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I have swapped out the 64l fuel tank on the 997 GT3 with a euro-spec 90l fuel tank during the winter. I have documentet all the work and will post full DIY next week after the calibration has been done by OPC.
It's not to difficult to do as a DIY, the only hard part is actually getting the fuel tank in and out due to little clearance.
I don't expect any issue calibrating the tank gauge, this is standard Porsche fuel level sensor and work will be done with Piwis.
Sorry for the delay, a slight issue came up when I thought everything was finished. The 90l fuel tank interfered with the carbon cannister quick connectors, and I belive this is the real reason that the US did not have the large fuel tanks on these cars. On the smaller tanks there is a small recess to allow space for the cannister connectors, and this recess is not on the 90l tank - and I missed that installing it resulting in the cannister being pushed up from its mounting point (and I didn't see it before trying to fit the trunk cover).
For me the easy solution was to replace the quick connectors on the carbon cannister with simple angeled fuel hoses of the correct Dimensions to get a lower profile, after trimming down the connector tubes on the cannister itself again to lower the profile. Very quick and easy to do when the tank is out of the car, but really hard to do afterwards like I had to do....
I will post all the necessary information to handle this as well, but in my opinion this is a very small issue easily resolved.
The car has been reprogrammed for 90l fuel tank, and calibration of the new fuel gauge has been done. 10 minutes job from OPC technician with PIWIS, no problem at all. Fuel gauge reads correctly in the car.
I installed a new fuel filter as well after reading a couple of other threads/DIYs on this forum, on my 997 GT3 that was 15 minutes job - and I had never done it before. No need to remove airbox either, plenty of space to do this as is.
I will post everything when I have started the car to make sure all is well, still have to install the calipers as they have been off the car this winter before startup.
Here is a photo of the two fuel tanks side by side, clearly showing where the extra fuel goes and where the small tank wastes space where a 4 wheel drive would have a differential and shafts.
I have marked in red the area that gives the issue with the carbon cannister as well, it's quite obvious in the photo - but a very easy fix while tank is out of the car.
Regarding the issues tcsracing1 reported when calibrating the fuel gauge, assuming that it was the correct part number for the floater I must say I think it had to be faulty. There is no reason this should be an issue, as the parts now installed inside my fuel tank is the same that came from factory in cars with the large tank.
Runet - did you ever post the entire DIY procedure? I cannot find it and I would like to do the same thing with my GT3, it is very thirsty at the track and the extra 26 liters would be helpful. Thanks!
Runet - did you ever post the entire DIY procedure? I cannot find it and I would like to do the same thing with my GT3, it is very thirsty at the track and the extra 26 liters would be helpful. Thanks!
Hi.
I have a pdf, but it is to large to upload here (apprx 7MB). Send me your email in a PM and I will mail it to you.
The pdf doesn't contain the bit of info regarding making the cabon cannister connector low profile, but it is very obvious to see and easy to fix. As mentioned before, just do it before installing the fuel tank permanently. A test fit will show how the 90l fuel tank slightly interfers with the connectors/cannister. This is not an issue on RW cars as they have the cannister in front of the passenger door. See photos below of old tank vs new tank installed, and a photo of the connectors for the cannister sticking far down into the space for the tank. This will hit the "flat spot" on the 90l tank if not adjusted, ref the photos above showing the different shapes of that corner on the tanks.
regards, Rune Old 64l tank New 90l tank Carbon cannister quick connector
Last edited by runet; 09-12-2022 at 04:40 AM.
Reason: Added info
Regarding calibration, when I had this done with PIWIS we had absolutly no issues. It only took a couple of minutes and the fuel indicator has been working perfectly for years.
Good luck for those who do this, I am very happy with the large fuel tank and would have done it again.
03-13-2017, 10:36 AM
997 GT3 90l fuel tank swap done - DIY to follow
