missed a gear and floored.7000rpm spike safe for 3.2?

[John91186]

So i was accelerating on a pretty steep uphill and when i red lined on 1st gear i tried to change to 2nd but somehow failed.I thought that the gear was in so i floored on neutral.The revīs went to 7000 for like 0.5 secs and came instantly down when i let of the gas.It really didnīt sound too bad so could it even be tachometer lag?Does this damage anything?The car sounds allright.I donīt hear any weird sounds from the engine and there is no power loss.At the time of the accident the car had just been on a full engine maintenance and the engine was in the best operating temperature + the car is driven only 60k miles.I just need some calming words.Thanks.

[Matt Monson]

Probably fine. Wasn't under load. Not like a 5th to 2nd shift at 90mph.

[Bob Kontak]

An only 7,000 rpm blip was probably the result of a rev limiter. It was "told" to hit 9,500 rpm, if you know what I mean - And would have, if it could have.

Sleep well.

My old MSD box has a 6500 RPM kill pill in it. It's really noticeable when it kicks in, but I am in gear. You were trying really hard to scatter the motor, unintentionally, and you were saved by engineers that know we have limitations.

[catuck]

Yep, rev limiter. I hit mine at every autocross. As long as you didn't do what Matt said, you're fine.

[Bob Kontak]

Originally Posted by Matt Monson

Not like a 5th to 2nd shift at 90mph.

Did that in an 85 300ZX. I swear it sounded like shattering glass. Little tiny punching arms poking holes through the block. Odd shaped partial piston lumps in the belly of the remains of the block.

My 4 year old thought it was pretty damned cool getting a ride home in the tow truck.

Thankfully, used Z motors can show up on your driveway for $500 from the bone yard.

Coulda been worse.

[LJ851]

The stock RPM limiter in a 3.2 is at 6250 rpm, tell me about why yours would go higher and maybe i would be concerned.

[John91186]

Originally Posted by LJ851

The stock RPM limiter in a 3.2 is at 6250 rpm, tell me about why yours would go higher and maybe i would be concerned.

I donīt know why it went so high.When accelerating normally it cuts the ignition at around 6300rpm as it is supposed to do.I am thinking it could also be somekind of a tachometer lag or something.I accelerated to about 6000 on 1st,clutch down -> changed to second gear (neutral in this case accidentally)-> floored -> tacho needle goes to 7000,i let of the gas and it drops instantly.Then i yelled swear words and changed to second and floored,wasnīt too concerned about it at the time but decided to ask from the forums just to be sure...

[LJ851]

Did you hear it hit the limiter?

[John91186]

Originally Posted by LJ851

Did you hear it hit the limiter?

I hear/see it to hit the limiter at normal accelerations.But in this case i tried to change to second from a fast acceleration and changed to neutral accidentally,then floored the gas pedal and i think the ignition was instantly cut off but after the tachometer needle went to 7000.The situation was so fast that could it just been a loose tacho needle or something?Im new to the 3.2,actually drove it first time yesterday but couldnīt resist to test it to the limits...

[matt f]

Originally Posted by Matt Monson

Probably fine. Wasn't under load. Not like a 5th to 2nd shift at 90mph.

4th to 1st going into turn 7 (toe of the boot) at "da Glen" doing way too fast!
Amazing how quickly these little buggers will spin.
Very lucky, no damage to engine or sheet metal.
Maybe a little to my ego.

[Bob Kontak]

Originally Posted by LJ851

The stock RPM limiter in a 3.2 is at 6250 rpm, tell me about why yours would go higher and maybe i would be concerned.

Exceeding max RPM while under load is one thing. You can feel the cut out, saving your ass. It's rude.

Under free revving throttle without load, it may act a little differently. Spinning up to 7k on the tach may be normal. Hell, it may have died at 6,300 and then spun up from momentum of the needle.

Sleep well, John.

Here's a tip. Move the transmission lever to where it is evident the gears are engaged. Then lift foot off the clutch.

[safe]

I have taken mine under load to 7000 and plenty of times to 6800.

[cabmandone]

What they all said about rev limiter. My dear brother while we were out for a drive asked "is it okay if I get on it?" I told him "I insist" moments later I said "are you going to shift or just keep hitting the rev limiter?" Apparently his SC doesn't pull to red line quite as fast as my 3.2. He's fixing that problem now with his 3.2 rebuild to replace his 3.0

Rev limiter makes a funny popping sound I've hit it twice, one myself and once with my brother.

