Revving through the Red Line???

It looks like a few of the boys have never put their car on a dyno to see where the power band really is.

 

Unless modified for higher RPM's and horsepower most engines make most of their horse power well below redline. After that you are making extra noise and creating unnecessary wear , if you don't blow it up in the process.

 

I don't think that 3.2 (328, Mondial 3.2) engines have rev limiters -- I'm not sure why. I would much rather they did

 

This is a very interesting thread. I imagine any mechanic could check the accuracy of the tach, as if it is inaccurate at 8K it will also be that way at 4K.

It is possible that engine can withstand revs to that level for reasonable periods of time. Remember that Ferrari has to put the redline where it will prevent massive numbers of in-warranty failures. If they put the redline at 10K there would be owners who picked up a new car and then drove around all day at 10K in first gear just to enjoy the sound. When the engine grenaded they would then expect Ferrari to give them a new engine, only to repeat the process. So they have to put the redline where even an idiot can't ruin the engine.

That said, you shouldn't be terribly surprised if your engine grenades during one of your runs, as it does put a lot of strain on the rods and crank.

 

Redline is *not* to tell you that you're leaving the optimum power range -- it's to tell you that you're going beyond the design limits. But you can bet there's a good "fudge/safety" factor in there of 10-20%.

But for all the nay-sayers, remember that we're not *holding* it at that 8500-9000 range, we're just nicking it in there during aggressive acceleration before shifting. I don't usually do it during street driving, but it's not uncommon for me to do that at the track... most recently I did it frequently at our FCA National Meet a couple of months ago (June) when we got to take our cars on both the Indianapolis Formula One circuit and also at the nearby motorsports Raceway Park track... and that's on 10-year-old 30k belts (yes, I do plan to have them changed out this Spring when my car approaches 60k miles) on my 308QV. Ferraris are meant to be driven -- hard and often!

 

The 328 doesn't have a rev limiter, and I have seen 8500 on mine. However, it's really not any advantage to rev over the redline on it. You can see in the dyno graph that the power is already dropping well before the 7800 RPM redline
Image Unavailable, Please Login

 

Chaa,
Is your engine modified? If your car redlines at 6500, and you're able to rev it up to 9-10k rpm, then I would think that it would have to be modified some how. Does the cars engine struggle beyond redline and does power drop off, or does it rev smoothly like it was made for it? Could you throw it on a dyno for us? Anybody, isn't the TR motor a derivative of ferrari's F-1 engine? That revs to more than 10k doesn't it? So could really be not such a big deal to rev it up to 9-10k rpm?
Jim

 

Engine was compleatly standard, but the limmiter broken.
Two or three years ago i could have used enjoythemusic, mcharness and tuttebenne input and support at the time of my posting Boy was i attacked for dare saying i did it I was standing alone with out back up of anyone else that had done it So i think times have maybe changed. It would have been interesting had i gone up to 5th gear, i wonder what speed it would have done, becourse remember i did 170mphish in 4th at 9000rpm. I know there are alot of moaners but hey i bet the story of a Testarossa with a broken rev limmiter has made its rounds in the pub talk And like i said you all love looking at the pictures and feel better about reving your engines just before red Go on say ya dont to the above LOL!!!
MB: Now i need to get my hands on one of them wonderfull 512Ms me think.....of course with a broken limmiter.........Oh relax dudes, have a smoke

 

Hi Tillman,

Is that really a dyno sheet for a 328? we're told they were 270 hp and about 225lb-ft of torque - your graph shows the numbers to be way down - maybe that why mine seems so slow!!

I guess you were measuring with some kind of rolling road dyno, so your trace shows power after losses from rolling resistance of wheels, transmission losses etc.?

Anybody got any more 328 traces? I'm trying to work out how the get the best outta my engine [rev the nuts off it!]

Thanks,

Rich.

Edit: I can only speak for 1 car but my 328 certainly does have a rev limiter - I know because I hit it pretty much every time I go out!!

 

Yup, rear wheel HP, and 223 is actually pretty good RWHP for a 3.2. The dyno guy said they use a 17% loss ratio, which works out to right at 260HP. That's what the factory said the US cars were rated at.

