Okay, I know these exhaust topics have been driven into the ground over and over and over again, but this one is a little different. So, please do all you can to help me. It's very important to me.

It looks like by the end of the year, I'm gonna need to get a new exhaust. My FMF silencer is about trashed, and I want a GREAT, full system race exhaust. Here are the full systems I've considered:
Sparks Racing X-4Duncan Racing Double BarrelLRD PerformanceCT Racing

The Sparks and Duncan exhaust look most appealing to me. What I want to know is: Which performs better for MX? Which one would perform better on a mildly modified motor like mine (stock-bore 11:1 compression piston, XR400 cam)? Which will give the most power gain?

Any information you all can give on these exhausts would be great (dyno charts, personal experiences, etc.) Hard, proven info and facts is what I'd like to see, but anything can be helpful. This is a lot of money that's going to be spent on an exhaust, and I want to know which will be the absolute BEST one to spend money on. Thank you all very much.

 

i see that you are not affrad to spend some money i would say that thas are good also another that i here is great is the DMC dubble barrel exhasts they are around $350 it think ??? good luck

 

I know this wasn't one of your choices, but I would consider Yoshimura or White Brothers. I've heard only good things about both. I have a White Brothers on my 300ex and haven't heard a better sounding pipe yet in my opinion.

 

Hey man, go for the sparks. I have heard nothing but good! if you are going to mod your enginge get the X6. Call GT thunder and ask them what they think, i hear that they are extremely helpfull.

 

A while back, ATV Sport Magazine did dyno runs with many exhaust systems. It said that they had work on this shootout for a long time, and it seemed like the results were correct, and fair. Unlike some that I've seen.

In this shootout, the Sparks exhaust came in first, and the Duncan second I believe. The Sparks looks like the best on the dyno. There was a greater amount of power everywhere. Especially on top end. What do you all think?

 

i would go with the sparks. the x-4 is for the stock engines. the x-6 is for a more modded engine.

 

I have those mods with an LRD exhaust system and it works out pretty good. Although i like the performance of the LRD exhuast, I do not care for the pipe, but i got the non chrome one too. I lost all my rivets and put self tapping screws in, the packing burns out too often and it has rusted alot, also it did not fit properly, i had to drill out the holes for the studs at the head, but as far as performance it's pretty good.

 

I had a sparks X-4 on a stock motor and it worked fine. Seemed to be a good improvement in throttle response. Also it held up really well under abusive jumping. Now, I have an X-6 with a full mod 440 motor and it also is very impressive. Sparks makes excellent products, but sometimes there can be a long wait. If you plan to go all out on your motor you might be better of with an X-6. My X-6 withstood a hit that shattered my swingarm. I dont think you will have problems jumping with this exhaust like others have had with some exhausts.

Adam Smith

99 400EX

 

I guess I'll try to call Sparks and ask them about it, but what do you all think? I think eventually, I'll have my motor built to a 416 or 440, but as of now, I only have small engine mods. Which one should I get at this time (X-4 or X-6)? Thanks.