4 speed vs 5??

dhaines · 06-12-2003, 01:04 PM

OK, I know many of you will scoff, but my '67 came stock with a 4 spped tranny. Still has one. I have often thought about picking up a 901 5 speed, but really don't know if the closer ratio is worth dealing with the dog leg 1st gear and the reliability issues. This is totally a street car, though like all of you enjoy a spirited drive through the hills. Here is the question, if I look for one, what do I look for? I hear of differnet ratios available, what is a good match and how do I tell what the tranny has? I rarely drive + 100 mph, so top end is not that important. Other than 2.2 bore, my engine is stock. This is all new, and would appreciate your thoughts.

dhaines · 06-12-2003, 05:58 PM

bump

rvanderpyl · rvanderpyl's Garage

I too have a 4 speed in my 68, that was the stock transmission, the 5 speed was an option (Although just about every car ended ordered with one) One of the advantages of the 4 speed is that if you increase the horsepower the 5 speed has a problem with first gear being hung out the front of the case along with reverse, and you can twist it right off if you apply to much power off the line. The 4 speed runs 1-4 in the 2-5 positions so 1st is supported better. I suppose that your top end is limited a bit, but unless you are on the race track I doubt it matters.
And if you are looking for the ultimate lightened car you get to save the weight of a set of gears

901/05 · 901/05's Garage

and my car has lost a bit more low rpm torque from s cams...but I try and use first gear as little as possible. It is too short of a gear and I am up shifting before I fully cross an intersection.

When traffic allows a nice rolling second gear start, and after I get above 2,500 prms, I can blast foreward (from pole position) very quickly. When on the hwy, fifth gear at 4,000 rpms, I am speeding along at about 75 mph and above.

I like the 901 5 speed (it's my third p car with that trans) Having never driven a 4 spd, the best information I could convey is that more is better, but remember first is a low gear. I drive my five speed more like a four speed. (two through five)

Shawn

dhaines · 06-13-2003, 10:24 AM

If I remember correctly the lowest and highest gear ratios are the same for both transmissions. So top speed remains the sam. Just have a closer ratio in the middle. I have a pretty good RPM drop from first to second.

ted · ted's Garage

A 5 speed is just going to help keep you in your Porsches narrow power band. Means something to me.