Word to the marketers.... I need a 7 or 8 speed gearbox about as bad as I need 20 or 21 inch wheels.

Which is another way of saying I won't buy your f'ing cars if that's what you offer me. More/bigger is not better in the real world.

JR

I have a 82SC-3.3-915 with goodies--top end 140mph- only
I had an opportunity to drive an 86-euro 930-- :) long drive
There is more shifting and more work with a 5speed. Gets annoying for long drives and more tired.
930-4speeed great on the highway--just goes--- 3rd to 4th--just hit the gas...nice enjoyment.
My car--4th comes in real fast on top end (revs faster) than a 4speed. There is more involvement, could be a good thing or a bad thing..
As for quicker revs and shifting faster my 915-KEP-lightweight-PP-Clutch is great.. But you have to be on your game or you can screw up pretty bad-money shift etc-- (short shift)-
Two different driving feels... I do like the 4speed. :)

I guess that a lot of this 4 v 5 discussion comes down to the driving characteristics that one likes.

No doubt an SC or Carrera would get an initial, extremely short lived, jump off of the line over a 930, but put them side by side on a highway onramp and check were the SC or Carrera is when the 930 has already hit the highway doing 80 mph (one of my favorite "moments" in my car - merge onto a highway going 15-20 mph faster than the traffic that is already on there :D). And not to mention "at speed" roll ons - no comparison there even with just a 4 speed to work with.

And obviously, the amount of shifting that one wants to do is completely personal preference. I enjoy not having to shift much since there is so much power/torque available, but others probably like to have the, errr ummmmm, "stick" in their hands as much as possible! :D

Oh, and my brother has a 951 - no doubt that would top ashen's list for 0-25 times.

I have 3 cars: a 4 speed a 5 speed and a 6 speed.

Practically speaking I think 5 speed is a good balance

idealistically/theoretically/philosophically more is better when it comes to gears if it doesn't add weight or decrease reliability. In this dream world you could have a 9 speed 930 transmission where 1-4 had 88 930 gearing and 5-9 had 89 gearing. You could pick either set as you see fit or mix and match.

also with all these fun philosophical discussions, and thoughts on preferences and higher order nuances, I have a simple question that I will ask more directly.


Is a bone stock 89 930 measurably faster than a bone stock 88 in any or all contests of speed?

I wasn't sure but I suspected as much

I threw that out there so I could blame "dog off the line" on CIS and 4 speed, rather than just early German turbocharging.

I enjoyed the four speed and thought it a good match for the engine. Pretty much drove around town in 1st and 2nd, when opportunities arose to jab the throttle (I was on a K27-HFS), that upshift to third always made me smile!!! And fourth worked well on the interstate or for long stretches.

Much of the off-the-line difference between the two boils down to the fact that 951s have much higher static compression than 930s - can definitely get away with a lot more of that with Motronic (as opposed to CIS) and water cooled heads.

yeah good point,

Air cooling is like 4 speed and CIS. It was a bit archaic and performance limiting even though it was effective and loved

Back in the day, to the uninitiated a five speed must be am overdrive with more top end.

To the engineer, it was a way to keep the same top end but fill any torque gaps along the way

Rear end final drive ratios was the way to achieve top end

Not a 930 wiz but was early Motronic that much better than late CIS? 84's piss fuel one bank at a time rather than all the time. The barn door thingie and all.

It is superior, but why? I honestly don't know.

What is the big driver? Does it have flywheel triggers? That would be a good thing.

Bob, I don't know the exact answers to your questions about CIS 'v' Motronic, but isn't the 930 CIS capable of delivering far more fuel than the Motronic system? I know that the fuel demands of the 930 are much higher than for a N/A 911, particularly under boost, and have theorized to myself that this was Porsche's reason for sticking with CIS for the Turbos. I don't have hard facts/data to back that up, however (no homo).

CIS isn't a bad system, compared to an early Motronic. It gets a bad rap because too many owners won't spend the time and money to fix their broken systems, or they modify them without really understanding how they work. Maybe 1 in 100 owners really knows what they have and how it all works.

Those of you that modify your 930 engines should be especially happy that you do not have Motronic. It's not nearly as adaptable as CIS, for the typical owner.

JR

I remember reading the 0-100km specs for an 88 and 89 stock 930 somewhere reputable (Porsche's numbers or buyer's guide book). The 88 beat the 89 by about ~0.1sec. I thought it was mainly due to lower wieght.

No homo is right.

From a non-pro standpoint, CIS, as vacuum/pressure driven as it is, is flexible. No maps to deal with. How much air you sucking? Oh, ok, here's your fuel.

Not pretty or sophisticated, just functional and scaleable without mods.

