Go Back   EcoModder Forum > EcoModding > DIY / How-to
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 02-21-2013, 09:20 PM   #41 (permalink)
EcoModding Lurker
 
Join Date: Jan 2013
Location: Oregon, US
Posts: 43

ZoomFreakingZoom - '88 Mazda RX7 Convertible
90 day: 19.02 mpg (US)

Geo - '96 Geo Prizm Base
90 day: 32.42 mpg (US)
Thanks: 2
Thanked 2 Times in 2 Posts
rotaries are unfortunately inefficient at low load due to the inefficiently shaped combustion chamber (large amount of surface area compared to the volume). A cylinder is a very normal 3 dimensional shape with alot of volume for how much surface area there is.

Rotary engines make great racing engines though. At high load, they are very efficient, and, properly built, they are inherently reliable due to the few moving parts and their simplistic design. A 400 hp rotary engine will use less fuel than a 400hp piston engine when driven hard on a racetrack

__________________
1988 rx7 convertible. Streetported, racing beat header and presilencer replacing all 3 catalytic converters. Atkins 6 port sleeves. K&N cone filter intake. 22mpg average, 27mpg max. Spreadsheet (updated regularly):
https://dl.dropbox.com/u/5310442/198...%20mileage.xls
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 02-21-2013, 09:55 PM   #42 (permalink)
MPG is not linear police
 
ciderbarrel's Avatar
 
Join Date: Jun 2011
Location: MD/DC area
Posts: 121

Cider - '13 Chevrolet Volt
Team Volt
Team Chevy
90 day: 63.19 mpg (US)
Thanks: 7
Thanked 10 Times in 9 Posts
Quote:
Originally Posted by 13B_88FC View Post
What kind of cold air intake is it? Is it just heatshielded or is it taking air directly from the outside?

Ramscoop style air filter w/ heatshield

C&L Racer Mustang Cold Air Intake (05-09 GT) 10699-05-PR - Free Shipping!
__________________
  Reply With Quote
Old 02-22-2013, 01:39 PM   #43 (permalink)
EcoModding Lurker
 
Join Date: Feb 2013
Location: United States
Posts: 18
Thanks: 1
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by 13B_88FC View Post
Yes, two completely different engines, that I wasn't trying to compare.

the later model 13b twin turbo's in the 3rd gen rx7 produced up to 276 hp (limited by japanese regualtions)

There were no 4 rotor street engine produced by mazda, however their 787B which won lemans (and of course was later banned) was a 4 rotor NON-turbo with 650hp.
650HP?!? WOW!!! That's MORE than 50% greater than what the original design proposal I read about stated the HP would likely be! Well, it's kinda too bad the engine was banned, but maybe that was due to the cowardice towards such an innovative engine design from Mazda, by their competitors. My understanding of such an innovative engine design is that, amongst other things, its Redline RPMs would top out at OVER 15k, at least in theory, even if not in practice.
  Reply With Quote
Old 02-22-2013, 02:48 PM   #44 (permalink)
EcoModding Lurker
 
Join Date: Jan 2013
Location: Oregon, US
Posts: 43

ZoomFreakingZoom - '88 Mazda RX7 Convertible
90 day: 19.02 mpg (US)

Geo - '96 Geo Prizm Base
90 day: 32.42 mpg (US)
Thanks: 2
Thanked 2 Times in 2 Posts
Yes the redline would be very high. Of course, 15k isn't unheard of for even racing piston engines (i've heard of some F1 engines revving to 18k), and I'm not sure what exactly the 787b's 26B rotary was revved to during the race.

I saw this car in rosamund california last summer at sevenstock 15/mazfest 2012. It's like someone is drumming on your chest when they rev the engine. It sounded incredible.

I just looked it up and it's actually a 900 horsepower engine, that was limited to 700 hp during the race for longevity.

Yes, 900 horsepower from a 2.6 liter engine NATURALLY ASPIRATED. It's pretty astounding.
__________________
1988 rx7 convertible. Streetported, racing beat header and presilencer replacing all 3 catalytic converters. Atkins 6 port sleeves. K&N cone filter intake. 22mpg average, 27mpg max. Spreadsheet (updated regularly):
https://dl.dropbox.com/u/5310442/198...%20mileage.xls
  Reply With Quote
Old 02-22-2013, 03:11 PM   #45 (permalink)
Master EcoModder
 
razor02097's Avatar
 
Join Date: Jan 2013
Location: ohio
Posts: 306

Tetanus - '95 Geo Tracker 4WD Base
90 day: 29.43 mpg (US)

300 - '82 Suzuki GS300 L
Last 3: 60.78 mpg (US)

Jeep - '98 Jeep XJ Cherokee Limited
90 day: 12.82 mpg (US)
Thanks: 28
Thanked 50 Times in 37 Posts
Quote:
Originally Posted by 13B_88FC View Post
Yes the redline would be very high. Of course, 15k isn't unheard of for even racing piston engines (i've heard of some F1 engines revving to 18k), and I'm not sure what exactly the 787b's 26B rotary was revved to during the race.

I saw this car in rosamund california last summer at sevenstock 15/mazfest 2012. It's like someone is drumming on your chest when they rev the engine. It sounded incredible.

I just looked it up and it's actually a 900 horsepower engine, that was limited to 700 hp during the race for longevity.

