[G37Sam]

Hello!

What are your thoughts on the M4 GP Exhaust? Read online that even though it's a slip-on, it deletes that stock catalytic and comes with an O2 oxygen sensor bung. Will that get my ECU to start acting funny or idle weird? I'd hate to have to tamper with my ECU.

Thanks,
Sam

 

[scotman623]

Hello!

What are your thoughts on the M4 GP Exhaust? Read online that even though it's a slip-on, it deletes that stock catalytic and comes with an O2 oxygen sensor bung. Will that get my ECU to start acting funny or idle weird? I'd hate to have to tamper with my ECU.

Thanks,
Sam

Good exhaust, But you will have to have the ECU flashed!!! Bike already comes lean to pass epa BS!!!Adding the exhaust will only make it run leaner..

 

[G37Sam]

Good exhaust, But you will have to have the ECU flashed!!! Bike already comes lean to pass epa BS!!!Adding the exhaust will only make it run leaner..

Even if I kept the stock cat on? I'd hate to experiment with tunes on a brand new bike

 

[scotman623]

Even if I kept the stock cat on? I'd hate to experiment with tunes on a brand new bike

If you leave the cat on and just do a slip on you could get away with it, remove the cat and you SHOULD get the ECU flashed...Like I stated they come lean from the factory..

 

[G37Sam]

Thanks for your help Scot! I'm assuming power commander with an off the shelf map would do? I'm not looking to milk the engine for power just safe enough to not melt a piston or start knocking.

 

[Gen-Eric]

I'm spamming my 2-cents (and that's more than what it's worth)

I prefer a quiet exhaust, not just for hearing protection, but for pissed off people and cager protection. In my opinion riding on street is a skill where you navigate who you are going to piss off and when. Ideally it is never, which means you only ride track.

However if you ride street, loud pipes really only save you when you are not aware of the situation you are in, which should never be the case. Mistakes happen, and I get it, but we also like to have fun, and loud pipes in my opinion will absolutely reduce your fun, and only bring extra unwanted attention to you.

I much prefer slipping through unaware, then a cager fully aware of me and trying to block me on purpose because they are raging.

 

[TennisFreak]

I did not want to mess with ECU and fueling issues.

I also did not want an obnoxiously loud exhaust (the M4 is IMO).

But I wanted something that looked nice, was lighter than stock, and sounded better than stock.

 

[ShawnG]

I run the m4 gp on my street bike and its extremely loud which i love, Sounds amazing imo. like you mentioned i dont think they make a version that does not remove the stock cat. I would just recommend sending your ecu out to a tuner that will reflash it. Dont mess with power commanders and that kind of stuff. If youre in the US your bike is running with a rope tied around its neck, if not you just need to simple tune, maybe more but not 100% sure since im state side.

 

[Porschenut]

To reiterate some of the comments above, the M4 GP is insanely loud. As in it will piss off your neighbours and set off car alarms loud. The low mount design of the GP exhaust puts it in the same location as the catalytic converter so that will be removed out of necessity. However, you want to ditch your cat because it's such a power restriction. I flashed my bike before removing my cat but once replaced it with a link pipe the power gain was really noticeable.

 

[G37Sam]

Thanks guys, I'm actually in Dubai and found a reputable tuner who recommended a PCV, seems like the popular solution here for fueling adjustment.

To be honest, I had the M4 GP on my ZX6R and absolutely loved it: https://www.instagram.com/p/BQp-TL-hANu/

I'd much rather be loud and heard to be honest, gets all the idiots texting and driving to drop their phones and pay attention at least, scares camels away too haha

 

[Boxboy10r]

I've always put a slip on and decated my last 3 new bike from day one . And never had them retuned . They've all run perfectly . I just picked up a gen5 last week and have no intention of having to tuned maybe after it's done 4000 kms just to put it on the dyno and see what it's doing and to get it tuned but not because it needs it . Just to see if I can get a bit more HP out of it . But it's not really necessary

 

[G37Sam]

I guess the only way to do so is to get a dyno run in post de-cat and measure AFR across the RPM range. M4 says a tune is not needed but will yield good results when done. I ordered a PCV and K&N filter anyways.

 

[lun471k]

I had the m4 GP slip-on on my 636. If I ever get an slip-on for my Gen 5 (seriously thinking about it, only waiting money-wise), it's gonna be an m4 GP slip-on. Sounds way too awesome.

 

[Gen-Eric]

Without a full dyno-tune, any slip on or full exhaust you get will decrease your HP and increase the cool factor of crackles and pops and flames due to the lean fuel/air mix.

Prove me wrong, give me one example of a slip on that really increases HP without a full dyno tune...

