[twocoolgliders]

Guys,

A few questions on after-market exhaust, and the FI system on the Royal Enfield.

1) when you are changing to a  "slip on" exhaust...is the Cat converter still in the system?...In fact where exactly is the cat converter located on the RE?

2) Are guys removing the cat converter?

3) If you remove the cat converter, do you remove/disable the secondary air system?

Does the RE have two oxygen sensors?  Upstream and down stream?  And is the FI system sophisticated enough to re-calibrate itself when you go with free flow exhaust and intake filter?

I'm only familiar with my Yamaha SR400....where the FI is a really crude system...only one oxygen sensor.  With free flow exhaust, you take out the cat converter.  With no cat converter there is no reason for secondary air system...so that's gone..some say you can overheat your exhaust pipes if you leave the secondary air but remove the cat converter!  The single oxygen sensor only "works" during Idle so that's gone too.  The FI system is not "self calibrating" so with all the above mods, you have to install a power commander and do the mapping on a dyno....If you don't disable the secondary air...you get backfire and popping.

Seems the RE guys are just changing the exhaust with slip on...and putting in free flow air filter with big opening..and letting the FI re-calibrate, and/ or using booster plug to change the mixture a bit richer?

Inquiring minds....

Cookie

[wildbill]

I think you are overdoing it.  in fact one certain youtuber claim the interceptor has a learning ecu and all euro 4 bike have this feature which helps with all of the above or a fair bit of it. especially if you put a free flow exhaust and filter on.

I put on a free flow exhaust plus booster plug and I had no pops/ back fires no nothing apart from very good power delivery. didn't have to wait for any ecu adjustment either. just 2 minute warm if that and got on and away.

this is the best result I ever had on all the bikes I have put a sports exhaust on in the enfield range.....all 15 I think
I would really like to see how this booster plug would run on a C5 with sports exhaust because in my opinion that bike was a real drama queen with snap/crackle and pops and jerky throttles

I think the cat is in the header pipe around the brake foot area. could be wrong but it was on a c5 or the newer version and on my interceptor there is that same type of bulge in the pipe.

[beagle]

I fitted some 19" hooligan emgos to mine and they were a bit loud. I then installed some aftermarket db killers that I trimmed down too much, took out the end baffle and squeezed to a part flat, and still too loud. Have ordered another set of killers and will install untouched this time. If you only do the pipes or filter, the ecu will accommodate, but I will be doing filter and pipes so installed a booster plug to be sure it never ran too lean. Biggest hassle is the muffler gasket needs to be replaced every time I remove the DB inserts as the inserts are bigger than the gasket. $26 a pair every time and getting them tacked in place at $5 a spot tack.

[9fingers]

REALLY good looking bike beagle!
9fingers

[darmahman]

The cat is in the muffler on the OEM exhaust. The street S&S muffler has a small cat in each muffler. Their race version does not.

[twocoolgliders]

Thanks...that answered one of my questions.



Cookie

The cat is in the muffler on the OEM exhaust. The street S&S muffler has a small cat in each muffler. Their race version does not.

[twocoolgliders]

So...does anybody have a photo of a "too lean condition" as in a light or whitish spark plug?  (as sometimes mentioned that the factory sets the mixture too lean for whatever reasons...and that a free flow intake and exhaust would exacerbate the issue?)



And if the above is the case, maybe a photo of the install of a booster plug making the plug that nice tannish brown color?


Cookie

[twocoolgliders]

Thanks for the info...So the FI system on the RE is more like a car? with two oxygen sensors, and a "closed loop" sensing?  or self learning?

Cookie

I think you are overdoing it.  in fact one certain youtuber claim the interceptor has a learning ecu and all euro 4 bike have this feature which helps with all of the above or a fair bit of it. especially if you put a free flow exhaust and filter on.

I put on a free flow exhaust plus booster plug and I had no pops/ back fires no nothing apart from very good power delivery. didn't have to wait for any ecu adjustment either. just 2 minute warm if that and got on and away.

this is the best result I ever had on all the bikes I have put a sports exhaust on in the enfield range.....all 15 I think
I would really like to see how this booster plug would run on a C5 with sports exhaust because in my opinion that bike was a real drama queen with snap/crackle and pops and jerky throttles

I think the cat is in the header pipe around the brake foot area. could be wrong but it was on a c5 or the newer version and on my interceptor there is that same type of bulge in the pipe.

[Mav]

As been said, the cat is in the silencer. And yes the ECU is self learning.

