Dyno Day

[JustAnothaM4]

Decided to put the GTS on the dyno for good measure before making anymore changes. I'm rather surprised by the results. Is the GTS horsepower rating underrated?

One thing I noticed is the extremely flat torque curve between 4k-6k rpm and then it just drops to redline.

Engine Modifications (Stock Tune/Map)
Eventuri v2 Intake
Akrapovic Exhaust
Akrapovic Downpipes
CSF Heat Exchanger
CSF Oil Cooler
CSF DCT Cooler
Vargas Silicone Charge pipes

[Wanted_M]

Nice ride and good power. Any videos on dyno?

[fiveohwblow]

My understanding is, almost all “ratings” are inaccurate. I’ve found most of the ratings given are “closer” to rwhp. I’d also suspect you’ve freed up a bit of power with your mod list, maybe 20 rwhp or so…?

I’m no expert, I’m sure others will chime in with much more experience.

[JustAnothaM4]

Originally Posted by Wanted_M

Nice ride and good power. Any videos on dyno?

Here you go

https://youtube.com/shorts/WSXMWEBMITI?feature=share

[TractionControlDelete]

Originally Posted by Project M4GTS

Decided to put the GTS on the dyno for good measure before making anymore changes. I'm rather surprised by the results. Is the GTS horsepower rating underrated?

One thing I noticed is the extremely flat torque curve between 4k-6k rpm and then it just drops to redline.

Engine Modifications (Stock Tune/Map)
Eventuri v2 Intake
Akrapovic Exhaust
Akrapovic Downpipes
CSF Heat Exchanger
CSF Oil Cooler
CSF DCT Cooler
Vargas Silicone Charge pipes

Great numbers and NICE steering wheel! Which one is it?

Any sense of how much power you've gained from your down pipe, heat exchanger, intake, and exhaust?

[SYT_Shadow]

That seems insanely powerful for the stock ecu

[coryf]

Very nice. I'm planning on dyno checking my car soon now that the weather is getting a bit cooler. Will be fun to compare.

[JustAnothaM4]

Originally Posted by fiveohwblow

My understanding is, almost all “ratings” are inaccurate. I’ve found most of the ratings given are “closer” to rwhp. I’d also suspect you’ve freed up a bit of power with your mod list, maybe 20 rwhp or so…?

I’m no expert, I’m sure others will chime in with much more experience.

Interesting...I mean the mods list didn't seem like anything too crazy. I certainly didn't expect that much of an improvement.

Originally Posted by F82KPowers

Great numbers and NICE steering wheel! Which one is it?

Any sense of how much power you've gained from your down pipe, heat exchanger, intake, and exhaust?

The steering wheel is made my KMP.

No, I never did a baseline dyno run before the modifications.

Originally Posted by SYT_Shadow

That seems insanely powerful for the stock ecu

My thoughts exactly.

Originally Posted by coryf

Very nice. I'm planning on dyno checking my car soon now that the weather is getting a bit cooler. Will be fun to compare.

Yeah, is your car completely stock or have you done some modifications? I'm interested to see your results especially if its 100% stock.

[Wanted_M]

Originally Posted by SYT_Shadow

That seems insanely powerful for the stock ecu

To me these two mods are the best bang for your buck and of course it has H20 injection which helps..
Akra Downpipes- Frees up power/tq.
CSF Heat Exchanger- Minimizes IC heat soak and faster recovery between runs.

[schnell325]

Any downpipe related CEL?

[JustAnothaM4]

Originally Posted by schnell325

Any downpipe related CEL?

No, I'm using non-foulers to avoid the CEL. Works perfect!

[schnell325]

Originally Posted by Project M4GTS

No, I'm using non-foulers to avoid the CEL. Works perfect!

Thought so!

[Wanted_M]

Originally Posted by Project M4GTS

No, I'm using non-foulers to avoid the CEL. Works perfect!

Which ones?

[heitzke]

Really solid numbers. One odd point though is that the torque/horsepower doesn't cross paths at 5252.

