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Owned 911 for 2 days before engine problems

infrasilver said:
I think the PDK box is a great thing but when they go wrong, and they do, it'll be one big bill. I'd rather tackle an engine rebuild that trying to fix one of those.

Its getting replacement parts that are the problem,many modern tiptronic boxes,and manuals too just dont carry repair items to fix the drivetrain..

Replace only :(
 
Being very old, I drove road and racing cars before rev-limiters were commonplace so have always had a healthy respect for the revs that I'm using and have virtually never seen the need to bounce a car off a rev-limiter.
My current GT3 produces maximum power at 7600 rpm which is 900 rpm below the rev limit and maximum torque at below 6000 rpm so I don't see the need to redline the car as once you hit a rev-limiter you are actually losing performance and the optimum will be achieved by changing gear before the rev-limiter interrupts power
The rev-limiter should be there to protect your engine if you over-rev it, not there as a change-up point
Just my humble opinion and not meant to criticise the original poster - or anyone else!
 
Fantastic news AeroAnt and as others have said all credit to you for the way you handled this very stressful situation. :thumb:
 
nineoneone;
I understand your point;
however (and i don't know, on hypothesising) surely by using the higher rpm above peak power in a lower gear will provide more acceleration than changing up early with a higher gear ?

I do know from looking at my cup car dyno's that the power does not drop off at all, right to the rev limiter.

Road car I guess has more limitations.

Regarding the new engine scenario of AeroAnt - can the OPC re-set the over rev data back to zero for the new engine ?
would make more sense to me as the engine is now quite different to the rev range readings that will currently be in the DME ?
 
david_yorkshire said:
nineoneone;
I understand your point;
however (and i don't know, on hypothesising) surely by using the higher rpm above peak power in a lower gear will provide more acceleration than changing up early with a higher gear ?

You are dead right, as was ninenineone. Ideally you should probably be changing up just before the rev limiter, the exact ideal rpm to change at will depend on the shape of the power curve and the gear ratios, but unless peak power is at peak rpm the ideal shift point will always be after peak power. If you are making more power in the current gear than you would be in the next gear you shouldn't be changing yet, the closer the gear ratios the closer to peak power you will be shifting.

MC
 
MisterCorn said:
david_yorkshire said:
nineoneone;
I understand your point;
however (and i don't know, on hypothesising) surely by using the higher rpm above peak power in a lower gear will provide more acceleration than changing up early with a higher gear ?

You are dead right, as was ninenineone. Ideally you should probably be changing up just before the rev limiter, the exact ideal rpm to change at will depend on the shape of the power curve and the gear ratios, but unless peak power is at peak rpm the ideal shift point will always be after peak power. If you are making more power in the current gear than you would be in the next gear you shouldn't be changing yet, the closer the gear ratios the closer to peak power you will be shifting.

MC

So just ignore torque characteristics, road gradient and other variables then!
 
nineoneone said:
Being very old, I drove road and racing cars before rev-limiters were commonplace so have always had a healthy respect for the revs that I'm using and have virtually never seen the need to bounce a car off a rev-limiter.
My current GT3 produces maximum power at 7600 rpm which is 900 rpm below the rev limit and maximum torque at below 6000 rpm so I don't see the need to redline the car as once you hit a rev-limiter you are actually losing performance and the optimum will be achieved by changing gear before the rev-limiter interrupts power
The rev-limiter should be there to protect your engine if you over-rev it, not there as a change-up point
Just my humble opinion and not meant to criticise the original poster - or anyone else!

Good post!
 
Driving a petrol engine to the limiter (note, not into) is great fun, and it sounds awesome. Is it not as simple as that?

It's a road, not a racetrack. I'd care about shift points if I was racing, but I'm not. My car makes power to the redline as far as I can tell, and even if it's not maximum power it sure as hell is enough for me. Plus, the higher in the revs the better the sound.


If it's a diesel then sure, shift up at max power or max torque or whatever you want as there's nothing at the end of the rev counter to be worth chasing. On a decent petrol engine though, that's where the fun is!
 
Regarding the new engine scenario of AeroAnt - can the OPC re-set the over rev data back to zero for the new engine ?
would make more sense to me as the engine is now quite different to the rev range readings that will currently be in the DME ?

I assumed this would be the case? Surely as the engine has now done 0.0Hrs rather that 1480hrs and 0 over revs it wouldn't make sense to have incorrect data recorded. I will check with the OPC next time i speak with them.
 
Picked her up about 1pm yesterday. SM advised there is no run-in period but in his opinion I should take it easy for first 500 miles. Just to monitor the coolant and oil levels over the coming months.Think ill be taking it easy for a bit longer than that just for peace of mind.

The weather and traffic was horrific yesterday but the car felt better than before, coming from a golf and diesel bmw everything so razor sharp.

Looking forward to years of trouble free motoring this time around
 
outstanding news! any ideas what they fitted, engine wise? New unit or repaired the old one? Either way a good result.
 
chiark said:
outstanding news! any ideas what they fitted, engine wise? New unit or repaired the old one? Either way a good result.

I was assured it was 100% a new engine by the service manager. He did say it was something he had questioned before, whether they are new or reman' but had it confirmed in writing by porsche that they are new engines but sometimes shown as reman... As far as I could work out this is due to the fact that they may use parts from a parts bin to complete the engine, which means that it cannot be described as new!?

Seems to make sense to me at least.

It was a complete unit so came with all new stater\pumps\sensors etc.
 
Excellent news; Happy Christmas!! :thumb:
 
chiark said:
outstanding news! any ideas what they fitted, engine wise? New unit or repaired the old one? Either way a good result.

It'll be a brand new crated engine, but some ancillaries and all induction/exhaust carried over.

EDIT: Oops, sorry for delay, was trying to find a picture of crated 997 M97 engine.
 

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