redline. Good or bad to do
#26
Insanely Yellow
Redline, but then don't shift so hard and let the revs fall to the right match before taking out the clutch.
Redlines do no harm to this car. The good they do, is theoretical at best. But I'm more than happy to redline it a couple of times daily!
I think the biggest thing it does is make you like the car more - it firmly attaches my grin every time I do it ...
#27
Registered User
Join Date: May 2007
Location: Arizona
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
i love owning this car bacause i can just leave it in a low gear like 2nd and drive around wherever and at whatever rpm it still wont hurt the car and when i have poeple riding with me they always say " man your gonna blow your motor if you keep driving like that" that just makes me smile because i know this car just begs to be driven even harder
#30
I <3 Sushi
iTrader: (21)
i love owning this car bacause i can just leave it in a low gear like 2nd and drive around wherever and at whatever rpm it still wont hurt the car and when i have poeple riding with me they always say " man your gonna blow your motor if you keep driving like that" that just makes me smile because i know this car just begs to be driven even harder
#31
Any theory on how throttle position while approaching redline daily, affects carbon buildup? In other words, does a slow build up to 8-9K work as well as a 1/2 or WOT acceleration to redline?
Mysql brings up an interesting point that only 7K is good enough to accomplish carbon cleaning. Any basis to this?
Another question is how the once a day redline affects gas mileage. According to my Scangauge, it doesn't mean all that much. Gas mileage seems to be mostly determined by how spirited and heavy footed the driving was for most of the day compared to a one time WOT carbon cleaning.
Mysql brings up an interesting point that only 7K is good enough to accomplish carbon cleaning. Any basis to this?
Another question is how the once a day redline affects gas mileage. According to my Scangauge, it doesn't mean all that much. Gas mileage seems to be mostly determined by how spirited and heavy footed the driving was for most of the day compared to a one time WOT carbon cleaning.
#32
Vtak just kicked in yo!!
iTrader: (1)
Join Date: Jun 2007
Location: Lake County IL
Posts: 4,053
Likes: 0
Received 0 Likes
on
0 Posts
wait, stew, so chirping my wheels from 1st to 2nd has given me all these problems??? I mean im clueless, I dont do it alot, but when Im getting on it I redline 1st then shift quick to second, not an abusive power shift, just an aggressive shift usually resulting in a chirp
#33
The devil made me do it
iTrader: (1)
Join Date: Jul 2007
Location: Colorado Springs, CO
Posts: 3,708
Likes: 0
Received 2 Likes
on
2 Posts
Yea...definitely out of your *** on this one. In order for you to blow out the carbon you need to open the third set of ports on the engine. This happens at the 7K RPM range. At 4K you barely just opened the second set so you aren't helping at all.
#36
the real question is what in high rpm cleans the engine. Is it the spinning of the components? Is it the air flow? The amount of fuel and the resulting explosion?
Because at 4k I have more of two of these than a NA car, and at 7k unless its the spinning force, I have 1/3rd more
Because at 4k I have more of two of these than a NA car, and at 7k unless its the spinning force, I have 1/3rd more
#37
The devil made me do it
iTrader: (1)
Join Date: Jul 2007
Location: Colorado Springs, CO
Posts: 3,708
Likes: 0
Received 2 Likes
on
2 Posts
my understanding from one of the other threads was that when the last set of ports open the carbon gets blown off. if you don't redline the carbon builds up on the port and eventually it fails to open properly.
#38
Insanely Yellow
wait, stew, so chirping my wheels from 1st to 2nd has given me all these problems??? I mean im clueless, I dont do it alot, but when Im getting on it I redline 1st then shift quick to second, not an abusive power shift, just an aggressive shift usually resulting in a chirp
Basically, what happens when you do that hard shift is what's called "driveline wind up" - it's the same thing that causes axle hop too. Easiest way to imagine it is that the car is trying to pop a wheelie when you slam all that power through the driveline. Since this isn't a bike weighing only 500 lbs with rider, and since the driveline isn't rigidly attached to the overall structure of the car, but is instead suspended under the frame, the hard slam of power (and by the way this also occurs if you dump the clutch at any revs over about 2500 from a standing start) causes the pinion in the differential to "climb down" the ring gear, thus rotating the front of the differential upwards - the pinion is the gear on the end of the driveshaft, and the ring gear is the big round gear in the diff that is at a 90 degree angle to the pinion (making it parallel to the rear wheels). That causes the entire differential to rotate it's front upwards - the amount is quite stunning if you've ever seen this on a high speed camera - as much as an inch or more of rotation - until the restriction of the suspension snaps it back into place and instead causes the wheels to spin.
That rotation of the differential takes it out of line with the rest of the driveline and puts side load on everything in the drivetrain - the output sleeve bearing/seal in the tranny, the u-joints, the input sleeve bearing/seal in the diff, etc. And that load causes those seals to fail.
So, ease up on the hard shifts and that should make stuff last longer.
