OMG! I hit over 8000 rpm!
#1
ok im racing this car, and im going 80 in 3rd and i shift into what i think is fourth, but it was 2nd!!!!!!!!! i hit over 8000 rpm! it was for about a second, so i put the clutch in, and cruz into a shopping center. theres no burnt smell or anything, so i drove it to work and its running fine. what should i check??? what should i replace? has this happned to anyone?
#2
Guest
Posts: n/a
Only stuff i would be worried about, would be engine bearings, and some other small internal engine parts that might not have been able to withstand the high rpm. Shouldn't have done anything that bad though. If you dont notice anything in a week or so, its nothing, or it will turn out to be a long term unnoticeable problem that will hit you hard one day, haha, but that is worst case scenario.
#4
ya, it does have a limiter, ive hit it on mistake before, but i dont know what happned, and when i hit the 8000 it made the worst noise, it made me want to cry! but im not getting the info i need here, what should should i do? what should i check and do i need to replace anything?
#5
Originally posted by madduck99
I would think you would have a electronic rev limiter to prevent excessive rpm just in case of what happened to you
I would think you would have a electronic rev limiter to prevent excessive rpm just in case of what happened to you
#6
Over-Rev
The only way a rev-limeter can limit engine rpm is to cut the spark or fuel... neither of which will keep help in this situation.
The car's momentum is what spun this engine to 8000rpm.
Chances are, the bottom end is fine, it's the valvetrain that will need examined. At extremely high rpm, the valve spring is not strong enough to make the valve follow the cam lobe. The valve gets lifted by the cam lobe, and when it is supposed to close, its inertia causes it to "float". If it is floating when the piston comes to the top of the bore, the piston strikes the valve... possibly bending it. If the valve becomes bent, it no longer seals the cylinder effectively.
You will want to do a leakdown or compression test to help evaluate the extent of the damage (if any).
Being a 4 valve DOHC engine helps you out big time. There are two intake and two exhaust valves... which are much lighter than a one large intake and exhaust valve. The lightweight valves are much less likely to float.
If this was a two valve per cylinder engine (like my mustang), I guarantee you'd have problems.
Good Luck!
The car's momentum is what spun this engine to 8000rpm.
Chances are, the bottom end is fine, it's the valvetrain that will need examined. At extremely high rpm, the valve spring is not strong enough to make the valve follow the cam lobe. The valve gets lifted by the cam lobe, and when it is supposed to close, its inertia causes it to "float". If it is floating when the piston comes to the top of the bore, the piston strikes the valve... possibly bending it. If the valve becomes bent, it no longer seals the cylinder effectively.
You will want to do a leakdown or compression test to help evaluate the extent of the damage (if any).
Being a 4 valve DOHC engine helps you out big time. There are two intake and two exhaust valves... which are much lighter than a one large intake and exhaust valve. The lightweight valves are much less likely to float.
If this was a two valve per cylinder engine (like my mustang), I guarantee you'd have problems.
Good Luck!
#8
I wouldn't worry about the engine. DOHC engines can withstand much higher RPM (sometimes over 2K higher) than what they are redlined at. My friend has an '89 Taurus SHO which has a 3.0L DOHC V-6 made by Yamaha, and he has a chip that raises his redline from around the high 6Ks to 8K and he hasn't had any problems becuase he has a whole underdrive pully kit. Remember this is the same design that is used in racing engines. I would however be worried about your accessories; Water pump, alternator, A/C compressor, Etc. those parts aren't designed to take that kind of RPM....and that's probably the sound you heard, DEFINITELY get it checked out by a mechanic, you can never be too careful.
#9
Originally posted by BriGuyMax
I wouldn't worry about the engine. DOHC engines can withstand much higher RPM (sometimes over 2K higher) than what they are redlined at. My friend has an '89 Taurus SHO which has a 3.0L DOHC V-6 made by Yamaha, and he has a chip that raises his redline from around the high 6Ks to 8K and he hasn't had any problems becuase he has a whole underdrive pully kit. Remember this is the same design that is used in racing engines. I would however be worried about your accessories; Water pump, alternator, A/C compressor, Etc. those parts aren't designed to take that kind of RPM....and that's probably the sound you heard, DEFINITELY get it checked out by a mechanic, you can never be too careful.
