Fifth Gear

[AriK]

Those Germans certainly are disciplined and know their stuff.

[Dawgme85]

I checked SHELOB today and, at 60 mph, she turns 4000 RPM in 4th, 3300 RPM in 5th. That's about 17.5% reduction.

[djape1977]

transmission in 124 has 0.88 fifth gear ratio.
transmission from polski 125 and fso polonez has fifth gear ratio of 0.82

i've never swapped just the fifth gear between 124 and 125 polski gearboxes, but i have swapped out whole garboxes. the rear portion of the housing and rods that selector forks attach to need to be swapped out in order to mount 124's remote shifter to a 125 polski gearbox. all bolt on and viola - 0.82 fifth gear!

[Dawgme85]

My mistake. According to my Spider Service Manual, 1975-78 transmissions have a .881 fifth gear, 1979-80 models have a .83 fifth gear, and 1981-82 returned to .881. I suspect there was a reason for the return to the higher ratio, probably not enough torque to pull that low of an engine speed, even with the 2L engine?

Either way, given that the twin cam is happy to run at 6000 rpm all day, and pulls right up to 7500, I'm happy with mine the way it is. As others have said, if I want quiet, I'll drive the Lexus!

[speedracer]

Either way, given that the twin cam is happy to run at 6000 rpm all day, and pulls right up to 7500, I'm happy with mine the way it is. As others have said, if I want quiet, I'll drive the Lexus!

Wow, 6000RPM all day long?

Long live the DOHC!

I really have to learn to trust this little engine more. I do 3000 to 3500 RPM for quite away without giving it to much thought, although that is still a lot compared to a modern car, but I'm not sure I would trust her at 6000RPM, mile after mile. Am I just babying this car to much?

[81SPIDERMATT]

yes ..yes you are

[speedracer]

yes ..yes you are

Thanks for the honesty Matt!

I promise, I'll give her a proper thrashing next time out!

[Dawgme85]

yes ..yes you are

Agreed! They don't start making any power until 4000 rpm or so. I try not to let the revs fall below 3000, for extended periods, to keep the plugs from fouling. That may just be due to it having a carburetor, though.

Let 'er rev!

[Redline]

Agreed! They don't start making any power until 4000 rpm or so. I try not to let the revs fall below 3000, for extended periods, to keep the plugs from fouling. That may just be due to it having a carburetor, though.

I have to re-program myself every time I switch from our turbodiesel. That rides a fat wave of torque, between 1500 - 2500. I nearly never need to venture beyond that 1000 rpm band to make very quick progress. Dull, but effective for a daily driver. I get into the Fiat and I have to nearly pinch myself the first few km to not lug the engine.

[djape1977]

if you want to make fiat go, rev it! it will happyly cruise all day long at 4-5k rpm. ocassional revving up to well over 6k won't hurt it.
driving a modern turbodiesel quickly is fantastically boring and tyresome for me. i'm always hunting that torque band that's so narrow... jut when it really starts to pull i need to shift up. bugger it, it's much more fun to put my foot down and watch both gauges climb untill i hear the engine screaming.

longer fifth does have it's appeal, but just as long as rear end ratio is kept short. i find 41/10 to be just right for these cars

[speedracer]

Well, I just went for a ride, and while I didn't hit the magical 6000RPM point, I did rev her pretty hard at 4500-5200 a number of times, and she really did well. I think I turned a few heads when I merged onto the parkway with the gas pedal mashed in third gear. She took off really well, and sounded great and it actually surprised me a bit. It was a pleasure getting her into the higher rpm limits. I promise I will take her to 6000 soon!

I'm glad I started this thread, because it's really helped me to appreciate this little gem of an engine better than I did before!

[81SPIDERMATT]

sure is fun aint it ... good for you

[baltobernie]

I drove mine from FFO Nashville directly home. 700 miles and averaged nearly 70mph. If you have any grey in your beard, you will find that the Spider's liquid capacity is almost identical to yours

My drive pales in comparison to Alvon "Iron Butt" Elrod and his wife Maureen, who drove across the country in a few days to another FFO.

http://www.tubechop.com/watch/2513620

[Exit98]

Well, I just went for a ride, and while I didn't hit the magical 6000RPM point

Speedracer,

You know that yellow line on your tach? When the needle gets there is when you should start thinking about maybe shifting to the next gear.

No kidding.

[mscafide]

Don't go under the redline with a 1608 or earlier. The earlier engines like to rev (later ones just a bit less) and are well balanced in stock form. You may not get much additional performance by doing it but it happens so quickly, what the hell. I have never had an engine break at 10k and neither have my friends. Italians like it to sound like "it's going fast" and the manufacturers of IT cars complied (till now).

Sometimes in an autocross you lose time shifting to a higher gear just to change back and get nothing for the effort! I had a friend in the early 70's with a 1969 124 coupe that had almost 80k miles on it. The autocross was on a go-cart track and he got tired of useless shifting. He said "Mike, for this run I'm leaving it in first gear", and he did. Everybody stopped dead in their tracks when they heard the car. He said he wrapped the tach back to zero and it sure sounded that way. If the tachs were any way near accurate that would be 12k. He drove it home with a trophy for FTD (fastest time of day).

Fiat made good engines, just make sure they have the fluids they need up to the proper level.

Mike