Umm is anyone else going at 80mph at 4000rpm??!?!
#42
ohh and 2.35 gas in gainesville was FTW $23 fill up was awesome it made me remember my highschool days!
#43
yeah this is something I don't get with the manual transmission. i use 5th gear to maintain 60km/h on a downhill......i am still within break-in period, so I don't want to gas it, but I wonder how it will drive like when I get it onto the highway....
#44
It's a Honda, revs will not hurt it and I get 39 mpg at 75 mph and 3,700 revs.
#45
ya got me. Whats wrong with 80 mph in 4th at 4000 rpm? May not be worth it to cruise there but on the way to top speed in fourth - about 110 mph - what would you do?
#48
I found a car for sale in Atlanta about a year ago on the internet. The guy drove from there to Seattle and back, every week, from the time he first bought it. It was a '95 Civic EX MT. With that S20 tranny it's much like the fit-- just a touch lower, figure 3400 rpm at 75mph. The z6 engine it had was still a short rod undersquare motor just like the L15 (bore/stroke was 75mm/90mm instead of the 73mm/89mm we have, and rod:stroke ratio a low 1.52:1).
The motor nor transmission were never rebuilt. Just got timing belts, clutches, brakes, tires, coolant changes, air filters, pretty much standard maintenance.
The thing was for sale with 943,000 miles on the clock and he claimed it STILL didn't burn oil.
If I can find it, I'll post it up.
Moral of the story, it is NOT something to worry about.
Heck look at all the people running b20 swaps with b16 trannies. Punched out LS block with skinny skinny sleeves churning 4000+ rpm down the highway... that's gotta go thru some petrol.
#49
It's nothing to worry about guys, it's perfectly normal for any "low torque" Japanese car.
In a muscle car, displacement = torque. And the larger the displacement, the harder it is for it to handle high rpm's. You ever wondered why a Ferrari engine is a technical masterpiece?
In a Japanese car like a Honda, rpm = torque. The FIT's engine/tranny is a just a glorified D-Series and, like its predecessor, is designed to handle high rpm (well, high rpm compared to larger displacement cars). Power-adders aside, if you had a long-geared transmission, you will be slower than a snail. Like mentioned above, Honda had to make a compromise between efficiency & acceleration.
For the Auto tranny, this is geared differently from the Manual which is why it sits at a lower rpm when compared with the Manual, but also has a torque converter which increases torque tremendously at lower rpm's. The higher the rpm though, the more balanced the torque distribution becomes (it's just the way torque converters work) which is why an Auto doesn't make more "peak torque" than a manual would.
In a muscle car, displacement = torque. And the larger the displacement, the harder it is for it to handle high rpm's. You ever wondered why a Ferrari engine is a technical masterpiece?
In a Japanese car like a Honda, rpm = torque. The FIT's engine/tranny is a just a glorified D-Series and, like its predecessor, is designed to handle high rpm (well, high rpm compared to larger displacement cars). Power-adders aside, if you had a long-geared transmission, you will be slower than a snail. Like mentioned above, Honda had to make a compromise between efficiency & acceleration.
For the Auto tranny, this is geared differently from the Manual which is why it sits at a lower rpm when compared with the Manual, but also has a torque converter which increases torque tremendously at lower rpm's. The higher the rpm though, the more balanced the torque distribution becomes (it's just the way torque converters work) which is why an Auto doesn't make more "peak torque" than a manual would.
#50
its kinda like the f1 series motors that are a v8 but only a 3.2 liter with no stroke but are constantly running in the 10,000+ rpm range. a small stroke can go up and down quicker and more reliably than a longer stroke.
#52
YouTube - Smart with Hayabusa engine
#53
Highway trip with the whole fam damily yesterday and I had to check to make sure. At 80 mph on my GPS receiver, I was turning roughly 3000 RPM. Never did get it up to 4000 RPM, as we hit a sustained 104 MPH at 3800 RPM. The only way I could see 4000 RPM for 80 MPH is if you have your car in 4th gear.
Of course, mine is a AT car which may make a slight difference.
Of course, mine is a AT car which may make a slight difference.
#55
I think Honda might have changed the MT gear ratio a bit starting in '08 models because they want to get the government tax credit, so that it's competitive with the Toyota Yaris (which does have the credit).........they need a combine highway/city fuel rating below 6.5L/100km in Canada in order to qualify.
But one thing that I am curious about is, does that mean the AT should have a higher top speed because of its higher gear ratio?
But one thing that I am curious about is, does that mean the AT should have a higher top speed because of its higher gear ratio?
#56
Currently, most high tech street engines of 1.5L displacement using high quality metals have to be limited to 3500 ft/minute at max rpm. Thats the feet of piston travel up and down the cylinder in a minute at max rpm. The Fit has a stroke of 89.4 mm which means the piston travels 7 inches with every engine revolution. Thats 0.5866 ft per rev; at 6500 rpm the piston travel is 3812 ft per minute. To keep piston travel to 2500 fpm, which is considered a good target for endurance race engines, the engine should not turned more than 2500 fpm for long periods of time like 24 hours.You may turn 4000 rpm steadily for long periods but you are shortening the life of your engine progressively because the piston speed is 2346 fpm, very close to the reasonable limit. (You don't want to calculate the valve and rocker arm speeds)
The closer to the limit the quicker you wear your piston rings, valves. and other mechanical items. There is no free lunch.
The smaller the engine the more rpm needed to generate the power to push the car thru the air and up hills. HP=torque times rpm divided by 5250. Torque is generated by the push of the combustion on the pistons and is generally equal to one foot-pound per cubic inch at maximum. When you need horsepower, add rpm. Increase torque, have larger displacement, pasrticularly piston diameter.
Still no free lunch.
Last edited by mahout; 11-12-2009 at 06:07 PM.
#59
Revs only in this case.
#60
To tone it down the lengthened the stroke to 90.7mm and dropped red line to 8,000 rpm; thus dropping piston speeds about 200 feet/minute. If you would rev the 2.2L to 9,000 RPM it would create piston speeds over 5,300 feet/minute and the result could be catastrophic.
I don't know about the newer rotary, but, the old school RX-7 rotary engines did not have a red line. Those cars were equipped with a light that came on warning that you should probably shift or else the alternator pulley might not handle it. Those rotary engines could rev and rev.