Question on Trucks and engines

[Josh D]

OK, I've read through all the archives and am more confused than when I
started.

I've been looking for a truck now for a few weeks and I thought I had
narrowed it down to a T-Maxx or a Savage. First question: Any opinions out
there for a first time Nitro user?

Second questions. With regards to the engines, I see the T-Maxx is a .15,
the Savage is a .25, but the T-maxx advertises a 2.5? What's the easiest way
to explain all the numbers?

Thanks,

Josh

[\Doc\]

Replies Inline........

"Josh D" <joshua.dunning@verizon.net> wrote in message
news:mB81f.623$la.565@trndny05...
> OK, I've read through all the archives and am more confused than when I
> started.

He he he he!

> I've been looking for a truck now for a few weeks and I thought I had
> narrowed it down to a T-Maxx or a Savage. First question: Any opinions out
> there for a first time Nitro user?

Savage is the only way to go IMO, but I'm biassed as I own one and love it.
My buddy has a T-Maxx and we bash pretty much every weekend. He has broken
far more parts than I, the Savage is faster, louder, jumps better, climbs
hills better, the list goes on and on. This is due to the powerplant
mostly, which I will explain below.

> Second questions. With regards to the engines, I see the T-Maxx is a .15,
> the Savage is a .25, but the T-maxx advertises a 2.5? What's the easiest
> way to explain all the numbers?

The most common way nitro engines are numbered is by cubic inches of
displacement. Generally speaking, the bigger the number the bigger the
motor and more power. .15 = .15 cubic inches of displacement. Traxxas
advertises their new engine as the TRX 2.5. This is 2.5 cubic CENTIMETERS
of displacement or .15 cubic inches. They did this to make it sound bigger
than it really is.

Smallblocks range from .12 to .18 cubic inches. Big blocks range from .21
to .32 cubic inches. There are some outliers like the Cen .46 and the
Thunder Tiger .70, but these are just that, outliers. The T-Maxx is a 1.35
HP .15 smallblock; the Savage 25 is a 2.5 HP .25 big block.

There is no replacement for displacement, and the bigger the motor the more
HP and more importantly in a monster truck, torque it will have. Last
weekend my bud and I went to an old sand and gravel pit and ran our trucks
out there. There was this wicked jump we were hitting, and about 15 feet
after the jump was a 20 foot cliff, so when you landed you had to hit the
brakes and turn real hard. Buddy broke his Maxx's front bumper and
bulkheads on a wimpy 4 foot high jump that he nosedived into the ground. I
hit the jump hard and unintentionally went OVER the cliff! The Savage
landed on it's wheels believe it or not, 20' below, and I drove it around to
a 60* hill, drove straight up and kept hitting the jump like nothing
happened.

I also own a Sportwerks Mayhem ST which is every bit as good as the Savage
and much faster, but not a true monster truck if that's what you're set on.

HTH,

Doc

[Josh D]

Hey! Thanks for the explanation! You said it better than the hobby shop
owner that looked at me like I had two heads...

I think I've settled on a used Savage, a few mods, and everything I need to
hit the ground running. Roughly $300, seems like a good deal to me.

Thanks again, I'm sure I'll be posting more questions once I start running
it!

