Fuel consumption, HP and MAF voltage
#1
Fuel consumption, HP and MAF voltage
Yes, first post, I know...but I've been reading here for a while, and strongly considering buying an RX-8 in the near future. Anyways, today, while researching the 8, I found this article:
http://www.rxtuner.com/farticles/Can...dExplained.pdf
Anyways, in that article, I noted a few interesting things which I havent seen generally discussed in its own thread (yes, I'm sure there have been posts related to this buried deep in other posts about HP or MPG)
- One rx-8 was making more HP stock then another
- Variances in MAF voltage noted
- .15 volt difference on the 4 volt MAF sensor is the difference in 20HP or 1 (their claim)
- 1/3 of RX-8s were significantly varied from the other 2/3rds of the RX-8s
So, I'm wondering if the stat of 1/3 of RX-8s they saw which had weird MAF voltages, lines up with the number of RX-8s that see horrible mileage of 12 mpg?
Also, wondering if this could be one of the symptoms of poor dyno readings?
Has anyone gone and recorded maf voltages and done any correlation that might explain cars that have very poor mileage?
Chris
http://www.rxtuner.com/farticles/Can...dExplained.pdf
Anyways, in that article, I noted a few interesting things which I havent seen generally discussed in its own thread (yes, I'm sure there have been posts related to this buried deep in other posts about HP or MPG)
- One rx-8 was making more HP stock then another
- Variances in MAF voltage noted
- .15 volt difference on the 4 volt MAF sensor is the difference in 20HP or 1 (their claim)
- 1/3 of RX-8s were significantly varied from the other 2/3rds of the RX-8s
So, I'm wondering if the stat of 1/3 of RX-8s they saw which had weird MAF voltages, lines up with the number of RX-8s that see horrible mileage of 12 mpg?
Also, wondering if this could be one of the symptoms of poor dyno readings?
Has anyone gone and recorded maf voltages and done any correlation that might explain cars that have very poor mileage?
Chris
#2
Administrator
yes. i collected maf voltages fom 20 or so people and the maf variance is significantly less than that. 1 out of the 20 was considerably different. but the small differences between the otherswere all seen at like 7k rpm. hardly where you would be for mpg.
so i would say no to both of your questions.
12 mpg people are a combination of problems some are driver some are car. until each person claiming this low mpg allows testing by the dealership or a 3rd party then no one can be certain. but my advice is get it done even if you have to pay.
dyno results are dyno results. if you dont like the results try a diffeent one. your results might improve. some charts can reveal an issue with ports or rpm pickup. but a clean chart with 170 hp to 200 hp is normal depending on type of dyno.
so i would say no to both of your questions.
12 mpg people are a combination of problems some are driver some are car. until each person claiming this low mpg allows testing by the dealership or a 3rd party then no one can be certain. but my advice is get it done even if you have to pay.
dyno results are dyno results. if you dont like the results try a diffeent one. your results might improve. some charts can reveal an issue with ports or rpm pickup. but a clean chart with 170 hp to 200 hp is normal depending on type of dyno.
#3
脾臓が痛みました
Join Date: Mar 2005
Location: Land of Peaches, Pecans, and Peanuts
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example on how much driver effects fuel economy. i bought my car used. my first tank on it, i got 23.5 mpg. since then my average fuel economy is 18.520 mpg. the previous owner is a member of this site also. she mentioned to me once that she never got the car above 16mpg. i don't think i've had a tank below 16mpg. we live in roughly the same area, so we have the same climate, same terrain, same traffic. major significant difference...the driver.
#6
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Originally Posted by RotaryNoob
So you drive like a grandpa and she drove like a madwoman... Makes sense.
driving like that is bad for the engine...doesn't get rid of any carbon deposits. my car gets redlined at least once a day, and many times more.
Last edited by Glyphon; 08-15-2005 at 02:21 PM.
#8
I drive it mostly in city, changing shift @3750-3500RPM and get 20MPG. This is from using 91 octane..since I only have 900 Miles on mine, I'm not redlining until I'm at least 1500 Miles on it..break-in period.
Off the subject, but do anyone know how many gallons is left when you get that lovely fuel light engaged? The stupid manual don't tell you, besides recommending that you don't let it fall below 1/4 tank..how useful is that???
Off the subject, but do anyone know how many gallons is left when you get that lovely fuel light engaged? The stupid manual don't tell you, besides recommending that you don't let it fall below 1/4 tank..how useful is that???
#9
Administrator
read this thread titled 'when does your gas light turn on' https://www.rx8club.com/series-i-tech-garage-22/when-does-your-gas-light-come-69007/
#10
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iTrader: (1)
Originally Posted by chrisnewton
So, I'm wondering if the stat of 1/3 of RX-8s they saw which had weird MAF voltages, lines up with the number of RX-8s that see horrible mileage of 12 mpg?
Chris
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