What would happen???

What would happen If I worked up the nerve to take my lil 4 banger past 4500 rpm??? Would it go back to the future? Would it blow up?(never) or would it just sound really cool when that vvti kicks in? THE WORLD MAY NEVER KNOW!

 

Isn't redline at 5500?

Nothing bad will happen. The ignition system has a rev limiter that will hold RPM.
Biggest concern is accidentally downshifting at too high of a speed... rev limiter can't protect against that.

Back in the 90s when electronic controls were phased into automatic transmissions, I was told by a Ford service manager that the TCU would not allow the trans to engage if it would result in an overrev... not sure that I'd trust that.

 

The red line on mine is 6000 but I think that it would be screaming at that. I've only had it up to 4500 and that was only stationary revving it. I shift at around 3500

 

Nothing. I rarely hit mine but do from time to time. 5500 froma 4 banger? Pretty sure they were conservative anyway.

 

Yes I agree the 5500 redline is probably conservative, as Toyota is with many other things (e.g. speedo error) although this is a large 4-cylinder. Anyway, I drive my truck gently 99% of the time, and since there's a brief, steep uphill climb in my weekly routine, it's a great excuse to "clear out the carbon" by completely flooring it every week in my 4cyl automatic until it decides to shift, usually around 5000-5500 RPM. I've been doing this for years, no problems whatsoever.

 

Ah, to be 18 again.

Hitting the rev limiter ain't good for any vehicle. Would recommend not to do it. Get a civic if you want an engine that likes high rpm's.

You can definately blow your motor if at the limiter. If it is only once for a split second, chances are not too much damage will be done.

 

Nothing will happen if you do it for short spurts, but I would not recommend it. Why take chances ruining your engine.

 

If you want to rev it, it's actually better to rev it while driving it and having some load on the engine than just free revving it. Free revving will cause rapid accelleration and decelleration which puts more tension on all the parts than gradual controlled tension while driving.

 

It's not the typical 4 cylinder like you'd find in a passenger car, it's designed for torque not horsepower. Compare the piston diameter and stroke to other 4 cylinders you'll see what I mean.

5500 rpm redline on this engine is as conservative as 6500 rpm redline on my wife's Honda.

 

I redline my truck about 2 or 3 times a week, and it hasnt blown up yet. its a 4cyl they like to be reved. When im driving on the highway up to school i put cruse control on at 75 mph and the rpm's are 3,250+ for hours and ive had no problems with it

 

I redline my little 3rz probably weekly, when trying to merge into freeway traffic on uphill onramps. Only hit rev limiter a couple times but thats rare, usually when snow wheeling.

 

You want to shift at peak HP.
Going too high on the power curve is as bad as going too low, it's just easier to recover.

My motorcycle's rev limiter is at 5500, but if I shift above 5200, there is a VERY noticeable loss of pull before the limiter hits.

If you hit the limiter, you've already lost the race if the other guy knows how to drive.

 

Word of warning.

Revving like that under no load (in neutral or park) can damage your crankshaft. It's not the final velocity of the crank that damages it, it's the sudden acceleration that can screw things up.

 

And, just because I used to race high power muscle cars on big tracks, I have to say this...

Not exactly. Many times, it's a better idea to shift higher than your peak HP RPM because the next gear will fall right into the power band, giving you an advantage in the next gear up. That all depends, however, on how badly your HP/TQ drops off after the peak. If it's not too bad a cliff, I'd keep going and then shift throwing you right into the powerband on the next gear.

 

About what an 81 Z28 would do off the showroom floor.

 

It does depend on your gearing.
On my Vulcan, the low end is pretty strong so it's no killer if I shift 500 before peak.

My dirtbike is a WR250F, and the wide-ratio trans does make for some interesting gear choices when the trail gets tight.

 

I used to rev my AE86 to 8k at least weekly, made that 100hp seem fast

You'll be fine.

 

You can feel the power roll off above 4800rpm, IMO; not much point in exceeding that in most situations. I have hit the rev limiter a few times in times of overexuberance, though; glad it was there.

I don't normally take mine over 5000 rpm. I do shift from 1st to 2nd at around 4800, when I'm trying to get up to speed; these trucks are not fast by any means. They don't really accelerate; they just gather speed.

 

The "redline" is what exactly? The maximum SAFE engine speed. So you could keep the engine running 100 RPM below the redline all day long and be fine.

Stop worrying. You could probably run the engine at 150% of the redline for a good long while and nothing but maybe a higher wear rate would happen.

I used to run small block Chevy and air cooled VW engines at 150% of the redline routinely and nothing bad ever happened. These Toyota engines aren't delicate little babies - they are tough, hell-for-stout Machines.

Yes; I would normally try to avoid exceeding the redline - but if I did go over; nothing bad would happen for a good long while. The redline is not some magical threshold - it's more of a suggestion.

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