Josh

""Doc"" <nospam@noway.com> wrote in message
news:P4ednf-mc9speNjenZ2dnUVZ_tCdnZ2d@adelphia.com...
> Replies Inline........
>
> "Josh D" <joshua.dunning@verizon.net> wrote in message
> news:mB81f.623$la.565@trndny05...
>> OK, I've read through all the archives and am more confused than when I
>> started.
>
> He he he he!
>
>> I've been looking for a truck now for a few weeks and I thought I had
>> narrowed it down to a T-Maxx or a Savage. First question: Any opinions
>> out there for a first time Nitro user?
>
> Savage is the only way to go IMO, but I'm biassed as I own one and love
> it. My buddy has a T-Maxx and we bash pretty much every weekend. He has
> broken far more parts than I, the Savage is faster, louder, jumps better,
> climbs hills better, the list goes on and on. This is due to the
> powerplant mostly, which I will explain below.
>
>> Second questions. With regards to the engines, I see the T-Maxx is a .15,
>> the Savage is a .25, but the T-maxx advertises a 2.5? What's the easiest
>> way to explain all the numbers?
>
> The most common way nitro engines are numbered is by cubic inches of
> displacement. Generally speaking, the bigger the number the bigger the
> motor and more power. .15 = .15 cubic inches of displacement. Traxxas
> advertises their new engine as the TRX 2.5. This is 2.5 cubic CENTIMETERS
> of displacement or .15 cubic inches. They did this to make it sound
> bigger than it really is.
>
> Smallblocks range from .12 to .18 cubic inches. Big blocks range from .21
> to .32 cubic inches. There are some outliers like the Cen .46 and the
> Thunder Tiger .70, but these are just that, outliers. The T-Maxx is a
> 1.35 HP .15 smallblock; the Savage 25 is a 2.5 HP .25 big block.
>
> There is no replacement for displacement, and the bigger the motor the
> more HP and more importantly in a monster truck, torque it will have.
> Last weekend my bud and I went to an old sand and gravel pit and ran our
> trucks out there. There was this wicked jump we were hitting, and about
> 15 feet after the jump was a 20 foot cliff, so when you landed you had to
> hit the brakes and turn real hard. Buddy broke his Maxx's front bumper
> and bulkheads on a wimpy 4 foot high jump that he nosedived into the
> ground. I hit the jump hard and unintentionally went OVER the cliff! The
> Savage landed on it's wheels believe it or not, 20' below, and I drove it
> around to a 60* hill, drove straight up and kept hitting the jump like
> nothing happened.
>
> I also own a Sportwerks Mayhem ST which is every bit as good as the Savage
> and much faster, but not a true monster truck if that's what you're set
> on.
>
> HTH,
>
> Doc
>

[Scotty]

"Josh D" <joshua.dunning@verizon.net> wrote in message
news:%su1f.1$t43.0@trndny02...
> Hey! Thanks for the explanation! You said it better than the hobby shop
> owner that looked at me like I had two heads...
>
> I think I've settled on a used Savage, a few mods, and everything I need
> to hit the ground running. Roughly $300, seems like a good deal to me.
>

You might want to look into a Traxxas Revo as well instead of the Tmaxx,
I've heard nothing but good things about it. A guy I run with races one and
it is FAST he also says it's pretty durable and good for bashing as well.

> Thanks again, I'm sure I'll be posting more questions once I start running
> it!
>
> Josh
>
> ""Doc"" <nospam@noway.com> wrote in message
> news:P4ednf-mc9speNjenZ2dnUVZ_tCdnZ2d@adelphia.com...
>> Replies Inline........
>>
>> "Josh D" <joshua.dunning@verizon.net> wrote in message
>> news:mB81f.623$la.565@trndny05...
>>> OK, I've read through all the archives and am more confused than when I
>>> started.
>>
>> He he he he!
>>
>>> I've been looking for a truck now for a few weeks and I thought I had
>>> narrowed it down to a T-Maxx or a Savage. First question: Any opinions
>>> out there for a first time Nitro user?
>>
>> Savage is the only way to go IMO, but I'm biassed as I own one and love
>> it. My buddy has a T-Maxx and we bash pretty much every weekend. He has
>> broken far more parts than I, the Savage is faster, louder, jumps better,
>> climbs hills better, the list goes on and on. This is due to the
>> powerplant mostly, which I will explain below.
>>
>>> Second questions. With regards to the engines, I see the T-Maxx is a
>>> .15, the Savage is a .25, but the T-maxx advertises a 2.5? What's the
>>> easiest way to explain all the numbers?
>>
>> The most common way nitro engines are numbered is by cubic inches of
>> displacement. Generally speaking, the bigger the number the bigger the
>> motor and more power. .15 = .15 cubic inches of displacement. Traxxas
>> advertises their new engine as the TRX 2.5. This is 2.5 cubic
>> CENTIMETERS of displacement or .15 cubic inches. They did this to make
>> it sound bigger than it really is.
>>
>> Smallblocks range from .12 to .18 cubic inches. Big blocks range from
>> .21 to .32 cubic inches. There are some outliers like the Cen .46 and
>> the Thunder Tiger .70, but these are just that, outliers. The T-Maxx is
>> a 1.35 HP .15 smallblock; the Savage 25 is a 2.5 HP .25 big block.
>>
>> There is no replacement for displacement, and the bigger the motor the
>> more HP and more importantly in a monster truck, torque it will have.
>> Last weekend my bud and I went to an old sand and gravel pit and ran our
>> trucks out there. There was this wicked jump we were hitting, and about
>> 15 feet after the jump was a 20 foot cliff, so when you landed you had to
>> hit the brakes and turn real hard. Buddy broke his Maxx's front bumper
>> and bulkheads on a wimpy 4 foot high jump that he nosedived into the
>> ground. I hit the jump hard and unintentionally went OVER the cliff!
>> The Savage landed on it's wheels believe it or not, 20' below, and I
>> drove it around to a 60* hill, drove straight up and kept hitting the
>> jump like nothing happened.
>>
>> I also own a Sportwerks Mayhem ST which is every bit as good as the
>> Savage and much faster, but not a true monster truck if that's what
>> you're set on.
>>
>> HTH,
>>
>> Doc
>>
>
>

