I do you not hit the rev limiter all the time?

Hi, It seems like they should have bumped up the rev limiter to 7500 on our beloved 996 3.4L. Do you agree? I can't drive it without hitting the rev limiter at least once or twice, it makes plenty of power at 7000.

Unless you're driving it only on a racetrack or only drive in first or second gear, your statement makes little sense...

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haha, good point.You would have to be a maniac if that happens in 5th. But even on the street in 2nd I find it hard to not hit the rev limiter. I have so many "Range 1" ignition and they are always very recent. Luckily no "Range 2". I am curious if 2nd is a bit short or something? I find it a little hard to rev match from 3rd to 2nd

They are indeed sporty engines....but hitting the rev limiter one or two times everytime you drive it sounds excessive, and perhaps a little bit abusive. Hope you have it fully warmed up before you do that. How many tire sets do you go through a year?

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Range 2 is considered over-rev. If you don't have any numbers in range 2, then you're fine. In fact, it's not uncommon for even the more skilled track junky to hit in range 2. That's why is smart to scan cars with a Durametric or other scanning tool. I wouldn't buy a 996 if it showed high numbers in range 2. The newer 911 cars have 6 ranges.

Maximum horsepower is achieved at 6,000 RPM, so bumping up to 7,300 RPM at rev limiter doesn't get you much that much more.

Here are the transmission drive ratios

I bought a durametic pro recently, primarily because I was curious about the number of over revs on my 99 C2. My car spent the first 42k miles of its life as a Michelin Research and Development tire testing track car. Has 92k miles now with the original untouched engine. The number of level 1 over revs are maxed out (a little over 3 minutes at the red line). The ECU doesn't record any more than that. There is no ECU data as to when the over revs hit the ECU limit. It could have a lot more than 3 minutes at the red line. I have hit the red line on second gear pulls myself, so the last level 1 is fairly recent. Fortunately, the number of level 2 over revs is low. About 3 seconds worth and they occurred years ago when it was a tire tester. Note that some people have had engine failures with less than 3 seconds of level 2. The ECU doesn't record the maximum RPM. Three seconds at 7800 rpm is not as significant as 0.25 seconds at 9000 rpm. My car came from Brumos Porsche with multiple mods when it was purchased by Michelin. One was an X51 type baffle which probably contributed greatly to the engine lasting this long. (I guess I can't say that the engine is untouched since it did have the X51 baffle installed very early in it's life). I use it primarily as a track car now. I drive it like I stole it and it's a ton of fun.

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Thanks! I thought that max power was about 6500 rpm? Can't find a stock dyno anywhere. But I remember seeing that power is pretty much the same from 6000 to 7000 rpm? You want to shift after max power so you get right back into the meat after your shift. With the gear ratios above this is the RPM you end up at if you shift at 7000 RPM: (1st->2nd): 4031 (2nd->3rd): 4836 (3rd->4th): 5618 (4th->5th): 5812 With the gear ratios above this is the RPM you end up at if you shift at 7300 RPM: (1st->2nd): 4204 (2nd->3rd):5044 (3rd->4th): 5859 (4th->5th): 6103 So if you over rev a little you end up where there is more power. Also looking at these ratio they really makes sense, I guess Porsche knows what they are doing. Going ***** to the walls in 4th->5th gives you a very nice 'area under the curve' power. With 2nd to 3rd you end up very close to torque max, that is also good. btw, I am far form an expert but happy to discuss.<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--><!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--><!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--><!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}-->

I think more relevant is the speed achieved in each gear at maximum RPM. If you are bumping the rev limiter in any thing other than 1st or 2nd, I do not know where you can do that except on a race track because you will be exceeding any normal type of driving situations.

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Looking at these numbers they don't make sense. 300hp @ 6000 RPM is 262.6 ftlb, more than the 259 ftlb at 4750. I think the owners manual came with a dyno?

It did. Torque drops considerably after 4750 RPM

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Thanks! Where did you find the engine specs you posted above? Seems to be a typo, max power is at 7000 rpm.

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I completely agree with Joe here. He makes a very important point. Hitting the rev limit once and blue moon is not a big deal, but pushing to the rev limit every time you drive is excessive and damaging to the motor. Plus, as you can see you're not adding anymore HP to the mix either.

This thread made me laugh.

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I totally agree! I need to get a shift light or something It's just that the engine tells you to rev more more more.

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Happy that we made you happy

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Yes it does!

It's threads like these that make me yearn for the days before the Internet. I liked not knowing people like this existed. I'm just kidding! I know this thread was made to be a silly joke.

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I guess the solution is to buy a GT3....... Having max power at redline is like giving a kid a candy bar they can't open.

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I just like to enjoy the 996 for the sportscar it's meant to be! Nothing wrong with that.

A lot of this discussion is about the best place to be in the power band based on graphs. The reality is that the track will determine where you are in the power band. At Road Atlanta, my 996 performs best in 4th gear for most of the track. Third up the hill after Turn 5 and 5th on the front and back straight. I am not good enough to hit the red line in 4th in most places except the straights, where I shift when it "feels right". I'm not racing, so shifting a little early is no big deal.

I think I can relate to what the OP is saying even though I rarely drive the car really hard and have never hit the rev limiter. With the 3.4, the real power doesn't happen until 6k. I know that's not what the power curve says, but that's been my experience in both my 996.1's. With that narrow band from 6000 RPM to 7000 RPM, you really have to time the shifts exactly right to get maximize power without over-revving. With the 3.6, the power comes on in lower rev ranges, so it doesn't need to be revved to the same extent as the 3.4 to develop maximum power.

