Cruising RPM

328. 80MPH (indicated) is ~4000 RPM in 5th

 

+1 on my 84 QV
Image Unavailable, Please Login

 

i like to "cruise" in the low 3000's so will put it in the appropriate gear for that. otherwise, at freeway speeds, I second/third the above 80mph/4000rpm rec.

 

You have a 6 speed? Low 3000s is 65 MPH for me in 5th

No worries, that's what they're designed to do. Trust me, they're loafing at this RPM. You're not even really up in the powerband

 

Maybe in terms of hearing loss...

Ferrari engines are designed to rev higher. It probably does mean the engine won't go 300K miles like a Honda four-banger, but that's not what Ferrari is about. The car is very responsive in that 4000rpm range -- it's all about keeping it in the power band.

 

I often go to redline durring acceleration, but sustained high revs make me nervous. No scientific reason, the engine just just sounds unhappy, like a singer who holds a note too long. Wish I had a 6th gear in the Mondi.
Dave

 

I was just about to start a thread on this. My 84 QV may be overstating speed, at 4K RPMs my speedo shows EXACTLY 80 MPH, not like Mike's which shows 4100 RPM or so at 80 MPH.

So, my question is, assuming your rolling circumference is OEM (tires/wheels OEM) what is the EXACT speed of a 84 QV at 4000 RPMs?

I ask because I was cruising last weekend and passed one of those neighborhood radar signs (speed limit 35, your speed XX). My speedo indicated about 40 MPH (38-39?) but the radar indicated 35. Almost a 5 MPH difference between speedo and radar. This community had 3 (yes THREE) of these little signs, so I trust the radar more than the speedo.

However, would that difference get higher as the speed/rpm increase (i.e. at 80 showing, its really 73)?

Just curious.

James in Denver

 

3,500 - 4,000 is indeeed 'cruising' range although I find my car is actually slowly accerating at a set throttle position in that range...

Gotta remeber these cars WARM UP using 3,000RPM.....LOL!

Idles down to 800- 1,000...no worries.

Really no comparison to say a 5.7L LT1 ( I have one of those also), that's apples to oranges......

 

5000 rpm or so.

Depends on where I am cruising... German Autobahn cruising will get you sustained 6000 rpm. No problems with that at all, the little car just smiles at that and cruises on.

Do realise that driving styles in Europe and the US are completely different. We Europeans tend to have a more.... errr... shall we say "spirited" driving style, and that gets worse the more Mediterranian you go. These cars are built for that kind of driving. Imagine a cocky Italian Stallion with bell-bottom trousers, whiskers and loads of money to burn. Then put him behind the wheel of this car. You don't seriously expect to see 3000 rpm then, do you??

The myth that 1970's and 1980's Ferraris are unreliable, and that you need a Porsche to cover some serious distances without breaking down is just that - a myth...

Hans

 

my 85qv is happy at 5-6k rpm,I take it higher before shifting,almost to the yellow line,If Im lower than3k-3.5k rpm she's not happy,she wants to go,not gallop

 

In my 79 gts, I like to cruise under 4k on the freeway, so like around 3800rpm or so. Once above 4k the car really starts to want to go, and I usually oblige and sometimes it's not a good thing. Plus my fuel mileage drops to about half once above 4k+ and if I have a good distance to cover it's a pain to get fuel every 150miles.

Jim

 

The stroke in a 308 is quite a bit shorter than a muscle car V8 so the maximum piston speed at 4K RPM in a 308 is about the same as at 3K RPM in a muscle car V8. It's true that the 308 bits are still reciprocating at a higher rate, but without pushrods and rocker arms and with smaller valves, much less risk. But the best thing F engines have going for them is that they have ways to dissipate the heat -- I grew up working on my father's 413CID and 440CID Mopars with plenty of power, but, with only 5 qts of oil and no oil cooler, they'd overheat if you held them at high power output for long periods.

