Pro-circuit T-4 or White Bros R4

[bpimpdaddy21]

Which one out of these two pipes is better for the 400ex? I am just looking power wise at these two pipes, and I want to know which one would give me better performance gains. I am going to install one of these (just the slip on) with a K&N air filter, and rejetting, and I am also going to grind the welds inside the header. So which one of these would be better? Any ideas? And also what are some other mods that I can do for more power without getting into the insides of the engine? And when I grind the header welds, do I need to get new gaskets for the header. Thanks in advance.

they both give you more bottom end but the R4 is louder and this is the SAME QUESTION I HAVE WHICH ONE SHOULD I GET lol

[MadcapEX]

If the R 4 is louder than the T 4 , GET THE T4 cause it is loud enuf!

[bpimpdaddy21]

cool, keep the responses coming, and any help on the other questions too!!

[kaneman23]

according to Marcum's they are the same pipe. They look and perform identical. Get the one you think looks the best...lol... The T4 is about 20 buck cheaper...

[bpimpdaddy21]

thanks. Any help on the other questions??

[bpimpdaddy21]

can anyone help me with my other questions from the first post besides the pipe question??

[kaneman23]

Calm down dude. You asked for help about 5 times all in the same day...lol.. Grinding the welds in the head pipes, KN filter, exhaust, and rejetting are all good power adders. You can also go with a 14T front sprocket that will give you more lowend. Have you adjusted the slack in your thumb throttle? You can make a gain just by removing the slack. Another thing you can do is remove the choke off the carb. This will allow the carb to flow better, but make sure you get a bigger pilot jet for cold starts. I am sure their are a few others on the board that can give you some more tips. You aren't going to gain an incredible amount of power until you do a bore kit and cam.

BTW, you don't need to replace the header gasket after welding.

[bpimpdaddy21]

yeah, sorry, got a little excited, but oh well. Thanks for the replies. I will be doing some sort of internal work next year or later, but I am going for just that basics now. Thanks for your help.

[kaneman23]

no problem bud, good luck.

[eldoexrider01]

if u were talking about the " which mods can i do with out gettin in the engine" question, one idea would be to scrape the wallet for the head pipe for the silencer. hope it helps. just an idea