it is SW-710006 or efra 2101 tune pipe set. my btt REALLY beat the other 4btt. it has linear power band and strong bottom great top. i never see 4btt run like that only clocked btt beat it

My local Nova guy loves running the 2084 pipe on a BTT in buggy. He has never run the 2096 before so he can't compare them for me. Can anyone out there compare the 2084 and 2096?

So I love my BTTS, but this thing runs really hot. It makes a ton of power with the 9901 and it trails smoke, and sounds right like a properly tuned motor does, but it is coming off the track at 270 or 280. If I run it at 240 it is fat as hell and wont clear out. Is my bottom too lean? It accelerates hard with a nice cloud of exhaust. it is in a Losi 3.0 that is free of drivetrain bind or clutch issues. I am running with a Nova #6 in 70 degree weather. The motor has 9 liters (2.5 gallons for the metrically challenged) through it, and has lost the really tight pinch and now has really good compression and ridiculous power. Am I worrying about nothing?

Ok put it to flush on both ends and try to tune again from there

That is a good temp for this engine!! I always run between 260-270 on all my Nova's and thats where they are the best at.

Yes, I had the same problem with 21-4C which is a similar Nova engine, basicly I was leaning the bottom end too much to get bottom end grunt out of it, and even though it appeared fine it kept overheating, especially when waiting for the race control to start the race etc, so I'm going with you got a lean bottom end.

If you find yourself lacking bottom end, try different clutch springs.

I know this is not a easy question, But looking for a head to fit the P5 Xlt. Mine got damaged and just wondering if anyone sells a reasonable after market or if another Novarossi ENgine head will work?

4btts ans keep off same thing, different rear bearing. Please do youself a favour and get the 9886 in any form if you dont run at efra sanctioned events. We dont get scrutineered on pipes in my country at big events so i know im lucky in that regard, but after trying the 9901 and then 2096 and still not being happy with my 4btts performance i tried the 9886 after reading Neal's advise on here. Best decision ever! Turns the 4btt into a different motor. Especially up top. Sounds great too. Ive converted our top driver into a believer too. Best kept secret imo. Neal recommends the 41001 header with the 9886 but i can tell you even with the 41021 the 4btts has way more than enough topend.

my local hobbyshop has the Older Odonnell cooling heads for the NOVA. THey used to be the must have aftermarket cooling head. Now they are selling them for $25 because nobody uses aftermarket heads anymore. Not sure where you live but shipping should not be that expensive.

The newer style Nova's with the lower profile heat sink heads (Bonito, Keep Off, BTT/S, Roma) run in that range. With the way you describe it runs, I'd say you got found the race tune. I wouldn't worry about it, sounds like you got one fine running engine...enjoy!

Oh and thanks for posting the gallons...I'm most definitely metric challenged.

So I was thinking about trying a different pipe and header combo on my BTT. I am currently running a 9901/41021 combo and normally can get around 11 min on a tank. I have seen Neal recommend the 9886/41001 combo and I have also seen that people have tried the 2058 and the 2096 pipes as well. I already have a 2058 sitting in my box and was wondering what I would gain/lose with this pipe. I also want some info such as which pipe/header combos give the best runtime, which pipe/header combos give more low end, top end and the smoothest delivery. Thanks, guys in advance.

It depends on the size of the track and the jumps, but as a general rule I keep 3 pipes in my arsenal.

9853ss This pipe is king on smaller tracks with short run ups. I use it with a 41005 or 41001 header. it is a dual chamber pipe and the engines run cool with it.

9886ss This pipe has been around for ages and still has no equal on overall power and smoothness. I like it on bigger tracks where top speed is important. Yes with the 41001 header it flat out sings and it's a dual chamber pipe...Neal knows his pipes.

2096ss is a great all around pipe that gives enough torque to be used on smaller tracks esp with low traction, and great top end on larger tracks. I like this pipe on engines with tons of power that need to be smoothed out a little. It is a three chamber pipe and for the right conditions it really makes great power. Different headers don't seem to change this pipe too much. 41029 or 41001 headers work great. the 41005 is a bit too long to fit inside a buggy as the 2096 is pretty long.

I consider the 2058 to be between the 9901 and 2096. IMHO it goes like this with the 41021 header
9901 good bottom end, seems to starve the motor on top end, ok fuel mileage
2058 good bottom end good top end, pretty good on mileage, I pulled 11:37 on this pipe to empty.
2096 smooth bottom end (don't read slow here) great top end.. Best mileage pipe I have. Actually best all around pipe. I'm going to brag so take it for what its worth...I pulled 13:30 on this pipe this past weekend with my plus 4 btta with HES tunes.

When a P5XLT is cold with glow plug removed after break in, is it normal that I feel very little pinch at the top when I turn the flywheel?

no glow plug = no compression.