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CRF 230... New exhaust vs. uncorking


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2005 CRF 230. I have an opportunity to buy a like new BBR exhaust (not the D2) for $100. Will it make much difference over removing/drilling out the stock baffle? I woll rejet and modify the airbox as well. Thanks for any input.

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Personally I don't feel that aftermarket exhaust systems are anything but a scam on 4 stroke bikes when power numbers are quoted. Typically your going to find your best performance range somewhere between a straight pipe of a large diameter and an exhaust system that provides some measure of back pressure.

Straight pipe = peak hp with a major loss of low end torque.

Exhaust system that is too restrictive = loss of top end but better all around low end driveability.

The area between wide open and too restrictive is extremely broad, and the power difference in that range is going to be minimal. Yes, you can tune a 4 stroke exhaust for peak hp with useable torque or peak torque with useable hp, but in the real world your actually looking for a good compromise of power and noise.

My point and my personal opinion: A stock exhaust opened up with the proper engine mods to utilize the free flowing exhaust is going to perform so close to the perfect aftermarket exhaust system as to be undetectible by anything other than a good dyno.

................. but the aftermarket exhaust systems will make your bike look cooler....... if that's what you're spending the hundreds of $$ looking to accomplish.

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Hard to say. I didnt ride it much with the old one. Sure sounds alot better! It seems to really have plenty of torque and runs great. Havent done any carb/airbox mods yet but plan to in the coming week. Project right now is putting on the new tires.

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  • 2 months later...

CoeShow dyno'd the CRF230 back to back with uncorked stocker and BBR. The diff was half horse.

That sounds tiny - but every little bit counts - it's possible it revs quicker too - so that could be an added benefit. (?)

Mikeee

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  • 7 years later...

My point and my personal opinion: A stock exhaust opened up with the proper engine mods to utilize the free flowing exhaust is going to perform so close to the perfect aftermarket exhaust system as to be undetectible by anything other than a good dyno.

 

 

I agree. The exhaust alone on a smaller displacement bike is not going to add any significant power. Porting the head, re-jetting and opening the airbox will add power. Boring it is the ultimate way, as "there is no substitute for cubic inches" , an old hot rodder's phrase. For example: my '85 XR200 runs like a strong 250. I ported the head, re-jetted richer, opened the air box, new Uni foam filter, replaced the coil & wire, and added an iridium plug. I also added a CRF230 muffler (local cycle salvage $50), with the baffle modified (4 additional holes). Strong low end, pulls well. I am very happy with it, not bad for a 31 year old XR.

Edited by HomerDodd
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