Joe - Do you think that flashing a car is bad for it in the long term? Following on with your logic on the rev-limiter, it would make sense then that the engine components are also designed to work at certain boost levels and since flashing typically increases boost levels, this would apparantly take the cars stock mechanincals outside its normal parameters. I'd be curious to hear your thoughts.

 

Hi. I've flashed my car. I have the Upsolute flash and I'm happy with it.
Flashing per se, just like (or including) altering the rev limiter is not
going to hurt the motor. What hurts the motor is running at higher RPMs
than the components can absorb in a resilient manner. The longer/more
often the safe limit is exceeded, the worse it is, and indeed if certain
types of damage occur, they do cause a downward spiral that will
proceed at much lower RPMs afterwards. So, yes, I understand and
believe that if the Upsolute flash increases my RPM limit, it will expose
me to the opportunity to shorten the life of my motor if I visit the
new higher redline very often or for very long. How much a risk is
unknown, and as you can see, I have chosen to take that risk,
though if I had the option with Upsolute to provide the extra boost
and programming benefits up to the stock max RPM, but to not raise
the limit, I would have chosen that. Most of the power I need for
the racing I do is between 2000 and 5000 RPMs. Track and drag folks
can more often use max RPMs.
The 996tt and GT2 have lower peak RPMs allowed than the GT3,
and we should look at the mechanical changes Porsche made to the
GT3 motor to understand what they thought was necessary to
strengthen and/or lighten to permit those higher RPMs.
The conservative raising of the RPM limit is not black-and-white
and it's risks or real damage might well be small enough to 'blend
in' with the normal overall wear-and-tear in an owner's usage of the
car, depending on how they drive, and the percentage of time at
high boost and RPMs. If you take meth only once a year, you can
take an arguable position that you have more fun at your yearly
all-weekend party, and you'll probably be OK. You can trash
most motors with stock setups too, by spending lots of time at
the high end of their stock RPM max too.
Yes, extra power, however it is achieved, is an added strain
and a risk, however it is obtained. There is no free lunch.
*Regular* power is a strain, when tapped. Of two Porsches,
both stock, where one is regularly taken to DEs and drag races,
where the other is rationally street driven with only an
occasional dip into max boost on safe on-ramps, I'd prefer to
inherit the latter car. However, which driver do you want
to be? As you can tell, I would rather be the former driver.
Enjoy your life, milk the car for as much fun as you can. Be
able to say you did with it what Porsches can let you do, not
what residual investment value you were able to recoup. I
just want the technical details as well known as possible so
we can make our choices better.

 

My limit is at 7,900 on a built motor, which is perfect for how I use my car.

 

I really don't think that incresing the rpm by 500 will damage the engine, even with stock internals.

 

Just ask yourself then, why Porsche would voluntarily leave
a good handful of power and excitement on the table by
setting a needlessly low RPM limit. You are, of course, free
to second-guess Porsche engineers. I am just suggesting
that you carefully weigh the information and qualifications
behind any decision to do so.

 

I'm not an engineer and my car is set at a stock RPM.

Manufacturers must provide a car that will reliably get them past their warranty period with little chance of failure. That means doing back to back top speed runs in 125 degree weather and suddenly shutting off the car with no cool down, that means ten thousand miles of track time (look at Tom Kerr's car), that means starting the car in minus 30 degree weather and punching it, It also means running 87 octane and really pushing the car with low coolant and a broken wastegate line (running 1.4 bar) just because. you get the point. They test the cars with what most us would simply call abuse, because someone, somewhere IS going to not care and want a warranty claim if something breaks.

IMO A conscientious enthusiast can safely tweak certain aspects of an engine, suspension, etc without putting too much long term stress on the motor. Again, we're talking conscientious enthusiast. Remember DMK? his philosophy was: I'm going to raise boost until something breaks. And it did.

So for me, the risk/reward quotient is high. I am astounded at how over engineered this engine is. Even with modified "safety valves" like upgraded flash, wastegates, blow off valves (diverters). I'm running stock turbos with a stock 1.3 BAR fuel cut. That's probably where factory engineers feel the limit is with this car's fueling system.

I really think a stock 911 turbo can run the 24 hours of lemans. So honestly what harm can I do with my daily commute and a few higher than stock boost acceleration runs on the way to work?

