Cool. Come over, and say hi sometime. I will let you try my +4 if you like. Maybe it will help you decide on which engine you prefer. Just ask someone where Uriah is pitting if you can't find me.

Hi guys has anyone tried the Novarossi new tune pipe (2096)?

I got a 2084 pipe for my +4 BTTS and it feels really flat on the top end compared to a 9901 in my buggy. Anyone else seeing this? After I got it, I heard this same opinion from a couple Novarossi factory guys. I wonder if changing this head shimming or header could make this pipe work better. I'm running the 41021 header. Last week I ran it on an Alpha orange head and it was ok though. That is a 7 port engine though.

The 2084 has a longer overall length than the 9901 but has less overall volume so what you are seeing is the stock blowdown timing of 18 degrees is being snuffed out with the length and volume on the 2084. The Plus 4 has higher transfer timing but lower exhaust timing in relation to the crank intake timing so what is happening is the exhaust port opens late and closes early and the scavaging pulse is taking too long to return to the port opening therefore the engine falls flat on top due to improper pipe length. This is why the Plus 4 works well with the shorter header and 9901 pipe as the 9901 is shorter in length but has more volume so the engine breathes harder and the returning pulse allows the engine to scavage more efficiently.

The reason the pipe setup worked on the Alpha better wasn't because of port count but the fact the Alpha has a longer duration allowing for the longer pipe to be more effective compared to the plus 4.

Hey guys, is the ceramic front bearing really the only difference between the TT and TTS? Pretty big price difference, just wondering..

have you tried a 41001 or 41005 header ;) just sayin:D

Thanks for the info guys. I think I have one of those headers so I'll try that before going back to the 9901.

got your engines here

How does this relate to the 9853? This pipe screams on the plus 4, yet i read here the 2084 which is a lot like the 9853 kills the top end. I know the 2084 is a 3 chamber pipe and the 9853 is 2 chamber. Does this make the difference? The extra chamber will most likely make it breath less.

Also...what engine would make a good combo with the 2084?

the 2084ss has a larger backpressure/baffle ring at the end of the diverging cone , puts more backpressure in the engine and releases less of the exhaust pulse which is why it usually yields more mileage ;)

2084ss isn't that far off the 9853ss but like i say if you want rippin power less mileage (still good) then use 9853ss if you want good power with more mileage then use the 2084ss

Thanks, thats what i thought aswell, have to say i like the 9853ss on the +4.

Btw: what about the 9901...i read/hear mixed stories about it...some consider it the perfect pipe for the +4 while others say it's flat on top/kills top end :confused:

9901ss is a killer pipe , usually runs a bit warmer as does the 2084ss as they have much more backpressure , why they get better mileage ;)

its hard to understand and even more difficult to measure the differences of the same engines that run completely different , i can have 20 engines of the same design and a few of them will not run near as good and a few of them will run exceptionally well . i do my best to match as many engines parts together as best i can , most of your real "team" engines are precision matched engines that are perfect in every way and that makes them efficient and fast . very few of the top guys use any "hand modded" engines ;)

I've heard that aswell about the real team engines, perfect matching/selecting of parts and perfect alignment of bearings etc. combined with a 100% tune can make quite the difference in power output.

Anyway, the 9901 is not flat on top then? I've heard quite a few times it's mainly a bottom end & milage pipe.

oh i have seen engines with 9901ss/41021 pipeset rippin on the track , there are many factors that can go into making an engine feel as if it is flat :nod: 9901ss usually yields decent top end output , if you want the pipe to scream you must run your engine leaner (higher temps) than most think are "ok"

Thanks for your insight Monty...appreciated :cool: