[boostm3]

Originally Posted by Stage IV

https://www.fabspeed.com/

dyno results with their catted DP:

+22whp/33wtq @4250
+32whp/27wtq @5500

No dyno done with their catless DP but I doubt the numbers are much better.

Are these your numbers, or the vendor's?

[Xchange43]

Originally Posted by boostm3

Are these your numbers, or the vendor's?

Sorry guys, i m trying to get my answer but look like i m stuck lol, do you know if with Bootmod3 i m able to remove the cel with stg 1?

[///M²]

Originally Posted by Xchange43

Sorry guys, i m trying to get my answer but look like i m stuck lol, do you know if with Bootmod3 i m able to remove the cel with stg 1?

Yes it will remove the cel, any flash tune will.

[No Boost]

Originally Posted by boostm3

Are these your numbers, or the vendor's?

The vendor's dyno so yeah, I can understand the skepticism. I've physically seen their dynojet so it does exist. You can click on the graph.

[alscks0414]

Originally Posted by Bee Pee

Why do lambda spacers work then ?

I believe lambda spacer simply moves the O2 sensor away from the major increased flow path of the exhaust gas which will make 2nd O2 sensor to be exposed more to ambient air inside the exhaust system and minimize the contact to sense the actual gas made from engine combustion.

O2 sensor examines the O2 proportion to determine indirectly if combustion has been completed as targeted. (That is why I mentioned about oxidation and reduction of NO and CO.)

Ambient air contents will make similar target O2 proportion different between 1st O2 and 2nd O2 sensors whereas catless DP will simply pass unburnt fuel and make 2nd O2 sensor to detect O2 proportion that is not ideal. Spacer is there to mimic as if the unburnt fuel is not there in the exhaust downstream by moving the sensor away from gas flow but close to the ambient air.


This is what I understood. Correct me if I am wrong

[boostm3]

Originally Posted by Stage IV

The vendor's dyno so yeah, I can understand the skepticism. I've physically seen their dynojet so it does exist. You can click on the graph.

Its really not a matter of seeing that they have a dynojet.. Dyno numbers can be skewed in so many dozens of ways to suit the purpose of the provider. Im not making a claim that that is what's being done here, but if ever there was a case of 'let the buyer beware', its in viewing the posting of dyno numbers by vendors for marketing purposes.

Its kind like when you buy a supplement and look at the before and after pictures. Not all posters and vendors are equally culpable but it certainly behooves the viewer or shopper to view these results with a bit of skepticism. Just append a YMMV in big red letters to any such postings in your mind

[Fedorov]

Originally Posted by nioh_lbbm2

Cons: you pollute the environment more

Pros: you can brag about gaining 5 more HP over a catted pipe


Don't be the dude that sends more pollution out than necessary

Couldn't agree more. People hunting small gains by sending even more toxins into the air. I'm not against anyone altering their car to do achieve whatever they want but the cats are there for a reason and that reason is not some bogus reason, it's a health concern reason that affects more people than the owner of the car.

So, please weight carefully the cost against the gain when removing the cats and I'm not talking about monetary costs.

Peace for everyone

[cecaa850]

Originally Posted by Fedorov

Couldn't agree more. People hunting small gains by sending even more toxins into the air. I'm not against anyone altering their car to do achieve whatever they want but the cats are there for a reason and that reason is not some bogus reason, it's a a health concern reason that affects more people than the owner of the car.

So, please weight carefully the cost against the gain when removing the cats and I'm not talking about monetary costs.

Peace for everyone

If a cat can still pass emission testing then I would think that the extra emissions are barely measurable. For those that are really concerned about this then maybe an M2 shouldn't be your first choice as a mode of transportation. Hybrids or EV's are much more eco friendly and may be a better option.

[GerardzM]

Nothing passes Cali if it ain't stock lol

Plus doesn't every downpipe manufacturer disclose in small print..."For off road use only"

Just tread lightly if you do go catless. Not every/any muffler shop will do the swap...due to fear of being fined and getting shutdown.

I mean there are even other forums that auto delete any mention of downpipe...or catless.

Just know its sort of a big deal when used on public roads.

