Installed granatelli coil packs 28-1812CP
Just installed a set of granatelli coil packs on my truck. My setup has a whipple supercharger/39lb cobra injectors/jba headers/magnaflow exhaust/SCT custom tuning. Initially, I was disappointed with the dyno numbers after the install. Granatelli advertizes about 10-15horsepower increase on N/A vehicles and up to around 20hp on Supercharged vehicles. I only got about 7-8rwhp increase with about 8rwtq increase. When I saw those numbers my heart kinda sank a bit. BUT...when I looked closer I reached those numbers about 600-700rpms sooner across the band. That kinda made me feel better. When I took the truck out for a spin I had a grin on my face (not a full on smile...but a grin). I definitely felt a better throttle response. So, my conclusion to this product would be get it (IF you can find a good price). I would not pay for list on this product to get that kind of result. I believe it lists for about $499-599. I got mine at lethalperformance.com for $379 shipped (this is with 5% off for holiday sale that they are having). Probably the limit I would pay for what I got out of it. I'm hoping it will payoff when I upgrade my supercharger to 10 lbs of boost from 8 lbs. Hope this helps anybody who's considering this product. Also, I did find a post out there that someone had problems with these coils at about 5000 miles. I'll see what happens with mine. I saw this post after I already had it installed. Wish me luck.