[mike@x-ph.com]

For over 30 years, Active Autowerke has been the one to turn to for high quality BMW performance products. Committed to enhancing the performance of BMWs through the highest quality products is what Active Autowerke is all about. The newest addition to our BMW F90 M5 Collection, these S63TU downpipes represents our outlook on creating innovative products with performance in mind.

Theu00a0S63TU downpipes are strategically engineered to virtually eliminate the immensely restrictive characteristics of the factory M5 downpipes therefore reducing radiant heat and increasing performance. Our M5 downpipes will significantly increase horsepower and torque throughout the powerband. They will reduce any turbo lag

Our F90 M5 downpipes are manufactured in house using 304 stainless steel. Each set is meticulously tig welded and checked for perfect fitment. Our design uses a factory matched 3.5" v-band inlet that tapers to a high flowing, mandrel bent" body and includes the lower section sold by others as a "mid-pipe".

**Our downpipes allow the use of the OEM O2 sensor heat shield. With the heat shield installed the engine bay remains stock-looking for a sleeper look!

This variant includes a pair of 4.5" high flow GESI catalytic converters that will NOT produce a CEL!

The GESi G-Sport Ultra High Output Catalytic Converter features full 304 stainless steel construction, including the substrate. GESi UHO-Series Catalytic Converters are EPA registered and compliant in 49 states and fully OBD2 compliant, perfect for use on 1996 and newer vehicles. GESi proprietary precious metal loading technology ensures greatly reduced emissions, eliminating most "Check Engine Lights". These high flow catalytic converters outperform stock converters and provide a reliable solution to the most common catalytic converter problems.

The GESi UHO-Series Catalytic Converters are rated for engines putting out between 500 and 850 horsepower while maintaining a high flow capacity. The reduced back-pressure from this high flow catalytic converter will allow you to maximize your engines horsepower without the harmful emissions. Say goodbye to Check Engine Lights and failed emissions tests!

Please Note: These catalytic converters are not legal for use on vehicles registered in the state of California as a result of California Vehicle Code Section 27156 and 38391.

NOTE: Federal law prohibits the tampering of an emissions control device. Mobile Source Enforcement Memorandum 1A, allows for aftermarket parts to be used in the repair or replacement of emissions control systems, provided the emissions aren't adversely affected. There is no mention or reference to cell density or converter volume dimension. The GESI catalytic converter will produce emissions that will meet the standards set by the EPA, not CARB.

Features:

NO CEL when using this downpipe

GESI EPA registered high flow and fully OBD2 compliant

Casted upper stainless steel V-Band for precise fitment

4.50" diameter piping allows for maximum power output

Quicker turbo spool

Rated for 500 to 850 hp applications

Withstands up to 1500 F

Can reach operational efficiency within 9 seconds of startup

Easily bolts-on no cutting or welding required
Accepts OEM O2 sensor heat shield

Durable construction from TIG welded 304 stainless steel

Precise fitment

Ultra high flow 400 cell per square inch catalyst

EPA compliant for use on OBD2 vehicles (1996 and newer) except in California

304 stainless steel substrate is furnace braised to the mantle for outstanding durability

GESi proprietary precious metal loading technology ensures greatly reduced emissions

Ideal for Forced Induction Applications with no loss of HP

Both passengers and drivers are safe from harmful emissions and noise

Covered by 5 Year / 50,000 Mile Warranty (on catalytic converter)

Made in Miami, Florida

[irablumberg]

Looks very nice. Would love to see some before and after dyno charts and 1/4 times for an otherwise stock car.

[pbonsalb]

Fabspeed might have dynos, using the easily compared Dynojet. It uses 200 cell cats. These AA pipes use more restrictive 400 cell, but at least the pipes are bigger than stock and you are eliminating the 2nd set of cats.

[DrivenAgain]

Has anyone installed these? Curious about the CEL.

[pbonsalb]

With 400 cell primaries like stock, you should not get a CEL just like you should not if you keep the stock primaries and just remove the secondaries. No dynos so gains versus stock with catless secondaries are questionable.

