It’s time to hand out some info and updates on Alternative Auto’s Bright Red G8. In a nut shell the best we achieved with our very mildly equipped G8 for the 2009 season was 12.95’s at 107ish mph. This was “without” the NOS system that was also added during the 2009 season. Only add-on and tweaks are; a VaraRam cold-air kit, SLP under drive crank pulley, our own in-house G8 custom tune, and with a very unique custom exhaust system consisting of a “double-X” pipe with four resonators, and two FlowMaster delta-50 mufflers, also known as 3-chamber mufflers. When the 125hp NOS kit was enabled – our 4100lbs G8 (with driver) and 6-speed auto went 11.90’s at over 116mph.
Now a bit of reasoning for our unique G8 exhaust system; Because the G8s 8 cylinder engine, and its engine management system has a feature known as “Displacement On Demand” (DOD), which essentially and in short, switches from V-8 mode to 4cyl mode depending on driver demand. This feature is for better fuel economy. As a result though, cars that are equipped with a DOD feature have to also be equipped with very quite exhaust systems as well. The reason for this is if they have loud or even moderately loud exhaust systems – when they are operating in DOD mode, it becomes very apparent that they are in DOD mode with louder exhaust, and basically they sound like a 4cylinder out the back. And as most true performance car enthusiast would agree “4 cylinders are to be seen and not heard”. And also because of my own personal taste and opining, we don’t always just purchase readily available exhaust kits that can typically end up sounding to loud and frappy under load, and/or high RPM. Our own designed and unique Double-X system with FlowMasters for the G8 has a clean deep tone with no frap what so ever… Either way we do have the ability to turn off DOD with our custom tuning for LSx engines. And we do disable it on most of the custom tunes we do for GM cars. We’ve found that depending on driving style that DOD mode doesn’t offer much better economy any way, and it’s hardly missed when disabled on an enthusiast car.
Another feature that worked out very nicely on our G8 is that we had the factory rear rims widened and made exactly 10” wide. Stock is 19 X 8”. This allowed a BFG 295/35/19 tire to neatly fill out the rear wheel wells. It looks great from all angles. The new larger back tire is only about 3/8” taller then the fronts, and about 2” wider than the front tires. This made for much better traction. Also cosmetically we’ve completely Dechromed the G8 on the outside, and also removed a few chrome badges too.
The 125hp NOS kit on this G8 is a little more elaborate than your typical “slap it on and go” type kit and install. We thought it through a bit more, and the goal was an extremely reliable NOS system that was not to aggressive, as some usually do especially in the LSx department, and we wanted to be able to just “punch it” and have the NOS system come-on gradually so that at the track and mostly on the street the rear tires did just go up in smoke once the NOS kicked in while in 1st gear. But we did want some of the benefit of the NOS as early as possible and not wait unit 2nd gear like most people often do to trigger the NOS. So our NOS kit is equipped with a wide open throttle enable switch, an RPM enable switch, and also a progressive controller. Basically this system won’t come on real hard all at once from a dead dig. It’ll come on only at WOT at about 2800rpm. And once it does come on at about 2800rpm, the progressive controller pulses the NOS solenoids for about the first two seconds to only give about ½ of its added horsepower, then ramps the rest of the 125hp shot. This allowed our G8 to have very usable extra power from a near standing start and made for a lot of fun on the street and the ¼ mile. Our G8’s NOS kit safely knocked one second off the ¼ mile ET and added nearly 10mph in the ¼. Equaling 11.90’s in the ¼ mile.
Also our G8’s NOS kit is equipped with an MSD “Timing Twister” device. This unit is an ignition retard box that ties into the crank trigger system and basically retards the ignition timing only when the NOS system is being triggered. This feature allows for us to continue to use our everyday more aggressive G8 tune full time, and then only when the NOS is being used a few degrees of timing is retarded for greater engine safety. So the day to day tune isn’t compromised when not using the NOS.
Click Images To Enlarge
Alternative Auto Performance
51945 Gratiot Ave, Chesterfield Twp., Michigan 48051
Phone: 586.949.7505 - Fax: 586.949.7501
Need a Map or Driving Directions to the Shop? Click Here
