[Info@mad-us.com]

Originally Posted by r33_RGSport

Don't you guys ever wonder why I never promote catless downpipe?

You should see the dyno result on catless downpipe by itself without tune vs midpipe by itself without tune.

1. Because you are in California and you can't sell them in your own state so you prefer to sell Catted versions. Don't blame you but let's be real California is the strictest state when it comes to car mods and emissions.

2. Catless downpipes won't make much power with out a tune because the Ecu reduces boost to hit the targeted factory set torque. This does NOT mean Downpipes do not create any power from less restriction. Midpipes will have the same effect once the ecu sees any additional gains created. A piggy back or flash tune will correct this.

[r33_RGSport]

Originally Posted by Info@mad-us.com

1. Because you are in California and you can't sell them in your own state so you prefer to sell Catted versions. Don't blame you but let's be real California is the strictest state when it comes to car mods and emissions.

2. Catless downpipes won't make much power with out a tune because the Ecu reduces boost to hit the targeted factory set torque. This does NOT mean Downpipes do not create any power from less restriction. Midpipes will have the same effect once the ecu sees any additional gains created. A piggy back or flash tune will correct this.

Uhm, proof?

[Info@mad-us.com]

Originally Posted by r33_RGSport

Uhm, proof?

Factory ecu torque limits and throttle closures are nothing new.. I've seen it in person after installing downpipes causing throttle closures to match factory torque from less restriction and quicker spool which results in over boosting. This goes for all mods not just downpipes. A flash is essential or a tunable piggy back such as a Jb4 . The car will even lower boost on cold days and raise boost on hot days because of the air density and the ecu's ability to always keep the same power. The days of cold weather and more boost are behind us unfortunately.

Great explanation of s58 logs and throttle closures even on factory cars @ 14 min.

Customer with our Downpipes. Read the comments that other have shared with him everyone is seeing Throttle closures and boost reductions.

You can see it here at 13 min when intakes filters are installed

[r33_RGSport]

Originally Posted by Info@mad-us.com

Exactly as stated in this video.

Here are dyno results on my '20 X3MC.

Catless with no tune. Shows HP/TQ loss with no tune.


Midpipe with no tune. Shows HP/TQ gain even with no tune.

[Info@mad-us.com]

Originally Posted by r33_RGSport

Exactly as stated in this video.

Here are dyno results on my '20 X3MC.

Catless with no tune. Shows HP/TQ loss with no tune.
Attachment 2892266

Midpipe with no tune. Shows HP/TQ gain even with no tune.
Attachment 2892267

I'd love to hear your explanation on that making any sense at all if its not closing throttle. Removing primary cat (most restrictive) VS removing a secondary cat (less restrictive) Its the tuning....


BTW the Thick lines in the video above are with the downpipe and the thin line was stock Downpipe.

You can clearly see it making more power till boost was reduced at 3300 rpm.



Jb4 tuned car with Dp vs stock dp

[r33_RGSport]

Originally Posted by Info@mad-us.com

I'd love to hear your explanation on that making any sense at all. Removing primary cat (most restrictive) VS removing a secondary cat (less restrictive) Its the tuning....


BTW the Thick lines in the video above are with the downpipe and the thin line was stock Downpipe.

You can clearly see it making more power till boost was reduced at 3300 rpm.



Jb4 tuned car with Dp vs stock do

Well, you are a manufacturer, you should have all the data and explanation on product that you develop, manufacture, market, and sell.
I am just a reseller who is bored and collect data to share.

Anyway, moving on.

[Info@mad-us.com]

Originally Posted by r33_RGSport

Well, you are a manufacturer, you should have all the data and explanation on product that you develop, manufacture, market, and sell.
I am just a reseller who is bored and collect data to share.

Anyway, moving on.

I explained it all in the first post Thanks for sharing your dynos though. Having worked with dynos for many years I always find it interesting how different samples can be from one another. There are so many factors that go into it that most don't know about.

Take care.

[thestimp]

The ECU has thresholds to which it can change parameters for power. The catless DP exceeds this (because of the missing O2 sensor input) in which case the engine retards power due to tolerances and stays within spec. The midpipe does not have the missing o2 input, nor does it exceed these tolerances therefor its allowed to push to an efficient "power boost" setting.

In short a catless DP without tune will result in power loss due to missing sensory data input. A midpipe will not because nothing is missing and less restriction of flow.

[Info@mad-us.com]

Originally Posted by thestimp

The ECU has thresholds to which it can change parameters for power. The catless DP exceeds this (because of the missing O2 sensor input) in which case the engine retards power due to tolerances and stays within spec. The midpipe does not have the missing o2 input, nor does it exceed these tolerances therefor its allowed to push to an efficient "power boost" setting.

In short a catless DP without tune will result in power loss due to missing sensory data input. A midpipe will not because nothing is missing and less restriction of flow.

What o2 is missing? We have both primary widebands and secondary o2s installed. Pic of our g80 Dps.

[thestimp]

Originally Posted by Info@mad-us.com

What o2 is missing? We have both primary widebands and secondary o2s installed. Pic of our g80 Dps.

A stock engine is not tuned for a non-catted downpipes output, its looking for specific parameters of post combustion in order to lean/rich the engine, so if its not able to see/hit what it needs to it will just stick to known specs in a safety known spread. Sticking an 02 sensor on it will just throw a CEL which is telling you "its not working properly". I'm not arguing here I'm just stating facts of how these work as an engineer. Putting a bigger mouth on you doesn't mean your lungs can handle more air, they handle as much as they are supposed to in order to work efficiently/properly.

This is the principal of how piggy backs work, they trick the engine into a different scale, you could potentially piggy back the o2 on the downpipes and trick the engine into thinking its operating properly ("DP Fix") these also exists and work better than bungs.

I dont even know where this is going, DP's work better on precision engines when there is a tune involved, otherwise the engine will be out of spec and junk happens. Mid pipes do not alter any thing in the tech chain which is why they produce some actionable results in "newer" engines with tighter tolerances due to smog and emission standards.

[Info@mad-us.com]

Originally Posted by thestimp

A stock engine is not tuned for a non-catted downpipes output, its looking for specific parameters of post combustion in order to lean/rich the engine, so if its not able to see/hit what it needs to it will just stick to known specs in a safety known spread. Sticking an 02 sensor on it will just throw a CEL which is telling you "its not working properly". I'm not arguing here I'm just stating facts of how these work as an engineer. Putting a bigger mouth on you doesn't mean your lungs can handle more air, they handle as much as they are supposed to in order to work efficiently/properly.

This is the principal of how piggy backs work, they trick the engine into a different scale, you could potentially piggy back the o2 on the downpipes and trick the engine into thinking its operating properly ("DP Fix") these also exists and work better than bungs.

I dont even know where this is going, DP's work better on precision engines when there is a tune involved, otherwise the engine will be out of spec and junk happens. Mid pipes do not alter any thing in the tech chain which is why they produce some actionable results in "newer" engines with tighter tolerances due to smog and emission standards.

Yeah you are correct! I just thought you were saying the rear 02's were disconnected in your previous post but, I understand what you meant now.