OMG Mis-Shift Ow! Ow! Ow!
#1
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From: Windsor-Quebec corridor
OMG Mis-Shift Ow! Ow! Ow!
So I was going to start a thread about Friday Night Races take 3, but before I even had the time to race once, it started raining. I knew it was only for a few minutes so I waited it out. Sure enough, after about 15-20 minutes, it was over. So half a dozen cars including myself started rolling to try and dry the track quicker.
I practiced wet lauches at the same time, though with my tires pretty worn out, I was at a loss for grip even in 3rd with the VSA on.
Then it started getting better. Even if the launches were still very delicate, I was doing about 88-90mph at the end of the ¼.
So then it happenned, just as I was about to cross the line, I was at the top of third, about to shift in 4th when (I believe) I hit the cutoff just as I was shifting, and the way it moved, I think I ended up putting it in 2nd instead of 4th. It went waaaay up, I remember seeing it pass 8000 before I stepped on the clutch again. I must have shot it at least at 8500rpm.
The stomach ache, eyes closed, the screeching echo in my head, time ticking... Then I rechecked, and the engine was idling as smoothly as ever, back at 600rpm.
So I went back to the pitlane, lifted the hood, and except for some valve ticking, everything seemed fine. The drive back home was as smooth as always, no loss of power, nothing.
It just seems too good to be true. Do any of you folks have any suggestion about someting I should do? Kurt Bradley especially, I'd like to hear your take on this.
I practiced wet lauches at the same time, though with my tires pretty worn out, I was at a loss for grip even in 3rd with the VSA on.
Then it started getting better. Even if the launches were still very delicate, I was doing about 88-90mph at the end of the ¼.
So then it happenned, just as I was about to cross the line, I was at the top of third, about to shift in 4th when (I believe) I hit the cutoff just as I was shifting, and the way it moved, I think I ended up putting it in 2nd instead of 4th. It went waaaay up, I remember seeing it pass 8000 before I stepped on the clutch again. I must have shot it at least at 8500rpm.
The stomach ache, eyes closed, the screeching echo in my head, time ticking... Then I rechecked, and the engine was idling as smoothly as ever, back at 600rpm.
So I went back to the pitlane, lifted the hood, and except for some valve ticking, everything seemed fine. The drive back home was as smooth as always, no loss of power, nothing.
It just seems too good to be true. Do any of you folks have any suggestion about someting I should do? Kurt Bradley especially, I'd like to hear your take on this.
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#8
Have you guys seen Japanese video magazine called Best Motoring? In that videos they race in Tsukuba race track with from Civic Sir to Ferrari F-50. They just shift down at the corner, many times pass redline in any cars. If shifting down and hitting above the redline is critical to engine, there should be many engine failures, but almost none of them had any, except for one blown clutch.
If the engine gets blown that easily without any boost, Japanese auto makers should loose their good reputations.
BTW, I let the engine pass the redline almost everyday, especially when I enter on-ramp.
If the engine gets blown that easily without any boost, Japanese auto makers should loose their good reputations.
BTW, I let the engine pass the redline almost everyday, especially when I enter on-ramp.
#10
Originally Posted by TSXEuphoria
Have you guys seen Japanese video magazine called Best Motoring? In that videos they race in Tsukuba race track with from Civic Sir to Ferrari F-50. They just shift down at the corner, many times pass redline in any cars. If shifting down and hitting above the redline is critical to engine, there should be many engine failures, but almost none of them had any, except for one blown clutch.
If the engine gets blown that easily without any boost, Japanese auto makers should loose their good reputations.
BTW, I let the engine pass the redline almost everyday, especially when I enter on-ramp.
If the engine gets blown that easily without any boost, Japanese auto makers should loose their good reputations.
BTW, I let the engine pass the redline almost everyday, especially when I enter on-ramp.
BTW, there is a huge difference between accelerating past redline and downshifting into redline. Accelerating you can't hurt the car as the fuel cutoff will stop you, when you downshift though, there's no cutoff and you can spike way past 7400.
#13
A few years ago I did the same thing on accident when I first got my 98 Prelude. I thought i really screwed myself that time, but I noticed that everything was just fine after my heart stopped pounding.
#14
i did this by mistake on my 1.7el a few years ago, it was fine. however i clutched back right after i let it out, so it was spinning at probably close to 9K but for less than a second, I think your TSX s/b ok.