[sonofabitchsky@hotmail.com]

"Doc" wrote:
> Replies Inline........
>
> "Josh D" <joshua.dunning@verizon.net> wrote in message
> news:mB81f.623$la.565@trndny05...
> > OK, I've read through all the archives and am more confused than when I
> > started.
>
> He he he he!
>
> > I've been looking for a truck now for a few weeks and I thought I had
> > narrowed it down to a T-Maxx or a Savage. First question: Any opinions out
> > there for a first time Nitro user?
>
> Savage is the only way to go IMO, but I'm biassed as I own one and love it.
> My buddy has a T-Maxx and we bash pretty much every weekend. He has broken
> far more parts than I, the Savage is faster, louder, jumps better, climbs
> hills better, the list goes on and on. This is due to the powerplant
> mostly, which I will explain below.
>
> > Second questions. With regards to the engines, I see the T-Maxx is a .15,
> > the Savage is a .25, but the T-maxx advertises a 2.5? What's the easiest
> > way to explain all the numbers?
>
> The most common way nitro engines are numbered is by cubic inches of
> displacement. Generally speaking, the bigger the number the bigger the
> motor and more power. .15 = .15 cubic inches of displacement. Traxxas
> advertises their new engine as the TRX 2.5. This is 2.5 cubic CENTIMETERS
> of displacement or .15 cubic inches. They did this to make it sound bigger
> than it really is.
>
> Smallblocks range from .12 to .18 cubic inches. Big blocks range from .21
> to .32 cubic inches. There are some outliers like the Cen .46 and the
> Thunder Tiger .70, but these are just that, outliers. The T-Maxx is a 1.35
> HP .15 smallblock; the Savage 25 is a 2.5 HP .25 big block.
>
> There is no replacement for displacement, and the bigger the motor the more
> HP and more importantly in a monster truck, torque it will have. Last
> weekend my bud and I went to an old sand and gravel pit and ran our trucks
> out there. There was this wicked jump we were hitting, and about 15 feet
> after the jump was a 20 foot cliff, so when you landed you had to hit the
> brakes and turn real hard. Buddy broke his Maxx's front bumper and
> bulkheads on a wimpy 4 foot high jump that he nosedived into the ground. I
> hit the jump hard and unintentionally went OVER the cliff! The Savage
> landed on it's wheels believe it or not, 20' below, and I drove it around to
> a 60* hill, drove straight up and kept hitting the jump like nothing
> happened.
>
> I also own a Sportwerks Mayhem ST which is every bit as good as the Savage
> and much faster, but not a true monster truck if that's what you're set on.
>
> HTH,
>
> Doc

Just curious. I know Traxxas used to use the Pro .15 engine. Now they
have the 2.5r enginge. Both are .15 cu inches, correct? They claim the
2.5r is up to 60% more powerful. How is that possible?

[\Doc\]

<sonofabitchsky@hotmail.com> wrote in message
news:1128702400.109720.250780@g49g2000cwa.googlegr oups.com...

> Just curious. I know Traxxas used to use the Pro .15 engine. Now they
> have the 2.5r enginge. Both are .15 cu inches, correct? They claim the
> 2.5r is up to 60% more powerful. How is that possible?

It's a combination of higher compression, better porting and a better carb.
If you know anything about 1:1 scale engines, take a Chevy 350 (5.7L) for
example. They range in HP from 150-450 from the factory, the only
differences being compression ratios, head porting and air/fuel induction
systems.

