4-1 always = loss of low/mid power?

[Guest]

I've read here that a 4-1 exhaust will add high-rpm hp (a small amount) but at the cost of low and mid-range power. Why is this? And is this always the case, or only when coupled with pod filters and a jet kit?

[Jedz123]

When I installed a Vance&Hines 4-1 to my 750 I didn't notice any low end to mid range loss. The bike screamed for sure to 9.5k rpm but the kicker was I dropped almost 25lbs over the stock exhaust so the bike felt faster and leaned quicker round turns. It still accelerated like a bat out of hell... My stock exhaust was shot to crap, you know holier than Swiss cheese partly why I got a new exhaust.

Never noticed what your stating.

[Graham]

I've read here that a 4-1 exhaust will add high-rpm hp (a small amount) but at the cost of low and mid-range power. Why is this? And is this always the case, or only when coupled with pod filters and a jet kit?

If you can feel a loss of power between a stock exhaust and a 4to1 then you don’t have the carbs set right. With a 4to1 megaphone you should feel more low-end torque. A 4to1 canister muffler should have a high-end power band with no real loss on the low-end.

[koolaid_kid]

Only a cam change would exhibit that behavior. A pipe and pods just allow more air to flow, which is why you also have to rejet so the AFR remains the same.