Clutch replacement $10,000?? - Page 8 - 6SpeedOnline - Porsche Forum and Luxury Car Resource

May 11, 2014 | 12:02 PM

#106

XWCGT

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Joined: Oct 2013

Posts: 620

From: saratoga

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Quote:

Originally Posted by dicktahoe

Closer? Well let's see. If Reverse we're half-way between the First and 2nd it would be at 10.1. The differences between 9.4, 10.1 (half-way) and 7.7 puts it significantly closer to 2nd gear. Even a 10.1 ratio would make Reverse a lot easier to work with.

hey, I agree. its definitely closer to 2nd by a good amount, but my point was thatour reverse is still very close to most car's 1st gears.

Quote:

Originally Posted by dicktahoe

Actually, the worst part of the car is probably the transmission. 1st gear is a little too low, reverse is too high and 6th gear is too low (3000 RM at 80MPH is way tooooo low, 6th should be an "overdrive gear"). My Audi cruises at 85MPH at 2,000 RPM. However, with that said, my favorite gear in the Aston for passing is 3rd--I can go from 45mph (3200RPM) to 100MPH (7100RPM) in 3rd without shifting.

agreed

Quote:

Originally Posted by dicktahoe

You're right but most times I go over 70 when passing. So when I'm on a two lane road getting ready to pass, maybe 2-3 cars, I just go down into 3rd to get ready (easier than 2nd and getting the RPMs up to 4,500-5,000) then just punch it and hold on.

You may have noticed that in 2nd--RPM is directly related to Speed--30mph is 3,000 RPM and 60 MPH is 6,000 RPM.

directly related by a factor of 100. so, 2nd can go to 78mph?

Quote:

Originally Posted by dicktahoe

Not an odd-ball at all. The discussion of "ratios" was initially around the "Reverse Ratio", which is too tall to be easily used--either you slip the clutch or stall the engine. First is fine, a little too low maybe, but that makes it very easy to control. Second is the same as in a lot of cars, where the RPM matches the speed (4000RPM = 40MPH). Third is a great gear for passing--I love it and I don't run out of RPMs.

So the primary complaint I have is with Reverse--ratio should be closer to 1st, and 6th where you are running 3,000 RPM at 80MPH. Of course if you moved 6th gear up, then 4th and 5th would have to be adjusted up as well--but that's OK.

I think the gears are nicely spaced . 1st just is a little too low. if you go by redline of the engine, then, yes, 1st gear isn't that bad, at 47mph redline MPH. however, that's more of an argument with the other gears, because just starting out in a gear, you don't need a lot of power to get rolling. a low first gear is easier on the clutch, especially in traffic where you can creep along. however I would have preferred at 10.5:1 1st, still shorter than many 1st gears, but it would get that 1st gear shift out to 50mph.
the big problem with 1st is the big RPM drop to 2nd after a shift. with our flywheel weight and engine off throttle RPM drop speed, its just too much of a pause to shift. hard on the clutch and synchos. a taller first would fix that , and we don't need the super low 12.5:1 1st to get out of the hole in a start. in fact, 2nd sometimes can be used, proving that 1st is just too low. And, keeping all the gears the same if you just changed 1st, would make a much better shift to 2nd too, which has a very useful range to near 80mph. however, the only other change would be 6th. no need to have it so close to 5th. a 10-15% taller gear would be nice to increase fuel economy and make the engine work a little less revs at cruising speeds.

Last edited by XWCGT; May 11, 2014 at 12:05 PM.