exhaust fueling and maps

[Mfservice]

need some advice please folks i have only had my rr for 4 weeks and the first on my list of toys was the sc project cr-t slip on can, since i have fitted it it seems to be running really rich and the pops and bangs are very frequent and loud, as soon as i roll back throttle its like the 4th of july fireworks! has anyone else had these issues?
secondly would a slip on cause over fueling? i get that adding exsaust can up performance and use more fuel.
on a ride out this evening i used a tank of fuel in about 111 miles which seems alot worse than with the standard exhaust(not sure if that is because of the fact im riding it harder as growing in confidence or its fueling related)
lastly its on 2 years bmw approved used warrenty if i was to change fuel maps or add power comander would it void my warrenty?
thanks in advance for your help

 

[fast_ryan]

Mapping

You would be best off taking the bike to your local Dyno Centre and requesting a baseline power run. This will identify if there are any issues with the A-F ratio and whether you need to have the bike mapped. Fitting a Power Commander, or similar fuel management system, will not void your warranty.

 

[Mfservice]

ok brillient thanks i do have a place not far from me pdq in taplow and will be booking it in tomorrow for a power run. i see there is loads of rr's with sc/ austin cans and assume they would be pritty simular in the way they behave if the rest of the bike is standard and being so new to these beautiful bikes dont have a standard to compare it to if that makes sence

 

[soofsayer]

I haven't heard of anyone saying they have fuelling issues with a slip on on the '15+ bike. Think Ryan is right to get it tested to find out what is going on. Did you buy your bike new or second hand? Dealer history?

 

[pof]

As above , get it dynod. Surprised you got that big a difference with just a slip on. Removing the cat would see big changes (did for me anyhows)

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[Mfservice]

It's second hand but from a bmw motorrad main dealer so have the 2 year Warrenty and cover that goes with it. Also only covered 2100 miles
I have never had issues with slip on 's on my other bikes however they have been more of a can than the hollow tube that is a sc project also have had the main silencer section underneath rather than the set up on my 2015

 

[HPlogger]

I must say that my bike (bought new 2 months ago) has the cr-t end can with standard exhaust downpipes too and back fires exactly the same as you described, on downshifts and shutting off the throttle.

 

[Mfservice]

Thanks hplogger it's good to know mine isn't the only one! it's hard to know how it should run with nothing to compare it to and never seing another out and about in the flesh with the same set up. I will get a power run done but I'm feeling more at ease after all the comments so far so pleased I joined the forum my wife is also as been driving her nuts talking exhaust!!

 

[HPlogger]

LOL
I'm very interested to know the outcome of the power run, and whether you do need to adjust the fueling to suit as I will do the same if needs be. Please could you post up what happens? Thanks.

 

[Loupe]

I have an Austin racing end can and the pops and bangs are really amplified without the baffle. Running it without the baffle drastically reduces fuel consumption too.
On journeys where I'd do a return journey on the standard exhaust, I'd have to fill up half way to get home!

 

[Mfservice]

Yeah for sure will be only to happy to show graghs and data im hoping they can fit me in this week and will post it all up here. may I ask also what sort of miles do you get from a tank if your out for a blast through the twisty 's? If you record it that is

 

[Mfservice]

Thanks loupe as I say I'm feeling more and more normal by the minute!!

 

[HPlogger]

That is interesting.
The sc-projects cr-t exhaust end can doesn't have a baffle at all. They also recommend NOT to fit one either, due to possible damaging the exhaust.

 

[CEZAR]

Mfservice got same here standard was poping very similar just quieter

I havent notice any power decrese after fiting sc project slip on. But I wonder how will showup on dyno.

 

[MacRR]

I have an Austin racing end can and the pops and bangs are really amplified without the baffle. Running it without the baffle drastically reduces fuel consumption too.
On journeys where I'd do a return journey on the standard exhaust, I'd have to fill up half way to get home!

I've got the std can back on my '15RR at the moment, my perception is that the fuelling is slightly smoother than when I have my AR GP1 fitted (baffle in) and I'm also getting an extra 10 miles from a tankful of gas, doesn't sound quite as good though!

 

[alex]

The 15's on do have a fueling/ignition map which leads to pops and bangs, the removal of the stock exhaust and fitting of a bean tin has made it a bigger 'event'.

 

[bananaman]

I've got the std can back on my '15RR at the moment, my perception is that the fuelling is slightly smoother than when I have my AR GP1 fitted (baffle in) and I'm also getting an extra 10 miles from a tankful of gas, doesn't sound quite as good though!

Shows how lean it must run then lol
If you dyno 5 new bikes, they will all run different to a lesser or greater degree hence it's always wise to have it dyno mapped especially with any alterations that have been made. Running at full chat with a lean mixture is a recipe for bangs and not just from the exhaust....

 

[Mick753]

This is a back pressure issue, when you fit something like a CRT can in place of something that is designed to offer the right amount of back pressure for the exhaust scavenge then there will always be some slight issues with the fueling, I can't imagine it running too rich either as it's more likely to run too lean if anything.

My SC CRT which is fitted to the HP4 system that came fitted to my bike grumbles really badly when trying to hold any constant throttle position between 3500-6000 rpm, it's not so much lumpy but it can actually sound like it's running on 3 at times, acceleration isn't affected and there are no issues with the power delivery and it is only the lower rev range that is affected too.

If you change intake or exhaust profiles then the fueling will change on anything that is not running a fully adaptable fueling system, particularly when you make an extreme change to the exhaust system (which is a tuned length of metal tubing designed to offer a set amount of back pressure to the cylinders), definitely worth getting it on a dyno and making sure it's not running too lean at the very least

 

[pof]

Not sure if back pressure is too much of an issue with the cat still in and oem headers with valve still in place. I fitted an arrow exhaust at the weekend for a forum member who had an akro slip on on already. After we took the slip on off we started it up and tbf it wasnt bad at all. Full arrow system sounded much better but definatly will need mapping

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[Mfservice]

thanks some great an educational comments there have a power run at the dyno booked for wednesday after noon will share my findings