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View Full Version : Tech Questions: Will BBK Underdrive Pulley's screw up my car


TA_Spanker
09-25-2004, 01:55 PM
****I just purchased BBK underdrive pulley's from JEGS for about $130, but I'm having buyers remorse. They said in the catalog that these are engineered to "not hurt charging or cooling performance." I haven't installed them yet, but definitely wouldn't mind an extra 10 ponies if they actually work.

****Also, does anybody know if buying a Harmonic Fluid Dampr is worth it? It makes sense in my head that it will balance the crank and provide something better than that huge rusted piece of steel that comes stock on my '99 Cobra, but I don't know if I want to shell out $350 for something if you guys don't think it's worth it. ???

****Last but not least, should I buy a computer chip now (which brand is best) without a supercharger, or wait until I get one later on when I buy a supercharger, or not get one and re-program my pc(is this going to make my car drive like $%#$ though and start running rich?), or just leave everything alone and just trust that SVT did a good enough job.

Sorry for all the tech questions, but I'm a new member...My car actually was a member of this club a couple years back, but in the 2 years I've owned it, I just never got around to joining a car-club until now. My best friend just did extensive internal engine work on his TransAm, and passed me in HP, so I'm looking for all the little items I can get (can't afford $5000 for after-cooled Vortech just yet).

Thanks guys. :thumbsup:

ausie
09-26-2004, 10:55 AM
Pullies are Pullies, they only change the final drive ratio on some components. Increasing the pully size may slow the water pump down but not by much. Increasing the leverage (larger pully) will reduce the amount HP to turn it since you affectively changed the torque required to turn it.

As for the rusty crank pully, (hey I have one of those too) you could gain a little more if the harmonic ballancer is slightly smaller than the stock part. Harmonic ballancers are best suited for generic type crank shafts which are not tuned or fully ballanced as is the case the the Cobra crank shaft. I do not think you would cause any harm if it was added. I cannot say it is worth it or not.

As for the chip, if you are planning on adding a supercharger, you may as well wait to change it. Some supercharger set ups may have a custom programmed chip as part of the package. Most chips will lean out the AF mixture and there are some power giains by doing that, the down fall is too lean a mixture followed by detonation. If you have not experienced the ping be happy. The pong is much worse, and my 01 has done both without any modifications (except for the CAI which was the cause of it).

tcrews
09-26-2004, 11:55 AM
I'm not sure which type the BBK pulleys are but you should be fine as long as they are not the "piggy back" style but replace the crank pulley as well. The crank is internally balanced so that "rusty" piece isn't affecting anything :)

Chips....not really worth it until you have a significant amount of mods and want them all to tie in as best as possible. The factory computer is tuned fairly well. I'd wait on the chip.

Lumpydogs
09-26-2004, 07:36 PM
I installed the Steeda pullies and all cooling systems are fine.
I wouldn't waste money on the chip just yet. I fully agree with the above
two posts. :)

TA_Spanker
09-27-2004, 09:02 AM
I can't even begin to thank you for the great advice.

I'm so glad I joined a car club finally.

Thanks Again :D

dewone
09-28-2004, 08:01 AM
Glad to see you installed your pullies. When you did so and matched the water pump, and alternator pullies to the orignal. You should note they were larger to comensate for the lower spin ratio from the smaller crank pulley.:thumbsup:
I also agree about glad to have joined the club everyone is very helpful, as well as knowledgible