I wouldn't worry about the engine. DOHC engines can withstand much higher RPM (sometimes over 2K higher) than what they are redlined at. My friend has an '89 Taurus SHO which has a 3.0L DOHC V-6 made by Yamaha, and he has a chip that raises his redline from around the high 6Ks to 8K and he hasn't had any problems becuase he has a whole underdrive pully kit. Remember this is the same design that is used in racing engines. I would however be worried about your accessories; Water pump, alternator, A/C compressor, Etc. those parts aren't designed to take that kind of RPM....and that's probably the sound you heard, DEFINITELY get it checked out by a mechanic, you can never be too careful.
-Shing
#10
Over-Rev
Originally posted by BriGuyMax
I would however be worried about your accessories; Water pump, alternator, A/C compressor, Etc. those parts aren't designed to take that kind of RPM....and that's probably the sound you heard,
I would however be worried about your accessories; Water pump, alternator, A/C compressor, Etc. those parts aren't designed to take that kind of RPM....and that's probably the sound you heard,
Good Luck!
#12
8000RPM ey??
Originally posted by tmoutlawz
ok im racing this car, and im going 80 in 3rd and i shift into what i think is fourth, but it was 2nd!!!!!!!!! i hit over 8000 rpm! it was for about a second, so i put the clutch in, and cruz into a shopping center. theres no burnt smell or anything, so i drove it to work and its running fine. what should i check??? what should i replace? has this happned to anyone?
ok im racing this car, and im going 80 in 3rd and i shift into what i think is fourth, but it was 2nd!!!!!!!!! i hit over 8000 rpm! it was for about a second, so i put the clutch in, and cruz into a shopping center. theres no burnt smell or anything, so i drove it to work and its running fine. what should i check??? what should i replace? has this happned to anyone?
#13
Don't race
Originally posted by tmoutlawz
ok im racing this car, and im going 80 in 3rd and i shift into what i think is fourth, but it was 2nd!!!!!!!!! i hit over 8000 rpm! it was for about a second, so i put the clutch in, and cruz into a shopping center. theres no burnt smell or anything, so i drove it to work and its running fine. what should i check??? what should i replace? has this happned to anyone?
ok im racing this car, and im going 80 in 3rd and i shift into what i think is fourth, but it was 2nd!!!!!!!!! i hit over 8000 rpm! it was for about a second, so i put the clutch in, and cruz into a shopping center. theres no burnt smell or anything, so i drove it to work and its running fine. what should i check??? what should i replace? has this happned to anyone?
At this point the damage is done. There is really nothing to check and nothing to replace.
I could lecture you on the dangers of racing... danger to your car, your safety, your drivers license... but I doubt you would listen. Some lessons have to be learned the hard way.
#14
Just another reason to be using synthetic oils. Not only for superior lubrication but for superior film strength to help protect your engine in situations like these. No it won't help protect if a stretched rod that contacts the valves during a overrev, but it might be the difference between a spun a crankshaft/cam bearing when they want to actually touch each other and having no damage at all.
#16
Thanks a lot guys
i really appreciate all of your opinions, the car is driving like normal, so i dont think there was any damage, and the reason that i shifted into second was because i broke my shift ****! i think that contributed to the mis shift, damn im really glad theres a forum like this where i can get my questions answered.
thanks
thanks
#17
that ain't bad
i've heard of celicas gts (new one's) drivers driving at like 90mph in six gear trying to switch to forth to race someone and instead of putting it in forth they put it in 2nd and the needle those goes straight around and a couple days later engine seased up and when carried to dealer they said the engine went to 14000 rpms. know that is crazy.
