I was wanting to change the pulley out in my truck and looking at jlp to get one. What is the advantage of changing out the upper or lower pulley and how much can a 99 lightning handle for boost. Does a chip have to be installed to for this mod and what is the factory boost for a 99 lightning?

 

You can put a 6lb on it, but I recommend 4lbs for best streetability. You'll need the chip custom programmed for the pulley. Get a lower pulley. An upper pulley needs a press to install and if you're not careful you can damage the supercharger. The time you save installing the lower pulley is worth the added expense.

 

Thanks for the advice.

 

When I was on my first motor I had the 4lb. lower pulley with a burned chip. Well when i went full throttle one night it over reved and blew 4 rods out the side of my block. When I took my truck up to get fixed they said they wouldnt warranty it because the seal on my computer cover had been broken. There was nothing on my truck. I took off the lower pulley, S.B. Throttle body, chip, airaid intake, and 95mm mas air. If you do put a chip be sure they tune it right because when i pulled the chip it had the stock boost code on it. Im going to use the predator programmer and not worry about the chip

 

Sounds like the tune provided was too lean.

 

The stock 99 puts 8lb's of boost to the ground just like the rest of the L's. If you add a pulley I suggest a 4lb, gives u the best performance for an everyday driver and will give you more power when u kick the trucks ***. I suggest NOT changing or flashing the ECU. The best and easiest way to take care of it, is to use the Predator or Superchips ECU tuners. The greatest part about them is it plugs right into your truck under the dash, you change a few things. If you then need to take the truck in for service work then all you have to do is hook up the tuner again and hit a button to set back to factory defaults and they never know you changed a thing.

 

Thanks a lot guys!!!!!!!!!

 

Way too lean. I agree with L1ghtn1ng SVT go with the predator, dont put a chip in, thats just my opinion (someone who had some idiot tune his chip wrong and spent 8,000 on a new motor, harness, etc.)

 

do what i did , i got a 6lb and a chip, but the most important part is i spent some dyno time immediately after install,
I descovered I was running way too lean like 14 to 15 . which would have caused me to put a picture window in my block most likely. So I sent my chip back to jlp with my dyno sheet showing the a/f ratio . they adjusted the chip and sent it back and now it is perfect. (i know because I dynoed and a/f tested when i put it back on.

hope this helps . p.s. i think the 4 lb is the way to go , i might go back to a 4 lb now.

 

question to the webmaster? when you say 4 lb for best streetability what do you mean by streetability.
I know this question sounds funny, but what i mean is do you believe it has too much power or that it puts too much stress on the engine, or that it helps a unuseable part of the powerband (on the street)

thanks,