How fast does a 308 really go at redline in 5th?

Theory is a wonderful thing but even so I would imagine that other variables would have to be taken into account. Things like altitude, humidity,temperature,wind direction and speed, composition of pavement, grade, type of tire even the gas used. Perhaps the right combination of all those things plus others that I can't think of might get you to a theoretical speed. Also, how accurate are the ratios that are published and how accurately were the gears made to the published specification?

However, in Willoughby's book Mel Nichols recounts the speedo in a 308 gtb carby recording OVER 160 while chasing a Daytona. This was in Car magazine 1976

 

I remember a Motor Trend article back in 1985 I believe testing top speeds of a 308 QV, 85 Corvette, a XJS, and some others. I believe they recorded something like 145-150 mph if memory serves correct.

 

+1

I also seem to recall the 308 at 150 miles .... The 328 had a claim of the 160 mark, and the Testarossa had a blistering 182....as the f40 was the first to ever reach 200....though, these could have been European numbers.

 

Note you specify GTB and S but am sure GT 4 relevant.

Easily attained 140mph with 2 up in76 euro GT4 on handheld geeper.

The ride was average as suspension stock and the road was a little lumpy as many of our roads are now post our big quakes in 2010/11.

I felt excluding handling it would have been a breeze to get to redline and a surge still remained under foot when I backed out. Suggest 155+ no worries at all if The road was good and one really wanted to prove a point ( which I have no interest in ).

 

Don't know if this is of interest, as these are data for the cousin, aka the 328, but nevertheless...

I still have the "special edition" of Auto-Hebdo, a french magazine, published beginning of 1986 (Hors série n°2, l'année Ferrari 1985/1986) that I bought at the time.
They tested a then-new 328 GTB at exactly 264,5 km/h (which would be 164,38 miles) measured, with 285 km/h indicated on the speedo.
The engine was doing 7650 rpm and they reached the engine speed restrictor (ignition cut-off).This was attained on the slightly most favorable of two passages.

They suspected that this GTB was indeed a fast one, as they managed to break twice under 25 sec (twice 24'9) for the standing kilometer, measuring its acceleration on a deserted highway, against 25'6 claimed by the factory.

Best

 

Just for the sake of it, I have un-earthed the following figures from period magazines;
of course, I cannot vouch for accuracy of measures, conditions of test, wind, tyres, etc:
Speed claimed as attained, for different variants of the "Berlinetta" (GTB)

308 GTB "vetroresina", Dry sump, July 1976, Autosport (GB) 249,6 km/h (= 155,13 miles per hour)
308 GTBi, US Version, Oct. 1980, Car & Driver (USA) 224 km/h (= 139,22 mph)
308 GTB QV, US Version, month ?? 1984, Road & Track (USA) 227,2 km/h (= 141,21 mph)
308 GTB QV, Euro, Oct 1983, Motor (GB) 248,6 km/h (= 154,51 mph)
308 GTB QV, Euro, Oct 1983, Auto Motor und Sport (Germany) 258 km/h (= 160,35 mph)
308 GTB QV, Euro, Nov 1984, Auto-Hebdo (France) 253 km/h (= 157,24 mph)

 

Getting any stock 308 to over 7k rpm in 5th gear requires a very good and well tuned engine. I have seen north of 6500rpm in 5th a number of times when my engine was stock, and anything further than that it could do I think, but the rpm needle was creeping to get up there. I think I had it around 6800rpm once or twice. I see no point in it for the sheer length of clear road that would be required to see how high it will spin. 10 miles or so would probably do it lol.

 

"The engine was doing 7650 rpm and they reached the engine speed restrictor "

Am I understanding that it hit the restrictor at 7650? I have hit my 328's cut out a couple of times in the low gears and the tach was indicating just a tad over 8k. Of course I'm sure the tach is not that accurate at that RPM but I would think that since the redline is 7800, the cut out would be right around 78-79. Of course the road test motor could have been hitting 7800 or thereabouts and the tach showing 7650. Per the gearing, it shouldn't have been able to hit that speed at 7650 unless Euro 328 gearing is taller than US 328 gearing.

 

Ok, just to be sure for this new owner.. there is a rev limiter?

Lester

 

Hi Mike, how you doing? In Mexico city or in Maryland?