[mike@x-ph.com]

Originally Posted by DrivenAgain

Has anyone installed these? Curious about the CEL.

No CEL

Originally Posted by pbonsalb

With 400 cell primaries like stock, you should not get a CEL just like you should not if you keep the stock primaries and just remove the secondaries. No dynos so gains versus stock with catless secondaries are questionable.

GESI cats air flow is significantly better than stock

[pbonsalb]

But not as well as Gesi 300 cell cats. And not as well as 200 cell HJS cats.

The stock cats were tested by a member here to flow very well. I’d like to see a dyno test to show how much gains there are from Gesi 400 cell primaries over stock 400 cell primaries with no other changes.

[mike@x-ph.com]

Originally Posted by pbonsalb

But not as well as Gesi 300 cell cats. And not as well as 200 cell HJS cats.

The stock cats were tested by a member here to flow very well. I’d like to see a dyno test to show how much gains there are from Gesi 400 cell primaries over stock 400 cell primaries with no other changes.

its been done on the B58 and N55 with dynos and it was showed a big improvement over stock

[pbonsalb]

They use 600 cell cats, don’t they? I would expect improvement from a 400 cell.

[mike@x-ph.com]

Originally Posted by pbonsalb

They use 600 cell cats, don’t they? I would expect improvement from a 400 cell.

Active uses 400 CEL

[Blackedm5f90]

Any dyno results comparing these to stock?

[pbonsalb]

Originally Posted by mike@x-ph.com

Active uses 400 CEL

There is no question that Active uses 400 cell cats; I was not asking about that. As support for your theory that Active 400 cell cats gain power over stock 400 cell cats on an F90 M5, you wrote that Active 400 cell cats gained power over stock cats on an N54. My response was that N54 use 600 cell primary cats. I would expect 400 cell cats to gain power over 600 cell cats.

[NCRob]

I see these are on sale now. Anyone use them?

[mike@x-ph.com]

Originally Posted by NCRob

I see these are on sale now. Anyone use them?

I sold ~10 sets, no complaints

[NCRob]

The secondarys are catless?

[Hoonigan]

Any sound clips of these?

Any dyno or dragy numbers to show gains?

If on a JB4, what additional tuning is needed with these for the car to run properly?

[mike@x-ph.com]

Originally Posted by Hoonigan

Any sound clips of these?

Any dyno or dragy numbers to show gains?

If on a JB4, what additional tuning is needed with these for the car to run properly?

No additional tuning is needed. These are higher flow than stock; you can target higher boosts with less pressure on your turbos.

If you run the same map you were running with the stock pipes, the spool will be faster, and the turbo pressure will be lower. If you want to take full advantage of the DP, you can run a custom map with a higher boost.

I don't have a dyno specific to these downpipes, but the benefits on high-flow pipes are the same no matter the brand and can be seen in all data logs.

These downpipes are unique because they are high flow and won't trigger the check engine light.

[mike@x-ph.com]

Originally Posted by NCRob

The secondarys are catless?

yes

[Hoonigan]

Sent you a PM

[Eli550]

Interested in these. Sent a PM

[Maverik259]

I’d be more interested in whether or not less heat is generated.

Ran the car up to the gym yesterday and an hour later came back. Decided to pop the hood to see if I could fix the CEL from the turbo inlets and I couldn’t touch even the plastic trim at the front of thr hood it was all so hot.

[pbonsalb]

They are 400 cell cats just like stock and the same size so I would not expect less heat from the primary cats. There should be some benefit from the catless secondaries since heat rises and the secondary cats are more in the engine compartment than under the car. I just don’t know how dramatic the difference would be.

You could wrap the cats but cat makers say not to wrap. I did not wrap mine but wrapped the pipes. I also installed turbine blankets on each turbo. And I put heat tape on the underside of the upper sheetmetal cover. All those things together probably help a little. I also use a colder coolant thermostat and programmed the fan to target a slightly lower coolant temp (this a feature in either the JB4 or BM3 — can’t recall which).