BTW, ya gotta finesse these into 2 at higher RPM's or at least I do mine and so does my brother.

[Quicksilver]

Originally Posted by John91186

I hear/see it to hit the limiter at normal accelerations.But in this case i tried to change to second from a fast acceleration and changed to neutral accidentally,then floored the gas pedal and i think the ignition was instantly cut off but after the tachometer needle went to 7000.The situation was so fast that could it just been a loose tacho needle or something?Im new to the 3.2,actually drove it first time yesterday but couldnīt resist to test it to the limits...

It isn't really a "loose" needle. It just has some mass so it swings a bit when it is moved really really fast. The engine won't accelerate past the rev limiter cut-off unless you stick it in a wrong gear and the trans forces it faster.
You are ok.

Originally Posted by safe

I have taken mine under load to 7000 and plenty of times to 6800.

Not a great idea in a 3.2 unless you upgraded the rod bolts. The factory rod bolts are stretch to torque and they are really pushing their limit at the rev limiter. When you get to an RPM where the cheesy stretch bolts can't take it you won't see a failure. What it will do is add a bit of stretch to the bolts reducing the clamp load and once the big end starts getting a little monkey motion at high rpms it will continue to degrade until it spins a bearing weeks, months, or years later.
Get some Raceware or ARP bolts in there so it has something that was designed to take the load.

[Maxhouse97]

Did they upgrade the rod bolts on the club sport, which had a 6800 redline from the factory? I have never seen that they have ... if so, how did they get by with 9mm rod bolts?

[Reiver]

[QUOTE=cabmando;8020648]What they all said about rev limiter. My dear brother while we were out for a drive asked "is it okay if I get on it?" I told him "I insist" moments later I said "are you going to shift or just keep hitting the rev limiter?" Apparently his SC doesn't pull to red line quite as fast as my 3.2. He's fixing that problem now with his 3.2 rebuild to replace his 3.0


Tell him to get a 930-10 euro 3.0.....then his redline will be 6800-7000 and he won't have to worry about that low 3.2 redline.

[cabmandone]

[QUOTE=Reiver;8020702]

Originally Posted by cabmando

What they all said about rev limiter. My dear brother while we were out for a drive asked "is it okay if I get on it?" I told him "I insist" moments later I said "are you going to shift or just keep hitting the rev limiter?" Apparently his SC doesn't pull to red line quite as fast as my 3.2. He's fixing that problem now with his 3.2 rebuild to replace his 3.0


Tell him to get a 930-10 euro 3.0.....then his redline will be 6800-7000 and he won't have to worry about that low 3.2 redline.

He's building a 3.2 with carbs and doing away with the motronic as I understand. It's a pretty sweet looking setup.

[Jerome74911S]

Originally Posted by Quicksilver

It isn't really a "loose" needle. It just has some mass so it swings a bit when it is moved really really fast.

This is the crucial part. I don't believe your engine revved to 7000 for 0.5 seconds. Rather, since the engine speed was increased very quickly, the needle continued to swing a bit because of its mass, therefore, going slightly beyond the engine's true speed.

In other words, this observation (for a very brief time) that the engine reached 7000 was an illusion.

[safe]

Originally Posted by Quicksilver

Not a great idea in a 3.2 unless you upgraded the rod bolts. The factory rod bolts are stretch to torque and they are really pushing their limit at the rev limiter. When you get to an RPM where the cheesy stretch bolts can't take it you won't see a failure. What it will do is add a bit of stretch to the bolts reducing the clamp load and once the big end starts getting a little monkey motion at high rpms it will continue to degrade until it spins a bearing weeks, months, or years later.
Get some Raceware or ARP bolts in there so it has something that was designed to take the load.

It totally stock and I know about the weakness. But my engine produce peak power at 6800 where I have my revlimiter set.
I take to 6800 almost every shift on track days, of which I've done ~8 a year the last 5 years. Its done about 20000 miles in this configuration.

New rods are on the bucket list for this engine...I'd like to go 7500 rpm.

[Bill Douglas]

I drove the SC like this for about 30 seconds. I spoke to my mechanic and he said either it would blow up at the time, and if it didn't it would be just fine

I was in 4th gear foot flat on the floor at about 120mph wondering why it wouldn't go faster, I thought I was in 5th.