#19
Re: that ain't bad
Originally posted by celica
i've heard of celicas gts (new one's) drivers driving at like 90mph in six gear trying to switch to forth to race someone and instead of putting it in forth they put it in 2nd and the needle those goes straight around and a couple days later engine seased up and when carried to dealer they said the engine went to 14000 rpms. know that is crazy.
i've heard of celicas gts (new one's) drivers driving at like 90mph in six gear trying to switch to forth to race someone and instead of putting it in forth they put it in 2nd and the needle those goes straight around and a couple days later engine seased up and when carried to dealer they said the engine went to 14000 rpms. know that is crazy.
#20
I had some real bad luck
i did the exact thing once only the oil pump shut down and the whole engine got scrapped...now i have a 96 max with 86k miles on the car and 60k miles on the engine....get it checked just in case....course my check engine light came on.
#21
hmmmmmmmmmm......
This brings up an interesting discussion...to my knowledge, the JWT ECU is supposed to bump your rev limiter up to 7K from the stock 6600 or so. Does anybody think it's highly dangerous to tread into this territory? For example...my brother has a 200SX SE-R with the same motor as the old sentra SE-R...the old sentra's redline was 7400, but his was 7100, for no apparent reason...same engine precisely. However, he got the ECU, which took his limiter up to 7700, and he occasionally goes that high. I would think that JWT has researched this a lot and wouldn't do something that could lead to blown engines...though I could understand if it might shorten engine life slightly. Comments?
#22
Turtle turtle... Moderator
iTrader: (25)
Joined: Aug 2000
Posts: 4,857
From: San Bruno, Petaluma, SF Bay area
my bro's SE-R with JWT ECU i think brings it to 7800. I got a custom programmed JWT ECU and they bring the rev up to 7500rpm. i think Nabil regularly brings his VQ above 6500 territory and has no probs.
#23
Unwise to exceed the red line
Originally posted by dental stud
... though I could understand if it might shorten engine life slightly. Comments?
... though I could understand if it might shorten engine life slightly. Comments?
Running your engine at the red line puts maximum strain on the connecting rods and their bearings. Piston rings are scraping the cylinder walls at maximum speed. Engine valves are slamming shut rather than being lowered onto their seats. Mechanical parts are being pushed to their design limits. Installing an ECU which allows you to exceed Nissan's red line is just plain asking for trouble. You are defeating a built-in safety device. Ultimately there is a price to be paid...
#24
i've done the same
i've done the exact same thing 3 times... hit 2nd when trying to get into 4th real hard (only while trying to go fast).. in my case i think its because i am used to my short throw shifter i had in my civic... the maxima shifter is like a skyscraper compared to that.... anyhow, i've noticed no i'll effects from it, just have to be careful to not do it any more. by the way, no rev limiter or electronic crap will stop a 3000 lb cars acceleration enough in an instant to prevent this... just work on not doing it...
Neal
Neal
#25
Guest
Posts: n/a
Re: i've done the same
Originally posted by Nealoc187
i've done the exact same thing 3 times... hit 2nd when trying to get into 4th real hard (only while trying to go fast).. in my case i think its because i am used to my short throw shifter i had in my civic... the maxima shifter is like a skyscraper compared to that.... anyhow, i've noticed no i'll effects from it, just have to be careful to not do it any more. by the way, no rev limiter or electronic crap will stop a 3000 lb cars acceleration enough in an instant to prevent this... just work on not doing it...
Neal
i've done the exact same thing 3 times... hit 2nd when trying to get into 4th real hard (only while trying to go fast).. in my case i think its because i am used to my short throw shifter i had in my civic... the maxima shifter is like a skyscraper compared to that.... anyhow, i've noticed no i'll effects from it, just have to be careful to not do it any more. by the way, no rev limiter or electronic crap will stop a 3000 lb cars acceleration enough in an instant to prevent this... just work on not doing it...
Neal
It lets you put it in 2nd at speeds that high? How hard are you jamming the shifteR?
#27
That ain't nothin'
I let our intern drive my Max and he went to do a 5-3 downshift and hit a 5-1 instead. If I wouldn't have had my seatbelt on it would have threw me into the dash. I don't know what the r's were at because it all happened too fast but I'm sure they were astronomical. No problems yet though! Knock on wood.
