looney tuned exhaust on 400ex

[newts250ex]

is there anyone here who is running the looney tuned dual exhaust on their 400ex? if so is it worth the $740.00

[bwamos]

I seriously doubt it. You get more HP out of a 2 into 1 system if it's tuned properly.

I dont think so.

from what i have heard. With dual exaust they have to much flow and have a hard time making big hp till you get into a 440+ bore.

[wilkin250r]

Originally posted by mittimj
I dont think so.

from what i have heard. With dual exaust they have to much flow and have a hard time making big hp till you get into a 440+ bore.

How can too much flow have a hard time making big HP?




Many places have noise level restrictions. And we all know, "quiet" pipes don't make as much power as their louder counterparts, because of more restrictions to flow. I think the LTE system is the answer. With the dual exhaust, you can have a set of quiet pipes to meet sound level requirements, but still have all the flow of a "loud" single pipe.

[bwamos]

Originally posted by wilkin250r
Many places have noise level restrictions. And we all know, "quiet" pipes don't make as much power as their louder counterparts, because of more restrictions to flow. I think the LTE system is the answer. With the dual exhaust, you can have a set of quiet pipes to meet sound level requirements, but still have all the flow of a "loud" single pipe.

Very true. Great point.

Running 2 pipes w/ Q series mufflers.. man you'd have a quiet quad.

[zeppelin]

Originally posted by wilkin250r
How can too much flow have a hard time making big HP?




Many places have noise level restrictions. And we all know, "quiet" pipes don't make as much power as their louder counterparts, because of more restrictions to flow. I think the LTE system is the answer. With the dual exhaust, you can have a set of quiet pipes to meet sound level requirements, but still have all the flow of a "loud" single pipe.
i am in no way trying to mean this in a disrespectull way, because you are a genious, but have you seen or heard about the new crf250r. it has duel pipes stock and every magazine so far has complained about it actualy being louder than the older single piped models. i found this hard to belive untill i heard it myself, and the new stocker is easliy just as loud, or maybe even louder the an older bike with an aftermarket pipe, eventhough for some reason they read quiter on using the curent Db testing methods

[wilkin250r]

Originally posted by zeppelin
i am in no way trying to mean this in a disrespectull way, because you are a genious, but have you seen or heard about the new crf250r. it has duel pipes stock and every magazine so far has complained about it actualy being louder than the older single piped models. i found this hard to belive untill i heard it myself, and the new stocker is easliy just as loud, or maybe even louder the an older bike with an aftermarket pipe, eventhough for some reason they read quiter on using the curent Db testing methods

It might be the actual frequency of the exhaust pulses. The human ear is more sensitive to certain frequencies.

It might be the direction the sound comes out, or how the pressure waves interact.

It might be a number of factors. Something about the pipe design, or the muffler end cap, or... who knows?!?

However, the real end-all is the measurement. If noise-level restrictions are an obstacle, then it doesn't matter what it "sounds" like, the only thing that matters is the number that pops up on the screen of the meter.

[bwamos]

Aye, the smaller pipes probabbly resonate a higher pitch and or pulse at a different interval. 4500rpm (75Hz) may have double pulses simulating a 9000rpm (150Hz) pulse.

I know a 110db siren sounds a lot louder than a 110db sub-woofer @ 40Hz.

I think the frequency coming out of a larger pipe is probably closer to the low frequency cutoff point of our hearing.. where as the frequency of the 2 smaller ones is probably right in our optimum frequency range.

[zeppelin]

well i guess you can look at it that way, but will it really help out or sport, i think it will only lead to even lower Db restrictions from people complaing about the noise

[CDCHONDAS]

back to the original question, and on the power aspect on a stock cc 400ex it only has to flow so much but if you put a pipe on that will flow much more than needed it probably won't be nearly as efficient, however when you can match the flow requirements of the motor to the flow characteristics of the exhaust you will be more efficient, so with a very high flowing exhaust it would show the most gains being put on a large displacement motor. so depending on what you have for a motor would be the answer to your question, I have seen these exhausts but have not researched them much so maybe I will now

[wboy62417]

Originally posted by wilkin250r
How can too much flow have a hard time making big HP?




Many places have noise level restrictions. And we all know, "quiet" pipes don't make as much power as their louder counterparts, because of more restrictions to flow. I think the LTE system is the answer. With the dual exhaust, you can have a set of quiet pipes to meet sound level requirements, but still have all the flow of a "loud" single pipe.

You need back pressure to have"big HP" and if you have duals it means less back pressure and could possible burn up a valve if you dont have enough back pressure

[stc416rider]

Originally posted by wboy62417
You need back pressure to have"big HP" and if you have duals it means less back pressure and could possible burn up a valve if you dont have enough back pressure

that is acually not true

if u have it jetted right u will not burn up valves

[KansasKidd]

One of my buddys has got the LTE system on his raptor. I dont know how well it would do on a smaller bore machine like a 400, but it kicks *** on the raptor. Sounds great and adds quite a bit of power. I would say go ahead and buy it, after all, you never know till u try. If u dont like it there is always a sucker on ebay.

peace

[2muchquad]

i think those duals are just another gimmick if you asked me.not to mention weight.for $750 i would be willing to bet they dont outperform a hmf or yoshi for half the price:)