Hi guys,

just got a used xray xb9(not 2013, hehe) and planning to get the nova btt tuned motor for it, what pipe and manifold will you recommend? Does the xb9 need specific narrower manifold like the mugen? I'm now looking at the 9901ss, and either the 41020 or 41021 for the manifold, please advice guys.

Thank you very much

My advice is to read the last three pages of this thread. It has been discussed ad nauseum.

9901ss is good on the BTT though IMO the 2096 is better. The 41021 fits the xb9...both '12 and '13 spec cars.

The 41029 header will fit better since the 2012 chassis is narrow. Like stated above, the 2096 is very good choice. Good luck with the XB9, if you have any questions about the buggy don't hesitate to ask.

Thanks a lot for the heads up man.

scrapsz and jonw, thanks a ton for the advices, so in what way is the 2096 better? For the manifold, actually what's the difference between a shorter and longer one?
And jonw, thanks for the kind offer, i think the xb9 is a good buggy, and i'm sure i'll ask questions in the future, of course i'll do it at the xb9 thread, cheers...

The 2096 has a touch more upper-midrange and top end pull.

One the manifolds... one is longer one is shorter. Effectively the 41021 is the one that works 99% of the time. The "long" manifold works on occasion in truggy and on *very* short tracks.

For any +4 family engine, the 41021/9901 is the standby combo. If you're on bigger more open/flowing tracks with a long straight (over 100') then the 2096 has a bit of an edge.

Thanks a ton for the heads up, so if the track i'm running has about 50' straight and quite some jumps and humps, the 9901 will be a better choice?

9886/41001 will give you the most power over the broadest RPM....really opens up the top end of this engine without giving up bottom

9901/41001 good combo..great bottom, great snap, and good top end...I find the 41001 makes the engine feel snappier and crisper then the 41021, also the top end is several MPH stronger with the 41001 over the 41021 on the 9901

IMO these 2 are the best combos for the engine...especially if you run with some traction and are looking for the most power, or are on a big track and looking for the most speed.......

If I wanted to neuter the engine some I would run the 2096/41021 or the 9901/41021......but only if i was looking to tone it down would I consider those 2 combo's.........

Rebuilding a Plus 4-C Team that ate dirt. Does anyone know at what connecting rod pin diameter the rod is considered toast?

Well if you're talking about the pin that goes in the piston, I guess that starts out at 4mm exactly, I just replaced one that measured 3.92.. then I guess if you're talking about the hole in the top of the conrod, I guess that starts out at 4mm to match.. so if it's more than what you think is safe out of spec, I'd get rid of that.. then if you're talking about the crank pin, that starts out at 5mm and also the con rod big hole is at 5mm, so if your crank pin is less than 4.91 Rayaracing told me that was "borderline" towards there being any point in fitting a new conrod.

As for the actual conrods, when they enlarge they don't seem to enlarge as fast as the crank pin or wrist pin, when I replace them they'll be like 5.04mm in the bottom hole for example.. I had one measure 5.09mm but that was extremely high mileage.

I was running 2096/41021 and I just tried 9886/41001 today and the difference is huge. BTT lives this combo

JJ

Finally, someone answer my question. Thank you Sir! This is some of the best pipe/header information I've ever see on here. One of my guys is running your engines and they are balls out fast! Definately looking at a Clocked BTTA/S for my next engine.

Awesome. Thanks for the info.

Guys,

Need some advise, what is the engine bearing size for
1) 4BTT
2) Bonito

What after market brand would you recommend or shud I just stick with nova bearings.

Tks
Kelv

Hi Neal,

Thanks a ton for all the helpful advices, so for manifold the 41001 will be the best bet for the btt, appreciate it man, cheers

Yes ! it gives the engine more snap, and more top end.........for anyone with a Plus4 or BTT looking for more power should look into the 41001 as well as the 9886........ The difference from a 2096/41021 to a 9886/41001 is like night and day, almost makes it a totally different engine....It is a shame how many people have never seen this engines true potential as they have never run anything but the pipes that neuter the performance.....