Tweet
[QUOTE=littleriver;501863]
X2
You will find a few doubters on here ... they seem to put in a lot of negative input towards tunes .. as others have also mentioned you get what you pay for - beware those companies that won't give warranty with their tunes ...
I think the biggest issue is with the "trust" of the accuracy of the before and after dyno charts and the "accepted fact" the these graphs can be fudged.
Power and torque graphs given by the vehicle manufacturer are always measured at the engine fly wheel and not the rear wheels. There will be always a significant difference in the 2 results, power will be down at the rear wheels due to extra load of the driveline, 25% to 35% is not uncommon for manual transmissions and up to 40% for automatics depending on the torque convertor and if it is even locked up and stays locked up during the dyno test. Torque will most times be much greater due to the multiplication effect of the driveline and what gear the test is conducted in. Do the test in 3rd and the torque is a massive improvement over factory numbers, do the dyno test in 4th and the torque numbers will be less. A reputable dyno graph will state what gear the test was done in and what the vehicle speed and engine RPM's were. What you are really looking at is a percentage improvement between the before and after tests and not raw numbers and that the test were conducted under the same conditions and methods.
An ECU tune or chip can increase both power and torque and in a 4wd you are looking for all the gains at the low and mid rpm ranges as this is where the engines are mostly operated and where the biggest improvement in drivability can be felt and appreciated. A tune done properly will give you these results, whether it is worth it is up to the individuals needs and expectations. Push the the tune too hard and you start to sacrafice engine and driveline reliability and longevity.
cheers, OJ.
Originally posted by Jas2909
View Post
X2
You will find a few doubters on here ... they seem to put in a lot of negative input towards tunes .. as others have also mentioned you get what you pay for - beware those companies that won't give warranty with their tunes ...
Power and torque graphs given by the vehicle manufacturer are always measured at the engine fly wheel and not the rear wheels. There will be always a significant difference in the 2 results, power will be down at the rear wheels due to extra load of the driveline, 25% to 35% is not uncommon for manual transmissions and up to 40% for automatics depending on the torque convertor and if it is even locked up and stays locked up during the dyno test. Torque will most times be much greater due to the multiplication effect of the driveline and what gear the test is conducted in. Do the test in 3rd and the torque is a massive improvement over factory numbers, do the dyno test in 4th and the torque numbers will be less. A reputable dyno graph will state what gear the test was done in and what the vehicle speed and engine RPM's were. What you are really looking at is a percentage improvement between the before and after tests and not raw numbers and that the test were conducted under the same conditions and methods.
An ECU tune or chip can increase both power and torque and in a 4wd you are looking for all the gains at the low and mid rpm ranges as this is where the engines are mostly operated and where the biggest improvement in drivability can be felt and appreciated. A tune done properly will give you these results, whether it is worth it is up to the individuals needs and expectations. Push the the tune too hard and you start to sacrafice engine and driveline reliability and longevity.
cheers, OJ.
Comment