Loss of power during spin/ fishtail

[slatec2s]

Loss of power during spin/ fishtail
2005 Carrera 997 S

Today after AutoX I stayed in the empty lot and decided to mess around a bit. It was raining and the lot was wet and slick so I wanted to push limits and learn something.

I had sport suspension engaged and PSM off.

I noticed that on hard acceleration in during a turn when the rear began to hang out I lost power. I began to do it purposefully to figure out what was going on. I noticed that when the rear really started to swing out and I hammered the accelerator - trying to purposefully counter the fish tail with adding power - that the car dropped the revs. It was almost as if there was some safety feature kicking in that was not allowing me to add power during a spin. Note that I had the PSM OFF. I cannot understand why I could not power my way out of the spin - it just would not let me. It was not a fluke because I was able to consistently replicate it. It almost felt like there was enough fuel getting the engine during the spin. I was hammering the gas and it just would not respond almost like it wanted to stall but it was not that bad.
Is there some safety/fail-safe feature that I don't know about or do I perhaps have an issue.

Now here is a little tid-bit that may or may not be related. A month ago I was also on the AutoX track and I noticed a few times that also during hard cornering the car hesitated (sometimes a couple of times) when I hammered the gas out of a turn. It FELT like a burp or brief stall or flood. It was suggested that I may have a crappy batch of gas (?Quicktrip?). This did NOT happen again on the track today (Chevron) - so I thought that I had solved the problem. Again - i have no idea if these issues are related but I thought it may be a clue.

Any suggestions or advice would be greatly appreciated.

[slatec2s]

bump

[emac]

Don't know anything about 997s but it sounds like it could be a clogged fuel filter just my 2c
Ernie 81sc

[Jdub]

You may be moving oil away from the oil pump scavenge and depriving your engine of oil. That would be felt as a loss of power, and a large drop in the size of your bank account.

[Dublinoh]

Might want to ask this is the 997 forum. Foot off the brake right? Could ABS do this?

[ruwoodbury]

Sounds like the stability program kicking in. Some cars won't let you turn the system completely off. It will still intervene under extreme conditions--like sliding the tail way out in wet conditions.
That's my guess.

[944 boy]

I have an '05 Boxster and with PASM on and PSM off I know that I can kick the back end out and hold it. However keep in mind that under hard braking the PSM will turn itself back on for safety and I don't know what it's threshold is to turn back off. So If you are braking hard then turning the PSM may still be active even though you turned it off with the switch. If you roll from a low speed and them drop the throttle and can achieve a nice drift. I would say it's PSM kicking in.

Were you low on fuel? Maybe it was starvation.

[Craig_D]

My sport suspension is always engaged, and I constantly adjust the PSM settings...in my brain.

[dcjones56]

Originally Posted by slatec2s

Loss of power during spin/ fishtail
2005 Carrera 997 S

Today after AutoX I stayed in the empty lot and decided to mess around a bit. It was raining and the lot was wet and slick so I wanted to push limits and learn something.

I had sport suspension engaged and PSM off.

I noticed that on hard acceleration in during a turn when the rear began to hang out I lost power. I began to do it purposefully to figure out what was going on. I noticed that when the rear really started to swing out and I hammered the accelerator - trying to purposefully counter the fish tail with adding power - that the car dropped the revs. It was almost as if there was some safety feature kicking in that was not allowing me to add power during a spin. Note that I had the PSM OFF. I cannot understand why I could not power my way out of the spin - it just would not let me. It was not a fluke because I was able to consistently replicate it. It almost felt like there was enough fuel getting the engine during the spin. I was hammering the gas and it just would not respond almost like it wanted to stall but it was not that bad.
Is there some safety/fail-safe feature that I don't know about or do I perhaps have an issue.

Now here is a little tid-bit that may or may not be related. A month ago I was also on the AutoX track and I noticed a few times that also during hard cornering the car hesitated (sometimes a couple of times) when I hammered the gas out of a turn. It FELT like a burp or brief stall or flood. It was suggested that I may have a crappy batch of gas (?Quicktrip?). This did NOT happen again on the track today (Chevron) - so I thought that I had solved the problem. Again - i have no idea if these issues are related but I thought it may be a clue.