I imagine you're probably about the same hp/torque given your mods.

[Lienrocs]

Do they have any other F8X's to compare your runs to? Almost 500 wheel seems too good to be true, even for a GTS. But I hope that's the case.

[SYT_Shadow]

Originally Posted by Lienrocs

Do they have any other F8X's to compare your runs to? Almost 500 wheel seems too good to be true, even for a GTS. But I hope that's the case.

It does sound too good to be true. I dyno'd mine on a dynojet, std correction, and got like 445whp

[Lienrocs]

Originally Posted by SYT_Shadow

It does sound too good to be true. I dyno'd mine on a dynojet, std correction, and got like 445whp

That seems more reasonable. 445 wheel is about right for a claimed 500 crank. 10-15 percent drive line loss gets you right at your number.

[SYT_Shadow]

Originally Posted by Lienrocs

That seems more reasonable. 445 wheel is about right for a claimed 500 crank. 10-15 percent drive line loss gets you right at your number.

I changed injectors/coils/plugs/air filters on the GTS1 after the dyno, and will dyno again.

On that same dyno, my CS gave 431whp. I thought the GTS1 result was low.
Before anyone wonders, my water injection is working perfectly, I went through 6 gal this weekend

I'll put the same wheels on GTS1, GTS2 and the CS for the next dyno to reduce variables

[JustAnothaM4]

Originally Posted by Lienrocs

That seems more reasonable. 445 wheel is about right for a claimed 500 crank. 10-15 percent drive line loss gets you right at your number.

Originally Posted by SYT_Shadow

I changed injectors/coils/plugs/air filters on the GTS1 after the dyno, and will dyno again.

On that same dyno, my CS gave 431whp. I thought the GTS1 result was low.
Before anyone wonders, my water injection is working perfectly, I went through 6 gal this weekend

I'll put the same wheels on GTS1, GTS2 and the CS for the next dyno to reduce variables

Other F8x cars were at the dyno as well and results all varied. All cars were modified with BM3 stage1/stage 2 pushing between 510-570.

Please note that my car is slightly modified a bit and I did have on my FI-R wheels which are extremely light (if that makes any difference ). I did notice after fixing stone filter issue it pulls muchhh harder at higher RPM and I see the sport display hit the 500hp+ hp consistently.

I dynoe'd my old M3 CS on this same dyno earlier this year and hit 510rwp with the below mods. The area under the curve was rather different as there is a huge torque spike in the lower 3-4k rpm range.

2018 M3 CS Modifications:
Akrapovic Exhaust & Downpipes
Silicone Charge Pipes
ECUTek Stage 1 tune (conservative)

[SYT_Shadow]

Originally Posted by Project M4GTS

Other F8x cars were at the dyno as well and results all varied. All cars were modified with BM3 stage1/stage 2 pushing between 510-570.

On 93 octane? Doesn't BM3 show ~510 for the Stage2 on 93?

I've seen a tuned stage 1 GTS from Epic, catless, with ~490whp or so

[JustAnothaM4]

Originally Posted by SYT_Shadow

On 93 octane? Doesn't BM3 show ~510 for the Stage2 on 93?

I've seen a tuned stage 1 GTS from Epic, catless, with ~490whp or so

Yes, thats about right on 93 and catless give or take a few. Those numbers will vary depending on car and I know some guys were running a mix of e85 hence the higher number runs.

The one key thing you notice with any OTS tune for the s55 is the crazy increase in torque. My car clearly doesnt show that is more along the lines for a stock map. Sooooo yeah...seems some bolt on mods puts down some nice power!

[JustAnothaM4]

Originally Posted by heitzke

Really solid numbers. One odd point though is that the torque/horsepower doesn't cross paths at 5252.

I imagine you're probably about the same hp/torque given your mods.

I'm glad you noticed that. The power delivery for the GTS is rather different from other variations. My torque.horespower doesn't cross paths until around 5800 rpm. The torque is very linear all the way to 6k rpm then it dies. I believe the GTS peak boost is around 21 unlike base/comp models.

For example...