 

I've been told with these and other German cars too low rpm's while moving, especially uphill, can have cumulative negative effects as well. These engines are made to rev and don't like being driven at low rpms. My 328 sure seems to have the torque to go up a hill in 3rd gear at 20 mph(not something I typically do but when cold and second gear is not engageable....) but I wonder how aware I should be about keeping the rpms up once warm. Thoughts?

Jeff

 

Hi, Rv5.

The Ferrari Factory also red-lines the engines for about 45 mins to an hour for testing, before putting them in the engine bay -- I'm trying to find the link that has the article that supports this assertion. My Ferrari technician, Rico Tenni (Ferrari and Lambo trained and certified), of Valtellina Automobili, also confirmed that Ferrari Factory red-line test the engines; however, the length of time at red-line (e.g., 45 mins to an hour or longer or shorter) is not certain.

Found it -- I forgot it was one of my threads: http://www.ferrarichat.com/forum/showthread.php?t=131247&highlight=mythbuster

The engines have to pass tests like this before they enter the engine bay -- once the cars are fully assembled, Ferrari takes them on the track and test drives them at speed before distribution to the dealerships.

The new Ferraris in the showroom have some miles on them from the track testing.

All Ferrari engines are designed for racing and hi-rev conditions -- Ferraris are top-end speed thoroughbreds; hence, 4k RPM is a walk in the park for us.

Check 6.

/s/ Alfonso

 

My '79 308 instruments look just like Miketuason's attachment, except the oil pressure is at 85psi...figure about 21mph per 1000 RPM's...as they say, do the math!

 

In the308 GT4 service manual, it has a whole disertation on bench running in the engine before its installed in the car. There have been allegations the engines are ran at 10,000 RPM, but there is no confirmation at all of that, and I would seriously question that suggestion. They list checking the power curve to 7500 rpm, but the highest sustained speed is 5700 for 40 minutes.

At that point the cars were driven. How far or how hard I dont think anyone really knows. There was a fellow on here who mentioned some routes heading north that are still used by factory test drivers. Whether our cars seen time on the Fiorano test track is equally unknown, but would be quite interesting.

As far as high engine speeds, as Steve pointed out the shorter stroke drops average piston speed done considerably. With a 2.79 inch stroke, 7000 rpm equals just over 3200 feet per minute. In comparison, a big motor with a 4 inch stroke would travel 4666 feet per minute at the same speed. The largest issue with high sustained speed on these cars isnt the bottom end, its the valves. The 2V motors have larger heavier valves, and the speed will cause faster wear up there. The QV cars can probably run twice as long just by having much reduced valve weight. When I drive mine I always try to keep the revs above 3000, cruise between 3 and 4 thousand, though sometimes higher, and try to keep engine speed below 6000 for the most part, with bursts to 7000 plus if I feel like it. They are quite remakable engines to be able to make good power over such a wide margin, and it sure makes it nice for passing.

 

In my 328 4000 RPM is about 80 - 85MPH... All I know is when I'm at that RPM I'm normally keeping up or slightly faster than ambient traffic on I-85 / 285....

As for using these engines at 4K plus RPM for a long time... I used to drive Atlanta to Pittsburgh at least 2x per year and spent 9 -10 hours at 4K - 4500 RPM... never had a problem. All the temps are good, its kind of like they like being used. I noticed that once I've got the car nicely warmed up it shifts a tad better too... my 308 was really smooth, the 328 is a bit more stiff...

 

On the highway, 4000 rpm is kind near the bottom of where I like to be. If I remember correctly, cruising at highway speeds (55-65mph) in 5th gear I think puts the engine speed in the high 3000's. The engine works fine at these rpm's but in my experience, in order to pass or move quickly through traffic the engine needs to be turning faster than that.

IMO the sweet spot at highway speeds is 4000-5000 rpm's (in 4th gear). In that range, the engine is just starting to work. Driving to 6000+ rpm's is just fine, it's just the engine starts to get kind of loud and in 4th gear, that is pretty fast for worry free (ticket free) driving.

Ferrari really did design these engines to operate near the redline and after driving near that range I think you will agree.

-F