Some of you may remember that last year i was playing around with the wastegate on my TD04HL16T turbo to my Z20NET.
well last year I took a gamble and had bought myself a Forge BPV to replace the stock BPV which i suspected of losing me some boost. Now there was not a replacement/uprated one specified for our engine (or the saab), but was one for a Volvo S40 (and others) and a Megane which i knew used the same turbo. I imagine the stock one would have been fine on an untuned or lightly tuned engine. However as i have modded my engine a fair amount and am running a stage 5/6 tuning level i was sure it was suffering..
I began to get turbo flutter when coming of the gas and sometimes could even get a double dump through the rev range on WOT run.
The problem was when i fitted this Forge unit to my turbo I kept getting DTCs relating to the CABV (charged air bypass valve) fitted near the throttle body. No matter what i did I could not stop this whenever i gave it the beans. After a week I removed it and put it back on the shelf for another day and refitted my stock BPV.
Code:
http://www.forgemotorsport.co.uk/content.asp?inc=product&cat=&product=FMDVRMR
Well recently while browsing another forum more dedicated to tuning these engines I came across a link to an American fella who had been playing with the same BPV. He had obviously persevered more than I and got his engine/turbo running correctly with this Forge unit and in turn solved his flutter issues..
Desperate to try mine again I could not wait for a dry day, and this afternoon I had another go.. Off came the stock unit and on went the Forge unit (only take about 15 minutes to swap over).. I then took it out for a run to warm it up.. Once warmed up I gave it the beans and it held the boost much better than before with no flutter when I came off the gas.. I decided to pull over and got out my Maptuner to re-apply my remap. Three minutes later I restarted the engine and let the oil come back up then off i went.. Wallop, all power seems to be back on.. a few runs around my test circuit was followed up with a WOT run. It pulled like a train all the way up to 6.7k with no double dump and then came down nicely..
Therefore if any of you guys who have done the TD04 upgrade you may benefit from this now, definitely over time.
Its not cheap but i my book its well worth it..
Pics below shows the difference on the business side of the wastegate diaphragm and the Forge BPV version and an external comparison..
IMG_2069.JPGIMG_2070.JPG
the thread below in the windows is the yank who got me to try mine again, he has done some pics which clearly show who you should fit it and the rest of the thread explains how it needs to be fitted.
Code:
http://www.saabcentral.com/forums/showthread.php?t=237232
I hope this helps some you either now or at some point in the future.. Its a worthwhile mod in my book..
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