Different bike after new exhaust

Guys,

I recently fitted a baffleless, Blueflame twin exit race can onto standard downpipes with a link pipe. I assumed the back pressure wiuldn't change greatly with standard downpipes.

The bike seems to have lost its grunt low down. It was previously very responsive and snatchy below 7000rpm and took off between 7-10.5rpm, felt like an extra oomph.

Since fitting the new exhaust it seems to be more lethargic, less responsive and more revvy to the redline with a flatter, steadier power curve.

I also had new chain and sprockets fitted at same time and part of me thinks it may be the different ratio sprockets from the s model, I'll nip out and count the rear teeth now in fact. If it ain't that then I'm assuming I'll need filter and dynojet?

Thoughts.

Bob

Originally Posted by yoda650

Guys,

I recently fitted a baffleless, Blueflame twin exit race can onto standard downpipes with a link pipe. I assumed the back pressure wiuldn't change greatly with standard downpipes.

The bike seems to have lost its grunt low down. It was previously very responsive and snatchy below 7000rpm and took off between 7-10.5rpm, felt like an extra oomph.

Since fitting the new exhaust it seems to be more lethargic, less responsive and more revvy to the redline with a flatter, steadier power curve.

I also had new chain and sprockets fitted at same time and part of me thinks it may be the different ratio sprockets from the s model, I'll nip out and count the rear teeth now in fact. If it ain't that then I'm assuming I'll need filter and dynojet?

Thoughts.

Bob

Just checked, it's definately not a case of the S version sprockets so the can's made some huge changes to my bike.

Will fitting baffles increase back pressure enough to avoid paying out for dynojet and filter?

Bob.

Try it! I just fitted a Devil full system with baffle out on my curvy and it has transformed the bike. More power in all gears and at all speeds except at top end. Tops 5mph less but i also have taken off my lower fairings. Before i had a blowy BOS system cut by previous owner and a stubby scorpion can fitted, an absolute mess. Exhausts make a big difference i think.

[timwilky]

Personal opinion so feel free to ignore.

Aftermarket slip on cans make so little difference to the performance characteristics of a standard SV that they are a waste of time. OK if you want to be a little boy making a lot of noise waste your money and join the willy waving with the extra 1bhp.

Back pressure is not so much an issue with 4 strokes but will impact on the scavenging. baffle less is not going to change things sufficient to warrant fueling mods especially with a simple slip on.

BTW how do you know your power curve has changed? Do you have before/after dyno runs to make the comparison. It certainly isn't something you can "feel" unless there is a problem.

[TamSV]

Originally Posted by timwilky

OK if you want to be a little boy making a lot of noise waste your money and join the willy waving with the extra 1bhp.

[NTECUK]

But they look better and sound so much better than stock, as long as they are not too loud .
I'd do a plug Chop and make sure its not running lean.

[Bibio]

only reason i changed mine was the OEM can is heavy and fugly. yes the new can sounds a bit nicer. i also keep the baffle in as baffleless exhaust drone gets a bit much after a few miles. as for performance gain/loss i feel that there is a bit more mid range oooomph which suits me just fine.

[Geodude]

Originally Posted by NTECUK

I'd do a plug Chop and make sure its not running lean.

Whats a plug chop?

[NTECUK]

Search on google . It's a pain on the sv as the front plug is silly to get at. The rear is best option. It's basically flat out for a bit cut the engine clutch in coast to a stop . Out with the plugs and look at there color . The fring tip prcilsin should be light tan . If it's white your running lean . That's not good things get hot

[Geodude]

Cheers for info on plug chop, nowt wrong with a bit more knowledge.