leggy with over
250,000 miles!

It's said that it's best to either run a light weight pulley OR a LW flywheel but not both together. I had an ACT StreetLite FW and a Go Fast Bits UD LW pulley on my '92 for a bit. I took the pulley off and went back to OEM and it seemed to make the car run better.

I never ran just the pulley but I sold it to a local guy that put it on his late 90's N/A Legacy wagon and he loved it.

The only negative effects will be less charging at lower engine speeds and the AC won't cool as well as the compressor is turning slower.

If you have a marginal charging system to start with then it will be even worse with the switch.

I have the Unorthodox Racing on mine with no ill affects. I have noticed that the AC doesn't workquite as well, but I rarely us it and I haven't noticed any charging problems.

Jeff

just get a perrin lt. wt. crank pulley.
i noticed a difference with it when i put it on my car. way better throttle response.
and it's not underdriven so all my accessories still work great.

underdriven pullies don't add THAT much extra power. so just go with a light weight one that's not underdriven and keep all your accessories running at full speed.

If you want more HP you need to go with an underdriven pulley. Throttle response will be better with both types, but you will get more horsepower with the underdriven pulley as it takes horsepower that was used to drive the accessories and puts it to use moving the car down the road.

Jeff

ah i see what you're saying.
either way...a light weight crank pulley is said to be equivelant to removing ~100lbs. from your car.

so yeah. go light weight. and underdriven if you want more HP i guess lol.

I think it would be better to have just a LW crank pulley. This means that the crank is easier for the engine to turn. An underdriven one makes the alternator, power steering, and A/C turn slower - which isn't good for their operation.

Actually it is better for the accessories as it turns them slower which wears them out less. An engine or accessory will wear out quicker the faster the rpm it runs. Thats why race engines have to be rebuilt much more often than a street car engine. Much more time spent at high rpms. An underdriven pulley works those accessories less because they are turning a slower rpm. Thats what makes the horsepower.

I would really like to see a dyno comparison backing up those claims of more horsepower from a lighter pulley. All I can see them doing is allowing the engine to rev quicker because it is accelerating less mass. I can see a slight gain might be possible, but I think it would be negligeble.

Jeff

i dunno. i think it would cause more wear and tear on your car too.


because that means that your powersteering and alternator aren't being charged as well. which means less power for steering and just less power lol. but i'm not an expert. just what i think would happen...

I know that a loss of 3 lb of rotating mass equates to an increase of 1 hp.