Yes, 900 horsepower from a 2.6 liter engine NATURALLY ASPIRATED. It's pretty astounding.
F1 engines have a tiny stroke and enormous bore.. that is why they can rev so high.
__________________



Project Avalon: E bike build
  Reply With Quote
Old 02-22-2013, 03:28 PM   #46 (permalink)
EcoModding Lurker
 
Join Date: Jan 2013
Location: Oregon, US
Posts: 43

ZoomFreakingZoom - '88 Mazda RX7 Convertible
90 day: 19.02 mpg (US)

Geo - '96 Geo Prizm Base
90 day: 32.42 mpg (US)
Thanks: 2
Thanked 2 Times in 2 Posts
Quote:
Originally Posted by razor02097 View Post
F1 engines have a tiny stroke and enormous bore.. that is why they can rev so high.
compared to the bore, the stroke is tiny, but both are pretty small since they are have so many cylinders for such a small displacment. (2.4 Liter v8's etc.) haha
__________________
1988 rx7 convertible. Streetported, racing beat header and presilencer replacing all 3 catalytic converters. Atkins 6 port sleeves. K&N cone filter intake. 22mpg average, 27mpg max. Spreadsheet (updated regularly):
https://dl.dropbox.com/u/5310442/198...%20mileage.xls
  Reply With Quote
Old 02-22-2013, 11:10 PM   #47 (permalink)
Moderate your Moderation.
 
Join Date: Nov 2008
Location: Troy, Pa.
Posts: 8,919

Pasta - '96 Volkswagen Passat TDi
90 day: 45.22 mpg (US)
Thanks: 1,369
Thanked 430 Times in 353 Posts
Everyone forgot about the pumping loss reduction from WAI. Warmer air = thinner and easier to compress. It also reduces the effective compression of the engine because there's just less air being pumped in, meaning less force on the piston required to reach TDC on compression, so less bearing/ring friction, etc.
__________________
"¿ʞɐǝɹɟ ɐ ǝɹ,noʎ uǝɥʍ 'ʇı ʇ,usı 'ʎlǝuol s,ʇı"

  Reply With Quote
Old 02-22-2013, 11:41 PM   #48 (permalink)
EcoModding Lurker
 
Join Date: Jan 2013
Location: Oregon, US
Posts: 43

ZoomFreakingZoom - '88 Mazda RX7 Convertible
90 day: 19.02 mpg (US)

Geo - '96 Geo Prizm Base
90 day: 32.42 mpg (US)
Thanks: 2
Thanked 2 Times in 2 Posts
Quote:
Originally Posted by Christ View Post
Everyone forgot about the pumping loss reduction from WAI. Warmer air = thinner and easier to compress. It also reduces the effective compression of the engine because there's just less air being pumped in, meaning less force on the piston required to reach TDC on compression, so less bearing/ring friction, etc.
I thought higher compression generally meant better efficiency? Or is it just that a higher compression, smaller displacement engine is more efficient than an equivalently powerful larger displacement engine with less compression?

Piston and bearing friction shouldn't be affected by compression, it's kinda like how there is the same rolling resistance from your tires if your going up a hill versus going on flat ground, at least that's how I see it. If it was effected, I suspect the difference would be very small.
__________________
1988 rx7 convertible. Streetported, racing beat header and presilencer replacing all 3 catalytic converters. Atkins 6 port sleeves. K&N cone filter intake. 22mpg average, 27mpg max. Spreadsheet (updated regularly):
https://dl.dropbox.com/u/5310442/198...%20mileage.xls
  Reply With Quote
Old 02-27-2013, 01:33 AM   #49 (permalink)
Depends on the Day
 
RH77's Avatar
 
Join Date: Nov 2007
Location: Kansas City Area
Posts: 1,761

Teggy - '98 Acura Integra LS
Sports Cars
90 day: 32.74 mpg (US)

IMA - '10 Honda Insight EX
Team Honda
90 day: 34.76 mpg (US)

Tessie - '06 Acura TSX Base
90 day: 28.2 mpg (US)
Thanks: 31
Thanked 40 Times in 34 Posts
Offset Crankshaft Discussion Moved, Per Request

Please refer to the Offset Crankshaft Thread for further discussion on that topic. Moved and Merged per request.
__________________
“If we knew what we were doing, it wouldn't be called research” ― Albert Einstein

_
_
  Reply With Quote
Old 06-14-2013, 06:02 PM   #50 (permalink)
Dr. J
 
jmmbmd2013ph's Avatar
 
Join Date: May 2013
Location: Philippines
Posts: 16
Thanks: 0
Thanked 0 Times in 0 Posts
good day guys, here's my question, would a WAI produce better FE to a carb engine? To add to that I live in the Philippines, average temperature for the day is 33C-36C (91.4F-96.8F).

  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Comparing Warm Air Intakes (WAI) & Cold Air Intakes (CAI) toomuch EcoModding Central 23 05-26-2019 05:41 AM
Warm air intake? how about warm fuel? ebacherville EcoModding Central 30 03-08-2010 09:37 PM
Grill block affected milleage mar5ka Aerodynamics 24 08-31-2008 10:17 AM
Moving air intake into the engine compartment? pasadena_commut Aerodynamics 5 07-25-2008 03:24 PM
carbed car .. think a warm air intake will help? ebacherville EcoModding Central 21 06-29-2008 09:16 AM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com