Doc

[\Doc\]

"Josh D" <joshua.dunning@verizon.net> wrote in message
news:%su1f.1$t43.0@trndny02...
> Hey! Thanks for the explanation! You said it better than the hobby shop
> owner that looked at me like I had two heads...
>
> I think I've settled on a used Savage, a few mods, and everything I need
> to hit the ground running. Roughly $300, seems like a good deal to me.
>
> Thanks again, I'm sure I'll be posting more questions once I start running
> it!
>
> Josh

Yeah, $300 for a slightly modded Savage in good running order is a good
price. A few things to check right off the bat:

1. Transmission outdrive cups (especially rear) can get pretty grooved and
create a bind in the driveline.
2. Differential outdrive cups (especially rear) can get pretty grooved and
create a bind in the driveline.
3. Axleshaft carrier bearings (sides of differentials) get sloppy then
explode without warning!
4. Plastic steering servo bushings (if not modded already) get really sloppy
really fast. Best fix is to replace with bearings instead of more plastic.
5. Replace wimpy stock clutch springs with Mugen 1.0mm springs. Hooks up
way better off the line and reduces clutchbell heat.

Those are the only parts I have found that wear pretty predictably.
Everything else on mine is pretty much original after 5 gallons of fuel
(aside from the parts I've replaced after some terrific crashes!). I keep
extra driveshafts and drive cups handy, and change my axleshaft carrier
bearings every 1-2 gallons as preventive maintenance.

Doc

//////////////////////////////////////////////////////////////////////////////////


>
> ""Doc"" <nospam@noway.com> wrote in message
> news:P4ednf-mc9speNjenZ2dnUVZ_tCdnZ2d@adelphia.com...
>> Replies Inline........
>>
>> "Josh D" <joshua.dunning@verizon.net> wrote in message
>> news:mB81f.623$la.565@trndny05...
>>> OK, I've read through all the archives and am more confused than when I
>>> started.
>>
>> He he he he!
>>
>>> I've been looking for a truck now for a few weeks and I thought I had
>>> narrowed it down to a T-Maxx or a Savage. First question: Any opinions
>>> out there for a first time Nitro user?
>>
>> Savage is the only way to go IMO, but I'm biassed as I own one and love
>> it. My buddy has a T-Maxx and we bash pretty much every weekend. He has
>> broken far more parts than I, the Savage is faster, louder, jumps better,
>> climbs hills better, the list goes on and on. This is due to the
>> powerplant mostly, which I will explain below.
>>
>>> Second questions. With regards to the engines, I see the T-Maxx is a
>>> .15, the Savage is a .25, but the T-maxx advertises a 2.5? What's the
>>> easiest way to explain all the numbers?
>>
>> The most common way nitro engines are numbered is by cubic inches of
>> displacement. Generally speaking, the bigger the number the bigger the
>> motor and more power. .15 = .15 cubic inches of displacement. Traxxas
>> advertises their new engine as the TRX 2.5. This is 2.5 cubic
>> CENTIMETERS of displacement or .15 cubic inches. They did this to make
>> it sound bigger than it really is.
>>
>> Smallblocks range from .12 to .18 cubic inches. Big blocks range from
>> .21 to .32 cubic inches. There are some outliers like the Cen .46 and
>> the Thunder Tiger .70, but these are just that, outliers. The T-Maxx is
>> a 1.35 HP .15 smallblock; the Savage 25 is a 2.5 HP .25 big block.
>>
>> There is no replacement for displacement, and the bigger the motor the
>> more HP and more importantly in a monster truck, torque it will have.
>> Last weekend my bud and I went to an old sand and gravel pit and ran our
>> trucks out there. There was this wicked jump we were hitting, and about
>> 15 feet after the jump was a 20 foot cliff, so when you landed you had to
>> hit the brakes and turn real hard. Buddy broke his Maxx's front bumper
>> and bulkheads on a wimpy 4 foot high jump that he nosedived into the
>> ground. I hit the jump hard and unintentionally went OVER the cliff!
>> The Savage landed on it's wheels believe it or not, 20' below, and I
>> drove it around to a 60* hill, drove straight up and kept hitting the
>> jump like nothing happened.
>>
>> I also own a Sportwerks Mayhem ST which is every bit as good as the
>> Savage and much faster, but not a true monster truck if that's what
>> you're set on.
>>
>> HTH,
>>
>> Doc
>>
>
>

[Dre]