Sorry for the long-winded answer, but figured you were interested in understanding the phenomenon at play.
BTW, as I said before, axle hop is also causes by driveline wind up - this is caused because the friction between the wheels and the pavement is more than the driveline windup - so in axle hop, the driveline rotates upwards, the suspension catches it, the wheels literally hop off the ground to correct things, and the driveline snaps DOWNWARDS this time as everything over-rotates, the wheels come back down and the cycle starts again. Axle hop is absolute HELL on your driveline.
Stew
#40
Atomic 8
Join Date: Sep 2007
Location: London, Ontario
Posts: 884
Likes: 0
Received 0 Likes
on
0 Posts
Someone here said redline but try to avoid hitting the fuel cut-off. Is that really important? I usually don't hit the fuel cutoff but it's pretty close and sometimes I do. Is that really bad? How to avoid it? It's a murky territory up there.
#41
The devil made me do it
iTrader: (1)
Join Date: Jul 2007
Location: Colorado Springs, CO
Posts: 3,708
Likes: 0
Received 2 Likes
on
2 Posts
![Bowdown](https://www.rx8club.com/images/smilies/bowdown.gif)
#43
wow I just learned a lot from this thread.
1. Don't pop your clutch
2. Burn Carbon above 7K (the third fuel port opens and causes this)
3. Don't shift at high revs, let the revs drop to a lower value (less stress on trans)
Great info, now to try it!
1. Don't pop your clutch
2. Burn Carbon above 7K (the third fuel port opens and causes this)
3. Don't shift at high revs, let the revs drop to a lower value (less stress on trans)
Great info, now to try it!
#44
Momentum Keeps Me Going
wow I just learned a lot from this thread.
1. Don't pop your clutch - CHECK!
2. Burn Carbon above 7K (the third fuel port opens and causes this) - CHECK!
3. Don't shift at high revs, let the revs drop to a lower value (less stress on trans) -
BETTER RETHINK THIS ONE!
Great info, now to try it!
1. Don't pop your clutch - CHECK!
2. Burn Carbon above 7K (the third fuel port opens and causes this) - CHECK!
3. Don't shift at high revs, let the revs drop to a lower value (less stress on trans) -
![Lol](https://www.rx8club.com/images/smilies/lol.gif)
Great info, now to try it!
#45
07 6M Black
Join Date: Jul 2007
Location: Apopka, Fl
Posts: 111
Likes: 0
Received 0 Likes
on
0 Posts
Use the clutch??? Lift off the gas??? whats that?
j/k. I dont power/speed shift this car. That's only for straight line runs. When in the twisties its all about smoothness.
j/k. I dont power/speed shift this car. That's only for straight line runs. When in the twisties its all about smoothness.
#46
I'll snap his neck.
Guess that means if you have a 4-port you only really need to rev to 4K, because I believe the secondary port opens somewhere around 3750 rpm. But what fun would that be?
#47
Registered User
Join Date: Nov 2006
Location: Brisbane
Posts: 1,432
Likes: 0
Received 0 Likes
on
0 Posts
I've just picked up on the discussion on carbon buildup, so a 7K> acceleration (to redline) is what we should be doing on a adhoc basis.
I appreciate Mazda will never recommend this course of action, and there seems to be a strong case here.....but is there evidence it will improve the performance or engine life long term?
I appreciate Mazda will never recommend this course of action, and there seems to be a strong case here.....but is there evidence it will improve the performance or engine life long term?
#48
They made me buy my RX8.
Join Date: Nov 2007
Location: Knoxville, TN
Posts: 270
Likes: 0
Received 0 Likes
on
0 Posts
I've just picked up on the discussion on carbon buildup, so a 7K> acceleration (to redline) is what we should be doing on a adhoc basis.
I appreciate Mazda will never recommend this course of action, and there seems to be a strong case here.....but is there evidence it will improve the performance or engine life long term?
I appreciate Mazda will never recommend this course of action, and there seems to be a strong case here.....but is there evidence it will improve the performance or engine life long term?
As far as someone else mentioning having just learned to not pop (drop) the clutch... of course that's not good for the tranny... that's true for any car....
#49
The devil made me do it
iTrader: (1)
Join Date: Jul 2007
Location: Colorado Springs, CO
Posts: 3,708
Likes: 0
Received 2 Likes
on
2 Posts
I've just picked up on the discussion on carbon buildup, so a 7K> acceleration (to redline) is what we should be doing on a adhoc basis.
I appreciate Mazda will never recommend this course of action, and there seems to be a strong case here.....but is there evidence it will improve the performance or engine life long term?
I appreciate Mazda will never recommend this course of action, and there seems to be a strong case here.....but is there evidence it will improve the performance or engine life long term?
#50
Guess that means if you have a 4-port you only really need to rev to 4K, because I believe the secondary port opens somewhere around 3750 rpm. But what fun would that be?
one only needs to get to 3750 rpm to open the 4-port and if so does this figure hold ture for both a manual and automatic?