[cecaa850]

Originally Posted by GerardzM

Nothing passes Cali if it ain't stock lol

Just know its sort of a big deal when used on public roads.

It all depends on where you live (I'm in TX). There is no emission testing in the county I live in. To pass a state inspection, a gasoline powered vehicle has to have a catalytic converter, it does not have to be OEM. It's rarely, if ever checked. In counties that have emission testing, you just have to pass the tail pipe sniff test.

[eatingpizzainthef87rules]

Originally Posted by Fedorov

Couldn't agree more. People hunting small gains by sending even more toxins into the air. I'm not against anyone altering their car to do achieve whatever they want but the cats are there for a reason and that reason is not some bogus reason, it's a a health concern reason that affects more people than the owner of the car.

So, please weight carefully the cost against the gain when removing the cats and I'm not talking about monetary costs.

Peace for everyone

To further this point - there are 0 gains to be had catless vs. catted on stock turbo on the F87 - the engine simply does not flow enough air to be any gain over a quality HFC.

Anyone who says there is has not dyno tested or is quoting old information to make their purchase more justified on a stock turbo N55

Only tangible differences are cost, sound, smell.

[GerardzM]

Originally Posted by bovairdf87

To further this point - there are 0 gains to be had catless vs. catted on stock turbo on the F87 - the engine simply does not flow enough air to be any gain over a quality HFC.

Anyone who says there is has not dyno tested or is quoting old information to make their purchase more justified on a stock turbo N55

Only tangible differences are cost, sound, smell.

No arguement here...but a benefit would be lower EGTs...and that does help.

Cats retain a **** ton of heat..

[GrabEmByTheBimmer]

Originally Posted by nioh_lbbm2

Cons: you pollute the environment more

Pros: you can brag about gaining 5 more HP over a catted pipe

[dtmpower98]

Pros: your car will sound like it has 800hp
Cons: I'd suggest keeping the windows up in traffic lol

[ceedawg]

Originally Posted by GerardzM

No arguement here...but a benefit would be lower EGTs...and that does help.

Cats retain a **** ton of heat..

I would ceramic coat the cat in that case or wrap heat shield it.

[Melsh113]

Personally I would go with the Fabspeed high flow cats over the catless downpipes. The sound difference is minimal I believe Fabspeed tested their HJS 200 cell cats and they were about 93% the flow of a catless pipe. So you still get all of the power and sound a catless downpipe would give you. The benefit of going with a high flow cat would be not throwing a CEL. Most companies will not tune out a CEL anymore and even provide a device to get rid of CEL. And Fabspeed is able to guarantee no CEL which a lot of companies aren't able to do. I believe the EPA is really starting to crack down on everything and companies will no longer be able to sell catless downpipes to street cars. Who knows what the world will be like in the near future. I would avoid all of the headache of having a CEL and not passing inspection. Just go with the high flow cats. They cost more but in the long run they will be well worth it.

[AmuroRay]

Pros: yes

Cons: No.

[AmuroRay]

Originally Posted by Melsh113

Personally I would go with the Fabspeed high flow cats over the catless downpipes. The sound difference is minimal I believe Fabspeed tested their HJS 200 cell cats and they were about 93% the flow of a catless pipe. So you still get all of the power and sound a catless downpipe would give you. The benefit of going with a high flow cat would be not throwing a CEL. Most companies will not tune out a CEL anymore and even provide a device to get rid of CEL. And Fabspeed is able to guarantee no CEL which a lot of companies aren't able to do. I believe the EPA is really starting to crack down on everything and companies will no longer be able to sell catless downpipes to street cars. Who knows what the world will be like in the near future. I would avoid all of the headache of having a CEL and not passing inspection. Just go with the high flow cats. They cost more but in the long run they will be well worth it.

you bumped a 4 year old thread - That being said, I agree with you. Climate change is an excuse for more government control.

[shaneguags]

Pros : (the obvious) it'll sound a lot louder, in my opinion it sounds better, (if tuned) you'll add power gains with less restrictive airflow, and aggressive burbles will be safe to use without a cat

Cons : you will gain potential gas smell, may experience emission testing issues, and you'll attract way more attention from police