ltc

Kevin,
My scenario is a bit different and perhaps I'm not describing it well enough...I apologize in advance.

What I am describing is a classic 'open loop' condition.
The rev limiter will work as you described under a 'normal closed loop' condition....keep your right foot to the floor (get rid of your left foot, no clutch allowed), 100% throttle right up to the Rev Limiter. As a classical control system, there will some small overshoot between the time the system recognizes you've reached a limit and taking action (cutting spark/fuel).

My scenario is much different.
Engine is under load, accelerating under full throttle in gear and, for whatever reason, the clutch is pressed, quickly removing the load on the engine....the RPM's will VERY quickly increase and go past the rev limiter value. Of course the rev limiter will kick in and cut fuel/spark, but angular momentum has carried the valvetrain well past rev limiter.

I guess the difference is also a matter of the rate at which you are approaching the rev limiter (classic differentiator)....in the first (normal) scenario, it is fairly well understood/modeled....in the second, it really isn't since you don't want to do that.

Of course it is hard to find people willing to test this.......

This is of course assuming that we are in fact discussing a Type 1 and not a Type2.

IamSMC

Did Mike say anything else regarding the readout?

Did Mike seem concern at all with the readout?

Reason I ask is that the engine is currently at 478.8hrs and the event occured at 478hrs.

Did Mike seem concerned if one of his techs did it during the 15k service?

Just wondering out loud...

NewYorkBuck

Mike seemed genuinely unconcerned with the event. He said he sees this "all the time" and is "nothing to worry about." He also said he has never seen a dealer deny warranty info because of this. He mentioned hes seen these well over 8k and still have nothing wrong with the engine.

He does own Power Tech, which is possibly the most reputible Porsche shop in NJ, so I dont take his suggestions lightly.

ltc

OK, now you lost me.
This engine likes NOTHING over 8K.....the only way I know of to spin this thing at 8K is a mechanically induced over rev (5-2 downshift....aka the 'money shift')
I'm sure Kevin will agree.

Please get a PST2/PIWIS readout and report back.

NewYorkBuck

I will when I get a chance. What I can say is the car seems to be running absolutely great right now - as good as it ever has.......

Fred R. C4S

[QUOTE=NewYorkBuck;5831416]they simply wrote on the bill - "RPM limits recorded as #1 (7300-7500) at 128.6 hours (before I owned the car) and #2 (7500-7700) at 478.0 hours./QUOTE]

I seem to remember reading somewhere that the ECU for 996 records overrevs differently than the 997. Doesn't the 996 have just two classes, Type 1 and Type 2? What IS the rev range for Type 1? Perhaps "Mike" is quoting the ranges for the 997. If not, and if the car did rev to 7500-7700 somebody seriously missed a shift. I can't believe the accelerating flywheel's inertia could zing all the way past 7500 under no load.

Puzzled.........

adam_

Maybe what you received was an 'interpretation' and the RPMs as stated are actually wrong.

Type one is from redline to redline+200, type 2 is 'redline+200' and above (on the 996 I don't think there are type 3s, other cars yes I think so)... maybe whomever typed up your report just used a wrong redline?

Chuck Jones

No....as I understand it...the newer DME's record a hell of a lot more information than the older ones (01-03). As I understand it....and I believe Loren at RennTech has better info on this....is that the newere 997 DME's record much more detailed information which allows PCNA to focus in much more critically and specifically on any given event. I believe that the breaking point was 02 to 03 when the DME was upgraded to record a much higher level of detailed data. Bottom line, the different data categories can be cross referenced to provide a better picture of the interaction between data fields...this correlation allows for a better ability to analyze any given event from a number of inputs. Much akin to the application of cross impact analysis. Bottom line....things that you used to be able to get away with with a rather innovative explanation are now subject to "cross examination" based upon the support of additonal data as provided by the enhanced version of the more "intelligent" DME. Usually results in the owner responding with a rather subdued...."Ohhhh...."

NewYorkBuck

Oh boy - here is the latest -

My car was VERY good on oil consumption - like a 1/2 of a quart per 1000 or so. Well - I just found that I am now using 1/4 every 20 miles or so. I thought it could have been from something missed from the oil change, but my garage floor is bone dry.

The car otherwise seems to be running fine. Please dont tell me this is from bent connecting rods from an overrev........

Kevin

So in 100 miles you are using a quart?

If you are using a quart every 100 miles or less, I would take your car in for a leakdown test.

This will tell you if you have a bent valve or broken ring.

Look at the bright side, your brother can now help you get new rods and a topend rebuild. With the new rods, you could hit 7500 RPM's provided that you upgrade your valve springs also.

I mention that in jest to bring some humor into a tough situation. I have a close brother (lives 500 feet away from me) so I can understand the situation..

If infact you are using that much oil please go in and get a leakdown. You don't want "worse" damage to happen.

BTW, no way can these engines stay together with a 8,000 RPM rev..

ltc

To go along with what Kevin said, if you are burning that much oil after "the event", I would not drive the car......the next major happening will likely be an expensive one....

If a PST2/PIWIS readout is not possible, it may be time to give your brother an all expense paid "vacation" at Gitmo.....perhaps some waterboarding....er, surfboarding time will help "clarify his memory of the event".....

I kid, I kid........

Chuck Jones

Ask your brother if he'd take a polygraph.....

kcphuah

Kevin, would a scenario such as bent rod or broken ring trigger a check engine light? Of indeed something was damaged, would the compression test be sufficient to prove it is damaged?

Kevin

kcphuah, these questions usually stem from a "event" that has happened.

Did you recently install GT28's?? The bent rod usually happen from detonation at high boost. Your rod bearings are also at risk. A check engine light can occur with a misfire with that damaged cylinder.

A leakdown test will detect a broken ring.. It will be tough to detect the bent rod. You should hear the rod noise. Or you will soon hear it. I would also pull your oil filter element and inspect for metal.

Pushing these engine with larger turbochargers with crap fuel and not enough fuel (injectors) puts these engines at risk.

kcphuah

Kevin, yes I have recently installed the garette gt28, and yes I am running into some troubles getting a few issue straightened out. Hopefully you can shed some light on my troubles.

I don't think I have a bent rod as I don't have any misfire issue but my car is consuming a lot of engine oil, there are no signs of oil smoke when the car is idling or driving. However, everytime as I start the engine in the morning or simply park and start there will be a huge cloud of smoke pushed through the exhaust as if there is a fire, but once the smoke clears, it does not puff out smoke.

Thanks in advance for sharing your thoughts.