gymdent

Yes, I know that in this rev crazy group this may sound like an odd question from a new RX-8 owner (400 miles), but how can you tell if your shift points are too low and the engine is lugging? I've read the treads about break in, shifting, etc., however, there has been no mention as to this topic. In a piston engine you have to be pretty dense to not be aware that you're lugging it. Not so easy, it seems, in a rotary. This is especially true if you've never driven a rotary and it's break in time.

Thanks!

DOMINION

Break in, I would say shift at 4,000 RPM's and change the oil after 1,000 miles.

gymdent

Thanks. I realize that, however, that was not my question. How can you tell if the shift point is too low and you are causing the engine to strain? With a piston engine there is vibration (that lugging sound). Done excessively, it can cause engine damage. What about a rotary?

Razz1

You need to red line it once a day.
Shift over 3500 RPM and keep the crusing above that RPM

Old Rotor

It's the same with a rotary just harder to tell because it's so smooth. The torque is so low at lower RPM's you will want to shift at higher point so you are still in the torque band.

gymdent

Why do you need to redline it once a day? Is this the carbon buildup issue? There's no mention of that in the owner's manual or the DVD that comes with the car.

My understanding of synthetic motor oils (Royal Purple) is that synthetics don't cause carbon buildup. I plan the switch to Royal Purple at 2,000 miles.

Jedi54

iTrader: (7)

you'll know if you bog it down because there won't be any power when you accelerate

Jedi54

iTrader: (7)

owner's manual doesn't mention the carbon build up but it'll definitely get there if you don't redline often enough.

Razz1

You still need to redline it. Try a search on redline if want more support on this.

Wat's da matter you don't believe in the force of the Jedi master?

"owner's manual doesn't mention the carbon build up but it'll definitely get there if you don't redline often enough."

daisuke

engines have had to be replaced because of carbon build-up, be nice to your engine and rev the crap out of it.

The engine has no power below 2.5k rpms, if you shift at around 4k then your next gear will be above that low point, and don't try to pull away at such low revs in anything above 3rd gear, you can cruise that low tho.

TrochoidMagic

i don't see anyone trying to answer his question. just the same reply...redline, redline, redline. thats for after he breaks in the motor.

gym: i don't see the 8 being any different from our piston motor vehicles. it'll hesitate still i.e. using 2nd gear to accel at 5mph. if you're smooth enough with the throttle...it should be no problem. but if it cuts back and forth... use the appropriate gear and rpms.

good luck breaking in your car.

gymdent

Thank you for reading! I do appreciate the input from all of you. Will check out the redline and carbon threads so as not to get this one off topic.

TrochoidMagic

if you feel that dearly about your 8 as i do...being this is my very FIRST new car.
i took my time to break her in. this is what I did,
-first 1k miles, shift at 4k rpm and light load, never holding at a certain rpm
-increase 400rpm every 100miles
-WOT after 2k miles.
but even then...i did cheat. its too hard to resist!

Huey52

iTrader: (2)

Carbon buildup comes from poorly combusted gasoline, not oil.

Detergent blended gasoline helps, but given the relatively low thermal mass of the rotary higher rev's are a good way to go. Plus it's fun and the reason most of us bought a high revving 'turbine' machine.

Sushi

What can a person with an Automatic do to avoid carbon? Also redlineing, do you just leave it in park and rev it up on the RPM's or while driving?

New Yorker

Well, like any car sold in the US, in the owner's manual you'll find two charts of "shift points" - one for accelerating, one for "cruising" - that give you the best mileage. Now basically no one follows these shift points, as they're really low (they'll have you shifting at around 3K or maybe even a bit lower), and if you follow them you'll be driving like an old man. A very old man. In a Buick.

I only mention them because they answer the OP's question; you can shift about as low as that without lugging the engine.

fugg

I noticed this problem as well. Normally with my civic, i'd be in 2nd around 5-15mph, but it seems to REALLY lug on the RX8 @ 5 mph.