Any suggestions or advice would be greatly appreciated.

When I had my 997 I was under the impression that even if you switched the Porsche Stability Management system off it would still kick in although it was in the off position. It would reactivate if the car got too carried away. At least that's what I remember. You may want to check your owner's manual.

[spuggy]

This is how it works, the PSM has yaw sensors that have a predetermined amount of slip angle in them. You can drift the car or even spin the car as long as you keep your foot in the gas, but the moment the car is out of shape and you tap the brakes the PSM continues tapping the brakes.

Conversely, if you are not tapping the brake and the PSM is interupting when you get just regular wheelspin, something is wrong with your PSM. You can completely disable it by disconnecting the charge pump in the boot lid.

I find that with PSM on, the ECU will cut throttle if I get excessively sideways in my drifting efforts.

From With PSM off, is traction control realy off? - 6speedonline.com Forums

Wow. But i guess that's what you expect from an SUV/sedan company.

[911SauCy]

Exactly why I have an "old" 911...car doesn't try to drive itself.

You can probably bring it to a Porsche shop that handles late model applications and have this remapped out of the PCM...or maybe not. These things are uber tech and usually encrypted so only a dealer could get in.

[pavegeno]

I drove a pair of used 05 997s at a dealership when we were searching for our new car. Had a great saleswoman who took me out to demo PSM. With PSM on, if the rear end swung out beyond 30 degrees from the path of the car, PSM kicked in, reduced power, applied differential rear wheel braking and brought the car back in line before giving you back control of the e-throttle. With PSM off, the system would let you get the tail up to 60 degrees out of whack with the car direction before engaging by reducing power and applying differential wheel braking and bringing you back to "safe" before giving you back the throttle. Believe PSM also engages regardless of switch position of brakes are engaged hard enough to activate ABS. Awesome demo.

[slatec2s]

Just to be clear - there was no braking (on my part) during the spin. On the contrary, I was trying to bring the car back into line with throttle.
I am disappointed by what I am understanding from everyone. I just find it hard to believe that Porsche has restricted the ability to completely turn off stability management.

I found this video on youtube of a 997 drifting nicely. This was basically my objective. I was unable to throttle through the slide AT ALL. As soon as the car significantly kicked out, throttle was cut back.
Will it drift? Porsche 911 Carrera 997 MkI - 1080p HD - YouTube

[slatec2s]

speed bump!
...still waiting for some solid technical facts and/or info.

[porterdog]

Originally Posted by slatec2s

...still waiting for some solid technical facts and/or info.

You do realize that this particular forum is aimed at pre-'89 911s, right? You'll find more people who know the complexities of the 997 in the 997 Area of Pelican.

[nineball]

the problem is your car is not old enough. i suggest something in the '78-'83 range.

[slatec2s]

Originally Posted by porterdog

You do realize that this particular forum is aimed at pre-'89 911s, right? You'll find more people who know the complexities of the 997 in the 997 Area of Pelican.

didnt realize....

*** ADMIN - would it be possible to shift thread to 997 forum? I can repost at 997 but thought I would try save what is already here.

[theiceman]

Originally Posted by slatec2s

speed bump!
...still waiting for some solid technical facts and/or info.

.... Still waiting for you to read post 5 ...... Pompus jackass

[DanielDudley]

Originally Posted by theiceman

.... Still waiting for you to read post 5 ......

Fixed it for you.

[slatec2s]

Hey iceman, I didn't mean to come across as a pompous jackass. It just seems that everyone was hypothesizing with no real solid facts about my situation. I am just seeking advice. I didn't mean to belittle anyone or disregard what anyone has suggested. Thank you for all of your repsonses. I apologize if it came across that way.

By the way exactly who is the pompous jackass?...Name calling on a P-forum anyway. How childish. You must be one of those very small people.

Quote de slatec2s

speed bump!

...still waiting for some solid technical facts and/or info.

.... Still waiting for you to read post 5 ...... Pompus jackass