I do think as javadog stated that Porsche was sucking cash wind in the early 90's. They could have jumped on a Motronic system with engineering advancements, but given strained cash allocation, other issues took precedent.

There is a reason why Porsche doesn't offer a 4-speed PDK Transmission(or a 4-speed manual) in any of it's current line-up...lack of flexibility in everyday, real-world driving.

Go the other end in a typical 4-speed 930 unit, say down to 2 or 3 speeds...it would greatly reduce the driving experience as lugging the engine down low until revs/boost come up to an appreciable level. Lack of low end torque from especially the early 3.0's combined with tall-gearing was part of the 'package' that contributed to the 'lag' until the turbo caught wind.

You might not NEED a short 1st-gear in a 5-speed to simply pull away from a light, but it's a bonus to have since most of us drive our cars in the real world, not a race-track.

Actually, the reason you see so many speeds in a modern PDK has to do with fuel ecomomy. They are trying to eek every last MPG out of these cars, to meet the dim-witted regulations coming down the pike. Launch a PDK car from an intersection in auto mode usung normal throttle openings and you'll be in fourth gear in the first hundred yards.

930 boost lag has more to do with the exhaust system design and Porsche's choice of the turbo they used. You can change either of them, or both and you'd be surprised how much the lag is reduced.

JR

We could debate "dim-witted" regulations are why we don't have 10-year old children working 18-hours a day in factories any longer in America.

And why not get better fuel economy, and cars which are MUCH faster than before since they actually burn most of the fuel coming into the combustion chamber. I have no problem with that.

Want to live right next door to a coal-buring smokestack...or stay behind a diesel truck belching out that toxic cloud? I'll bet you don't to take a deep breath of it.

Take away even for a single day the regulations we live by in terms of everyday law...pick even a leap-year Feb 29th. And for that 24 hours...there will be no response from police/law enforcement anywhere in the country.
You'll see the 'nobility' of mankind very quickly that would make the LA Riots look like model citizens.

Taken from my friend who used to field a fuel economy race team for a few years, he discovered by accident that his last minute engine project came close to winning because he hand't taken the time to lean it out as much as other teams.

The current trend at that time in fuel economy competitions was to create an engine that sipped fuel across the range.

With his entry they had invested so much time in the chassis that the engine was a gas pig, so they ran it in short hard bursts alternating between power and coasting, and did very well.

Next year he expanded on this technique by building essentially a dragster motor for the fuel economy class.

Here is how fuel economy competition engineering has evolved over the years:
Era 1) lean out an engine (similar to the era where big V8s made less than 150 hp)
Era 2) Bump and coast - on the gas hard, coast, repeat.
Era 3) Tune for an extremely narrow but highly efficient power band, and use an infinite number of gears to keep it in the most efficient range (constant velocity transmissions - like snowmobiles use)

Translated to street cars, we now see models with constant velocity transmissions, or an ungodly number of actual gears, to allow the engine to stay in the sweet spot.

(BTW, both fuel economy and performance driving share the same need for a sweet spot. The reasons engines make so much power where they do is because they are highly efficient at using the fuel at that rpm)

Variable valve trains are a similar approach but instead of varying the gears so much, the power band is able to be varied with a constant sweet spot.

My truck has both a variable valve train and a 6 speed. In the real world I use 1, 2, 4, 6.
Meanwhile the fuel economy ratings are produced using all gears in a controlled test.

Automatically shifting manual transmissions (floppy paddle types) probably shift more efficiently than I do without that, but there is no way that I need as many gears to get the job done even when hauling. My torque curve is broad enough that I can skip gears without falling out of the power. I'll bet a modern 911 does that even better.;)

Not a real fair comparison, there...

I say dim-witted because the government is fond of passing regulations before we have the ability to meet them. Nothing new, they've been doing it for decades. Remember how ****ty the first "emmisions era" cars ran? The regulations ran ahead of our ability to meet them and the good old consumer took it in the shorts. Think Porsche is ready for the 35.5 mpg CAFE standard that was passed for 2016? How about the 54.5 mpg standard for 2025? Think you'll still be able to buy a GT2 in 2025? Or will the Porsche of 2025 be a hot Prius? Even today's Prius won't meet the 2025 numbers.

How about the ethanol bull****? They are starting to admit that it damages engines, hurts world food availability and prices, doesn't really have a positive impact on the energy "problem" in this country and it also ****s up the environment. How's that for stupid? We pass this ill-thought-out crap and then once we figure out we were wrong, we don't do anything to change it.

Wanna fix the pollution problem? Start where it's bad. China. India. Most of Asia. Ocean-going ships. Etc...

See where I'm coming from?