#15
Originally Posted by xizor
I would never let the BEst Motoring guys drive my car, they have no respect for someone else's stuff at all!
BTW, there is a huge difference between accelerating past redline and downshifting into redline. Accelerating you can't hurt the car as the fuel cutoff will stop you, when you downshift though, there's no cutoff and you can spike way past 7400.
BTW, there is a huge difference between accelerating past redline and downshifting into redline. Accelerating you can't hurt the car as the fuel cutoff will stop you, when you downshift though, there's no cutoff and you can spike way past 7400.
#16
Originally Posted by TSXEuphoria
Now I got it. Thanks for your info. But I was wondering shouldn't be there mechanical block throwing down to 2nd gear if rpm would hit pass redline?
#17
Originally Posted by sauceman
So I was going to start a thread about Friday Night Races take 3, but before I even had the time to race once, it started raining. I knew it was only for a few minutes so I waited it out. Sure enough, after about 15-20 minutes, it was over. So half a dozen cars including myself started rolling to try and dry the track quicker.
I practiced wet lauches at the same time, though with my tires pretty worn out, I was at a loss for grip even in 3rd with the VSA on.
Then it started getting better. Even if the launches were still very delicate, I was doing about 88-90mph at the end of the ¼.
So then it happenned, just as I was about to cross the line, I was at the top of third, about to shift in 4th when (I believe) I hit the cutoff just as I was shifting, and the way it moved, I think I ended up putting it in 2nd instead of 4th. It went waaaay up, I remember seeing it pass 8000 before I stepped on the clutch again. I must have shot it at least at 8500rpm.
The stomach ache, eyes closed, the screeching echo in my head, time ticking... Then I rechecked, and the engine was idling as smoothly as ever, back at 600rpm.
So I went back to the pitlane, lifted the hood, and except for some valve ticking, everything seemed fine. The drive back home was as smooth as always, no loss of power, nothing.
It just seems too good to be true. Do any of you folks have any suggestion about someting I should do? Kurt Bradley especially, I'd like to hear your take on this.
I practiced wet lauches at the same time, though with my tires pretty worn out, I was at a loss for grip even in 3rd with the VSA on.
Then it started getting better. Even if the launches were still very delicate, I was doing about 88-90mph at the end of the ¼.
So then it happenned, just as I was about to cross the line, I was at the top of third, about to shift in 4th when (I believe) I hit the cutoff just as I was shifting, and the way it moved, I think I ended up putting it in 2nd instead of 4th. It went waaaay up, I remember seeing it pass 8000 before I stepped on the clutch again. I must have shot it at least at 8500rpm.
The stomach ache, eyes closed, the screeching echo in my head, time ticking... Then I rechecked, and the engine was idling as smoothly as ever, back at 600rpm.
So I went back to the pitlane, lifted the hood, and except for some valve ticking, everything seemed fine. The drive back home was as smooth as always, no loss of power, nothing.
It just seems too good to be true. Do any of you folks have any suggestion about someting I should do? Kurt Bradley especially, I'd like to hear your take on this.
Ken
#18
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Joined: Jul 2003
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From: Windsor-Quebec corridor
Originally Posted by kendroz
The same did happen to me and that valve ticking will increase, believe me those are valves that were hurt. On my case the exhaust valves of piston one and three were damaged. Go and recheck compression please before is too late.
Ken
Ken
I've driven about a 100 miles today, and still the same smoothness, as well as good power along with it.
I'm off tomorrow on a business trip for the week in Northern Quebec, so if ever I am to have problems with the engine I'll know soon enough but there's nothing I can do about it anyway, if it has to happen, it's going to happen. I'll then try and deal with it and get it covered under the still valid powertrain warranty.
#21
I'm taking a guess that your car isn't boosted and your car is still relativtly new. Then your engines fine if it idles smooth like you said. Eventhough now the K series have very tight tolorences compared to the B series, I'm sure it can still take some beating. Just try not to do it again!!!
P.S. Do a search on the ClubRsx forum. You might be scared to find out how many people bent their valves or even benting cranks on the K20As
P.S. Do a search on the ClubRsx forum. You might be scared to find out how many people bent their valves or even benting cranks on the K20As
#22
Originally Posted by JeffTSX
I'm taking a guess that your car isn't boosted and your car is still relativtly new. Then your engines fine if it idles smooth like you said. Eventhough now the K series have very tight tolorences compared to the B series, I'm sure it can still take some beating. Just try not to do it again!!!
