Enhancing Downpipes for Improved Performance

[veinedpanty]

Approximately two months ago, I succumbed to temptation and installed catless main and secondary downpipes from [email protected].

My reflections:

1.) The CEL is undoubtedly present. Lately, I have been using BimmerLink and an ENET Wi-Fi OBD II device to eliminate the error code. It occurs about every 100-150 kilometers. Initially, the presence of the CEL was bothersome, but I eventually used to it due to its undeniable value. Currently, I just delete the code in order to preserve the functionality of remote start.

2.) The disparity in sound and satisfaction is starkly contrasting. I really enjoyed the automobile in its original condition, but it was undeniably lacking a certain element. Currently, the sound produced by the exhaust is very loud. When the engine is revved to its maximum, it emits a powerful and thunderous noise similar to that of the mythical god Thor. Additionally, the turbochargers provide a high-pitched whistling sound reminiscent of a Calvo Viper. Furthermore, the upshifts are characterized by a forceful and impactful sensation. The ZF8 exhaust emits a loud noise and sometimes comes in its original state, but it becomes very powerful when the catalytic converters are removed.

3.) Many individuals have conflicting opinions on the use of running downpipes with a stock tune. While the majority acknowledge that it is achievable and acceptable, a few individuals may claim that the vehicle exhibits peculiar behavior and sometimes experiences power loss.

What are my opinions on the assertion? I have performed many Dragy tests on my vehicle in its standard configuration, as well as a few times with the addition of downpipes.

The stock acceleration time from 60 to 130 miles per hour is between 8.1 and 8.4 seconds, with some exceptional runs achieving 8.0 seconds.
The acceleration time from 60 to 130 miles per hour for vehicles equipped with downpipes is between 7.7 and 7.9 seconds.

If I were to have an exceptional performance in ideal weather conditions without any obstacles, I believe I could achieve a time of 7.6 seconds to accelerate from 60 to 130 miles per hour.

I have not yet had the opportunity to test the vehicle in the same weather conditions as when I achieved a time of 8.0 seconds with no modifications. However, with a temperature of 75°F and an altitude of 2700 feet above sea level, the car achieved a time of 7.8 seconds. The stock time for comparison in those weather is around 8.3 seconds.

The turbochargers now reach their maximum rotational speed more quickly, resulting in little delay in power delivery known as turbo lag.

It is evident that the assertions about the automobile running slower or performing worse are false. Is it possible that this may be true in the future when the automobile has accumulated more mileage? I am uncertain. One observation I have made is that the low-end power is, at most, equal to the stock power when starting from 0-20-40 mph. However, the significant difference in top-end power compensates for this.

I do oil changes at intervals of 5,000 miles and want to begin replacing my spark plugs every 15,000 miles now that I no longer have a catalytic converter.

In summary, I have a strong affection for both the automobile itself and the sound it produces. This is the ideal version of the M8 that should have been produced initially, but unfortunately, it was not feasible.

[chantana]

Without a video, this topic lacks use.

It was predictable.

[veinedpanty]

ha ha ha ha . Do you want a video of the exhaust system or a video of the car running?

[chantana]

Sound produced by the exhaust system.

[veinedpanty]

https://youtube.com/shorts/ZbsMIj40c...qe-0T-qbgiPy4M

[veinedpanty]

 

[veinedpanty]

I hope that the audio quality of the film accurately represents its true nature. The difference in volume is certainly noticeable, but seeing it firsthand is just mind-blowing. I have friends who have modified their vehicles and they have advised me that if I make any more changes to the exhaust system, which is now in its original condition, it will result in excessive noise.

[veinedpanty]

What is inside the car?

[teara23]

I would want to express my thoughts:

In my opinion, this object likely produces an impressive and authentic sound when subjected to a WOT pull.

My only grievance with very forceful exhaust systems (those without catalytic converters or with high flow catalytic converters, etc.) in turbocharged vehicles is their noise level at low velocities, such as while driving in residential areas. Their sound evokes the resemblance to that of vehicles, which is unpleasant.

I am aware of this since my 992 Porsche Carrera S has a very forceful exhaust system. I experienced discomfort due to its sound at low velocities, however the sound it produced at wide open throttle (WOT) certainly compensated for it.

[dramarena]

Indeed, turbocharged automobiles do not provide the same pleasing sound as naturally aspirated or supercharged engines. The wife's GTS with Soul performance emits a melodious sound that is reminiscent of music, and it is powered by a naturally aspirated 6-cylinder engine.

However, the explosive and aggressive pops and burbles produced by the M8, especially when equipped with a high-quality sound system, convey a strong desire for conflict.

[chantana]

The occurrence of pops at low speed is both vexing and unseemly for a sophisticated machine such as the M8. That is only my own viewpoint.

Query. Is there any issue with eliminating primary elements while keeping secondary elements? Does it represent a satisfactory compromise?

[dramarena]

You have the option to deactivate or significantly minimize the presence of them. I believe that removing the secondary catalytic converters will not cause any discomfort. However, it is important to note that these converters primarily serve as high flow catalysts, which may potentially help in reducing odors.

[veinedpanty]

Could you please provide a precise definition of the term "trucks"?

[veinedpanty]

By just deleting the primary components, the resulting sound will undoubtedly be louder compared to solely removing the secondary components.

Based on your preference for a lower volume, I suggest removing just the secondary components. In addition, the removal of merely the secondary components does not activate the Check Engine Light (CEL). My buddy has installed a secondary cat delete on his F90 vehicle. However, I found it to be unimpressive, so I decided to completely remove the catalytic converter.

Variations in preferences exist among individuals.

[chantana]

Indeed, it is logical to expect that it will produce a higher volume. We have not seen anybody do such action.

[silver6933]

Excellent audio quality. What is the intensity of the odor when there are no cats present? That is the one obstacle that has hindered my progress so far.......

I am considering completely removing all components and replacing them with Highflow aftermarket secondaries.

At now, I am using a DME STG 1.5 Engine Control Unit (ECU) and a Weisstech STG 1 transmission tune, in addition to employing Cold Air Intake (CAI) intakes.