[pal]

Last Saturday (Nov 12, 2022) three of us got a chance to put our cars on a Dynojet. Below is the current state of the cars wrt engine modifications

User: bentom2
2018 M2
Stock Tune, AA Gesi downpipe, CSF intercooler, CSF charge pipe

User: pal
2018 M2
Dinantronics Stage 1 harness, Akra downpipe, Akra catback, ER intercooler, ER charge pipe

User: AlexB77
2017 M2
VF Stage 2 Tune, Fabspeed 200 cell downpipe, CSF intercooler, CSF chargepipe

bentom2 also dyno'd his car stock in the past, so we will use that for comparison here.

I am using Dynojet's SAE correction factor as I've found that to be consistent across days and dynos. SAE corrected numbers are also what we would expect for wheel horsepower on these cars given the BMW published crank numbers. Obvious insights that we have here are:

- Bolt ons like downpipe and intercooler give gains across the powerband, even without a tune. Peak number here may not be representative of the improvements.
- 5th gear pulls for us yielded better results
- And tunes are better than no tunes for power - more boost
- Uncorrected numbers can be hugely different compared to SAE correction. In this case we saw 20+ more whp since we dyno'd on a cool day.

[hihowareyougood]

Thank you for sharing! On the first graph, I found it interesting that the stock tune w/ DP/IC/CP makes both less hp & tq compared to bone stock just between 6000-6500 rpm. I get that stock dyno was done on a different day so there could be other variables at play, but any other clue as to why that dip would exist?

[pal]

We noticed the sine wave pattern over 5500 rpm on both the stock tune dynos for bentom's car, and to a lesser extent on my Dinantronics Stage 1 car. I think that wave is some function of the stock tune trying to control something - maybe boost?

[AmuroRay]

Awesome. The load based tuning logic is likely going to allow the car to add power where the restriction is the highest - but peak power generally will not be changed much because at the higher RPM, it's turbo limited. A turbo inlet will net about 10WHP on top end and give a more linear power curve.

SAE is about 2.2% lower than STD - the biggest considerations are having a baseline and using the same calculations pre and post.

The Dinan is adding boost to the stock profile - do you know how much?
Did anyone log any of the runs?

And finally, have you done an IAT comparison? I personally think the ER should be superior to the CSF, especially if you trimmed that upper shroud, but I still want the data.

My former FBO N52 with MILVS on STD vs SAE correction:

[mike@x-ph.com]

thank you for sharing

[pal]

Ah, totally forgot that bentom2's car has the MST inlet pipe as well.

I did do some logging via VCDS' OBDII function and got some boost data. Will try to remember and upload the excel plots and post here later this evening. From memory, stock seems to shoot for around 14psi, Dinantronics is about 1-2 psi more and VF Stage 2 is about 4'ish psi more than stock.

It was a cold day so IATs were not interesting on the dyno. They have a big fan and it's a fairly open shop/dyno area. As you can see on the Uncorrected file, the temp in the shop was around 52°F. A bit cooler outside.

[AmuroRay]

Originally Posted by hihowareyougood

Thank you for sharing! On the first graph, I found it interesting that the stock tune w/ DP/IC/CP makes both less hp & tq compared to bone stock just between 6000-6500 rpm. I get that stock dyno was done on a different day so there could be other variables at play, but any other clue as to why that dip would exist?

Without logs, it’s hard to tell what it is exactly, it could be timing pull due to fuel quality or plug/coil conditions.

[pal]

AmuroRay, just for you

Here is one lap at Thunderhill from earlier this year, in 95+ degree weather. I plotted IAT, RPM and GPS Speed for you to look at.

[AmuroRay]

Yes!

Did you remove or trim your upper fan shroud?

[pal]

Originally Posted by AmuroRay

Yes!

Did you remove or trim your upper fan shroud?

The lower one is off the car, the upper one is not. Since it doesn't block the intercooler, Inleft it there. I can see how not having it could be better for airflow though.

[AmuroRay]

Originally Posted by pal

The lower one is off the car, the upper one is not. Since it doesn't block the intercooler, Inleft it there. I can see how not having it could be better for airflow though.

[IMG]https://media.fotki.com/2v2aHTFEjxu6LVA.jpg[/IMG]

Yeah, there was a thread in the F30 side that showed a reduction of 20F when the upper shroud was removed/trimmed, as it blocks airflow to the top of the intercooler. The Evo 3 is so tall, it includes a upper shroud to direct more airflow in.

So if you're looking for improved IATs, I would start there.