P.S. Do a search on the ClubRsx forum. You might be scared to find out how many people bent their valves or even benting cranks on the K20As
P.S. Do a search on the ClubRsx forum. You might be scared to find out how many people bent their valves or even benting cranks on the K20As
#24
Hmmm.. I wonder if mechanical over-rev (to a given RPM) is less stressful overall than an over-rev under engine power, since in the former case the pistons and valve train are just being dragged along by the vehicle momentum via the drive-train. (Any engineers hanging out here?) Did you hit the gas while pulling the clutch out or did you immediately realize your mistake and reclutch?
As long as the rods held, it seems like the main question was how much valve float occurred. As others have recommended, a compression test would be a good (and relatively inexpensive) first step...
As long as the rods held, it seems like the main question was how much valve float occurred. As others have recommended, a compression test would be a good (and relatively inexpensive) first step...
#25
Hitting the rev-limiter is way less damaging than a mis-shift. Actually assuming that you haven't removed the rev-limiter it's practically impossible to over-rev an engine without mis-shifting.
#26
Drive the s**t out of your TSX
Gosh...you guys really stressing your TSX like it's a frigging rental car.
>>2004 Acura TSX 6MT Silver/Ebony #134 85,000Km
How the heck did you manage to put that much milage on a 2004 car ???
>>BTW, I let the engine pass the redline almost everyday, especially when I enter on-ramp.
I feel sorry for whoever would be buying that car after you are done driving the crap out of it.
:shit:
>>2004 Acura TSX 6MT Silver/Ebony #134 85,000Km
How the heck did you manage to put that much milage on a 2004 car ???
>>BTW, I let the engine pass the redline almost everyday, especially when I enter on-ramp.
I feel sorry for whoever would be buying that car after you are done driving the crap out of it.
:shit:
#28
Originally Posted by Dan Martin
Hitting the rev-limiter is way less damaging than a mis-shift. Actually assuming that you haven't removed the rev-limiter it's practically impossible to over-rev an engine without mis-shifting.
To rephrase, say I have replaced the ECU to remove the rev-limiter. (Tuning folks do this all the time). Which is worse (and why)?
(1) I rev the engine to 8000 RPM under engine power?
(2) I mis-shift and the engine goes to 8000 RPM before I can get the clutch back in.
(I really don't know the answer)
#29
Thanks for clarifying. I would guess they're probably the same. The loads should be balanced in both cases. I know that clutch in and throttled up to 8000rpm is a because the engine is unloaded that's why they put a rev limit of 5500 if you try to rev at a stoplight and have the clutch depressed.
#30
Originally Posted by Stokeless_TSX
k24's are just stronger then the k20
Originally Posted by Dan Martin
Hitting the rev-limiter is way less damaging than a mis-shift. Actually assuming that you haven't removed the rev-limiter it's practically impossible to over-rev an engine without mis-shifting.
#31
Originally Posted by Dan Martin
The loads should be balanced in both cases.
It takes a comparatively long time to overrev just by stepping on the gas (while in gear), since the power generated by the engine is somewhat balanced by the inertia of the vehicle (plus drive-train friction and wind resistance, to be sure).
If you miss a shift and engage the clutch, the engine rev's up almost as fast (faster?) as it does if you're in neutral at a light and floor it. The inertia of the car in motion "drags" the engine to the high RPM, with nothing but engine compression and drive-train friction to offset it.
Just pseudo-informed speculation on my part...
#32
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From: Windsor-Quebec corridor
Originally Posted by rb1
Hmmm.. I wonder if mechanical over-rev (to a given RPM) is less stressful overall than an over-rev under engine power, since in the former case the pistons and valve train are just being dragged along by the vehicle momentum via the drive-train. (Any engineers hanging out here?) Did you hit the gas while pulling the clutch out or did you immediately realize your mistake and reclutch?
As long as the rods held, it seems like the main question was how much valve float occurred. As others have recommended, a compression test would be a good (and relatively inexpensive) first step...
As long as the rods held, it seems like the main question was how much valve float occurred. As others have recommended, a compression test would be a good (and relatively inexpensive) first step...