The 270 is for Euro spec cars, they have a slightly higher compression ratio.

At what RPM do you hit your limiter? I've never hit one on my 328.

 

For two reasons:

Some drivers are idiots and don't know when to stop.

It limits top speed and some feel this also limits liability.

 

And if you by a mistake miss a gear, and f. eks go from 3rd to 2nd by a mistake (meaning to go to 4th) you don't blow your Ferrari's hearth to peaces!

 

The rev limiters I am aware of are electronic. They control either spark or fuel injection on the run UP the rev range. At a specific point they cut out sufficiently to keep the revs at the pre=set limit. I am not aware of any limiter that will protect against an inadvertent down shift. Ouch!

 

Hi Tillman,

Sorry for slow reply - some boring bloke rang me up and it took ages to get off the phone...

Mine hits the rev limiter at 7,800 rpm indicated on the tacho, which incidentally is where the red line actually is, too. When it hits it goes sort of cack-cack-cack, such that 3 cacks take about a second. Mine's a UK spec car.


Plus sometimes, but not always, a little red LED-type light in the bottom left of the speedo (near the 0mph marker) flashes rapidly. I guess this is showing the rev limiter on operation? There's also one at the other end of the scale, which I've never seen come on. The Owner's manual says absolutley zip about them - can anybody tell me what they are..?

Cheers!

Rich.

 

Rich,

Is your car stock? I haven't seen that behaviour in mine, nor do I have a LED in my speedo (the car's not right here, but I would bet big money on it). Maybe there's an aftermarket ignition in your car?

The K-jet doesn't have any capability of reading the RPM on the car, so any limiter you have must be in the ignition.

EDIT: Here's a shot of my instruments. The lower red lights in the speedo relate to the brake system.
Image Unavailable, Please Login

 

That's one of the reasons why you have a limiter. The car will probably lock the rear tires, and the engine rides on the limiter until the tires get's down to the speed that matches the rpm's.

 

Actually, a rev limiter will do nothing to protect an engine in the case of an accidental down shift. The wheels are connected directly to the crank via the drivetrain. If you drop the trans in 2nd at 100mph, the wheels are going to spin the motor to a huge over rev and the rpm reached will be directly related to tire diameter X gear ratio. The only thing that will save you is clutching in an instant, and my reflexes aren't that fast. Most likely the valves hitting the pistons will ultimately limit the revving. ;-)

Rev limiters usually come in two types. "Soft" which retards the ignition advance and doesn't allow reving past a certain pre-set limit, or "hard" which shuts down ignition in rolling pulses. They only work on accelleration.

John

 

Hey Tillman,

As far as I know its stock - and nothing looks like an obvious aftermarket ignition component in the engine bay... It's a pretty late model (ABS) one - maybe there were some extra bits and bobs the Factory did on these beyond the brakes (I know about stuff like the rubber surrounds to the door handles, but not anything significant like diff. ignition).

It's a bit late for me to get out to the garage take a pic now, but I'll post one tomorrow - the are definitely two little LEDs in the faceplate of the dial.

Cheers!

Rich.

 

Hmm.. okey! Thanks

 

Hi Folks/Tillman,

OK - here's a picture of my 328 speedo - the little LEDs I'm talking about are at the 0mph and 180mph marks. Like I said, I think I see the 0mph one blink rapidly when I hit the rev limiter (though I don't think that happens *every* time - I'm kind of paying attention to what's happening on the road to look to closely). I don't know what the other does (warn me I'm about to go back to 1955?)

Has anyone else got these?

Cheers!

Rich.

Edit: Actually I see that these appear to be on Tillman's photo as well (note they're on the speedo, not the tacho). I guess they are standard, but what exactly do they mean?
Image Unavailable, Please Login

 

My car self limits (on acceleration) at about 7k RPMs via valve float.

Ken

 

I have an event coming up where the rev limiter, I mean my wife will be in the car with me for hours.
I think she is set to squawk at 6k rpm and dig fingernails into arm at 7k rpm.