Rev limits

The "redline" for the 355 is 8500rpm though the "limiter" kicks in at 8750rpm.

I don't see why the 348 is limited so low. I am certain the valvetrain should handle 8500rpm. The cams may need to be re-timed for the engine to benefit from the higher rev's.

 

348 Competizione LM's had 9000 RPM limits.

I've taken the chips out of my 348 Spider, scanned them in, and our rev limiter sub-routine starts at 7560 RPMs (exceed that for too many seconds and the rev limiter kicks in, or go more than 200 RPMs over 7560 and the rev limiter kicks in almost instantly).

7200 RPM limit for the early 348's (I've scanned in the 2.5 chips from an '89 348).

Can you bump up these limits?

Absolutely. Obviously wear is going to increase, but you aren't likely to blow the motor if even briefly hitting 9000 RPMs (24 hours of Le Mans racing brought a 348 CLM into 2nd place...that's a lot of high RPM driving on our engines).

 

I read somewhere that the 348 engine can safely rev to 9500RPM without 'blowing up'. I am sure the 355 would be able to do the same. Not 100% sure how true that is. They set the rev limiter on these engines for engine longitivity.

 

Thats right mate. Ferrari does not want to be to be known for having bad/quick wearing engines. They would set a conservative rev limiter for each engine they develop and then work on making a good/reliable engine from there. Ferrari makes the best engines in the world!
As Enzo Ferrari once quoted-"You pay for the engine, the rest of the car is free."

 

Schumacher's ex 355 has a 10000 rpm limit if I remember correctly.

 

Well if you are gonna bump the rpm on a 348 you had better make sure you have springs that can't handle the extra rpm's. I am pretty sure that the LM cars had higher rated springs in them to prevent floating a valve.

 

my euro 90 model have a rev limiter at 7800 RPM not 7200...
the power peak is at 7200 so rev limiter couldn't be at 7200...
I think that 90 us version have rev limiter at 7400.

 

I have my shift light set at 8200 and rev limiter set at 8500.ive been told i could go to 9000 with no problems but decided not to push to extremes.

 

I know you track your car Andy, so how often do you see 8200 rpm?

 

Indeed you are correct As was my Testarossa
1st gear, 2nd gear, 3rd gear=140+Mph.
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Crazy bastard!

 

Track or road once its warm, every gear change.

 

And they all me the crazy bastard

 

You are a crazy bastard.
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You crazy bastards!

 

You are welcome to mail me one of your ECU chips if you want me to scan in your version.

So far I've scanned in an '89 Mondial T, and '89 348, and a '94 348 Spider.

Mondial T = 7200 RPM limit.
'89 348 = 7200 RPM limit.
'94 348 = 7560 RPM limit.

But, keep in mind that the rev limiter has ***two*** software triggers.

If you drive over the above limits for more than a few seconds (5 to 15), then the limiter kicks in (e.g. if you drive at 7210 RPMs for 15 seconds in the '89 348, then the rev limiter will kick in).

OR

If you go 200 RPMs over those thresholds, then the limiter kicks in almost immediately.

So for a brief surge, the Mondial T can momentarily hit 7400 RPMs, as can the '89 348.

The '94 Spider can briefly hit 7760 (really, 7800 because of the software delay).

Two triggers. Time above Threshold or +200 peak RPMs.

 

It sure does!

 

Did you do anything to the car or, the engine internals in your Testarossa to get it to rev to 10,000rpm's without any problems? That must have sounded amazing!!! How long did it take to run it through to 140mph?

Jim

 

I have this addiction to drifting around turns in our Mondial t. I just can't help myself. However, I sometimes see 8000 rpm or more when the tires break free under full throttle.

My question is why doesn't the rev limiter catch the overspeed? Is there a limit to how much or how quickly it can retard the throttle or perhaps is the limiter not working or disabled? Is there a way to safely test the limiter?
thanks,
dave

 

I think you'll find the RPM gauge coil over reads. When you break break free a surge is sent to the RPM gauge which takes a few seconds to adjust.

Try driving at 60 mph in 5th, stay in gear and switch the engine off. Give it a second or two then turn the key back on - don't go to starter, just to "on" - the engine will restart, being turned over by the wheels, but your RPM gauge will bounce by 4/500 RPM's and come back to normal after a sec or two.

Blip your throttle with a digital RPM reader and compare maximums, your RPM gauge will overread by a couple of 100 RPM's...

M

 

On my '94 ch I have hit the rev limiter at 7800. The timing has been advanced past stock though. On the dyno the tech shut it down at around 7500, but the hp curve was still going up. I have seen dyno results on earlier 348's were the power band drops off after 7200. Without changing the timing it would not really be much benefit to go past 7200?

 

Unless you are looking for the sound or bragging rights, it really doesn't matter.

If the cam profile is not tuned for it, power will fall off. So even though it is turning 9000, the power is not there. Yes, you can make more hp by turning the same motor faster, but you have to have the cam profile to match.

An (lower tech) example is our Cobra. The valvetrain is safe well into the 7s, but I can tell you that the cam is ground for a peak around 6200 rpm, and by 6800 it is just making noise. Shifting at 6500 is about right.

 

Agreed, but we don't really know where the top of the power curve is for the 348 engine yet once you start modding the intake and exhaust system. At some point the spark advance/cam profile become less efficient and power drops off. I'd like to know exactly where this point is. So far no matter what we do, the engine makes less power at redline than earlier even if we feed it more air and fuel and increase its volumetric efficiency (I love that term). As a result I think we max the cams at 7200 or so, but they still make good power until redline. The object would be to step up the curve even if we have to live with its profile. I can gain 10-15 HP at the peak, but I still lose 5% at the redline. It's still better than stock. We're still playing with this. I can't forget that HP is a derived value and we are measuring torque.