This has been posted before, Stuart tells you in the clip how to reset the ECU

https://youtu.be/XjHjpuSjDvM

All the reports I have seen on the booster plug say it just riches the mixture at low revs, again a Clip on how to fit and what it does.

https://youtu.be/VbSDQrGqL50

[Dr Mayhem]

As been said, the cat is in the silencer. And yes the ECU is self learning.

This has been posted before, Stuart tells you in the clip how to reset the ECU

https://youtu.be/XjHjpuSjDvM

All the reports I have seen on the booster plug say it just riches the mixture at low revs, again a Clip on how to fit and what it does.

https://youtu.be/VbSDQrGqL50

The opinion Stuart expressed on this subject is erroneous however well intended

This add on unit to the power commander V with it's wide band O2 sensors will however do just that, learn.
See the video by Lemmy for a basic overview

https://youtu.be/N0X_nBAUdsY

[Dr Mayhem]

Thanks for the info...So the FI system on the RE is more like a car? with two oxygen sensors, and a "closed loop" sensing?  or self learning?

Cookie

Our system is only closed loop at idle, steady state cruise & under light acceleration. You crack the throttle under load and bike is fueled 100% by the map

[Dr Mayhem]

If you watched the video you saw how Lemmy was fixated on the wide band O2 sensors. He didn't really mention the most important part. That is, it's learning capability actually changes the map so that when you're not in closed loop you still have ideal (not lean) fueling when the throttle is whacked open!

[twocoolgliders]

Hmmmmm....

Thanks for all the replies....

I'm more confused than ever...I'll keep reading and watching YOUTUBE and learning!

Yeah...I'm probably making a big deal out of something which is not...I just like to understand how stuff really works!

Cookie

[BRG-BIRD]

I have S&S exhaust and the only thing I have done is ride the bike. It fuels perfectly for me with no flat spots, hiccups or after fire. No booster plug or anything aftermarket

[jimku]

I have the AEW silencers.
I am not using the DB Killer baffles and have removed all of the fiberglass packing.
I love how they sound.  Loud but not too loud, not as loud as many Harleys I encounter, nice deep rumble and with a nice "bark".  The packing kills that "bark".
Before I installed my Booster Plug, my pipes would pop when quickly rolling off the throttle.  With the booster plug, it is just one long smooth continuous roar.

[NuttyRusty]

Hi everyone, am I wrong,  or does the booster plug simply modify/ fool the ecu into reading a lower intake temperature when opening the throttle from a closed position. ? Thus giving a richer boost or less of a delay  in acceleration. Bit like pumper carbs.

[Dr Mayhem]

Hi everyone, am I wrong,  or does the booster plug simply modify/ fool the ecu into reading a lower intake temperature when opening the throttle from a closed position. ? Thus giving a richer boost or less of a delay  in acceleration. Bit like pumper carbs.

My take also. One day I'll probably snoop other forums to see if this device has been data logged to see what/where, how much exactly is this fuel enrichment happening

[jhark37]

Hi everyone, am I wrong,  or does the booster plug simply modify/ fool the ecu into reading a lower intake temperature when opening the throttle from a closed position. ? Thus giving a richer boost or less of a delay  in acceleration. Bit like pumper carbs.

The Booster Plug website gives lots of info and graphs.  But basically, yes, it fools the ecu into thinking it's 20 degrees (C) cooler than actual, resulting in about 6% more fuel.  Occurs only during 'open loop' operation, not steady state/closed loop.  Surprisingly, my first fillup with the Booster Plug gave no change in mpg.  Still at 70.  So the small adjustment only during throttle change is small enough to be almost undetectable in mpg, but very noticeable in drivability.

I like it so much on my RE that I just ordered one for my KTM Duke 390!

John

John

[NuttyRusty]

Jhark 37,  well that looks like another sale for me then.  Is there any downsides ?

[LongMan]

I fitted some 19" hooligan emgos to mine and they were a bit loud. I then installed some aftermarket db killers that I trimmed down too much, took out the end baffle and squeezed to a part flat, and still too loud. Have ordered another set of killers and will install untouched this time. If you only do the pipes or filter, the ecu will accommodate, but I will be doing filter and pipes so installed a booster plug to be sure it never ran too lean. Biggest hassle is the muffler gasket needs to be replaced every time I remove the DB inserts as the inserts are bigger than the gasket. $26 a pair every time and getting them tacked in place at $5 a spot tack.

Beagle,
nothing particular to contribute to the discussion. Just wanted to say that your bike is an absolute beauty! Congratulations!