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Title: n249 retrofit + big turbo Post by: BoobieTrap on April 21, 2018, 06:27:06 AM After dual DV did not solve my boost spike issue on gear shift, I decided to re-fit the N249 that the original owner removed.
Few questions to those in the know: 1) Should I modify any of the N249 maps if I'm running bit turbo on a 1.8T? 2) I'm running additional external brake vacuum reservoir, any reason not to plumb into it for the N249 vacuum source? Title: Re: n249 retrofit + big turbo Post by: BoobieTrap on May 12, 2018, 01:42:52 PM Well I went ahead and plumbed into my external additional brake vacuum reservoir with no ill effects so far.
For the maps, my 1.8T had the idle functionality disabled (SVDLDUVS all set to 1, which can never be true with a pre throttle body MAP sensor). I have re-enabled it by copying it from one the other files (1.11 at 600rpm and rising to 1.38 by 25000 RPM). This should be more beneficial on my setup, where the DVs are located right before the throttle plate so all the intake including turbo and IC can be by passed under light load. I have also increased GWPLDU to about 6% to prevent the DVs opening on small throttle fluctuations. Boost spikes completely gone and I confirmed that the DVs are open during cruise. Title: Re: n249 retrofit + big turbo Post by: nyet on May 12, 2018, 05:20:52 PM nicely done.
Good to see someone actually paying attention to why the N249 is not something that should just be deleted because somebody on AZ said it was a good idea. Title: Re: n249 retrofit + big turbo Post by: zamzu on November 21, 2019, 09:16:14 AM Hi,
I´ve done the exact same thing with the N249 because of a terrible boost spike after I release the thottle. Now I see next challange... getting rid of this turbo flutter I have (you can see from PrtSc). Btw dv is splitter, works well no mil etc... I was thinking to modify the splitter valve, because I think there are too small holes inside the valve for releasing all the pressure (between the pressure and intake side). Could it work? or is it more likely software issue? PS: running GT2871R (testing and learning step by step). Title: Re: n249 retrofit + big turbo Post by: prj on November 21, 2019, 12:12:08 PM 1. Remove bullshit
2. Fit 710P 3. Problem solved. If you need bigger, Forge makes a supersized recirculated dump valve. Title: Re: n249 retrofit + big turbo Post by: dilly on November 22, 2019, 01:15:24 AM I have also increased GWPLDU to about 6% to prevent the DVs opening on small throttle fluctuations. i assume GWPLDU is a map. how did you define it? what are the axes?Boost spikes completely gone and I confirmed that the DVs are open during cruise. Title: Re: n249 retrofit + big turbo Post by: armageddon on November 22, 2019, 03:15:00 AM And what explanation for boost spike with n249 in place?
My S4 does that, it did on k03 and it does on k04. I even bought a new valve without any change. Two friends with rs4 same issue. Mine and one RS4 with 710P and one with 007 replica. Mine and one rs4 with stock bi-pipes and other with the-tuner. Ps. Sorry to invade this topic, but same subject. |