Attention Installers.
The Guides provided here are written with the assumption you are a professional, have a very firm grasp on your cars fueling, wiring systems, and have the proper tools, and expertise in installing these types of products. If you are a DIY’r, please note, SMG will not provide installation support, you will need to consult a professional if you are not 100% confident in what you are about to install.
By no means should these guides be considered a comprehensive step by step how-to.
Due to continuous product improvement, These guides may not reflect the current version of the kit you are installing.
AUX and Flex Fuel Kits REQUIRE Tuning to work. Neither can be simply plugged in and used without tuning. Flex Tables need to be activated for the Flex Kits, and FSCM adjustments need to be made for the additional fuel flow. SMG does not provide ANY Tuning advice. Consult your Tuning professional.
Flex kit notes:
- Note all current flex kits use a new plug and play coil jumper harness and no longer tap the fuse box nor have a dedicated ground wire.
- Simply connect our sensor at the fuel rail, then connect the jumper harness at the nearest ignition coil. Lastly, route the white signal wire to the PCM.
- A handy weather proof disconnect inline of the white signal wire will allow easier routing and connection at the PCM.
- If you need PCM pin out information, refer to the universal PCM Guide below (not all makes models are covered, consult your tuner if you are unsure)
Aux Kit Notes:
- All current AUX Fuel kits feature new Weather Proof Connections for Hobbs, Relay and Primary Fuse, utilize a static Hobbs, meaning it is pre-set to a trigger pressure and does not require adjustment.
- A length of vacuum rated line, and T-fitting are provided to tap boost reference for the Hobbs. (where you tap this is up to you and your build).
- If you use this kit in a non-boosted application, you will need to replace the Hobbs with a window or RPM switch. We do not provide support for this and you will be entirely on your own.
- Aux Kits wiring is simple, Under hood, the main connections are a Large Red Ring Terminal to Battery +, Large Black Ring Terminal to Ground, Fuse Tap to a “switched” circuit (if you are unsure how to determine which is a switched circuit, then you should probably consult a professional for this installation). Then the long power lead is routed to your Aux pump under the car. Connections at the pump are + and – Positive lead from under hood and the short black Ground wire connects from pump to frame mounting point. (Note, if installing a aux kit on a corvette, the long lead from under hood will contain both + and – leads).
- Fuel connections will require tapping your fuel tank and a NPT 90* fitting is provided for this purpose. You will need to drill and tap a hole at a suitable location rear most of the tank to ensure fuel is available under extreme acceleration, (Drills and tap kit is available on our aux fuel page).
- Fuel lines are pre-terminated and allow a small amount of flexibility in mounting location to best fit your specific needs.
- Our kits also tap into the factory fuel feed and a supplied fuel “T” and will allow you to do so without cutting. Simply insert T at factory fuel line quick disconnect near fuel tank. Then attach the 6an Fuel line to the T.
- Our guides are provided only as a reference for the professional installer and not to be used as a comprehensive “how to”. If you are not entirely sure how to install this kit and need step-by-step instructions, please refer to a professional installer.


We are working towards simplifying these guides and hope to have most of them replaced this year (Fall 2022). If you do not see a guide for your application below, that means we likely don’t have one made for your vehicle and you will need to refer to the universal guide or your local tuner for pin out help.
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SMG CAM6 FLEX FUEL INSTALL GUIDE
Download
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SMG CAM6 ZL1 FLEX INSTALL GUIDE
Download
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SMG CHEVY SS FLEX FUEL INSTALL GUIDE
Download
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SMG CTSV-2 FLEX FUEL KIT GUIDE
Download
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Skid Mark Garage Flex Fuel Kit G8 (pdf)
Download
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SMG Universal PCM Guide
Download
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SMG CAM5 SEAT DELETE GUIDE
Download
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SMG 2016+ REAR REFLECTOR GUIDE
Download
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SMG CAM5/6 AUX FUEL INSTALL GUIDE
Download
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SMG CAM5 FLEX FUEL INSTALL GUIDE
Download
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SMG CAM6 SEAT DELETE GUIDE
Download
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SMG C6 FLEX FUEL INSTALL GUIDE
Download
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SMG C7 FLEX FUEL INSTALL GUIDE
Download
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SMG CTSV-2 AUX INSTALL GUIDE
Download
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SMG 14+ FULL SIZE TRUCK/SUV AUX FUEL INSTALL GUIDE
Download