hey everyone
im new here, jsut joined the forum.

im selling my truck trhis summer for a G8 and have some questions.

one, im going to turbo the G8 or supercharge it, but which is better on gas mileage, im guessing turbo?

Ill be in the city alot and need to maintain the best gas mileage i can, but the extra power is for the track.

secondly, since the G8 has a Fuel Managment System making is a 4 cyclinder basically when not WOT, how will turbos and superchargers work with it? I know theres already turbo and twin turbo system out for it since its a Commodore and a Vauxhall. But will they kick in even when not at WOT, and it acting like a turbo or sueprcharged 4 cylinder? or what?

I think the AFM would have little effect on operation of a turbo. It still takes as much air and fuel to maintain speed, regardless of cylinders.

DOD/AFM only kicks in during low load, cruise conditions such as on highway at 100 kmh - any sort of a hill or speed over ~130 kmh and you are kicked back into the v8 mode.

Typically you need to exceed a certain speed for DOD/AFM to activate. This means that you will be in V8 mode at anything under 60 - 80kph - at least that has been my experience over the last 2.5 years.

It's been 20 years since I had a turbo car, but i recall that a turbo provides boost at less than WOT.

The engine will be under load at any time that boost happens, so I doubt you will ever see boost when in V4 mode.

thanks guys

i know i wont see boost in V4 mode and i dont care, i was just wondering, how does the turbo/sueprhcrager know whent o kcik in when engine is switching between V8 and V4, and say im on highway

it is in V4 mode, and i gun it, you know?

It'll kick in when the exhaust increases in velocity. It'll start building pressure the moment you mash it.

awesome....so which do yall say would be better to have for me being in city most the time?? and im not sure if a sinlge turbo or sueprhcarger will be producing more power, im sure a superhcarger will. but are there any out for the L76?

awesome....so which do yall say would be better to have for me being in city most the time?? and im not sure if a sinlge turbo or sueprhcarger will be producing more power, im sure a superhcarger will. but are there any out for the L76?

The G8 GT will be the first car in the states with the car version of the L76, so no one has had a chance to develop either kit for it. I think the Aussie L98 kits will get adapted to the L76 pretty quickly once the G8s start selling, so you might want to start looking at the Aussie Commodore boards.

I think that twin turbos with an intercooler will be your best bet for power and fuel economy. Some people claim slightly improved mileage vs. stock…

im pretty certain ill get a turbo. though i do love the whine of a supercharger....thena gian turbos have a nice spool up sound...plus a blow off valve.

The G8 GT will be the first car in the states with the car version of the L76, so no one has had a chance to develop either kit for it. I think the Aussie L98 kits will get adapted to the L76 pretty quickly once the G8s start selling, so you might want to start looking at the Aussie Commodore boards.

I think that twin turbos with an intercooler will be your best bet for power and fuel economy. Some people claim slightly improved mileage vs. stock…

I think LS1Turbo and APS both offer a twin turbo kit for the G8 GT - these are essentially the systems that have already been developed for the Commodore.

Just make sure you don't forget the Inter cooler. ;)

Of course with a turbo or supercharger you will need to get a good tune. I have had both supercharged and turbo cars and I think the turbo wins on the performance level and the supercharger wins on the cosmetic level.

Of course with a turbo or supercharger you will need to get a good tune. I have had both supercharged and turbo cars and I think the turbo wins on the performance level and the supercharger wins on the cosmetic level.
Although turbos might have higher peak hp and therefore be better for tracks, they won't (at least initially) throw the passengers into their seats and make the no-low-end-torque ricer crap his pants when you launch off the line. Am I right? I'm all for shock and awe... and not so much about numbers and actual/legal races. :burnout:

Although turbos might have higher peak hp and therefore be better for tracks, they won't (at least initially) throw the passengers into their seats and make the no-low-end-torque ricer crap his pants when you launch off the line. Am I right? I'm all for shock and awe... and not so much about numbers and actual/legal races. :burnout:

Since the motor hits peak torque in the 5,200 RPM range, I would think that if you installed a 60mm turbo you would hit peak torque in the 3,900 RPM. Anyone else have any ideas?

Since the motor hits peak torque in the 5,200 RPM range, I would think that if you installed a 60mm turbo you would hit peak torque in the 3,900 RPM. Anyone else have any ideas?

meaning what exactly?? sorry i come from a turck world...i know cars....and some about aftermarket engine but not a whole lot.

but im guessing you mean at WOT off the line from a stop light ill be able to put people in their seat and beat all the other guys on the road.

meaning what exactly?? sorry i come from a turck world...i know cars....and some about aftermarket engine but not a whole lot.

but im guessing you mean at WOT off the line from a stop light ill be able to put people in their seat and beat all the other guys on the road.

A supercharger works better in the lower RPM's as far as throw you in your seat (torque), but it is usually short lived once the mechanical strain takes place on the motor spinning the blower. A turbo will also throw you back in the seat, but not until it spools up around 3,500 RPM's and from there it will out perform a supercharger. The supercharger/turbo debate will never die, but if you want something to pin you to the seat from a stop light, go the blower route.

If you have a supercharged L76 and a turbocharged L76 (both with around the same max PSI), which is likely to last longer? I know the supercharger will put more direct mechanical strain on the engine but the turbo will suffocate the exhalation and get real hot, so I'm not sure which is more reliable in the long haul.

im going to go turbo route...

just need to get the car first.

then comes rims, then comes stereo then turbo.

If you have a supercharged L76 and a turbocharged L76 (both with around the same max PSI), which is likely to last longer? I know the supercharger will put more direct mechanical strain on the engine but the turbo will suffocate the exhalation and get real hot, so I'm not sure which is more reliable in the long haul.

As I said in the other thread. The most reliable is waiting too see what a GXP comes with, and get that extra HP with a warranty. Most secure.

good idea i didnt even think of that.....but i wonder how long it will take for the GXP to come out...