#29
Originally posted by SprintMax
just be happy you didn't have a BMW. .that would have been a blown motor.. especially an M3
just be happy you didn't have a BMW. .that would have been a blown motor.. especially an M3
-hype
#30
Originally posted by xHypex
Any reason for the backfill A year and 6 months is a long time ago.
-hype
Any reason for the backfill A year and 6 months is a long time ago.
-hype
#31
Originally posted by SprintMax
I was doing a search for Mike on tranny hard to shift into gear.. and this was one of the threads i came up with.. then i remembered two people who had E36 M3's and they blew their engines with a misshift.. i also remembered all the Celica GT-S that blew from the famous mishift.. figure i would post..
I was doing a search for Mike on tranny hard to shift into gear.. and this was one of the threads i came up with.. then i remembered two people who had E36 M3's and they blew their engines with a misshift.. i also remembered all the Celica GT-S that blew from the famous mishift.. figure i would post..
Carry on.
-hype
#33
Re: Don't race
Originally posted by Daniel B. Martin
One way to look at it is that you put 20K miles of normal wear on your engine in just one second.
One way to look at it is that you put 20K miles of normal wear on your engine in just one second.
Like everyone on this board, I trust your advice & take it seriously.
I am of the impression that the lower you keep your rpms, the longer your engine will last. True or False? Comparing all rpms below the Nissan specified 6500 redline.
90% of the time, I keep the rpms below 4500 and must've redlined (6500 rpms) maybe three or four times. Am I really playing safe or wear & tear just doesn't matter, as long as I keep below redline.
Thanks in advance.
#34
Re: Re: Don't race
he doesn't post here anymore
Originally posted by dashingMax
Hi Daniel B. Martin:
Like everyone on this board, I trust your advice & take it seriously.
I am of the impression that the lower you keep your rpms, the longer your engine will last. True or False? Comparing all rpms below the Nissan specified 6500 redline.
90% of the time, I keep the rpms below 4500 and must've redlined (6500 rpms) maybe three or four times. Am I really playing safe or wear & tear just doesn't matter, as long as I keep below redline.
Thanks in advance.
Hi Daniel B. Martin:
Like everyone on this board, I trust your advice & take it seriously.
I am of the impression that the lower you keep your rpms, the longer your engine will last. True or False? Comparing all rpms below the Nissan specified 6500 redline.
90% of the time, I keep the rpms below 4500 and must've redlined (6500 rpms) maybe three or four times. Am I really playing safe or wear & tear just doesn't matter, as long as I keep below redline.
Thanks in advance.
#35
Re: Re: Re: Don't race
Originally posted by SprintMax
he doesn't post here anymore
he doesn't post here anymore
edit: typo on numbers in original post
#36
Re: Re: Re: Re: Don't race
Originally posted by nadir_s
this thread reminded me of when brittany spears misshifted her ferarri and did $250,000 of damage to her car.
this thread reminded me of when brittany spears misshifted her ferarri and did $250,000 of damage to her car.
#37
Re: Re: Re: Re: Re: Don't race
Originally posted by Bluebird
What? I know its OT but please enlighten me.
What? I know its OT but please enlighten me.
http://entertainment.iafrica.com/news/732041.htm
#40
8k? is that even possible?
the highest i EVER hit was 7400 (dont ask) and that was verified by my SAFC with Peak RPM hold..
as you might suspect i was kicking myself in the butt all week long.. did a compression test immediately the next day to check if i f***ed the valve springs or pistons in anyway.
but really. i didnt think 8k was possible unless you were Turtle95Max.. i think his redline is around 8.5->9k.
the highest i EVER hit was 7400 (dont ask) and that was verified by my SAFC with Peak RPM hold..
as you might suspect i was kicking myself in the butt all week long.. did a compression test immediately the next day to check if i f***ed the valve springs or pistons in anyway.
but really. i didnt think 8k was possible unless you were Turtle95Max.. i think his redline is around 8.5->9k.