rgs944

With more time inside I hope I don't get stale posting threads but here is another one. For those of you that have maxed out your cars. What happens at 156. Does the governor kick in or do you just run out of power with your foot to the floor? If the governor kicks in does that mean you should be able to achieve a higher top speed with a promax chip. I did see a youtube video that a guy took his 968 to 162mph.

Thom

On a NA you run out of power.

On a turbo you run out of gears

odurandina

i haven't reached that speed since friday evening on interstate.... ok, it was only 155.


got to that speed fairly quickly... i had more speed left in the kitchen but it would have required about 5 more miles of straight to get there. my speedo and tach read accurate to within ~ +/-0.005


running a slightly larger tire, and straight pipe, my car tops out at 162~163 mph.

User 41221

Ideally, you hold the throttle just below that threshhold so that you don't blow up your engine. Its just like redlining your engine in lower gears except that you don't have another gear to shift into. NA or turbo doesn't matter, redline is redline.

When you hit the rev limiter, the engine momentarily cuts out until the rpms have dropped enough for it to resume running.

Dave in Chicago

At 156 mph in your 968, you are going so fast you begin to go back in time...

ninefourfourt

145mph was scary in my 951. Wiper arms start shifting from the wind, vision starts getting narrow. Can't imagine another 15mph on top of that!

Fox944

Stock cars run out of breath at that speed (if they can even achieve it...meaning they must b in proper running order). There is no electronic speed limiter, top speed on a 968 is HP/Drag limited for bone stock cars.

Lord_Galva

You go back to when 968's were new and parts are plenteful.
Been there and came back, awesome place.
Forgot to pick up rear drive axles and valve guides.

RajDatta

I take the above statement back. Looks like a very reliable source was able to hit 7200rpm in his tip.

Regards.
Raj

odurandina

our older, 968 engines have lost some power. the gasoline sucks, and the cats are slightly clogged. under maximum breathing situations, these factors cause problems. but the '68 engine is a beast. get rid of the cat, get the right muffler and the power comes back up.


you won't ever see 156 mph unless you make some changes. a stock 968 running small, 25" tires, aging cat, etc will top out about 145~150 mph. use your GPS, you'll see... your speedo will be reading almost 160 by the time that happens because you have about 3~4 mph defect built into the speedo, and that's if you're running slightly larger 25.5" tires (like 275-35-18s)... but you're likely you're running 25" tires which are too small to give you your true speed. this is actually good. you'll get the car much closer to the redline, only that will happen before you eclipse 150 mph. don't worry, that's still fast. but you're not likely to be killed.


my '87 944S was 3 years old when i got it... at 130 mph, it felt like the front end of the car was going to float up off the ground. not what i was looking for at that speed. the 968 is like a brick. the faster you go the more solid the car feels. there's no tellling how fast you can corner on a smooth patch of interstate but it's way up there (140~150 seems to work ok).... but, it's not right to drive like that.

ramius665

I've had our 968 cab up to about 140mph indicated (with slightly larger 17" boxster wheels) and that was fast enough for me. With our 951 I've had it up to a GPS-verified 156mph and ran out of nerves but not speed. At anything north of 130mph I start to think about what components I haven't checked in the last 6 months and wonder which one might fail. It's like Duke says, "Go big and tow home." I did note that the 968 felt much more composed at high speed than my 951 did. Once I installed a front splitter on the 951 it settled down quite a bit but still didn't feel as good as the 968.

rgs944

For those of you with cabs, what is the fastest you have been with the top down?

User 41221

I've been in the 140's with the top down on the Kansas Speedway before I had to slow down so that I didn't pass the pace car. I've also been *ahem* "told" that they can do better than 150 with the top down with a tip tranny. Both are indicated speeds, not gps verified, altho the Kansas Speedway event was pretty well documented and the F-40 driver that went flying by me on the track later said he was surprised at how fast I had the car wound up.

As to the rev limiter, I know better than to question Raj on stuff like this, but I've been told for years by some very knowledgeable folks that the 968 DME was programmed to drop the rev limit down to 6200rpm if it sensed an aftermarket chip. I am assuming the newer batch of chips found a way to bypass that, but since I have never run an aftermarket chip in my cab I can't speak on it. I do recall a magazine article not terribly long ago testing a 93 CS where they talked about the rather abrupt cut-out when they hit the rev limit (7200 rpm, I believe). Pretty much everything else that Porsche was producing at the time also have rev limiters, why would they exclude the 968?

I have never bounced my 968 off a rev limiter, but I have done so on 944's and 951's a bunch of times. I am surprised to find out its different but I have never actually looked into it to find out.

RajDatta

I have never been able to hit the rev limiter on any of my porsches in top gear. I saw an indicated 168mph on my 951S, while my friend drove it. Car was completely stock and rock steady. This was back in 1994. It was a long time back but I think the car did hit the rev limiter and I don't remember the ignition cutting off or maybe it was drag limited. It was too long back, so it's hard to remember.
I have never been faster that 155mph in the 968 turbo. This going back to 2004, when it made less power. I was still in 5th gear with plenty left.
Never attempted a fast speed run in the cab. I guess, as you get older, you start to worry about your license/getting arrested. Too much to lose, too little to gain. I would be embrassed to explain on job applications why I was arrested, lol.
If someone told me that the road is safe with no cops, I could see going for an all out run in the 968 turbo. I would expect it to go atleast 185mph. This based on my car making 150hp and 100lbs/ft more torque than a factory 968 turbo S. The factory car reached 175mph with 305hp. Actually I wonder how our cars compare to a modern carrera/gt3/tt as far as CD. This would give a good guesstimate of what our cars can do with proper gearing and additional power.
Scott, you have been in my turbo. If you had to guess, what do you think it could do?

blue44

a few track days will help with the urge to push it real hard on the highway...

hey, we could caravan out to bonneville next august and run club class...

safe travels... Donn