Puffwagon Puff Gold Donating Members 15,984 Member For: 9y 10m 25d Gender: Male Location: South Australia Posted 05/04/21 07:14 AM Share Posted 05/04/21 07:14 AM It can either be the preload being tight, it can be the wgdc being set too high for too long in the rev range, it can be the underboost set too close to the target or a combination of them all. Given that you can only loosen the preload atm, I would back it off a touch and see if you can get it to not have the spike. Having a bigger dump/exhaust will exacerbate the spike and will also cause it to make more boost per duty, especially after about 4500 - 5000rpm. End of the day you can only try, it might work and it might not. Given the size of the spike I would tend to think preload adjustment will work, rather than not. I wonder if putting it back to stock will lose all the credits used for the boost by gear etc? It might just need to be flashed back to stock and then the credits will be there for further use. I think this is the case as the tunes are vin locked. I've got the whole suite of credits and can remake various custom tunes for boost by gear/speed/temp etc and reflash them at will. Link to comment Share on other sites More sharing options...
hjtrbo Bronze Donating Members 320 Member For: 13y 11m 6d Posted 05/04/21 08:15 AM Author Share Posted 05/04/21 08:15 AM Hey, not sure on the credits. I haven't looked into it but a quick support email to PCMtec will answer that for me if the need arose... Can get the air compressor out and make some notes whilst adjusting half a turn at a time. Will be a good learning exercise for me. I'll also get some better logs of the MAP and a few other bits and will update the thread. Link to comment Share on other sites More sharing options...
cat007 Member 236 Member For: 6y 3m 20d Posted 06/04/21 08:57 AM Share Posted 06/04/21 08:57 AM Would have thought the credits are to you (or whoever owned the car when it was tuned) and/or the physical ECU? Not locked to the tuner's account? Link to comment Share on other sites More sharing options...
hjtrbo Bronze Donating Members 320 Member For: 13y 11m 6d Posted 04/08/21 04:40 AM Author Share Posted 04/08/21 04:40 AM Took me a while. Have got an accessible tune now which is awesome. Ended up keeping the stock dump and went with a 3.5" cat pipe and gutted cat to bolt up to the already existing 3.5" cat back system that came with the car when I bought it. To get a roadie I had to put a cat on and that caused a 2psi boost spike around the point where the wastegate opened. Now with the new system she's boosting mint (I think, still learning). Still learning this turbo stuff. My other is a Expensive Daewoo with a PD blower and that is much easier to tune. The Fords are a different beast to get used to. Without pulling the turbo off to test the pre-load with a mityvac I am presuming that the point in the attached graph where the initial boost rise rolls over is the rough cracking pressure of the gate? I did a pull with the WGDC set at 0% and the boost curve is very similar albeit a couple of psi down up top. The wastegate preload would have been set by Maxx Performance when the turbo was replaced with the F6 unit that is on the car now. And lastly, the knock system is pulling up to 0.8deg on standard knock sensor settings. Is that normal or should I pull some timing / boost out to see if it goes away? AFR is spot on commanded (0.8 to 0.82 lambda on 98) Link to comment Share on other sites More sharing options...
hjtrbo Bronze Donating Members 320 Member For: 13y 11m 6d Posted 04/08/21 06:53 AM Author Share Posted 04/08/21 06:53 AM Log shot attached Link to comment Share on other sites More sharing options...
hjtrbo Bronze Donating Members 320 Member For: 13y 11m 6d Posted 06/08/21 04:54 AM Author Share Posted 06/08/21 04:54 AM (edited) Fark, this forum is good. I read this thread today Anyway, whilst doing an air check on the wastegate it was leaking big time. Thought the boost seemed a little high lol. The actuator is a Turbosmart IWG-75. All the o-rings in the banjo fitting had gone hard and weren't sealing. Trip to Pirtek and 63 cents for 3 off appropriately sized o-rings and she's all fixed. Boost pressure is back to 14psi, way lower than the 22psi it was running with the banjo fitting leak. Man, so so lucky the engine didn't go pop! Thanks to this forum! Edited 06/08/21 04:55 AM by hjtrbo added picture of failed banjo fitting Link to comment Share on other sites More sharing options...
jas98 Member 1,043 Member For: 12y 5m 2d Gender: Male Location: Maryborough Qld Posted 07/08/21 10:38 PM Share Posted 07/08/21 10:38 PM Good stuff Curious. That banjo. Is it supposed to spin freely? Like really easily. I'm yet to check air leaks on it but just noticed since new it seems really easy to spin compared to one my mate had for his. Link to comment Share on other sites More sharing options...
hjtrbo Bronze Donating Members 320 Member For: 13y 11m 6d Posted 07/08/21 11:07 PM Author Share Posted 07/08/21 11:07 PM Yeah was really loose aye. 10mm bolt to remove under the fuse box to get the boost solenoid bracket out. Then pull the bottom hose off the solenoid and blow into with your mouth as a quick easy test. Mine pissed out with air just by using my breath. Link to comment Share on other sites More sharing options...
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