Just like the title says, I'm looking for a GT2 or GT3 flat bottom fuel tank. Some guys might have acquired these in the past but gave up on the idea of installing it as you end up loosing your fuel level gauge in the swap, which not many people want to do. Anyway, looking for one.

 

Is it not possible to reconfigure the cluster as a GT2 with PIWIS or Durametric or similar? I can not imagine it is too difficult (once the necessary systems have been reverse engineered :-p).

I know for you it plays no role, but for those of us who want to keep our stock clusters...

EDIT: BTW, I know of a GT2 gas tank here in Germany. Seller wants €400 but I have purchased quite a bit from him and might be able to get a better deal. I'd assume shipping can be done for about $250-300... All in all you'd probably have it for just under $1000. AFAIAC that is a lot for a tank. But I have no idea what they go for in the US.

 

Unfortunately it can not be reprogrammed via PIWIS or PST2. The code is unique to each cluster and various aspects of it can not be reconfigured. My shop has a very talented computer brainiac that does all their cluster repairs and coding. He's cracked the code on some of the clusters but its a very long and arduous process. He has not been able to crack the fuel side of it (yet).

My car has a GT2 cluster in it and the fuel gauge would only work in the very top 1/4 of the hump tank. After that the needle would begin to swing wildly as the fuel tank algorithm of the cluster does not match that of the fuel tank shape. The gauge basically goes haywire as the float signal does not match what the fuel cluster algorithm is expecting to see.

In my case, the fuel gauge, or other stock cluster info, makes no difference as we are displaying all the information via my Motec dash which is fully configurable. The stock cluster is not used at all and really is not needed in the car. With the fuel level, we feed the tank float voltage to the Motec and calibrated it by filling to a known quantity starting with an empty tank. For the last 5 gallons in the tank where fuel is in the humps below the fuel float, Motec automatically switches to "fuel used" and subtracts it from 5 gallons automatically displaying fuel remaining. It is seamless and dead accurate (unlike the factory system) all the way to empty. Motec than displays the fuel level by displaying the average of the last few reading over the last 30 second time frame which dampens out the fluctuations of displayed fuel level you would get due to the float level bobbing up and down when the fuel is sloshing around in the tank.

If I switch tanks, we just do a quick calibration of the new tank again. That's the beauty of Motec.

Finally, there is a lot more to it than just sticking a GT2/3/Cup tank in the car. First of all, you need a ORVR (US spec) tank that has the EPA vapor recovery provision on it. This is critical to keep the emission system working properly so you can pass emission. You also need a new fuel pump basket, new jet pump (yes, the GT2 has one listed in PET while the turbo has 2), and a new filler neck which is also different. All in all, the extra fuel tank parts all add up to $1200 or so plus the tank itself. A new tank retail for $1200 at the dealer. My cost on a new tank is under $1000. I figured if I can find one for $3-400 than it would be worth it.

It is about 10 hrs of labor to install the tank as the whole front suspension including subframes and steering rack need to come out. Obviously a new alignment will be needed.

An interesting tid bit, a 997.2GT3/RS uses a hump tank which is shared with the Turbo and C4S.

Hope this clears it up..

 

Price: that is what I figured. Too bad there is all that water to cross. The tank here is the tank alone: no pump, basket, or flange with connectors on top - just the open tank.

I used to convert cars to US spec. I am quite familiar with the evaporative emissions systems. I'm going to have to look at the PET for the tank, though. Is there really a RoW tank and a US tank? Very hard to imagine. The evap system might be different, but the connections required to the tank should be the same. Tooling for a separate RoW and US tank would be silly. And European emissions regulations have come a long way. In general, today's EU requirements are more or less on par with US regulations.

I cannot imagine that the coding in the cluster is unique to each vehicle. Vehicle type, yes. Here again, it does not make sense from a manufacturing standpoint. There are often provisions for sub-systems to be coded according to VIN to make theft and re-VINing a vehicle as difficult as possible. And anything involving the cluster is generally more complex than the rest as the cluster acts as a gateway module in most modern vehicles; all vehicle bus systems come together in the cluster. Calibration issues I am aware of. Can not imagine that there is an additional ECU between the cluster and the fuel sender, though, so proper coding and calibration should do it.

Are you saying your GT2 cluster communicates flawlessly with the rest of the vehicle and you would not be able to calibrate a GT2 sending unit in a GT2 tank?

If one guy working on something like the cluster on the side manages to reverse engineer any significant portions of the cluster's firmware, he really is a brainiac . We have 2 guys dedicated to doing almost nothing but that on Land Rover and a number of others performing other tasks who come in and support them occasionally. And reverse engineering a systems firmware is a major, major task. I would have been surprised if Porsche allowed general re-coding - especially of the cluster. That's why I asked about Durametric. This is our niche in the Land Rover world: we go much deeper than nearly everyone else and pass some of that functionality on to users.

All that said, I have not studied the 996 electronics in any detail (yet), so I could be wrong about most of what I've written...

 

I've got a spare GT3 gas tank from a 997, I will send a PM. And located in the US

 

You can not reprogram a tank selection within the GT2 or Turbo cluster via Durametric, PIWIS, or PST2. The only way to do it is jail break it and isolate the fuel tank programming from one cluster and transfer it to the other. Our cluster guru has not been able to do that but he has broken the code on other features of base 996 clusters and Boxster clusters.

My GT2 cluster communicates with the car and has a functioning RPM gauge, volt meter, and engine temp. The central display works also. The speedometer and odometer does not work in the cluster due to the fact that it is looking for a signal from the ABS unit via CAN. I am running a Motorsport 996Cup ABS which sends a signal to the cluster via K-line. If I run the Cup cluster the speedo and odo would work but then a bunch of the other stuff would not work. As such, my GT2 instrument cluster has a ABS fail light illuminated and an ABS failure message displayed. None of this is relevant as all of the information the is normally displayed on the OEM cluster is sent to the MOTEC dash display which is positioned in front of the factory cluster so none of the information is needed on the factory cluster in my case. Motec will accept K-line, CAN bus, or direct inputs.

The turbo cluster works in my car also but it will continuously spit out PSM failure messages every 30 minutes since it is looking for a signal from the PSM pump. I have no PSM on the car and as such the continual chimes are annoying.

 

Subscribed. Just dropped in GT2 tank in my 996tt. Check Ebay. It is where I found my tank.

 

Don, what are you using to get an accurate fuel level reading? GT2 tank with an Turbo cluster will indicate that you have 5 gallons left when in fact you are empty. The fuel float algorithms is different which will cause the level to indicate higher than it actually is. Did you use a different filler neck with the GT2 tank or the stock TT one. PET shows them different.

 

Found this if you haven't seen it yet.

https://www.ebay.ca/ulk/itm/121820214779

 

i have a GT2 tank that i am not using

 

I have not installed fuel pump or filler neck yet. Just have the tank in for now.

 

Got a tank from Prodigy. Thanks to all those that replied...

 

Mark, what's the word on the Jet pump that was included with the tank? Still have not received it. It's been weeks now. Let me know what the deal is with that please...