Nissan 370Z Forum  

Uprev Tune

For those of you who had the Uprev tune, what did it do to your MPG? My stock tune was a little too rich and I assumed the MPG would

Go Back   Nissan 370Z Forum > Nissan 370Z Tech Area > Engine & Drivetrain > Tuning


Reply
 
LinkBack Thread Tools Display Modes
Old 01-09-2010, 06:34 PM   #1 (permalink)
Enthusiast Member
 
Join Date: Feb 2009
Location: Washington State
Posts: 440
Drives: 370Z Tour MT w/Spt
Rep Power: 16
jpit will become famous soon enough
Default Uprev Tune

For those of you who had the Uprev tune, what did it do to your MPG? My stock tune was a little too rich and I assumed the MPG would go up a little after leaning the A/F ratio. But I lost about 2 MPG with the tune. I can switch back between stock and tune so I have been able to verify the loss in MPG.
jpit is offline   Reply With Quote
Old 01-09-2010, 07:28 PM   #2 (permalink)
A True Z Fanatic
 
G37Sam's Avatar
 
Join Date: Dec 2008
Location: Dubai, UAE
Posts: 1,507
Drives: RB'd G37
Rep Power: 20
G37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud of
Default

How did you arrive to the conclusion that you lost 2 MPG? Maybe your driving style changed. A tune is meant to make your car more aggressive, I've never heard of anyone who got tuned to save 2 bux with every gas up.
__________________
'14 Viper GTS
'08 RB'd G37S - Sold
G37Sam is offline   Reply With Quote
Old 01-09-2010, 07:42 PM   #3 (permalink)
A True Z Fanatic
 
Snakes709's Avatar
 
Join Date: Aug 2009
Location: Edmonton
Posts: 1,205
Drives: 2011 Evo-X GSR
Rep Power: 17
Snakes709 is on a distinguished road
Default

Quote:
Originally Posted by G37Sam View Post
How did you arrive to the conclusion that you lost 2 MPG? Maybe your driving style changed. A tune is meant to make your car more aggressive, I've never heard of anyone who got tuned to save 2 bux with every gas up.
he could be correct. When i changed my tune/parts to my old car i got better gas mileage...seems like everything i did i got better mileage as long as i wasnt stomping on the gas all the time.
__________________
2011 Evo-GSR AMS 2.4 stroker/ bore, FP Black build in progress.
Sponsor: DSG Performance
Snakes709 is offline   Reply With Quote
Old 01-09-2010, 08:08 PM   #4 (permalink)
Enthusiast Member
 
Join Date: Feb 2009
Location: Washington State
Posts: 440
Drives: 370Z Tour MT w/Spt
Rep Power: 16
jpit will become famous soon enough
Default

I can change from tune to stock with a touch of a button. Over the past few weeks I have switched back and forth driving the same routes, with the same driving style and am getting 2 mpg better with the stock tune. I didn't get the tune to save money but to increase performance. However, I assumed that when leaning a mixture (with all other conditions the same) you will get better gas mileage.
jpit is offline   Reply With Quote
Old 01-09-2010, 09:28 PM   #5 (permalink)
A True Z Fanatic
 
G37Sam's Avatar
 
Join Date: Dec 2008
Location: Dubai, UAE
Posts: 1,507
Drives: RB'd G37
Rep Power: 20
G37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud of
Default

That is not necessarily correct.

To achieve the highest MPG, you need to be running at the most optimum AFR, not too rich nor too lean. It is at the point that your engine is running at it's maximum efficiency. Once you're running at the highest efficiency, you will also be getting the maximum MPG.

How?

Let's say you want to cruise on the highway at 80mph, let's also assume for that to be achieved, you'd have to be doing 2.5k rpm in 6th (gearing designed like that). Let's also assume that you're current AFR (before tune) is at AFR 14:1. Now at 2.5k rpm, the throttle needs to be open at say 30% to let in X amount of air which will combust with X/14 amount of fuel to produce the 100bhp needed to overcome road friction and aerodynamic resistance, just enough bhp to keep that car going at a constant speed (zero acceleration). Now let's say, our engine are most efficient at an AFR of 12.0:1 and you got a tune to get you do 12.0:1 @ 2.5k rpm. In this case, to generate that same 100bhp to do 80mph, you won't need the throttle to be open at 30%, you can now get it to open at 25% only since you're getting a more efficient combustion now. You automatically will be burning less fuel per same distance traveled @ 80mph which is what yields the higher MPG number.

Hope that makes any sense

PS: the numbers I used were completely random just for the sake of comparison
__________________
'14 Viper GTS
'08 RB'd G37S - Sold

Last edited by G37Sam; 01-10-2010 at 12:27 AM.
G37Sam is offline   Reply With Quote
Old 01-09-2010, 11:37 PM   #6 (permalink)
The370Z.com Sponsor
 
Josh@STILLEN's Avatar
 
Join Date: Dec 2008
Location: Costa Mesa, CA
Posts: 1,197
Drives: 2004 G35 Coupe 6MT
Rep Power: 533
Josh@STILLEN has a reputation beyond reputeJosh@STILLEN has a reputation beyond reputeJosh@STILLEN has a reputation beyond reputeJosh@STILLEN has a reputation beyond reputeJosh@STILLEN has a reputation beyond reputeJosh@STILLEN has a reputation beyond reputeJosh@STILLEN has a reputation beyond reputeJosh@STILLEN has a reputation beyond reputeJosh@STILLEN has a reputation beyond reputeJosh@STILLEN has a reputation beyond reputeJosh@STILLEN has a reputation beyond repute
Default

Unless you're tuning for economy reasons, you can throw all math out of the window. There are thousands of adjustments than can be made to the fuel maps, at any level of throttle position, whether or not its in open or closed loop, knock retard maps, etc etc etc

Every variable is potentially tunable if it's worked on, but it all needs to be considered for the final goal..
Josh@STILLEN is offline   Reply With Quote
Old 01-10-2010, 12:22 AM   #7 (permalink)
Enthusiast Member
 
Chris@FsP's Avatar
 
Join Date: Dec 2009
Location: Tulsa, OK
Posts: 430
Drives: 2008 350Z TT
Rep Power: 368
Chris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond repute
Default

Quote:
Originally Posted by G37Sam View Post
That is not necessarily correct.

