It's too easy to over steer if you have more air in the rear tires than the front.... I found out by rotating my tires and forgetting to add air to the front tires and reduce the pressure in the rear.... A rear anti sway bar has the same effect unless you put a heavier anti sway bar on the front, then all 4 wheels can lose traction at the same time... I prefer a little under steer, it is easier to recover from on a FWD car.

 

"It's only "too low" if it's below idle. anything north of 1K is fine"

Makes sense to me . We know that the Fit idles below 1500 rpms. During this time, oil is properly flowing to all vital parts, so no damage is occuring, right?

 

Yes and no. The moment you let out the clutch, you're placing the engine under load, and that's where the potential for damage occurs because you're not winding it hard enough. Better more revs than less.

I lack specifics but I've read a few times that prolonged, habitual lugging isn't very good for most engines - especially those that don't have mountains of torque off idle. In principle it may be down to the mismatch between engine and road speed and how it'd affect stuff like your axles, compression, crankshaft, conrods...basically the reverse of severe engine braking.

Correct me if I'm wrong

 

I'd be concerned with the oil pressure. I may be forever paranoid after putting so many miles on the y8 with its anemic oil pump, but when that car was warmed up it made between 5-10 psi at idle and got up to about 25 pounds at 2000 rpm. On this car the vtec would NOT engage if oil pressure at the cylinder head was not in excess of 65 pounds, which of course was just below where the pressure would plateau thanks to the relief valve. Being as this car developed 35 pounds at 3000 rpm, the pressure was actually within Honda's service specs.

Larger motors have larger pumps and can take the beating because they develop pressure down there. A big pump like that would be a significant detriment to our fuel economy so we don't get one.

If anyone knows the flow rate of the Fit pump it might be helpful. Z6 engines didn't have bearing issues because its larger pump flowed 54 gpm @ 5500 rpm, and thus had higher pressure at low rpm. The shrunken y8 pump only flowed 35 gpm at a much higher 6600 rpm, and thus there were a whole rash of spun bearings with that motor.

Long-term lugging isn't good because the higher dynamic compression and increased fuel use that goes along with it creates high exhaust and valve temperatures, open-loop lugging which runs the engine rich can create carbon deposits, and not to mention the comparatively fast flame front generating peak cylinder pressure so much closer to piston TDC compared to higher engine speeds that it can exacerbate an oil pressure issue if you have one, especially if carbon deposits bring about some pinging.

 

Ah but remember in this condition the engine is running at about 20" of vacuum in the manifold - hardly any combustion pressure - and the greatest force exerted at this time is the air pressure in the crankcase pushing up against the pistons when at BDC.

 

Really having trouble understanding your scenario. What speed are you driving at and how sharp are these corners?

One thing that has impressed me with my 2010 FIT is how high a gear I can drive in - without any indication of 'lugging'. Neighborhood driving at 25mph is a breeze in third gear - 1st and 2nd are there to get me rolling, I don't remember 'driving' anywhere in second gear. Once I'm above 40mph it's easy to keep it in 5th unless a hill gets in the way then 4th is where I go.

I'm thinking you're simply not carrying enough ground speed - but again, not understanding your scenario.

It would really surprise me if 'lugging' the Fit would really do any harm unless you're consistently trying to find the low end limits of each gear - in manual transmission driving that's totally unintuitive.

 

From all that's been said, it sounds like higher revs are better than lower. As regards the recommended shift points, maybe the Honda engineers determined that the optimum RPMs would only be achieved at the recommended points even though the Fit seems to want to go to a higher gear before getting to the recommended shift soeed?

 

"how long is a piece of string"



lets just say, in all my 4cyl, i never drive it under 2k. most of the time, nevre under 2.5k

 

dang boy you are overthinking this

 

On most 4 cylinders 2.5k is the upshift point for normal/eco driving...

I've done 2 auto-x events with the fit, around the same pressure all around, and for me it was very neutral, understeer wasn't too strong, and oversteer was easy to handle. You just countersteer and slam the gas pedal to save it...
I've seen more impressive "saved" oversteer in fwd than rwd.

 

Feel the force... be ONE with your Fit... Feel it and it will come to you...

 

[quote=Krimson_Cardnal;911601]Really having trouble understanding your scenario. What speed are you driving at and how sharp are these corners?

We're talking your basic 90 degree intersection corner. Since you say you use 1st and 2nd only to get rolling, do you take corners in 3rd? If so, how low do your rpms go?

 

Romulus On rolling 90d intersection corners I'll slow to appropriate speed and take them in second and quickly get into third. How low do the rpm's go, I really would need to look - no idea. Stick driving is intuitive to me. By 'feel' and experience I can tell if I'm in the correct gear.

I anticipate the upcoming turn and decide before I enter it what gear I might need to drop to. I'll rev to match the lower gear and simply slip into it - always using the clutch - if needed. My objective is to get back to the higher gear as soon as possible.

Sometimes I miss judge and search for the right gear - then I know I was day dreaming or, as in my younger years, checking skirts...

This isn't high performance driving, however, it is based upon the exact same principals, only lower speeds. You're most always wanting to be in the highest gear possible.

In thinking about your original question I believe you're feeling a slight engine overload. With the Fit it's most likely minimal and you pass through it quickly. Momentum usually takes care of it - you should not feel as if the engine is bogging down - if so you're entry speed is too slow [a few mph - not a huge amount]. Touching second is perfectly normal - just to keep it all going, but you should be quickly out of it and back to third. If you need to get to first you probably blew through a stop sign or should have stopped anyway.

Stick driving is primarily the drivers job. You decide how fast you want to be in each gear you choose. You need to think about it, each and every time you press the clutch to the floor, to keep the car under control and performing to your needs.

It's why manual shifting is so much fun - you are part of it. Keep it moving forward.

K_C_

 

[QUOTE=Krimson_Cardnal;911945]Romulus On rolling 90d intersection corners I'll slow to appropriate speed and take them in second and quickly get into third. How low do the rpm's go, I really would need to look - no idea. Stick driving is intuitive to me. By 'feel' and experience I can tell if I'm in the correct gear.

I anticipate the upcoming turn and decide before I enter it what gear I might need to drop to. I'll rev to match the lower gear and simply slip into it - always using the clutch - if needed. My objective is to get back to the higher gear as soon as possible.

Sometimes I miss judge and search for the right gear - then I know I was day dreaming or, as in my younger years, checking skirts...;


In my Fit I would be in third for turns if I was down shifting and If I was taking off from a light I would be in second. High performance driving you want the rpm around peak torque to move you out faster. It so second nature that I dont have to think about it anymore when I drive.