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Old 12-24-2009, 03:52 AM   #1
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Default Tuning??? OS Speed 12XZ ...

Hi guys,
new to the scene and was hoping to get abit of insight
I recently purchased a brand new OS Speed 12XZ motor for my nt1 09 with an OS 3 chamber pipe ...
Ive ran it in properly with the supplied p3 plug for around 1Litre of 15% nitro fuel, and ive ran it ever since with a p6 plug and its had probably a total of just over 2 Litres [inclusive of breaking in] of 15% nitro fuel which contains 15% syn 5% cast.
The engine has been ran a little on the rich side throughout as im not too keen on running the motor lean ...
Ive had an expert look at the motor and he says it still looks and feels very much like a virgin
Need an opinion on tuning this thing ...

Down the straight [whether it be from stand still or rolling out of the corner], if i hold the throttle at about 1/4 - 1/3 open, the thing screams to high heaven and sings so nicely [with a slow gradual increase in throttle to about 3/4 open] ...
However ... if i full throttle it instantly [either stand still or rolling out of the corner] it revs without hesitation [no bogging or signs of struggle] however it just doesnt build up as well and doesnt sound or sing as nicely/high pitched as holding it 1/4 - 1/3 and increasing to 3/4 open ... its as though when i full throttle it instantly, it only reaches 80% of its potential, but holding the throttle at 1/4 - 1/3 open and gradually increasing throttle to 3/4 open allows it to reach 100% potential ...

What is my issue / problem? How can i tune it so that full throttle gives me 100% potential and allow it to sing to high heaven?

Appreciate the help and input guys
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Old 12-24-2009, 04:04 AM   #2
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Quote:
Originally Posted by Kwayziviet View Post
Hi guys,
new to the scene and was hoping to get abit of insight
I recently purchased a brand new OS Speed 12XZ motor for my nt1 09 with an OS 3 chamber pipe ...
Ive ran it in properly with the supplied p3 plug for around 1Litre of 15% nitro fuel, and ive ran it ever since with a p6 plug and its had probably a total of just over 2 Litres [inclusive of breaking in] of 15% nitro fuel which contains 15% syn 5% cast.
The engine has been ran a little on the rich side throughout as im not too keen on running the motor lean ...
Ive had an expert look at the motor and he says it still looks and feels very much like a virgin
Need an opinion on tuning this thing ...

Down the straight [whether it be from stand still or rolling out of the corner], if i hold the throttle at about 1/4 - 1/3 open, the thing screams to high heaven and sings so nicely [with a slow gradual increase in throttle to about 3/4 open] ...
However ... if i full throttle it instantly [either stand still or rolling out of the corner] it revs without hesitation [no bogging or signs of struggle] however it just doesnt build up as well and doesnt sound or sing as nicely/high pitched as holding it 1/4 - 1/3 and increasing to 3/4 open ... its as though when i full throttle it instantly, it only reaches 80% of its potential, but holding the throttle at 1/4 - 1/3 open and gradually increasing throttle to 3/4 open allows it to reach 100% potential ...

What is my issue / problem? How can i tune it so that full throttle gives me 100% potential and allow it to sing to high heaven?

Appreciate the help and input guys
I think it is not engine issue
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Old 12-24-2009, 04:17 AM   #3
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Quote:
Originally Posted by Kwayziviet View Post
Hi guys,
new to the scene and was hoping to get abit of insight
I recently purchased a brand new OS Speed 12XZ motor for my nt1 09 with an OS 3 chamber pipe ...
Ive ran it in properly with the supplied p3 plug for around 1Litre of 15% nitro fuel, and ive ran it ever since with a p6 plug and its had probably a total of just over 2 Litres [inclusive of breaking in] of 15% nitro fuel which contains 15% syn 5% cast.
The engine has been ran a little on the rich side throughout as im not too keen on running the motor lean ...
Ive had an expert look at the motor and he says it still looks and feels very much like a virgin
Need an opinion on tuning this thing ...

Down the straight [whether it be from stand still or rolling out of the corner], if i hold the throttle at about 1/4 - 1/3 open, the thing screams to high heaven and sings so nicely [with a slow gradual increase in throttle to about 3/4 open] ...
However ... if i full throttle it instantly [either stand still or rolling out of the corner] it revs without hesitation [no bogging or signs of struggle] however it just doesnt build up as well and doesnt sound or sing as nicely/high pitched as holding it 1/4 - 1/3 and increasing to 3/4 open ... its as though when i full throttle it instantly, it only reaches 80% of its potential, but holding the throttle at 1/4 - 1/3 open and gradually increasing throttle to 3/4 open allows it to reach 100% potential ...

What is my issue / problem? How can i tune it so that full throttle gives me 100% potential and allow it to sing to high heaven?

Appreciate the help and input guys
are you sure it came with P3 plug, Speed 12 XZ should came with a RP6 plug and you can found in the manual book, it also state that RP6/7 work well on this engine.
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Old 12-24-2009, 04:29 AM   #4
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Quote:
Originally Posted by kakluote View Post
I think it is not engine issue
i dont think so too .. i think its a tuning issues .. hence i asked if anyone could possibly help me tune / tweak this motor?

Quote:
Originally Posted by FF25510 View Post
are you sure it came with P3 plug, Speed 12 XZ should came with a RP6 plug and you can found in the manual book, it also state that RP6/7 work well on this engine.
pretty sure ... it was an os p3 ... i used that for about 1 litre while breaking in the motor ... i now use an os p6 ... my concern is more or less with the throttle % vs real potential ... im pretty sure its got something to do with tuning?
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Old 12-24-2009, 12:47 PM   #5
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Check your clutch. When you start from a stand still its really hard on the clutch. It might not be engaging properly.

Shawn.
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Old 12-24-2009, 01:27 PM   #6
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You say you're still running the engine quite rich?.
If so, this is probably the cause of the problem.
When you gradually increase the throttle the glowplug has the time to burn the increasing fuel/air mixture.
When you hit full throttle instantly the glowplug doesn't have the time to burn all that extra fuel and the glow will weaken, so less spark, less explosion= lower revs and a different sound.
The first thing you could try is a new plug, if this doesn't cure the problem start leaning the high speed needle till the engine start screaming even when you hit full throttle instantly. Check the temperature of the engine while doing this.
Btw, most time it is better to build up the throttle while exciting the corner, gives you more exit speed because you don't upset the car as much.
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Old 12-24-2009, 03:05 PM   #7
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Yep, sounds rich. It's probably really crisp off the line because it's lean on the bottom end. Lean the top, richen the bottom.
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