These guys tuned my 2016 Sierra and after having it for about two days now, I absolutely love how it changed this truck. Better fuel economy, none of that sluggish GM shift points. 10/10 in my books and A+ customer service, I would trust these guys with any performance work that you need.... See MoreSee Less
GPI Is one of the BEST performance shops around. I have been using them for performance parts for my 5th Gen and 6th Gen Camaros for the past 4 years. I could not be more pleased and happy with their camshafts, tuning, 6L80 trans bench build, and overall build advice. If you are looking for proven performance, GPI is the right place for you. They do not just dyno their products, they actually track race them and get real data. Their customer service is top notch and they will bend over backwards to make sure their customers are happy. A++... See MoreSee Less
I've been accumulating GPI parts all winter, from the SS1 VVT cam kit, to the ported GPI intake rod mod. Dan, Ryan, Aaron - everyone I have dealt with has been A+. These guys have a great reputation for what they can do for your car, but its also nice to know theyre some of the best in the business to work with. Money well spent for both perfomance and support, so thanks for everything GPI.... See MoreSee Less
Great customer service. Been bothering Dan for 3 days asking many questions, some over and over again, and he answered all of them like an expert. Bought 3.91 gears from them yesterday and will be going back shortly for a cam. Appreciate it fellas!... See MoreSee Less
I recently took my '07 C6 Z06 to GPI to have quite a bit of mods performed. They did an incredible job! They were timely in getting me my car back as promised. They are very, very professional and they go out of their way to make you feel valued. I've been getting non-stop compliments on how good my car sounds now. I've had no trouble out of it thus far. I would HIGHLY recommend GPI to anyone! Great people!... See MoreSee Less
These guys are awesome!! Every paranoid question or doubt of information gathered from the keyboard mechanics, these guys set the facts straight. Never felt more confident in a purchase, customer service is tighter than the "Jesus bolt"... See MoreSee Less
Running a GPI SS4 cam in my personal car and I couldn't be happier! Performance is exceptional, and customer service is second to none. I recommend their products to all of my customers. Will happily continue doing business with GPI in the future! #TeamGPI... See MoreSee Less
Guys were great to deal with, and Mike even helped me load the Camaro for it's trip home today. Keep up the good work!... See MoreSee Less
Service, and tech support is 2nd to none!! Always a pleasure to do business with them, and they make everybody feel like your apart of team GPI... See MoreSee Less
Could not be happier with my car Gwatney built. Almost 1000 wheel horsepower and i could drive it anywhere. The work under the hood is flawless.... See MoreSee Less
I just ordered the ss3 vvt camkit, and I'm beyond excited to get it and install it. Literally a 5 star rating based on just responsiveness to emails and willing to answer any questions you may have. The answers are in detail as well, not just shortened responses. I've seen the way these 5th gens are running with this cam package and its far beyond the competition.... See MoreSee Less
5 stars does not begin to describe the level of Knowledge and Service you will receive from the guys at GPI. Trust me when I say, these guys know the LS Platform inside and out. I've had my car upgraded at other performance shops, but nothing has ever came close to the level of expertise, service, and performance they put together for me. My car was the test car for the Max Performance LS3 package and I could not be happier, this new package is what you should be looking for if you want your LS3 to go to places that other shops say are impossible on stock bottom end cars. From Aaron putting the package together with only the needed components, to Ryan and his tuning skills giving you everything your car can offer and still retain driveability to take it anywhere. My car will never go to anyone else. Thanks Again to Everyone @ GPI for all your hard work, never stop pushing the envelope.... See MoreSee Less
The GPI guys were well worth the 12 hour drive from Jupiter Florida to Jacksonville Arkansas!! Thank you for making my 2015 Camaro V6 twin turbo dyno at over 600 RWHP!! Aaron is a Great person to work with. Thank you everyone at GPI!!!... See MoreSee Less
Aaron, James and Ryan are class act guys who really know their stuff. Did a awesome job turning my 5th Gen into a beast! This is the only place you should take your Camaro.... See MoreSee Less
Dan - James - "Patient" online chats, phone calls, 2 of the best guys to work with, when your a novice such as myself you need extra hand holding
They were available to answer all questions - Totally recommend them... See MoreSee Less
They had the best customer service in any business I've ever dealt with . Thank you Dan .I have a 2011 camaro ss An can't wait to see what my power gains will be with there ss3 cam . Supporting modes are 1-7/8headers,3inch exhaust , an cold air intake... See MoreSee Less
Excellent experience at GPI. Made a 700 mile/11 hours trip down to make sure things were done right, and they were! Couldn't be happier with the entire process from communication with James, 1 day engine tear down AND rebuild with Nathan, and of course the VVT cam tuning with Ryan. Definitely can recommend these guys!... See MoreSee Less
Initial impression was great while dropping off my car for modifications. Can't wait to get back a monster. I have the utmost confidence they will meet expectations based on past customer recommendations.... See MoreSee Less