I have tracked my car twice and made sure to put in 100 octane on a conservative 91 octane flash. I properly warmed up the car and cooled it down between runs, checked oil levels, coolant levels etc... And I left mid-day on both occasions simply because I was done. Trust me someone out there has done a LOT worse and cared a LOT less and the car is designed to absorb it.

 

Outstanding post, Ari. Very well said.

 

Yes, we have a wonderful piece of engineering, not doubt.
IFRC, Tom is on his second motor. The first, running in
stock form, blew up after 10,000 miles.

 

OK! Who wants to buy my car?

JK

 

Sorry Joe but I disagree with you. Look at how they enhanced the 997tt ECU. It is far superior to the 996. Porsche only extends technology to where their price point makes sense to them and they are very conservative at spending money they don't have to in order to be somewhere in the front of the pack.

But, look at the piece of junk they they use for a regular 996/997 engine! That is all they need and it works great, until it blows itself apart. They don't care what happens to the down the line customer who doesn't have a warranty.

I happen to be fond of the Boxsters but rather than do a 996 swap in one to get some real performance I simply bought an M roadster....

The TT and GT3s engine technology go all the way back to the very well known traditional 911, split case engine of the late 70s. Only the newer ones are superior in most ways. Look at how enthusiasts have been extending the performance of these old engines for decades and the engines do NOT blow apart unless people do stupid things to them. I have had many of these and they are FINE to at least 7000rpm with NO internal changes. My old but very potent built 79 930 good for 7300 but I use all Racewear. [Presuming we are all know that the 3.2 Carreras used weak rod bolts so they didn't handle revs.]

When I started playing with my GT2 I happened to be talking with one of the preeminent Porsche race car builders in the country about what was safe to do with my engine. He started laughing and reminded me that it was simply an upgraded version of my old 930. He said it was fine to 7300. I don't need the revs and limit it to 7k. And, yes, I can live with the Type 2s just fine. I bought the car to use it.

The info I have stated about the ECUs is clearly stated in the Factory Service Manual. It is huge and hard to find some things but it is all there and most of the things people continue to question here is answered in the Manual. You want the TRUTH? Just read the manual.
JR

In factij

 

Hi John! Can you say what you think I said that you disagree with?
Simply stated, and physically inarguable, is that higher RPMs =
higher stress. What does the manual say about actual maximum safe RPM?
Race motor builders have an easier job in some ways. They don't have
to build a motor to go 100,000 miles. Heck, the best race oil doesn't
even have base or detergent additives because the motor's going to be
completely rebuild in 40 hours anyway. Tom Kerr may pipe in about being
on his second stock unchipped motor after 10,000 miles with a lot of track
time.

 

Nuts,
I am not on this site often enough. I get an email advising me someone has responded and I fail to read all the posts and start yapping without undestanding where a lot of the dialoge has been.... sorry.

I still go with what I said... however, Joe has a solid statement about ...excessive revs. I DO agree that revs= wear [up to a point]. Too little revs is VERY hard on your crank and bearings. I have been warned about this as in my old age I don't spin the revs like I used to. Please understand that I don't rev my GT2 that much and I am referring to older n/a 911s that I have. A 2.0-2.2 Ltr 911S with excellent maintence will pull 8,000 day and night and last an easy 200,000 miles. Yes, really. My brother has proved this twice. He sold one engine with almost 300k miles to a guy who put almost 100k more before overhauling it. His last one was much the same and went to a guy who put it in a time trial car.

Now.. about ..relatively excessive revs. In the first place the GT3/RS, et all are n/a engines. The only way they can make big power is by either big displacement or big revs. Porsche chose revs. [Think of F1 and their 18-19k revs]. So Porsche put a lot of advanced technology to make those suckers spin and live. Don't forget they get their payback with all those race cars they sell.

Except for very extreme engines and power, turbos use those wonderful puffers to make their big power and simply don't require such huge revs to make them work. Porsche doesn't waste extra money designing them to live with GT3 type rev s as there is no need to. If we start pushing revs "too" high or boost "too" high we get past the upper design parameters of the engines. Lots of boost alone causes lots of other problems and doesn't honestly work all that well. How you push your particular engine also makes a huge difference. You always pay attention to a proper warm up before using boost? You make sure you oil is the highest quality and change it regularly? You pay attention to you temp gauge? You drive on the street and use all your power once-in-a-while? You time trial and run it REALLY hard? Every factor will affect how long that engine remains happy.

