Just like the topic said. I have a comptech supercharger with A/C and the stock pulley. If I want to go with a 7lbs pulley do I have to upgrade anything else, like the AEM EMS unit and the bigger injector? Or can I get away with it with the stock parts from comptech. And what about tuning the car? thanks for all of your input.

 

Won't need EMS or injectors. Will need to get AFR checked and do tuning on a dyno. Most likely will need to richen things up a bit, but go by the numbers and use a pro.

 

You prob want a wideband to make sure if your AFR is in check.

Thanks,
Tom
Gruppes
510-783-5300

 

Just check your air/fuel to be safe. It would not hurt to get a V-AFC or the AEM EMS but the AEM is quit costly if you don't plan on going higher boost later. The more you can fine tune your car the better but it might not need to be done at 7lbs.

 

Thanks for all of the responses guys!! got one more question though, if I do go with the 7lbs pulley and everything else is stock, how much more horse power gain can I expect as compare to the stock 5lbs pulley from comptech.

 

another 10-15 horses....maybe a little more with tuning.

 

^ sounds about right. If you tune it with a V-AFC and add exhaust and header then you should get even more gains by maximising air flow combined with tuning.

 

Stock is 6psi. Let us know what your gains are.. ie before and after if possible.

 

My stock boost with comptech is 5lbs (I have a boost gauge). Is that because I have an aftercooler? I read somewhere on this forum that with the A/C, you can expect to loose ~1 or so boost. Is that right?

 

You do lose .5 to 1 lb of boost with the AC but you gain more in cooler temps. Less boost cooler temps means safer setup.