achauha3560

Hi guys. I just got this SiR and i was doing some research, i don't claim this as gospel so please correct me if i am wrong. The peak torque for a 2000 SiR is (very low) 111Lbft at 7000RPM and pumps 160hp at 7500RPM. What RPM should i be shifting for each gear for best resuls. anyone know? Thanks alot

imported_BlazeInEk

Depends on your goal.

Max. Acceleration:
I'd say as late as you can before redline...it'd be pretty hard to shift at one specific rpm.

Most Efficient:
Around 2000 and 3500rpm.

achauha3560

Thanks. More over, For best performance and acceleration should it be at highest torque or hp?

imported_t_dot_SiR

torque gets you moving, hp keeps you moving...

you probably want to get close to redline where HP peaks to shift if you want best....

if i'm not mistaken, i think torque peaks a lot earlier than hp... around 2000 rpm less.... some cars peak torque at 3000 rpm and redline at like 6800rpm and hp peaks at like 6000... try to search for a dyno chart of a stock b16 to give you a rough idea, but no car have identical graph for sure... just an estimate...

my cousin has a b16, and he feels no more power after 7000 rpm (stock)... the power really kicks in between 4800 to 6000 when the vtec is like mad kicking..... that's why i always i think it peaks around 7000..

one more thing, no matter where the torque peaks on a b16, you won't feel it... i say it ends about 5000... it is the short gearing on the b16 tranny that makes you feel the torque is mad lots haha

VTEC_Thunder

Torque in a b16 is basically non-existant...lol.

I dyno'd my 2000 SiR with short ram intake and axle back tanabe exhaust: 141whp at about 7500-7600 and a HUGE 101ft-lbs @ the wheels at an rpm I can't remember.

In normal driving I shift at 2500-3000rpm more or less, and have pushed up to 37mpg by doing that. Shifting at 3000 you have decent power to accelerate respectfully.

For racing I shift just as the needle touches the red zone on the tach (8grand) just before the limiter. If you look at the dyno chart, it is making good power right up to the limiter, so might as well make use of it.

Hope that helps.

Enjoy your new ride!!!

Mulder

I would think shift right above the point where you think your engine is 'struggling' to accelerate to get best fuel mileage. A smooth a/f mixture, and low engine temps is what you need. Thus dont shift at under 1500rpms (a/f) or 4000 (temp). I usually shift @ 2200 - @2400rpm for level ground and a little higher for uphill.

For performance, higher the rpm the better since when you shift going at a higher speed, you travel further than if you shifted at a slower speed resulting in faster 1/4 mile times. Just make sure you are still making power at the high rpm. For 0 - 60mph times, shift so that the average power u make when u shift and the power u make in the next gear at the shift is the highest. 1/4 mile times its better to hold out just a little (hundreths of seconds) longer. Now this also depends on the car

kwikb16a2

Shifting too low is no good, especially at 2200 RPM. You want to get up to speed then throw it in 5th. I found little to no difference shifting at around 2000RPM opposed to 3000 RPM. Key to good gas mileage is to keep the throttle at one position rather than operating it like an on -off switch. If i had a 6 cylinder than i would be shifting nice and low but on our cars its no good.

imported_t_dot_SiR

the key to good gas mileage is not flooring your pedal haha... gently let the car speed up and go upto about 3000rpm before you switch gear.......i always shift at around 3000-3200rpm because when i shift at 2500 or lower, after i change gear, my rpm would be at around 1600-1800 which is very low, you'll feel the car not moving and take a hard time to accel.... so i switch at 3000, drops to 2000, climbs to 3000, drops to 2000... until i hit fifth gear.... and each gear, i don't floor the pedal, i gently accel... so i'm not pushing it hard

good fuel mileage on my old civic with gsr =)

Mulder

last tank i got 5.8 L/100km or around 40 mpg..stock civic...I record every refill so thats pretty accurate. And that is with 150km trips with rush hour once a week and city (4km a day starting on/off 6 times a day) mixed in.

Mulder

btw...I do a lot of driving in 4th gear..unless im over 100 in 4th, i dont switch to 5th.

ADR3NLYN_EK

lets remember that he has a sir which has very short gears, if he were doing 90 km/h in 4th he would be at around 5,000 rpm's...i also have a b16 and if im doing over 60 km/h im always in 5th (and still just under 2,500)...thats normal driving

if youre at the track with a stock sir i suggest shofting between 7,900 and 8,100 rpm's...my motor is chiped and tuned and i shift at 8,500 and (which is my redline) and achieve best results on the 1/4 mile track...

imported_snguy82

5.8L/100km? Wow! How did u achieve those numbers? I have a stock DX and best I've gotten is around 34 mpg or around 7L/100km; but then again, I do a lot of city driving.

I do a lot driving in 5th gear in the city (50-65km)...does this effect my mpg a lot? Or should i just be sticking to 4th?

thanx

Mulder

5.8 was actually my best average. 90% of the time I average around 6.3. Note: I accelerate like a granny on weed..slowwww. What the heck though, its easier to shift at lower rpms, less wear and tear, better fuel mileage, and you can enjoy the scenery instead of the red light ahead.

I recall driving city about 70 - 80% of tank one time - Think I got around 550 km / 40Litres. Thats about 7.2L / 100km. Even on that one tank (we've all been there) when there was a rush and speeds topped the double century, I didn't get less than 500km/ 40 Litres.

ADR3NLYN_EK, yup you're right. My DX at 100km/h in 5th is @ 2500rpm. in 4th 3000rpm.

But snguy82, Fill tank to the top, take a long trip on the highway around 300 km one way @ the speed limit. Then when you come back, fill it up max again and let us know the numbers. Also, MAKE SURE YOUR TIRES ARE PROPERLY INFLATED AND YOUR CAR IS TUNED UP

imported_snguy82

i thought civic tanks were 45L? Or close to 12 gals.

Anyway, I've been keeping track of fuel consumption after every pump. My goal is for 5.8L/100km now. Still averaging around 7L/100km - not bad right? I drive like a grandma too these days.

I've done the major tune up on my car: New distributor, cap, rotars, plugs and wires. Still need to change fuel filter and clean out injectors. Am I missing anything else?

(Sorry I probably should start a new thread for this)

1sykcoupe

three grand