Wow, just a little harsh on Houston don't you think? He helps out a lot of people on here easy rhere bud.

I was running the 9901/21 setup with the roma and tried the 9853/41001 and performance was alot better especially top end will be sticking with that setup in my 6TR for 2013unless a bonito comes my way!
9901/21 better for buggy I reckon
for more grunt try softer clutch springs,shoes/smaller bell/thicker diff fluids/softer tires and up your carb insert, take your crank out get a hobby tool give it a good polish (less friction happy engine) that usually works for me

I really think the track surface plays a huge role in which pipe a person would prefer..... We run on very high bite and I dislike the 2096/41021 combo as it lacks bottom end power for my taste.... I find the 9901/41021 lacks too much top end for my taste...... Swap the 9901 to a 41001 manifold and it wakes up on top a fair bit and seems to even snap better in the bottom....but its still nothing impressive IMHO...... As soon as you have some real traction you can really see which pipes make good power and which ones do not........We have a very short run triple and it gives us a great reference point for which combo's make the bottom end power and which ones do not, add in we have a 180' straight rolling into a wide open sweeper, so we get to see the top end too...........For me on the BTT the 9886/41001 offered it all, it could pop the triple with ease and rings like a banshee down the straight,...good luck trying to clear our triple with a 2096/41001.... it just does not have the grunt to do it, the 9901/41021 will clear the triple but gets eaten alive down the straight............i just do not like the 41021 manifold on these engines, as it really doesn't make enough power for my track conditions......to me it makes the engines feel lazy......But until you run on a track with grip like mine you just couldn't understand........imagine a surface with so much grip your shoes squeak when you kick your feet, and where a truggy with a OS 25 can't even spin the tires from a dead stop...... I Am not saying those combo's are bad, but they certainly don't offer the strongest performance, they are IMO lazy !

about 4MPH better top speed swapping the 41001 in place of the 41021 on the stock BTT with 9901...bottom end seemed slightly better as well..... IMO the 41001 wakes the 9901 up pretty substantially over the 41021.....

Before I get anyone all fired up I am under the belief that the surface you run on play a huge role in what pipe your going to prefer.........High bite surfaces and slick surfaces are radically different loads to our engines....And how a 2 stroke engine reacts and throttles is very dependent on the load load placed upon the engine.....Different pipes and headers will react differently depending on the load working against the engine...so what is ideal on slippery tracks may not be ideal on high bite tracks and visa versa....Also to factor into it is the reactivity of the fuel being used...some fuels are naturally extremely crispy and other fuels are much less crispy........Some will look towards using a bottom end pipe and long manifold to overcome the laziness of a high oil fuel or low nitro fuel........whereas with a reactive fuel we can run more top end oriented setups and still have all the crispy low end throttle response we can handle........

Ofna 086 its cheaper and has great all round power.

My most favorite setup is the 9853ss with the 41005 manifold. I started out with the 41001 and it was great, but the slightly longer header makes that 9853 even better overall. it barely fits length wise in my Mugen though.

for sure, but the durability doesn't match the 9886 Super Strongs we have... Plus they do have a different feeling powerband....the OFNA pipe is a little more on/off the 9886 is a little smoother...similar overall power tho....

I currently run the 9886/41001 combo on many tracks and really like it. I don't like how the 41001 makes the pipe hit my fuel tank. I was told the 41019 makes the same power as the 41001 but angles the pipe away from the fuel tank. Anyone else notice this?

I agree anyone on a budget and want to try its a great option. I run this pipe @ times its a performer

bang for the buck is amazing !!!

Yes, we have noticed this also on some cars Dan and I prefer using the 41019, just on my Serpents to give it a touch more clearance. Just remember that the 41019 does not come with header to pipe short springs so you will have to buy them separately (NOV60003). The 41001 comes with them.

Put two wodden pices inside your header, and you can bend your header to any angle you need. A "little adjustment" needed on many heaers :-)

totally agree track surface is a massive factor, there is a huge difference on our track between running a dry surface or every few races sprinkled with water and your setup will be adjusted to suit, we run mostly dry tracks and engine power is alot of the time wasted cause there is so much wheel spin

You know guys sometimes it pays to be more practical. I'll admit, I'm a power whore, but pretty much every .21 on the market is already too much power for most of us who race. I've run a lot of powerful engines over the years and I seem to go faster on the track when I run a stock less powerful engine, whether it's on high bite low bite, high altitude, low altitude wherever. I guess it all depends on what your purpose is, bashing, drag racing, or off road racing. I'll be the first one to say it's cool as hell to see your car fly past everyone down the straight, but the straight is the smallest part of the track. The real time on a track is almost always made up in the infield. The last few times I spoke to Adam Drake at a race he was running the 9901 with the 41021 header. One race was indoor high bite, one was outdoor medium bite, and another was indoor low bite. I've been running that same combo on my P5XLT and Bonito for about six months now with great results. I have no problem making big jumps out of corners, I don't get pulled down the straight, and my runtimes are good. I am looking forward to trying the 41001 though. Not trying to ruffle anybody's feathers but I think sometimes we forget more isn't always better.....

On another note, even though we may not always agree on things, Monty Houston's engine, pipe, clutch set up advice has been pretty spot on IMHO!