Jms Chip & Performance

"Saw the PedalMax on Youtube reviewed by Hammerdown Motorsports. Based on his experience I went over to JMS and immediately ordered it for my 2014 GMC Yukon Denali. It took me about 10 minutes to install, and it is a game-changer! The first time in kicked in, it released so much power it freaked me out! I've had it installed for about 2 weeks and I've done my fair share of smoking many an unsuspecting sports car from the light!"

"Purchased chip for stalling issues associated with a Coyote swap. Their website claims to "have the cure". Unfortunately it doesn't work and they're unable or not willing to fix it further. They reccomended me to spend more money and see a tuner locally. Would not do business with this company."

"DO NOT LET JMS TUNE YOUR S550. I had a 2017 Mustang GT with intake, Pypes LT’s, exhaust and an 18 manifold. IMRC’s were locked out. After following their instructions and data logging .... 1st tune had codes everywhere. They didn’t adjust for the control runners. 2nd tune had throttle issues. They didn’t even tune VCT. 3rd time still had issues and I was told that I shouldn’t be having them and wasn’t on “their end”. The shift firmness was all over the place. I tried to arrange to being the car to them since they’re not too far away and all I got from Charley was “how busy they were” and how they were “backed up for months”. They do sell their SCTx4’s with a free tune. And that’s exactly the caliber of work I got. The free kind. I only ever dealt with Charley. You could never tell what kind of mood he was going to be in. Also took forever to get through these tunes as they regularly left early or just weren’t in the office. Supposedly their tuner Monty is supposed to to have tons of experience and knowledge with Mustangs. This is not the case with an S550 running an 18 mani. I eventually went with AED and all my issues were sorted on the first tune after logging. Do yourself a favor and go with an AED or Lund tune."

"They tuned my fox body mustang after I did an H/C/I swap. I needed to have it done and didn't have time to make an appointment a week or two ahead of time, so after calling around they said to bring it tomorrow and they would take care of it. I drove well over an hour away to get my car tuned and they did a great job. They fixed my idling issues and the tuning they did definitely woke my car up. Great customer service!"

"It's been over a month now since ordering a Boostmax set up and still no sign of it being delivered. Upon making follow up calls, JMS doesn't even have the product and doesn't manufacture it. They're currently waiting for someone else to produce it but meanwhile are taking orders and peoples money for what they can't deliver. Poor service and business model. All they can say is they don't have the product yet and when they do it's still likely weeks away before shipping pending on where someone is on the list. Poor experience to date....."