I just came back from my trip in Northern Quebec, with about 4000km travelled, and absolutely no sign of anything wrong. Actually, I bested my fuel economy. (see sig)
So now I am at 92,000km, and at my 96,000km maintenance I'll have it looked after.
#33
Originally Posted by rb1
Well, this is partly why I specified "to a given RPM", since there is absolutely no protection from a mechanical over-rev.
To rephrase, say I have replaced the ECU to remove the rev-limiter. (Tuning folks do this all the time). Which is worse (and why)?
(1) I rev the engine to 8000 RPM under engine power?
(2) I mis-shift and the engine goes to 8000 RPM before I can get the clutch back in.
(I really don't know the answer)
To rephrase, say I have replaced the ECU to remove the rev-limiter. (Tuning folks do this all the time). Which is worse (and why)?
(1) I rev the engine to 8000 RPM under engine power?
(2) I mis-shift and the engine goes to 8000 RPM before I can get the clutch back in.
(I really don't know the answer)
No difference. The most likely problem with over revs (in this case the dreaded "money shift") is valve float. Valve float is when the valve springs are not strong enough to pull the valve shut quickly enough and it causes the valves to touch the pistons, under load or not it is the same.
I would get the compression checked ASAP, but that said normally engines with bent valves don't run long, but a minor bend might go unnoticed for a while constantly doing damage to the sleeves etc.
I know the instant pain of a money shift, my most recent adventure was when I was fighting off a 996 at Road Atlanta earlier this year going into a turn at 6000 RPM, I started my braking and while watching my rear view I missed my down shift dumped it into 1st and after a later software dump found out my S54 hit 9563 prm, 1400 over red line (thank God I got back in the clutch QUICK)! At the time I was sure I was out a $18k engine, but after 5,000 more miles it still runs like a top. I did a compression test BEFORE leaving the track!!!
Money shifts suck but you sound like you were lucky!
Vandy
#34
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From: Windsor-Quebec corridor
Results in
Well, for those who care about knowing, I got my compression test done today, and the numbers are great: 160-160-165-160. I now have 98,100km on my TSX.
So I guess I got either very lucky, or the TSX engine is built bulletproof, or both.
On another note, following the suggestions of a member here, I asked my service manager to also perform a "TKO" otherwise known as an intake manifold cleaning. This because of the rather high amount of oil that can get gulped in because of the PCV.
So I guess I got either very lucky, or the TSX engine is built bulletproof, or both.
On another note, following the suggestions of a member here, I asked my service manager to also perform a "TKO" otherwise known as an intake manifold cleaning. This because of the rather high amount of oil that can get gulped in because of the PCV.
#36
Originally Posted by sauceman
Well, for those who care about knowing, I got my compression test done today, and the numbers are great: 160-160-165-160. I now have 98,100km on my TSX.
So I guess I got either very lucky, or the TSX engine is built bulletproof, or both.
On another note, following the suggestions of a member here, I asked my service manager to also perform a "TKO" otherwise known as an intake manifold cleaning. This because of the rather high amount of oil that can get gulped in because of the PCV.
So I guess I got either very lucky, or the TSX engine is built bulletproof, or both.
On another note, following the suggestions of a member here, I asked my service manager to also perform a "TKO" otherwise known as an intake manifold cleaning. This because of the rather high amount of oil that can get gulped in because of the PCV.
#37
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From: Windsor-Quebec corridor
Originally Posted by fdl
Hey sauceman, you said you say the tach read 8500? Well thats not bad at all. Are you sure it wasnt higher?
I'm sort of reassured, although I had already gone back to the tracks for some fun last friday ( http://www.acura-tsx.com/forums/showthread.php?t=12631 ).
jlukja, yeah, the dealer proclaimed me their official pionneer, lol. I follow the strict service schedule (every 8000km / 5000miles). All maintenance done at the dealership, following Acura suggested maintenance list. I'll try and do this until I reach my goal mileage (500,000km). I don't have any specific requirements as far as oil is concerned, my guess is they put in Honda-approved oil. Only things I've added so far was the TKO and compression test. I'll probably keep doing this every 100,000km as well.
#40
damn. so much for honda clutches being weak. You got close to 100k and you take your car to the track and is still on the original clutch. This says two things, either your a really really good driver or people whom replace clutches at 20k are really really bad drivers.