Yes it will... That's why you should only dump as much "ROCKET FUEL" into your tank as you're going to need for your event. Drain it out if you plan on letting your car sit for weeks on end... But if you are just going to do a weekend race / drag, you can always refill the tank with pump gas and dilute the mixture after the event and everything will be fine... This will only affect rubber / plastic parts if you let it sit for long periods of time...

I now always trailer my car to the track with a nearly empty tank, then fill it with enough fuel to make the amount of laps I'm going to do... then refill as needed. It saves me weight...