Carista & Fusion OBD2 - Readings from a 'Stock' MKV FSI

[delavmkv]

Hey Guys,

I'm hoping those wiser than me can shed some light on the results from Fusion OBD2 on a "stock" FSI MVK.

As context - I've had my 2008 mkv (GLI, FSI,6M) since 2011 after purchasing it CPO from a VW dealer. It's up to date with maintenance (timing belt, plugs, brakes, cam followers, etc) and I've upgraded the PCV, Diverter Valve and struts with the thought of tuning the engine, but never took the plunge. At 90k it runs great but just kind of hangs out in the garage as our 3rd car behind our 4Runner and Forester. I only drive it a few thousand miles a year, mainly for fun.

To my knowledge, the car is not tuned although though it always felt quicker than the ~200 hp/~200 tq.

Recently, and thanks to less travel due to COVID-19, I've decided to start tinkering and was preparing to do a clutch, downpipe, intake and Stage 2 tune. I still like the car and this route is far cheaper than a MKVII Golf R, so the decision was made. However, before making any modifications I wanted to get some baseline figures and I purchased the Carista OBD2 and Fusion OBD2 app for iOS based on feedback from ECS tuning.

I was surprised by the baseline results (see below), and I wanted to get feedback from those wiser than I on what they might mean:

1. Are the results for boost, HP and TQ generally reliably with a BT OBD2 reader like Carista?
2. Have others found that the Fusion OBD2 app is accurate?
3. Given the ~250 HP / 250TQ and 23/20 PSI that Carista/Fusion OBD2 are seeing, I'm guessing owner 1 tuned my car and I never knew it. Is there a way to verify this?

Thanks all!

Adam

 

[ROH ECHT]

Given the boost alone, if accurate; it is tuned. Stock boost is 14 psi max. As far as the accuracy...I don't know. I use VAG-COM VCDS, and since it figures boost and torque(used to figure HP) correctly...then pretty sure yours does also. I just saw on an audi forum; one posting their OBD app first read 30 psi and they added a gauge because they knew that wasn't true and their boost was 19 psi. Yours not seeming that far fetched means one might believe it, right? Do you have another car you can use the app on to test its accuracy on a car with a more known power? I see some discussion of "user setting; PIDxx" setting may be off. But again, I am unfamiliar with it. You may want to research this a bit...here is the topic I am commenting on9scroll to about post #10 regarding PID talk; https://www.audizine.com/forum/showthread.php/856286-OBD-Fusion

 

[delavmkv]

Hey - man, thank you for the help.

Based on what I believe the car to be (likely an early APR Stage 1 for FSI) my guess is that these values may be accurate, but I want to learn more about how this software is reading data from the ECM.

That's a good read and I'm going to do some digging. Can you share the photo here (image 8206) from Post #10 in that thread? I'm trying to create a custom PID but I'm not 100% sure how the OBD Mode and PID Number need to be setup for this car. I'm going to do some diggin.

 

[ROH ECHT]

 

[delavmkv]

Thanks for that. I'm thinking the PID Number may be specific to the Bosch system on the B8 S4 (that thread) and I haven't come across any MKV threads using this app to see what others have done.

That said, it sounds like there are some setup fields for volumetric efficiency abd brake specific fuel consumption that need to be defined for the vehicle that will impact the boost interpretation and power output figures. All that to say, the app is likely not the most accurate measurement...

I've got a friend with a mechanical boost gauge and basic stage 1 build. We're going to see what his results are against the APR specified output.

Thanks for the help ROH!

 

[ROH ECHT]

Yeah, I couldn't find discussion on it in MK5 GTI forums...if you find someone with vcds you could see data there. It would automatically adjust once it reads your ecu.

But yes, the gauge will tell of the boost accuracy and answer the tuned or not question. Good luck.