Does this "lugging" feeling (followed by the chug chug jerks of the car) damage the transmission at all? I fear I'm shifting too damn early.

Socket7

Thats because you should be in first gear for anything below 15mph. If you drop down to <10mph, you can easily double clutch smoothly into first, where just shifting it will take a while for the syncros to engage. at <5MPH, it should smoothly slip into first no problems. If you try and shift into first at greater then 10mph, you'll make your syncros cry.

I try and keep my engine at around 2.5k RPM while cruising to keep fuel costs down. At that RPM, it accelerates like a Vespa Scooter until you hit 3k RPM, where the hand of god reaches down and shoves your car forward. I usually shift at 4k, which is a drop to around 2k RPM from 1st to 2nd gear, and about 1k RPM drop from 2nd to 3rd, 3rd to 4th and 4th to 5th.

Highway on ramps are taken at WOT, and at least once a drive i get the revs up to 8k or more to take care of any carbon buildup from puttering around town.

fugg

^ thanks for the reply. But I cant seem to shift from 2nd ----> 1st gear at 5mph-10mph.

If I do, I have to JAM THAT GEAR into place. I feel like I'm about to break something whenever I shift back down to first. It's not a satifying "lock" that the other gears give me. A loud CRUNCH ensues while shifting down. Just doesn't sound or feel healthy for the car. Not to mention I have to put in a crap load of force into the shift ****.

Just yesterday, I decided to shift to 1st gear from 2nd gear at 7mph. Same "problem".

I'm guessing thats not normal? The cars only 950 miles old.

max5roadster

try bringing the revs up to match... Unless you are already doing that, in which case, Is the tranny at operating temps? If so, switch to Red Line MT90 trans lube. If not, then wait till it is hot and try it.

Socket7

Shift into neutral, release the clutch and coast down to 7mph, blip the throttle up to about 3K, then clutch in and shift to first. You shouldn't get grinding ever. grinding is bad.

You will find a speed which it will slip into gear smoothly. It probably varies from car to car, but when you find it, thats where you should shift it, rather then jamming it into gear. The times when it won't shift into first I usually just keep the clutch in and apply steady pressure on the gearshift until the syncros catch and it drops in on it's own. If it takes more then a second, I'll go back to neutral, let the car slow a bit more and try to double clutch again.

Sage

I think that the engine begins to lug as the revs get very close to 2,000. I try to keep the revs between 2,200-2,500 while cruising. If I am on any kind of an incline at all I will downshift to higher RPM. I can tell the engine does not like at 2,500 or below and you going uphill. Even on very slight inclines.

In regards to shifting. My MT is the same exact way 1st to 2nd when shifting at 5,500 RPM or lower. When I move the shifter into neutral, I can feel that I need to hesitate for a 1/2 second before moving the shifter into 2nd gear. If I move the shifter without a hesitation, it will crunch. When I do the hesitation thing I can feel something sort of grab at the shifter and then it nicely moves into 2nd gear.

At higher RPMs the shift from 1st to 2nd is very sweet, no hesitation needed. I am not sure why this is only on the 1st to 2nd shift. It is not like that on any of the other shifts or downshifts. Is it the 1st gear lock out mechanism getting in the way??? The funny thing is that I can down shift from 3rd to 2nd and never have a problem, it is only on the 1st to 2nd shift. During the first 3,000 miles the problem has gotten a little better and hopefully as I put more miles on the car, the gearbox will loosen up a bit more and provide better 1st to 2nd shifts.

gymdent

Fugg, if you're down around 5 mph or so and accelerate moderately you should be fine. Putting a load on the engine by accelerating heavily at that speed is going to stress it.

fugg

im going to take a wild guess and say thats the infamous "double clutching", right?

SpIcEz

forcing the tranny into first gear ??

There should never be any reason to downgrade to first gear...

Am I the only one who thinks this doesn't make sense ?

First gear is to take off... for any speed once you are rolling, 2nd gear will do.