997 GT3 3.8 motor swap
10-18-2012, 12:02 PM
#3
Rennlist Member
Sorry I forgot to answer your PM earlier...but, I don't think it would require much at all. Nothing that any competent installer wouldn't be able to handle as-it-comes...
Obviously it will bolt right in. There should be no problem with the 02 sensor wire lengths, whether you go with 997 or 996 style exhausts. Connection to the main coolant hoses is identical. Power steering connection looks the same.
AC lines LOOK different, by visual observation. The ends that mate to the pump have a section of metal pipe, whereas the 996 lines are rubber in their entire length. I have no idea on the coolant hoses that go to and from the gearbox cooler, those might have changed.
Generally speaking, I want to guess that it will be plug and play.
10-18-2012, 01:02 PM
#4
Rennlist Member
Do u need the ecu from the 997? Or just modify the 996 ecu? Probably takes less down time then rebuilding motor and u still have a 6gt3 motor to sell. Mike
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10-19-2012, 07:03 AM
#10
Ugh... That's not what you want to hear... Man. I've done a bunch of motor swaps over the last 25 years. None on Porsches, and ALL blew the "expected" budget formula of "double the estimate and pray it doesn't go over THAT figure".
Selling yours as a roller might be a great option for someone looking to buy a project to turn into a racecar. Or that 3.8 swap could be the ticket. $15K to get a stock GT3 motor back to stock is a lot of scratch for the net gain of getting it running again. Bigger question is "why" it broke and what may have contributed.
I sold my 996TT because the motor had been modified from 6 months after original purchase and I got scared of the thought of having to go into that motor. The 6GT3 has less stress on it since it isn't boosted. I'd hope this is an isolated case and would be interested to know what the exact failure was. In any event, if the car is a "keeper", I'd personally look at the 3.8 option. You're already in for $15K, so another $10K gets you a lot more performance for less than the cost of stroking the existing powerplant.
Again, only if it is a keeper.
Selling yours as a roller might be a great option for someone looking to buy a project to turn into a racecar. Or that 3.8 swap could be the ticket. $15K to get a stock GT3 motor back to stock is a lot of scratch for the net gain of getting it running again. Bigger question is "why" it broke and what may have contributed.
I sold my 996TT because the motor had been modified from 6 months after original purchase and I got scared of the thought of having to go into that motor. The 6GT3 has less stress on it since it isn't boosted. I'd hope this is an isolated case and would be interested to know what the exact failure was. In any event, if the car is a "keeper", I'd personally look at the 3.8 option. You're already in for $15K, so another $10K gets you a lot more performance for less than the cost of stroking the existing powerplant.
Again, only if it is a keeper.
10-21-2012, 11:26 AM
#12
Nordschleife Master
3.8 swap makes LOTS of sense, if you can get the electronics to cooperate.
I've thought about this for "when the time comes". Get a low mileage stock powerplant from a written-off RS and go nuts.
I've thought about this for "when the time comes". Get a low mileage stock powerplant from a written-off RS and go nuts.
10-21-2012, 07:04 PM
#14
Nordschleife Master
I would not even consider it frankly. These are not the cars of old where you can swap a wiring harness or ECU and all is good. The cars today are TOTAL systems. They look for and work with EVERYTHING else in the car. In your case your car has a Gateway unit where all ECUs in everything are registered. No way to enter a 7 ECU in that and have it talk to anything else. So how will the ECU react? How will the rest of the car react? You will be about $25K into the project before you can answer these last two questions.
To give you an idea of what can happen in WAYS you or anyone will an idea about until stuff just doesnt work. On a 996TT, take the MAF out of it and recalibrate for pressure sensing now for air volume intake (a very common mod for many turbos) and the ABS unit stops functioning. The ABS unit looks for the value from the MAF to make sure car is working OK. When it does not see a value, it turns off. Now the motor has no issue not seeing this value and works fine. This is a basic part of the ABS computer and there is no fix (well we did a fix sort of, we removed the ABS and installed a 7 Cupcar manual brake system). On a 997S when you remove many of the cars systems registered in the Gateway (like door ecus, seats, climate control, etc) the brake pedal goes soft. No codes displayed, stored, etc. Remove the entries from the Gateway and the pedal becomes hard again.
These are just a couple items of some STRANGE things that have cost customers many $$$$s trying to solve. Seriously save your money and time and just get another motor for your car. Then if you want a 7 GT3, buy one. OK now this will sound a little self serving, buy I do have a motor and tranny out of a 6 GT3 for sale at the moment...
To give you an idea of what can happen in WAYS you or anyone will an idea about until stuff just doesnt work. On a 996TT, take the MAF out of it and recalibrate for pressure sensing now for air volume intake (a very common mod for many turbos) and the ABS unit stops functioning. The ABS unit looks for the value from the MAF to make sure car is working OK. When it does not see a value, it turns off. Now the motor has no issue not seeing this value and works fine. This is a basic part of the ABS computer and there is no fix (well we did a fix sort of, we removed the ABS and installed a 7 Cupcar manual brake system). On a 997S when you remove many of the cars systems registered in the Gateway (like door ecus, seats, climate control, etc) the brake pedal goes soft. No codes displayed, stored, etc. Remove the entries from the Gateway and the pedal becomes hard again.
These are just a couple items of some STRANGE things that have cost customers many $$$$s trying to solve. Seriously save your money and time and just get another motor for your car. Then if you want a 7 GT3, buy one. OK now this will sound a little self serving, buy I do have a motor and tranny out of a 6 GT3 for sale at the moment...
10-21-2012, 07:29 PM
#15
Race Director
+1 for what ViperBob posted. I know he has been there done that with these cars and has the experience first hand.