HomicidalBunny

iTrader: (4)

So what pipe is recommended to use in a buggy with this engine? 2090?

What are the characteristics of the 2090 and the 2060?

Sean Dickinson

iTrader: (7)

I have been running the 2090 on my B2101 for the past few weeks. Basically the 2060 is a top end pipe with a very smooth bottom end, while the 2090 helps make the bottom end response more crisp and not providing quite the top end power the 2060 does.

I prefer the 2090 on this engine as it already has an extreme top end and could use a little bit of bottom end at Fear Farm. For some smaller tracks with a loose surface, the 2060 would be prefered, but with a higher bite surface, you really can't go wrong with the 2090.

HomicidalBunny

iTrader: (4)

Which one has yielded better mileage?

Sean Dickinson

iTrader: (7)

Hard to say, I still don't have enough time on the engine to get the best mileage yet. Also haven't ran the 2060 long enough to go for mileage. You know what I mean? I basically just go for the power output, and as long as I can make 7:30 to 8 at my local track I'm fine. Will know more in the coming weeks.

Bill8Truggy

iTrader: (3)

I've timed for a mate, 13+ minutes in a truggy with a 2090 - 6mm venturi.

(At race pace, on a blown-out track and bald tyres)

We were going to try a 2060, but thought 'what could the 2060 achieve that the 2090 was not already doing'!

HomicidalBunny

iTrader: (4)

That's impressive

Bill8Truggy

iTrader: (3)

Yeah, not a bad effort at all.

http://www.youtube.com/watch?v=rpCoh...ature=youtu.be

This is our track . . .

HomicidalBunny

iTrader: (4)

Neato! Looks like a sweet track. Anywhoo, I guess I know which pipe to try first if I get a B2101 soon

shanef

iTrader: (38)

I've found the new b2101 to be a very aggressive engine. Personally the 2090 is too much pipe in a buggy as it makes you be very careful on the gas, the 2060 i find is better suited on a buggy as it smooths out the power and makes it easier to drive. Unfortunately it's not a 10+min buggy engine and is marginal in truggy. The reds engines i ran previous were much better on fuel but lacked the brute power of the new os.

Sean Dickinson

iTrader: (7)

Ya I believe that this is mostly due to the track. I watched the video of your track, and I would run 12 minute pits all day if I were on that track.

http://www.rctech.net/forum/13602121-post142.html

I saw your post a couple pages back, and you shouldn't be making this claim. You said you were running the smallest Nitro-mizer insert, these inserts get their mileage from eliminating the torque of the engine so that even heavy-finger guys can get better mileage. Comparing the small nitro mizer to a standard 6mm insert is like comparing a 5mm insert to no insert at all and then being surprised that having no insert makes more power.

I have ran the Reds Team Edition like you have, and this is the only stock engine I have ran the will blow the doors off of a speed long stroke, both bottom and top end. I have never before seen an engine pull as hard on the bottom end as the Reds does.

A more apt comparison of the bottom end of this engine is that the Protek short stroke engine with the 2060 top end pipe has a more explosive bottom than the B2101 does. I will stand by my claim that the B21 is the most tame speed in years.

am

That is also the statment from Os. The b2101 is not ment to replace the Xz-B speed, but to be used were the XZ-B is to much of an engine.

HomicidalBunny

iTrader: (4)

Keeping that in mind, would it then be better to run an Speed XZ-B Spec II or the B2101 on a medium sized, moderately technical track with a mix of low-speed and high-speed corners, and large jumps with short run-ups that can (in some cases) need decent low-end torque to clear?

My understanding is that if the B2101 has "less" torque, it is therefore a smoother engine on power delivery, and may need some more time to spool up?

Sean Dickinson

iTrader: (7)

Not in a buggy. The XZ-B has ridiculous bottom end, and without an insanely high-bite track, a buggy cannot put that power down. In a buggy, the B2101 will be plenty, but considering your track description, I would definitely recommend the 2090 for you.

And it's hard to explain in those terms, its not that the b21 takes longer to spool up, it's that it makes more power at a higher rpm and a smooth growth of power. The XZ-B just makes more power at a much lower rpm.

Bill8Truggy

iTrader: (3)

You would be the only one doing 12 minute pits at our club . . .

I guess the point you were making is that the type of track and driving style has much to do with fuel consumption; which is the reason I showed our track - the short stroke 2101/6mm/2090, with its' torque/HP higher in the RPM band was able to push a truggy around a tight, twisty track (with short ramps) and still had decent mileage.


I agree with what you are saying - If one was to compare the performance of different engines, back to back tests should be conducted with a 6, 6.5, 7mm venturi in each engine; then make the comparison.

I suggest that it's not just size that matters (she said ) - it is to do with efficiency of the carb and the venturi affect.


IMO - effectively the mizer does two things - it detrimentally affects the efficiency of the carb lower in the RPM range and limits the total of CFM (CIM?!) that the carb can flow higher in the RPM range.

IMO - The Nitro-Mizer detrimentally affects the efficiency of the carb lower in the RPM range as it lacks the contour/shape of a venturi (one side of a mizer insert is not a "venturi" at all - it is a flat face; thus reducing the beneficial 'venturi affect'. (Carbs only work because of the venturi affect) - IMO - the mizer is a "restrictor insert", not a "venturi insert" . . .


FYI - Last race meet I replaced my 5.4mm (purple) mizer with a 6mm OS venturi, and I was required to lean my HSN by 2+ hours - this is because the change in airspeed / venturi effect. (The 6mm OS venturi insert actually increased the airspeed/draw through the carb - thus I could limit the fuel flow)


A shorter stroke engine compared to a longer stroke engine:-

- they might produce the same amount of HP, however the shorter stroke engine will start to produce more significant amounts of HP higher in the RPM range, compared to a long stroke motor, which will start to produce the HP it is going to make lower in the RPM range.

- the air speed through the carb of a long stroke engine turning at 10,000rpm will be higher than the air speed through the same carb fitted to a short stroke engine turning at 10,000rpm.


The same size venturi, or a mizer fitted to a long stroke vs a short stroke engine will affect the engine's differently.


A long stroke engine with a small mizer fitted might be acceptable on a short, tight track. (Longer stroke keeps up air speed through the mizer restrictor at lower rpm / limited high RPM is of little consequence on the short tight track and the long stroke has already delivered its' best power earlier in the RPM range)

A short stroke engine with a small mizer fitted will feel horrible on a short tight track, and worse on a flowing fast track (more limited bottom-end where HP was low anyway / limited top-end where it want to make it's power)


This also explains why the mizers are more suited to modded engines - as the RPMs of a modded engine may increase more quickly, and/or air speed through the carb may increase more quickly.

shanef

iTrader: (38)

My last post was after further testing with the nitro mizers in the new speed, so it was an apples-apples comparison. For the way i drive, the speed is not as good on fuel.