Chromatic Posted March 18, 2014 Share Posted March 18, 2014 Can you elaborate on this ? ROFL! 1 Quote Link to comment Share on other sites More sharing options...
GIXXERUK Posted March 18, 2014 Share Posted March 18, 2014 Can you elaborate on this ? ROFL! Quote Link to comment Share on other sites More sharing options...
Jimbo Mahoney Posted April 30, 2014 Share Posted April 30, 2014 (edited) Thanks for the cool graph and explanation Chromatic. On my DE, I've set the indicator to 6000 because by the time I notice it come on, I'm around 6500. As for fuel economy, from previous experience (and surprise), I've found the general rule of lowest RPMs = best fuel efficiency. I had assumed something like peak torque would be best, but it's actually the lowest throttle position that gives best fuel economy. Granted this was in a different car, but I did experiment a lot with an OBD reader in various gears. There's a graph (admittedly of an RX8, which is a very different beast) over at PistonHeads: http://www.pistonhea...ic.asp?t=991641 showing the MPG at various speeds and gears. I think it's fair to say that this backs up my hunch of lowest RPM = best fuel economy. When driving for fun, I'm going continue shifting around 6500. When driving for fuel economy, I'll be sticking to 5th gear for 30 mph to 50 mph. Edited April 30, 2014 by Jimbo Mahoney 1 Quote Link to comment Share on other sites More sharing options...
Exotic Posted May 1, 2014 Share Posted May 1, 2014 Chromatic - that explanation's legendary mate and always kinda ties in to the way I drive. 1st class honours kinda explanation! 1 Quote Link to comment Share on other sites More sharing options...
docwra Posted May 1, 2014 Share Posted May 1, 2014 Jesus guys, its just changing gear, just do it when it feels right ........... Almost reminds me when wannabe drifters come onto forums and ask about "practicing shifting techniques" - say what? Quote Link to comment Share on other sites More sharing options...
Exotic Posted May 1, 2014 Share Posted May 1, 2014 Jesus guys, its just changing gear, just do it when it feels right ........... Almost reminds me when wannabe drifters come onto forums and ask about "practicing shifting techniques" - say what? Nowt wrong getting a bit technical though! 1 Quote Link to comment Share on other sites More sharing options...
Chromatic Posted May 2, 2014 Share Posted May 2, 2014 Thanks for the cool graph and explanation Chromatic. Please.. I love analyzing .. it's what I do .. And when it comes to things I am passionate about, well, I get a little carried away. On my DE, I've set the indicator to 6000 because by the time I notice it come on, I'm around 6500. It's the same for the HR -- Well not the indicator/shift point.. but the Shift light coming on early. -- My "testing" has shown the Shift light comes on between 300-600 Rpm BEFORE the RPM you set it at. (There is an exact RPM that will apply to all 350's.. I just didn't test that specifically.. someone will know, otherwise I'll find out tomorrow ) -- Anyhow.. So I set my Shift light at 8000. My Rev limiter is 7800,.. So that pulls the light on at about 7500 or so.... Which is just about right with the Tune/mods and is right in general anyways.. We just don't want to let it hit the Limiter (wherever it is in your particular car) as then the Fuel cuts off repeatedly and that's going to kill your performance and shifts.. So for me, having the initial light blink at 7500 or so is Juuuuuust about right for my shift to hit before it hits the Fuel cut off. The light changes it's frequency as well.. That initial blink(ing) is slower/less often than the closer you get to the actual setting. Personally I don't need 5 blinks before I notice it.. I love how the RPM gauge is the largest and Center gauge in our cars.. the first blink of that trips my peripheral to shift.. Plus after a while you get used to the noise, and can get VERY close to shifting by sound alone at these high rpms. (We can all shift by sound (I hope) in normal driving ). As for fuel economy, from previous experience (and surprise), I've found the general rule of lowest RPMs = best fuel efficiency. I There's a graph (admittedly of an RX8, which is a very different beast) over at PistonHeads: http://www.pistonhea...ic.asp?t=991641 showing the MPG at various speeds and gears. I think it's fair to say that this backs up my hunch of lowest RPM = best fuel economy. When driving for fun, I'm going continue shifting around 6500. When driving for fuel economy, I'll be sticking to 5th gear for 30 mph to 50 mph. Interesting.. I'm very interested in the exact RPM for each gear (or if it's one RPM across the board) for absolute best MPG. With my tuning Hardware, software (osiris, Cipher, etc) It doesn't have a fuel economy readout (not directly anyway.. I'm sure it can calculate based on A/F mixture and all the other readings).. So we can't really get a real time MPG readout.. especially over time. So be nice to get this done.. by a tuner, or someone who could create a program to take the OBD paremeters and calculate them in real time on their laptop (or phone I guess) as you drive. Then post a similar graph for the DE, and HR motors.. So we know. The lowest RPM as a "general rule" is right.. but as you get higher in gear (or lower, however you look at it..) -- Ie: Say past 3rd gear or so,.. There is a bit of an issue with lower RPM and torque. If you notice you will have to press the gas pedal in further with say a 1500 rpm shift in 5th gear than a 2200 or so. So I think there's a little more specific RPM to shift that's a touch higher than the lowest possible for maximum MPG. In street driving you need to keep acceleration at least average to the other cars on the road for it to be applicable for normal driving.. otherwise you could be at 2 percent throttle and take X minutes getting to speed lol. Of note: Post Tune I get 21 MPG solid (after it's learned the tune/fuel settings) -- That's a little lower than stock form, but not too terrible imo. Also of note: The worst MPG I get (over longer runs) when I am slamming the car (primarily tested this when I was doing my data logging for tunes.. where I'd be slamming it from 1500-7800RPM full throttle in 3rd and 4th gears.. among other such.. just lots of hard driving over 40-50 miles in a few hours of logging that my worst MPG calculation was 15.7 mph,.. I was a little surprised it was that high. At full throttle driving and being about as hard on the throttle as you can expect I figured it to be running well under 10mpg. Quote Link to comment Share on other sites More sharing options...
Chromatic Posted May 2, 2014 Share Posted May 2, 2014 (edited) Chromatic - that explanation's legendary mate and always kinda ties in to the way I drive. 1st class honours kinda explanation! Glad you liked it. Jesus guys, its just changing gear, just do it when it feels right ........... Almost reminds me when wannabe drifters come onto forums and ask about "practicing shifting techniques" - say what? Some people are analytical, thinkers, curious, (you need these type of people for all your gadgets and innovation etc..) -- People like this enjoy what you seem to think is being , well, ridiculous I suppose. To each their own,.. I don't knock your kind,.. don't knock mine. Edited May 2, 2014 by Chromatic 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.