Offroad-Express

hi iv just brought another truck its a bighorn repowered with a supercharged commadore V6 , it runs 36" swampers. im unsure of diff ratios but what im wanting to no is, does it seem normal to be only getting just over 200km to a full tank of gas.think its a 60L tank and that was travelling at 100km.the motor was sitting at about 2000revs would it be worth getting someone to look over it.any help would be great.thanks Rich

There is only one way to turn tyres that size at the speed limit, and it involves lots of fuel. If you have a vacum gauge in there, and a 5 speed box, you will notice that the vacum at 100kph in 4th is not as high as 100kph in 5th, irrespective of the revs.

If you want economy, put on smaller tyres. My surf used to do around 400 -500 k's to a tank on 32's, but only 280 k's on the 36's. Don't even want to know what it does on the 40's

whole damn 200ks to 60l is ridiculous i would have thought. i have a 3.8 v6 normally aspirated engine in my surf and get 400ks to 50l which i thought was bad. good luck sounds like fun otherwise

rokhound wrote:There is only one way to turn tyres that size at the speed limit, and it involves lots of fuel. If you have a vacum gauge in there, and a 5 speed box, you will notice that the vacum at 100kph in 4th is not as high as 100kph in 5th, irrespective of the revs.

If you want economy, put on smaller tyres. My surf used to do around 400 -500 k's to a tank on 32's, but only 280 k's on the 36's. Don't even want to know what it does on the 40's

looks like i'm gonna be carrying my 36s to the track when i get them then

Hi Rich, That does seam an excessive amount of Fuel, but when checking fuel usage abouts aren't good enough. Do a check with exact amount of fuel in tank, my tank is supposed to hold 80lts but with the shape of it now it only holds 70lts,( to many dings). Check your Trip counter against a GPS to see if you have the right km, and then do a run and calculations.
Other things to check, does it blow black smoke ( running rich ), do a run and remove spark plugs and check the colour of the burn area, should be a nice light brown colour. What boost is the motor running ?, may be the supercharger has been spooled for high output and the ECU is compensating for more air. Check with the guys who built the vehicle as they spent meager bucks on it. Out your way you have a couple of performance workshops, Lee Summerfield, and Paul Williams, I think I have there names right may be a chat to either of them, they should be able to do a run with an exhaust gas analyzer connected that should shed some light on the fuel consumption.

HOPE YOU HAVEN'T GOT IT FOR A EVERY DAY DRIVER,

FITZY.

thanks for all the advice guys , i have noticed that the clutch on the supercharger has gone walk about it was on there when i brought it but seems the nut that holds it in place has come lose thus the clutch coming off somewhere between here and hoki. it runs a switch to disengauge the supercharger and turn it off, now theres no clutch its not working at all. i believe the computers been mapped to run the supercharger, without this working would that cause it to be pushing more fuel through than its meant to? so once iv found a replacement part( does anyone no where i can get one its a crs, think there made in auzzy) i can work out the fuel consumption . think il definitly look into getting some other tires. the truck is just a weekend toy but i want to try and make it reliable as possible. Summerfield is good to deal with hes done work on my wrx, and Paul does my wofs so they may be the men to have alook over it. doesnt blow any smoke and was told it had, had full rebuild only done 800km. Rich

i think it is the same as you find on a toyota estima ven, look on trade me under supercharger, there is a few on there

sweet il check trademe out and see what i can find.

if it is the bighorn I saw on trademe, it will be a toyota sc14 supercharger

that looked like a cool toy

yip it is the one off trademe, its pritty well set up seems like alot of money has been spent on it