OP is my spirit animal.

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+1 What are you gaining if you are not in a race with prize money more than the cost of a M96?

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Great observation. The chart definitely shows peak power at 7k -- so either there is a typo in the specs or the chart is wrong. I suspect the specs are wrong since it's difficult to have a "typo" on a chart. The 4700 rpm torque peak is consistent across the chart and specs.

This is all wrong, it's not a rev limiter, it's a shift indicator!

*fun limiter FTFY

HP is one thing, torque is another Torque is a rotating force produced by an engine�s crankshaft. The more torque an engine produces, the greater its ability to perform work. The measurement is the same as work, but slightly different. Since torque is a vector (acting in a certain direction), it�s quantified by the units pound-feet and newton-meters. When the torque curve falls off, the ability to perform work (move the car thru the air and tire friction loss) lessens. Berra�s theorem, torque is the capacity to do work, while power is how quickly some strenuous task can be accomplished. In other words, power is the rate of completing work (or applying torque) in a given amount of time. Mathematically, horsepower equals torque multiplied by rpm. H = T x rpm/5252, where H is horsepower, T is pound-feet, rpm is how fast the engine is spinning, and 5252 is a constant that makes the units jibe. So, to make more power an engine needs to generate more torque, operate at higher rpm, or both. But even at higher RPM, if the torque drops off, the car is producing less power, and that lessens the work the engine is able to do. Go ahead...kill me now. The simple rule is "stay within the maximum torque curve for maximum power", i.e, the ability to do work (move the car forward).

Ahhhhh well...just hit the rev limiter on every shift and enjoy yourself, and your car!

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I agree with all of the above and usually am much more concerned about torque than HP. A short drive in a Subaru BRZ will tell anyone everything they need to know about HP vs. torque. All this rampant agreement being said, however, both of my 3.4's felt a lot more like the acceleration followed the 996 horsepower curve and not the torque curve. I would never guess that torque peaks at 4700 rpm. In fact, I still don't believe it peaks at 4700 -- just doesn't feel that way to me. I rarely push my car to redline though, so my memory may not be perfect.

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Right on!

The fastest way to drive this car is to shift at redline. You can hit redline easily in 2nd, I agree. To hit it in 3rd requires 100+.

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The manual weighs more than the auto...?!

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Indicated 106mph in my 99.. and I'll be darn if the limiter doesn't come up quick in first..

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yes ... most probably the dual mass flywheel accounts for the extra engine weight. Don�t forget the auto transmission on itself weighs a lot more. 100-120lbs.

Regarding the above discussion on operating at max engine torque: Don't forget the effect of the gear ratio. If you plot the torque available in each gear up to redline, you will find that even though the engine is not at peak torque, there is more torque available to the wheels at higher RPM and lower gear. For example, at 7000 RPM there is 1695 ft lbs in second gear going into the final drive. In third gear at 4500 RPM there is 1380 ft lbs going into the final drive. If you plot all the gear ratios, you will see that there is always more torque available to the wheels in the lower gears. That is why we shift at redline. Regards, Lang G

I need to get my 99 on a dyno. I could swear that on my drive earlier today that the torque swell starts just after 4000 and relatively short shifting it (which for me is anything less than redline) it gets down the road pretty quickly. I've built a custom x pipe exhaust, catless, and my goal was to maintain backpressure to keep the torque at a usable RPM, as well as a rip snorting wail at WOT. Hit on all regards.. now I just need the powerband proven on paper.

^^ It might feel faster, but Lang G is right.

autocrossers really bang on the 2nd gear limiter a lot...miata dudes will just lay into it for seconds at a time. I have tapped the 2nd gear one many a time and even the 3rd gear one on occasion. The x51 engine with muffler bypass makes it even worse because it really moves all the power up high and 7k rpm will sneak up on you. Personally...the limiter is there for a reason. Don't bang it with the car in neutral, but tapping it every now and then in gear isn't the end of the world

Italian tune ups!

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ouch !

Posting on an old thread because my son gave me the answer why it's faster to shift at or near redline despite the torque curve tapering off much earlier. This is common knowledge to those of you who track your cars, so I apologize for (the guy who was educated by his son) preaching to the choir, but since it was an open/unresolved question in this thread, it seems worthwhile to comment. The reason for revving beyond the torque peak is not for acceleration in the gear you are in, but so that the engine is set up to be in the meat of the torque curve after you shift into the next gear. I still feel (quite possibly incorrectly) like acceleration gets stronger in the current gear as you rise above the torque peak to redline (at least in my 996), so that part of the question isn't answered by this, but there is no question it is faster to shift at or near redline if you are going to go through several gears (despite the power curve showing much earlier peak torque).

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That�s just your auditory senses and visual cortex taking over. It�s the reason why some low horsepower cars that aren�t really that fast yet still feel very exciting and fast when you drive them. They feel fast. The drop off in torque after the peak isn�t really that pronounced on these cars either, which I think makes it feel like the car pulls strong all the way to redline.

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That�s a great point. However, technically, it�s not just for the next gear, it�s also for the gear you are in because even though torque has dropped off, you are still using a gear multiplier that offer greater resultant torque than if you shifted into the next gear. So it�s for both - the current gear, and the next gear.

I rev you long time.

For track its sometimes its also beneficial to overrev because you are busy turning/braking/passing. This is where computer controlled pad shifters are so superior, unless you are a good track driver its hard to shift properly in a split second while you are doing 1000 other things.