I tend to agree with those to recommend moderate boost and revs if you want to enjoy a long term and trouble free ownership experience. Also, last comment..honest... to make these REALLY make huge power cost so much that I think it is much better to keep these relative stock and build an older 930 up. You can have a turbo with a LOT less weight and an easy 450-550 hp, depending on how much you want to spend that will easily go with the huge hp late cars. Power to weight. That is it. My old 930 is silly fast. I am not positive that it will pull my GT2 but you really feel everythng the old beast it does. Think early 911S compared to 997. No, not at all refined but pure driving experience.

Enjoy your rides!
JR

 

Solution to the problem: a la carte custom programming from EPL.
Tony would gladly set your boost limit at .9 bar and your Rev limiter at 5200 if you asked him to.
Everyone can get what they are looking for.

 

Well since I have been mentioned several times I will pipe in. I blew my engine at a DE PCA Club event. it let go on a warm up lap in the instructor session coming out of a corner.
Up to that point the car had about 10k of DE time trialing and open passing laps on it. everything but wheel to wheel racing.
I had a REVO flash, straight pipe, DV and boost hose up grades, stock rev limiter.
oil and filter changed after EVERY event. no missed shifts ever. ALWAYS proper warm up and turbo cool down.
that to this day is all I know. crank broke and engine blew up big time.
Kevin at UMW got me the new engine (thanks again) and has my old one but was never able to shed any more light on the subject.
I have a shift light set at 6k and make sure I shift before 6600 rpm. I believe (as do the Cup car drivers) that the higher the rpm the more wear and tear.
I wont increase my rev limiter. currently run race gas only at the track, also have a boost control, oil temp, and AFR gauge that monitor the engine.
that said the car now runs Protomotive software and hybrid K-24 turbos.
Yes I still drive as fast and as aggressively as I can at the track. that is what I bought the car for. I will do what is right for the engine but I will not baby this car. Currently setting the car up as full RWD 50/80 lockup adding large RSR wing and trying to set a NASA time trial record.....I love this car but will not drive it like a Puss@.
PS after reviewing the about posts on this thread I totally agree with all Joe's posts and am glad he takes the time to spell out where he is coming from.

tom

 

Errr, Joe. You posted and asked so it is only appropriate that I answer your question. I was referring to:

Originally Posted by Joe Weinstein
Just ask yourself then, why Porsche would voluntarily leave
a good handful of power and excitement on the table by
setting a needlessly low RPM limit. You are, of course, free
to second-guess Porsche engineers. I am just suggesting
that you carefully weigh the information and qualifications
behind any decision to do so.
--------------
Joe,
I yapped all around a lot of the answer. Not sure I made the point. Simply, Porsche engineers leave power on the table because it gives them room down the line to enhance their performance when they need it to keep up with the competition, or sales fall off and they need something to advertise. No, not always, but they have been doing things like this for decades.

I am not trying to get personal with you but I have heard so much pure crap about Porsche engineering and how the good Dr. wouldn't want you trying to improve upon his products since I first started playing with these in the late 60s. WOW, I am guilty of hot rodding these cars for 30 years now. :->

Just to give a little history. Remember the first wonderful 2.0 911S of 1967? Do you guys realize that Porsche coordinated the release of the first S with the slight re-engineering of the standard 911... by adding restricters in the exhaust headers! Oh, yes, Porsche engineering at it's most glorious. They did this because they realized that the early S was not much faster than a normal 911. With a simple a/c change and rejetting, the standard 911 was pretty much as fast as the slick new S. Porsche Panorama even ran an article on how to simply improve the power of your standard 911 by r&ring your heat exchangers and knocking the superbly engineered restricters out. Porsche engineers have done subtle and not-so-subtle things like this ever since.

I admit that I do like their spit case engines and think they are wonderful as is. I still maintain their new-tec and low cost engines are something they should be ashamed of. If you look at the "quality" of much of the new Porsche hardware, it simply doesn't compare to what they use to build. It breaks my heart to see the obvious cost cutting on the cars. My old 911s and 930... even my older Lexus makes my GT2 look terrible in terms of overall build quality. There is no excuse for this. So, "Porsche engineers/engineering" raises red flags for me as it is meaningless in terms of final product. They CAN do wonderful things. They many times do not choose to.
JR