Suzuki Boulevard C90 Exhaust Chop question

[mynemesis]

So....

I'm thinking of chopping the mufflers off my Boulevard 1500 and chucking some short butchered baffles up there. Is this likely to need the FI system to be remapped or do you think I'll get away with it?

I can't just debaffle the mufflers as the exhaust system is one of those annoying joint collector box systems and I can't go aftermarket, as I'm cheap assing it.

Thanks for any feedback.

[gsxr]

Why ???
Are you looking to devalue the bike.
If you cant afford to do it properly dont do it at all .

[mynemesis]

No I'm trying to massively increase the value of my second hand old bike....

[awayatc]

Keep your original mufflers etc.
You butcher yours and fail the noise test or wof what you gonna do?
If you want to experiment buy cheap whatever's and play with that.

Being loud for loudness sake is not that smart nor pleasant to ride,
Nothing worse then some gutless something rather making a huge racket without much progress.....

[mynemesis]

Yeah I actually picked up a cheap standard exhaust system off trademe for 30 dollars that will be used and keep the good system as back up.

Don't want too loud but I like enough noise to keep cage drivers aware.

[nzspokes]

Loud pipes are cool if you are a fashion biker. If you really ride they just suck.

[OddDuck]

Exhaust systems are usually tuned to help the engine breath properly - if you've got overlap in the valve timing then the exhaust pulse is used to draw fresh charge into the cylinder, overfill it, surge a little way past the exhaust valve, then get tamped in again by the return pulse. It provides a mild supercharging effect. The exhaust system will be tuned to match the engine and the inlet tract, so messing with any of these things will affect the tuning for all of them.

It's possible to out-do the OEM system at one RPM range, but very, very difficult to beat it in terms of overall rideability. A back garage chop job is almost certainly going to cost you HP and torque.

What you've already said you're doing sounds like a sensible option. See how you go with the swap-in muffler, if there are any problems, I'd suggest repair or replace the OEM muffler and try again with that.

[AllanB]

Give it heaps mate :-)

The C90 sounds great with a bit of a deep pipe on it. Too loud and you and others around you will find it somewhat offensive. I've always piped my bikes but found with the aftermarket systems (often high end) the supplied db reducing inserts are not much different from stock in noise (just deeper sound) but if you remove them the muffler tends to be too loud. Solution is to either modify the db killer (shorten it) or make an alternative one. That way you can get a nice sounding pipe without being offensively and annoyingly loud.

If I am reading correctly you have picked up a second set of stock mufflers and want to modify them? Not a bad plan - there have been plent of people core stock pipes and insert a perforated inner core and then pack the pipe with muffler packing. Trick is ensuring it is all nicely fitted and joints well and you may need to head off to a decent muffler shop for supplies and parts.

Autobend in nz sell bits - http://www.autobend.co.nz/Files/Tube.pdf for cores their louver units work well in reducing volume of sound but retaining a deep note. Make sure they face the right way (the small 'hole' of the punched louvers faces the outlet). I can give you a link to a USA site sellign really nice stainless steel perf cores in various sizes - just like the high end brand slips-ons but with shipping not that 'budget'

Also - there are a couple of NZ pipe makers who can professionally gut and re-core a stock set of mufflers for a meatier sound. Worth asking for a price IMO.

Back to original question - EFI will adjust itself to a degree and provided you are not running open pipes with F-all actual muffling or back pressure it will be no different from just about every other NZ bike tearing around with a set of aftermarket mufflers. Shit Suzuki year after year offer Summer Fest deals on bikes usually with one or two having a free Yoshi fitted - they do absolutely nothing to the bike other than bolt the muffler on. If you have the coin a power commander and tune set-up or similar will improve even a stock set-up.

Interestingly the Termis I purchased for my Ducati come with a Ducati Performance total replacement ECU. Mind you they should for the price .........

PS - not keen on the use of the term 'butchered' - replace with carefully modified :-)

[mynemesis]

Thanks for the great feedback, info and suggestions guys.

Looks like it's going to require more skill and time then I am able to give the job currently so looking into an aftermarket system and a gman bully efi system when able.

I will look into the custom pipes mentioned above as it seems the cost of a new system is a pretty penny anyway and this collector box system. It currently has is next to silent. Seriously I can hear the mechanicals whirring above any actual combustion noise.

I picked up the bike couple days ago and loving this weird new style of riding. It feels somewhat akin to truck driving with that long throw between rider and front wheel. Takes some getting used to, but so far so good.

Here's to a few more nice riding days before the bike goes into hiding for winter and it's transformation.

[AllanB]

You can pick up a nice reverse cone muffler in NZ for around the 120 mark. Fitted one to a mates Savage recently. Two types - the one you'd want has a removable perf core and allow you to experiment more .......

If a pair of these bad boys is the look you are after they may suit.