TOP SPEED 328!

Well, Ferrari (owners manual) says that the US 328 can do the 1/4 in 14.6 seconds and US road tests showed that it was actually somewhat quicker at 14.2. So I figure that since Ferrari says the 328's top speed is 156 and they were conservative on the 1/4, I'm pretty comfortable that it will do the quoted 156 with no trouble. If they were equally conservative - maybe 160. I've had mine at an indicated 145 and it was quite willing to accelerate so I feel pretty confident that the 156 is certainly reasonable.

People ask me how fast my 328 will go and I tell them, "The speedometer says 180."

 

5th gear in a 328 equals about 20mph per 1K rpm. So it is more or less rev limited at about 155. You would need a LOT of space to confirm it.

Dave

 

I would not want to be in the car at 155... no matter how much room you have!

 

Based on the gearing, hp, redline, etc...one should be able to exceed the 156 mph redline-limited top speed. The car will rev safely beyond its redline for brief periods of time. (I, for one, have seen 8100 in my 328 in first gear and it was still pulling!)

My guess is that the car would be capable of around 162 mph, possibly higher, but it takes so long to gain mph at the top end that I would think it would start to risk coming apart. It should have just enough hp to play in the 160s.

 

Around here, I hit zero-to-thirty in like a SECOND! I can hit 70-80 MPH on the freeway,
if there's no cops nearby.... once hit 100 on a long onramp, but backed off to 65 in
a 60 cuz I saw a State Patrol car. And around town, in 3rd, I regularly run 4k to 5k
on the tachometer and it sounds AMAZING!!!!..... without much exceeding the limits.

Top speed? NO IDEA and likely never will .... GOD I love this car....



Jedi

 

I have see an indicted 140mph and she felt like it had a bit more.

 

+1

 

On the track, I was able to get my '78 308 GTS up to 135 to 140 with no problem, with room to spare on the rpms. With the 328 being a bit more powerful, I would suspect it would go higher than the 308. It seems Ferrari bases the 156 on the gearing and rpm redline of the car, so that is probably a good estimate, though some might be able to take it a bit higher.

As for not wanting to be in the car at 155+, well, the 308 was stable as could be at 135 to 140. I've had my Corvette over 150, and you know you are going fast. I'm quite content at this point to just drive them on the street and enjoy life. Not looking to set any land-speed records any more.

 

At an indicated 145mph on a decent road, the 328 is perfectly stable with no feeling of being "light" or in any way unnerving. It feels perfectly comfortable. Slowing down to 100mph makes you feel like you could get out and walk.

IMO if these cars are in good repair they are quite capable of running at any speed up to their top speed (whatever that might be) with no worries at all. Everything about the car can handle it.

 

If anyone knows and will post here the cd and frontal area, I can calculate the theoretical top speed.

 

At around 125-130 or so, my US spec 308 would get pretty light in the front end. I think it's due to the short lower US spoiler. I would imagine the euro deep spoiler wouldn't allow as much air under the car.

I haven't had the 328 on the track yet so from what I'm reading here, it should be a bit more stable.

 

That is why this is such a hard question to answer. The Euro spoiler will keep you from careening off the road at 150 mph, but will increase enough drag to bring the maximum number down a bit.

 

"The Euro spoiler will keep you from careening off the road at 150 mph,"

Hard to believe that a US 328 would go from perfectly stable/comfortable at 145 to "careening off the road" at 150.

 

I found a website that listed the Cd @ .36 and the Frontal Area at 17.87 sqft. These seem about right for a GTB (a GTS would be have a slightly worse Cd). Running that through a calculator assuming 15% driveline losses and 12% rolling friction losses would yield 165mph as a drag terminal velocity with 270 crank hp.

That same website list the top speed of a 328 at 163mph.

All the same math would put a 308Qv at 155mph.

Best,


Ron

 

Interesting stuff - now who is going to test it out to confirm this...





PDG

 

I love when smart guys with calculators come up with answers similar to the ones I come up with when shooting mostly from the hip

 

Interesting thread. Hope you guys don't really believe the speedos on these cars.

My 308 is doing an indicated 15 mph ...... parked in the garage. These speedos have always been a little optimistic but that just adds to the mystique and it is impressive when someone pokes their head in and sees a speedo that tops out at 180 mph.

BTW, to legitimately get a car to jump from 140 to 160 mph takes far more than 20-30 ponies that separate the 328 and the carb or QV 308s. I would guess that it would probably take 60-80 horsepower to get that extra 20 mph.

Cheers-Colin Firth-Ontario Canada

 

Hey Mike,
I think Tommy was referring to the 308. I haven't had my 328 up to 130 and beyond yet but I am imagining it should be more stable than my 308. It was a very noticable difference in the amount of steering effort and reaction to steering inputs at that speed in the 308.
One other factor that someone who raced his 308 mentioned was the rake of the 308 contributing to this lightness in steering.

 

i'd guess the Euro 308 would top out at 155 or so but you'd need A LOT of room. Also, early on in the car it had front left and she felt unsafe/floating on the front. After reworking the suspension and corner weight the front lift was cured as a result (not aimed for, it simply was part of the overall tuning).

The (metal) 308 is actually a VERY solid car and have seen them walled at good speed at the track a few times and the drivers were fine. Of course those gas tanks could easily be cracked open so...

 

Calculating it, I got the following:

140 in a 308 would take 167 crank hp
160 in a 328 would take 249 crank hp

That is 82hp, so you were right on. You're exactly right about how much hp it takes to overcome aero drag once the speed gets over 130mph.

FWIW, it would take 485hp to reach 200.

Of course all these calculations assume otherwise perfect conditions.

Best,


Ron

 

All the road tests I have been able to find that did a top speed on the 328 show from 163 to 166MPH. So apparently Ferrrari's owner's manual times/speeds was conservative all the way around - both TS and acceleration was noticeably better than published.

I have always wondered about this - folks say that Ferrari was very "optimistic" with their various figures (HP, weight, etc) yet the test figures on the 328 show just the opposite.

 

Many of those tests are suspect because they used "indicated speed".

Dave

 

If they could pick out "163" or "166" on a 328 speedometer, that's some pretty good vision and some even better interpolation!

 

Speedo accuracy isn't too bad on my 85 308, I have taken it to 8000 RPM in 5th, just over an indicated 145 close to 150 a couple of times. Then add some tire streach that should be worth a couple of mph, maybe 2 that probably makes up for speedo accuracy.

On the interstate you don't watch the speedo as much as what's in front/behind and oil pressure. I have driven many cars at higher speeds, the 308 was very stable at 150, not light at all.