Yes, you read me correctly:the article indeed states that the engine hit the restrictor at 7650 rpm. Please keep in mind that I am only quoting from a magazine which is now 26 years old (and I was 26 years old when I bought it...).
This is also a bit weird to me, as my GTB cut at about 7800 rpm today; I never push its sister the GTS that far...but I do it from time to time for the "B", just to blow the cobwebs away.
For your information, the article I was quoting also mentionned that the "B" they tested was not fully finely tuned as for brakes, for instance: the front ones were locking from time to time.
And, to answer your last question about gear ratios: yes, they are indeed different for a US and an Euro car.
Most sources give, US market car (first figure) vs euro (second figure):
first: 1:13,4259 vs 1:12,670
second: 1:9,2401 vs 1:8,719
third: 1:6,6490 vs 1:6,274
fourth: 1:4,8870 vs 1:4,610
fifth: 1:3,6111 vs 1:3,407
reverse: 1:12,7546 vs 1:12,039
final drive: 16/65 vs 17/63

Does this make sense to you?

I have one source (Dirk-Michael Konradt's book, in german) that also states that the gear ratios for euros cars were changed during the production run for the 328, to provide better acceleration, but I was never able to find any confirmation for this. I even opened a thread about this on this forum a few months ago, but nobody confirmed.

And should you ever be somewhere near the french/german border, and want a nostalgic trip to Heidelberg, we can do it either in an Euro GTB or an Euro GTS: my cars are ready!

Best,

 

I'm back in Mexico - left the 328 to fend for itself in MD for a couple of months!

Great info re gearing, road tests, etc. Makes sense to me that the Euro 328 would be faster top-end wise than the US version. The US version, in theory, should accelerate quicker but perhaps the 10 more HP from the euro makes up for that though my gut feeling is that it wouldn't

Lester - yes, the 328 has a rev limiter; I don't know about 308's.

 

I submitted the post earlier before I was done typing...

Thanks for the offer for a trip to H-Berg! That would be fun!

 

<Lester - yes, the 328 has a rev limiter; I don't know about 308's.>

I can't speak to all 308s, but neither of my 77 GTBs have/had one. I had my first one to 7900 in 5th and 8500 in 3rd. Only checked 3rd gear in my current car (8000).

 

Had my GT4 to 7800 in 5th, and it was still pulling (on a cold day at sea level, so ideal conditions for the engine). The speedo read 165 mph then. Which I later found is around 150 mph true.

 

Soooo....are gt4's faster than gt/gts'?

 

My 85 does not have a rev limiter, not sure how acurate the tach is though, I have had mine to 8k+ a few times and she was still pulling.

Too many old parts, strike that, EXPENSIVE parts moving way to fast to do that very often.

 

My GT4 is EXACTLY as fast as the very nice and well-sorted GTB QV of a friend here.

Both Euro, both with aftermarket mufflers (mine: X-Ost, his: Tubi). We did a pull from roughly 50 mph to maybe 130-140 mph and there was no telling who had won. If anything, it could not have been more than a two-inch difference.

Sounded like our gear ratios were the same too, as we shifted at exactly the same time, every time.

 

You Dutch...so diplomatic...

 

I do 240KM/h +( divide by 1,609 for miles) once in a while in Austria. It feels very stable, no fuss.stays straight like an arrow. ( Not like my 1980 Porsche SC)
Its scary at first, cause its such a small car and you sit so low, but after a while I feel I could go that speed forever.After you get out you think you just drove Lemans at 350 Km/h Ha! Eurospec ( Italy) 308 GTB, black, all original.58.000 KM.

 

I have played with my 85 us 308 ... cool night on long straight road with hand held GPS ... I managed 154 mph ... but the car felt very light at those speeds and a bit scary. I did not hit any rev limiter.

 

Did you have the spare in the car?

I don't believe there is a rev limiter in a 308, my 85 doesn't have one, maybe the 328's

 

Do you have a Euro front spoiler? The installation of this spoiler on my 308 corrected that light feeling immediately even at hwy speeds!

QUOTE=rskdsk;141713647]I have played with my 85 us 308 ... cool night on long straight road with hand held GPS ... I managed 154 mph ... but the car felt very light at those speeds and a bit scary. I did not hit any rev limiter.[/QUOTE]

 

I had my stock 84 QV 70K mile at that time with spare tire at 145+ MPH and still going faster, had to slow down due to need to exit up head.

 

"I don't believe there is a rev limiter in a 308, my 85 doesn't have one, maybe the 328's"

The '89 USA 28 definitely has a rev limiter at around 8100RPM (per the cars tach).I can't speak for any other 3x8 model.