No, aftermarket coils will have no affect on performance with a stock or bolt-on car. You may see some improvement with a highly modded car...I'm talking boost with cam and headers. But otherwise no. As long as these have been out there has never been an independent 3rd party tester to prove the gains on a stock or bolt-on car. Not knocking Granatelli, but this is a load of crap. The stock coils and plugs are absolutely fine even up to around 700 rwhp.
If anyone doubts what I'm saying, lets put it to a test. I will buy a set, take my car to a dyno, dyno it 3 times with the stock coils, then replace the stock coils with the Granatelli coils, and dyno it 3 times with the Granatellis. If the HP/TQ does not change by a realistic and significant amount, then you pay for the coils and the dyno time. If it does change, then I'll buy you a set. How about it?
Granatelli Sales, if I buy your coils and do not get any change in hp/tq, would you be willing to either take your coils and packs back, refund my money, and pay for my dyno time or let me keep the coils and and packs and give me my money back for them? If they do increase hp/tq, I'll record the entire process and post the video as an independent 3rd party tester on Camaro5, Youtube, and here. Serious offer here.
2017 Camaro ZL-1 A10
2013 Jeep Grand Cherokee Hemi 5.7 - Tuned!!
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