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Finished installing the turbos also made some custom straight pipes, but dont know why it does a bit more boost than before..I run 12psi WGs springs and used to do 12psi, now I am reaching even 1bar
@1.2bar sometimes I see on the greddy even 1.4-1.5bar afert pulls till 5th gear, even the durametric log seems to look fine for 3rd-4th gear log..
Will look more into the problem, if anybody knows the answer please let me know, I was considering some reasons might be load targets and boost request vs load, but the spring will open the WG anyway so doesnt make so much sense, maybe some overboost as the turbos spool like crazy ? or maybe huge boost spikes ?
Turbos are reaching 1bar @3200rpms in 3rd gear, pump gas, already been able to lower my track time by 3 seconds from 1:42 to 1:39, looking for some more data the next days, tomorrow going out for some new track fun
I found on alpha 28s I would get a boost spike - even slightly with external gates. I re did my wastegate lines picking up pressure from the comp housing to the lower port of the wastegate. Lines are just a few inches. This helped a lot.
Fadi, can you describe your wastegate hose setup? I'm getting very short boost spike when I let off the gas and believe it's because my boost source supplies the external wastegates, the Greddy boost solenoid and the controller all from the same source, from the y-pipe. I'm using 0.7 bar springs and hold 0.9 bar with the Greddy off with quick spikes of 1.4 bar flashing on the Greddy when I let of the gas.
I might try a setup like LQQK mentioned, sounds like it would have better control.
Last edited by Jeanmarcboilard; Aug 8, 2015 at 08:32 PM.
Fadi, can you describe your wastegate hose setup? I'm getting very short boost spike when I let off the gas and believe it's because my boost source supplies the external wastegates, the Greddy boost solenoid and the controller all from the same source, from the y-pipe. I'm using 0.7 bar springs and hold 0.9 bar with the Greddy off with quick spikes of 1.4 bar flashing on the Greddy when I let of the gas.
I might try a setup like LQQK mentioned, sounds like it would have better control.
Yeah something isn't right here. You don't want your wastegate to ever see vacuum - so your boost source shouldn't be connected where you greedy is.
I run both lower and upper ports on my wastegates. Lower port has very short line to compressor housing which was the trick to solving boost spike. The upper ports are connected to the boost solenoid which connects to the ypipe. I have the solenoid on a 90deg an fitting mounted hard to the ypipe.
Your greedy then picks up boost off the plenum - where the fuel pressure comes from.
Yeah something isn't right here. You don't want your wastegate to ever see vacuum - so your boost source shouldn't be connected where you greedy is.
I run both lower and upper ports on my wastegates. Lower port has very short line to compressor housing which was the trick to solving boost spike. The upper ports are connected to the boost solenoid which connects to the ypipe. I have the solenoid on a 90deg an fitting mounted hard to the ypipe.
Your greedy then picks up boost off the plenum - where the fuel pressure comes from.
Happy to send some pics if people like.
Can you explain exactly where on the plenum the boost to the Greddy controller comes from? I've figured out what most of the hoses there do, except for where the fuel pressure comes from.
As for the main wastegate supply, I don't have a tap on my compressor housing, but I can tap into the 2.5" boost hoses on the compressor outlet with a special fitting I found.
Fadi, sorry for the hijack but hopefully this helps you as well.
Last edited by Jeanmarcboilard; Aug 8, 2015 at 10:44 PM.
Can you explain exactly where on the plenum the boost to the Greddy controller comes from? I've figured out what most of the hoses there do, except for where the fuel pressure comes from.
As for the main wastegate supply, I don't have a tap on my compressor housing, but I can tap into the 2.5" boost hoses on the compressor outlet with a special fitting I found.
Fadi, sorry for the hijack but hopefully this helps you as well.
The fuel pressure comes off one of 3 fittings that are on the front left hand side of the plenum. They are located to the left of the throttle body behind the oil filter. They are small rubber vacuum lines. 2 have black and white check valves - you don't want to connect to these. The other is the fuel pressure fitting.
The other option you have is to connect to the other end of the fuel pressure line at the regulator. This is on the right side. This can be easier to do. The controller should see vacuum and boost.
The fuel pressure comes off one of 3 fittings that are on the front left hand side of the plenum. They are located to the left of the throttle body behind the oil filter. They are small rubber vacuum lines. 2 have black and white check valves - you don't want to connect to these. The other is the fuel pressure fitting.
The other option you have is to connect to the other end of the fuel pressure line at the regulator. This is on the right side. This can be easier to do. The controller should see vacuum and boost.
Ok, that vacuum line would be the one closest to the throttle body out of the 3.
Thanks
Here is the line from compressor to wastegate for me.
That's convenient, but my Garretts don't have those fittings. I picked up 2 spare large boost hoses that I can play around with installing the fittings I bought. The fittings are installed from the inside, has a backing plate to prevent it from coming out and the nut screws on the outside so no chance of anything falling off inside.
Any of you guys have a wiring diagram for 996tt ECU and plex? Maybe including Aquamist too... Guess not but will skip a lot of effort if I can find one
Turbos are doing great, 1bar @3200rpms in 3rd, still not going over 1.1-1.2bar
The guys from plex were incredible, I ordered it yesterday by email, they issued the paypal, I paid, they shipped and today I had it delivered already !!!!! Crazy fast !
I scheduled install for tomorrow morning by 10AM local time, will see how will make it work, just downloaded the ECU wiring diagram, will send an email to Plex to check if they can help me out to save some time
The Plex guys are great - including sending my custom flash updates weekly while we worked on some new capabilities
The install is pretty easy - but here is a few main points.
1) obd connects to the abs hi/lo canbus for the 996 at the ecu. This is different to the 997 and the wiring diagram.
2) pick up the rpm from the ecu too instead of canbus. I used the same rpm input that aquamist uses.
3) think about how you want to use the 2 inputs and lay wires out. I would recommend Fuel pressure sensor, and AFR (AFR needs a 0-5v input and I use an aem gauge for that). Both fuel pressure and AFR can be programmed as failsafes.
4) if you want to use the aquamist to trigger a boost preset (ie drop to low boost setting) - then run the pink wire from the aquamist to the one of the grey switch wires I the Plex. Then you can configure. The switch is a negative input.
5) think how you want to use the output. I use it to activate my second fuel pump. Again it's a negative switch that I use to trigger realy.
sure, your reply above does help me a lot, thanks will keep you updated
1. not very clear what you meant here, ohhhh I must checked the manual and its clear now
2. yes, will do
3. this is just wow, like a light version standalone, dont have any AEM gauge and might just use it later on and keep just the basics for now
4. yes I would like to integrate aquamist too
5. I use 2x044 in parallel+surge tank, still thinking what other applications I might need, but maybe time will tell, glad we have the option there
sure, your reply above does help me a lot, thanks will keep you updated
1. not very clear what you meant here, ohhhh I must checked the manual and its clear now
2. yes, will do
3. this is just wow, like a light version standalone, dont have any AEM gauge and might just use it later on and keep just the basics for now
4. yes I would like to integrate aquamist too
5. I use 2x044 in parallel+surge tank, still thinking what other applications I might need, but maybe time will tell, glad we have the option there
Great. Plex updated their wiring for the 996. It took me a while to figure it out and went back and forth until I found out they used the ABS canbus in the ecu.
Looking at the instructions in your link, the speedometer wire can go to the radio wire. I didn't do this, I am using the canbus /obd data for speed. For me, the speedometer wire is connected to a ethanol sensor and I can measure ethanol content in the fuel - then I just flash the time to match. It's super nice.