 

[G37Sam]

Without a full dyno-tune, any slip on or full exhaust you get will decrease your HP and increase the cool factor of crackles and pops and flames due to the lean fuel/air mix.

Do you have a dyno chart or an AFR log to go with that claim?

 

[Gen-Eric]

Do you have a dyno chart or an AFR log to go with that claim?

LOL, you prove me wrong. If slip on increased HP without tune, they would not crackle and pop because their fuel/air ratio would be correct - hence a possible increase in HP.

It's not a claim, it is common sense. Even I as a non-mechanic knows this. So you prove to me that a m4 exhaust slip on without a dyno tune will increase HP.

 

[G37Sam]

LOL, you prove me wrong. If slip on increased HP without tune, they would not crackle and pop because their fuel/air ratio would be correct - hence a possible increase in HP.

The crackle and popping happen when you release throttle, which is a point where you're not even asking for power. Even with the stock exhaust you hear very minor crackle/popping, an aftermarket exhaust only amplifies that.

It's not a claim, it is common sense. Even I as a non-mechanic knows this. So you prove to me that a m4 exhaust slip on without a dyno tune will increase HP.

It is not common sense, it actually doesn't even make sense. I never claimed the M4 made hp nor am I after hp with the M4 exhaust, it's purely for the GP sound and to get rid of the ugly looking OEM exhaust. I'd even sacrifice a few hp's for that I don't mind.

The extra air flow you get from an exhaust causes your engine to run lean, meaning there's not enough fuel being burnt actually, so how does that translate to popping and backfiring? If there's not enough fuel being burnt in the chamber you think there'd be enough left to burn in your exhaust and cause popping and backfiring? :dontknow:

 

[Gen-Eric]

The crackle and popping happen when you release throttle, which is a point where you're not even asking for power. Even with the stock exhaust you hear very minor crackle/popping, an aftermarket exhaust only amplifies that.



It is not common sense, it actually doesn't even make sense. I never claimed the M4 made hp nor am I after hp with the M4 exhaust, it's purely for the GP sound and to get rid of the ugly looking OEM exhaust. I'd even sacrifice a few hp's for that I don't mind.

The extra air flow you get from an exhaust causes your engine to run lean, meaning there's not enough fuel being burnt actually, so how does that translate to popping and backfiring? If there's not enough fuel being burnt in the chamber you think there'd be enough left to burn in your exhaust and cause popping and backfiring? :dontknow:

Ahh ok, so you essentially concede that slip on without a full dyno tune will cost you HP, and add some crackle and pops, and sacrifice overall engine longevity is acceptable.

That's ok, you are not the exception to this rule, rather you are the norm.

 

[Ron Mears]

Anybody run the "db killer" insert in the M4 GP exhaust? That was the first thing I did was remove it before installing the exhaust on my bike. Just wondered how much of a difference it makes.

 

[skidooboy]

it is really funny to me that people "don't want to flash the ecu" but, will spend more money on buying a pcv or bazzaz unit, and have to install, and deal with all of their software hardware, and customer service issues. AND THEN HAVE TO PAY TO GET IT TUNED ON TOP OF BUYING THE HARDWARE PACKAGE.

pcv and bazzaz are middle men, and need signals from the throttle position sensor, via the ecu, then they correct the fueling, timing, send the signal to the ignition, and injectors via the ecu... it is a wiring information loop with a slight lag or delay.

in laymans terms, the fueling/timing add ons (pcv bazzaz) sample at 1000 times a second (which is fast, don't get me wrong). the ecu samples at 10,000 times a second with no middle man between your throttle position sensor, ecu, and injectors. faster, smoother inputs, and outputs, equal crisper throttle response, and a more noticeable improvement.

also with a pcv YOU CANNOT, UNRESTRICT THE TIMING CURVES, GOVT MANDATED LIMITS, TURN OFF THE FUEL CUT ON DECELERATION, ECT... you can only augment timing and fueling.

you would be better to find a good reputable tuner that has a good flash, and map for your set up, and send the ecu, to them for a "canned set up" installed in your ecu, v.s paying the same or more money for a pcv, or bazzaz unit, and tuning via that. if you have a tuner that can flash via flashtune, woolich ect... ALL THE BETTER... USE THEM. it is ALOT BETTER, than using an add on fuel, ignition controller.

ecu flashing and tuning is where it is at. the future is now, power commanders, with add on functions had their place when we couldn't tune the ecu. we (you) don't NEED them ANY LONGER, IN THIS DAY AND AGE. you don't need to spend that money on the hardware, then tune it with the hardware. you would spend less with an ecu flash and dyno tune, and be done with it... with no added on CRAP, that can and will cause problems in tuning and rideability of the bike. Ski