To achieve the highest MPG, you need to be running at the most optimum AFR, not too rich nor too lean. It is at the point that your engine is running at it's maximum efficiency. Once you're running at the highest efficiency, you will also be getting the maximum MPG.

How?

Let's say you want to cruise on the highway at 80mph, let's also assume for that to be achieved, you'd have to be doing 2.5k rpm in 6th (gearing designed like that). Let's also assume that you're current AFR (before tune) is at AFR 14:1. Now at 2.5k rpm, the throttle needs to be open at say 30% to let in X amount of air which will combust with X/14 amount of fuel to produce the 100bhp needed to overcome road friction and aerodynamic resistance, just enough bhp to keep that car going at a constant speed (zero acceleration). Now let's say, our engine are most efficient at an AFR of 12.0:1 and you got a tune to get you do 12.0:1 @ 2.5k rpm. In this case, to generate that same 100bhp to do 80mph, you won't need the throttle to be open at 30%, you can now get it to open at 25% only since you're getting a more efficient combustion now. You automatically will be burning less fuel per same distance traveled @ 80mph which is what yields the higher MPG number.

Hope that makes any sense
So, you're saying that a richer mixture yields better gas mileage because you use less throttle? And who tunes a car to cruise at 12:1 anyway?
Chris@FsP is offline   Reply With Quote
Old 01-10-2010, 12:25 AM   #8 (permalink)
A True Z Fanatic
 
G37Sam's Avatar
 
Join Date: Dec 2008
Location: Dubai, UAE
Posts: 1,507
Drives: RB'd G37
Rep Power: 20
G37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud of
Default

Quote:
Originally Posted by FailsafePerf View Post
So, you're saying that a richer mixture yields better gas mileage because you use less throttle? And who tunes a car to cruise at 12:1 anyway?
The numbers I gave were out of my azz just for the sake of demonstration, but yes, the best gas mileage will be achieved when the engine is operating at it's maximum Thermal Efficiency, regardless of whether you had to go richer or leaner.
__________________
'14 Viper GTS
'08 RB'd G37S - Sold

Last edited by G37Sam; 01-10-2010 at 12:28 AM.
G37Sam is offline   Reply With Quote
Old 01-10-2010, 12:45 AM   #9 (permalink)
Enthusiast Member
 
Chris@FsP's Avatar
 
Join Date: Dec 2009
Location: Tulsa, OK
Posts: 430
Drives: 2008 350Z TT
Rep Power: 368
Chris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond reputeChris@FsP has a reputation beyond repute
Default

Quote:
Originally Posted by G37Sam View Post
The numbers I gave were out of my azz just for the sake of demonstration, but yes, the best gas mileage will be achieved when the engine is operating at it's maximum Thermal Efficiency, regardless of whether you had to go richer or leaner.
I disagree. The best gas mileage occurs when the least amount of fuel necessary for healthy combustion is injected into the cylinders That's why we shoot for mixtures of 14.7:1 for idle/cruise (if the cams permit this lean of an idle), and sometimes even leaner if we're really trying to go for maximum fuel economy under cruise conditions.

Last edited by Chris@FsP; 01-10-2010 at 12:50 AM.
Chris@FsP is offline   Reply With Quote
Old 01-10-2010, 08:59 AM   #10 (permalink)
Base Member
 
Join Date: Nov 2009
Location: Montgomery, TX
Posts: 119
Drives: 2010 370Z 7at sp pg
Rep Power: 15
KEVTEX is on a distinguished road
Default

Have you asked UpRev for an explanation? They would be more likely to know why your results are different than your expectations. Perhaps a tune could be created using the stock profile up to 80% throttle, then phase in to the performance tune up to full throttle to get the best of both tunes. Let us know what UpRev has to say.
KEVTEX is offline   Reply With Quote
Old 01-13-2010, 06:23 PM   #11 (permalink)
A True Z Fanatic
 
G37Sam's Avatar
 
Join Date: Dec 2008
Location: Dubai, UAE
Posts: 1,507
Drives: RB'd G37
Rep Power: 20
G37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud ofG37Sam has much to be proud of
Default

Quote:
Originally Posted by FailsafePerf View Post
I disagree. The best gas mileage occurs when the least amount of fuel necessary for healthy combustion is injected into the cylinders That's why we shoot for mixtures of 14.7:1 for idle/cruise (if the cams permit this lean of an idle), and sometimes even leaner if we're really trying to go for maximum fuel economy under cruise conditions.
What is it you mean by healthy combustion? Sure you can get a healthy combustion, but that won't necessarily be your optimum or most efficient point. Theoretically speaking, it is only at that efficient point that you get the most HP out of Fuel burned or in other words, the least amount of fuel required to achieve a certain HP which is what you're looking at to keep you cruising at the highest MPG
__________________
'14 Viper GTS
'08 RB'd G37S - Sold

Last edited by G37Sam; 01-13-2010 at 06:26 PM.
G37Sam is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 05:15 AM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.0 PL2