GPI is by far the best! Excellent customer service and willing to answer questions for whatever you need. Definitely will be buying more from them. Love my SS3 VVT cam in my 2012 Camaro SS!!... See MoreSee Less
The whole crew at GPI are class acts. From Ryan on the dyno, Aaron pointing the customers to the best $$$ spent to James making sure you leave satisfied. The dyno tuned a twin turbo 2015 Camaro for me and install some other items for safe horsepower...... See MoreSee Less
these guys make power for the SS Camaro! Minimal mods and I am over 470 rwhp and rwtq!... See MoreSee Less
Great customer service. Very knowledgeable great parts. Thanks Aaron!... See MoreSee Less
Hands down best customer service and expertise on GM vehicles. LT headers, y-pipe, and tune on my '17 Silverado. Couldn't be happier! Will definitely be back for cam upgrade and more goodies 😉 Thanks guys, keep up the awesome work!... See MoreSee Less
Great product and even better service!!! Loving my new blower cam.... See MoreSee Less
Being that my 15 ss is the first car I'm building I received nothing but the best customer service I've ever experienced from anywhere. They broke everything down for me as what to expect the positives and negatives of each part and what all I would need to do based on how aggressive of a build I want to do. I live up in md so they won't be installing the parts but I ordered the ss3 vvt cam package with the afm delete kit and a few other optional pieces. Complimented by a circle d 4000 triple disc stall. I will order the 3.91 gear set soon as well and she will be track ready. Videos and times and numbers will be shared with them. Can't wait.... See MoreSee Less
I recently had the GPI SS3 VVT camshaft and a new torque converter installed in my 2012 Camaro SS. Now when I hit the gas pedal my car explodes down the street and the cam sounds absolutely incredible! Ryan took a lot of time to answer a ton of my questions. His exceptional advice and expertise guided me on what parts to buy to reach the specific goals I was seeking for my car. I cannot thank Ryan enough for his help and sharing his knowledge with me. If you are in the market for a camshaft, look no further than GPI and their awesome staff for expert support!... See MoreSee Less
Just a great group of guys to deal with. Friendly, professional, and very knowledgeable. Aaron answered my numerous emails and provided a wealth of information.... See MoreSee Less
Ordered the SS3 cam kit for my Camaro and it came in and was beautiful. Can't wait to have it put in and tuned. Only thing I noticed was there was no cam card for it so I don't know the exact specs of the cam. Will be doing the rod mod and heads soon.... See MoreSee Less
Aaron was fast in replying to my emails and gave me quick info, James got me in very quickly and showed great customer service, the crew did great when installing my headers, and Ryan tuned my 2012 SS and it performs better than I ever could have thought! Awesome place with an awesome crew. I will be going back for future modifications.... See MoreSee Less
After having just moved in the area, I asked friends in my Corvette Club where to take my car to get the most out it by just tuning. They recommended GPI. I took my c6 in to get tuned.
I called James on the phone and he said that we will take care of it. Well, low and behold they did! Ryan, James and Arron did what they said they would do! It shifts firm but not hard and way more power than any other tuners got out of it! Drive ability is fantastic! I really can't say enough about this performance shop!
Oh,by the way, the car is powered by a Chevrolet crate motor. I blew the LS2 up at 80000 miles. It has a beefed 6L80E trans. The motor is a stock LSX454.... See MoreSee Less
Excellent service, bought my 2010 Cobalt from here, always bring it to them for services.... See MoreSee Less
great service and support! did everything right and on time!... See MoreSee Less
Love my car and how it performs after the tune....snatches second and third like a champ! Huge thanks to James for always hooking me up and taking care of my babe!!!... See MoreSee Less
Amazing customer service! Very highly recommend for all your LS needs... See MoreSee Less
I have an ongoing oil leak problem on my car, they fixed the leak twice so far, but they are trying to get to the root cause of the problem, my hometown dealer who I purchased six vehicles from told me he didnt want to work on my car. Why?? Because they never fixed my oil leak. Aaron, Ryan, Mike, James, and Josh are great guys, they got me fixed, and are willing to do what it takes to make it right, I've been seeing Ryan on forums as a tuner/ engine builder since 2003 or 2004, he's been very helpful and knowledgeable.... See MoreSee Less
This is the shop to take your car too!!
The guys are friendly and know their cars!
They turned my 13's sec. into a 10 sec car.
GREAT JOB!!! GPI... See MoreSee Less
Awesome place ! Ryan Stephens is an expert in his field !
He did wonders to a friends car.... See MoreSee Less
Great bunch of guys with tons of knowledge. Willing to go above and beyond to make the customer happy.... See MoreSee Less
GPI has an awesome team, great place to take your hot rod. I have lost count how many 5hr trips I've made from Dallas just for these guys to work on my 5th gen.... See MoreSee Less
Great guys, great service, great performance! Do not hesitate to call them with any of your performance ideas/goals. They can get it done! 5/5!... See MoreSee Less
Second to none knowledge and just friendly service! Ryan did the tuning on my car and I'll never look to anyone else again.... See MoreSee Less
Don't expect new valve stems with a new tire purchase, and be ready to wait 4 hours to get 4 tires installed. Oil change is a hour to hour and a half wait. Otherwise good mechanics on hand to fix what fails hopefully the first time and not repeatedly. Good people work here is why I keep coming back.... See MoreSee Less