""Doc"" <nospam@noway.com> wrote in message
news:X4-dndJmQ4JxZNveRVn-3A@adelphia.com...
>
> "Josh D" <joshua.dunning@verizon.net> wrote in message
> news:%su1f.1$t43.0@trndny02...
> > Hey! Thanks for the explanation! You said it better than the hobby shop
> > owner that looked at me like I had two heads...
> >
> > I think I've settled on a used Savage, a few mods, and everything I need
> > to hit the ground running. Roughly $300, seems like a good deal to me.
> >
> > Thanks again, I'm sure I'll be posting more questions once I start
running
> > it!
> >
> > Josh
>
> Yeah, $300 for a slightly modded Savage in good running order is a good
> price. A few things to check right off the bat:
>
> 1. Transmission outdrive cups (especially rear) can get pretty grooved and
> create a bind in the driveline.
> 2. Differential outdrive cups (especially rear) can get pretty grooved and
> create a bind in the driveline.
> 3. Axleshaft carrier bearings (sides of differentials) get sloppy then
> explode without warning!
> 4. Plastic steering servo bushings (if not modded already) get really
sloppy
> really fast. Best fix is to replace with bearings instead of more
plastic.
> 5. Replace wimpy stock clutch springs with Mugen 1.0mm springs. Hooks up
> way better off the line and reduces clutchbell heat.
>
> Those are the only parts I have found that wear pretty predictably.
> Everything else on mine is pretty much original after 5 gallons of fuel
> (aside from the parts I've replaced after some terrific crashes!). I keep
> extra driveshafts and drive cups handy, and change my axleshaft carrier
> bearings every 1-2 gallons as preventive maintenance.
>
> Doc
>
<snip>
Hey Doc, can I ask why you changed your clutch springs to tighter ones? I
assume that you did that so the clutch shoes dont rub when its idling??

Cheers Dre

[\Doc\]

"Dre" <blah@somewhere.com> wrote in message
news:434ae7e8$1@patrick.nettas.net...
> <snip>
> Hey Doc, can I ask why you changed your clutch springs to tighter ones? I
> assume that you did that so the clutch shoes dont rub when its idling??
>
> Cheers Dre

I wanted the truck to hook up harder off the line from a dead stop, and the
stiffer springs allow the engine to get the revs up before the clutch
engages, so the engine is producing more power when the clutch engages and
she takes off. A definite improvement in off-the-line punch, she kinda
"leaps" off the line now. I can also set my idle much higher than before
and get zero clutch rubbing, which is nice when she's first fired up and the
engine is cold, as she likes a fast idle until she hits 200* or so.

I had an intermittant bog off the line I couldn't tune out, and I think this
was partially due to the softer springs (clutch engaging when engine was at
low RPM and producing very little useable power) After changing to the
1.0mm springs, I haven't had a single bog off the line in six or so tanks.
Wheelies are gone for some reason or another with the stiffer springs, which
I don't really mind as I was really mashing my bodies up quickly and they
were getting kind of annoying.

I stuck with the original, stock shoes, which still look brand new after 5
gallons of fuel! I just sanded the glaze off em' and roughed up the
clutchbell a bit before reassembley. I'm seriously considering grabbing a
Sportwerks .26, 7-port motor for the Sav over the winter as I have one in my
Mayhem ST and it is insanely powerful, VERY reliable, and holds a tune like
you wouldn't believe. I also like the Sportwerks starting system much
better than HPI's rotostart. As soon as Sportwerks comes out with a MT I'll
be the first in line to buy one. They started with buggies, then ST's, the
next logical step is a MT!

Doc

[Dre]

""Doc"" <nospam@noway.com> wrote in message
news:kpGdnTbwbf_PjNbeRVn-sw@adelphia.com...
>
> "Dre" <blah@somewhere.com> wrote in message
> news:434ae7e8$1@patrick.nettas.net...
> > <snip>
> > Hey Doc, can I ask why you changed your clutch springs to tighter ones?
I
> > assume that you did that so the clutch shoes dont rub when its idling??
> >
> > Cheers Dre
>
> I wanted the truck to hook up harder off the line from a dead stop, and
the
> stiffer springs allow the engine to get the revs up before the clutch
> engages, so the engine is producing more power when the clutch engages and
> she takes off. A definite improvement in off-the-line punch, she kinda
> "leaps" off the line now. I can also set my idle much higher than before
> and get zero clutch rubbing, which is nice when she's first fired up and
the
> engine is cold, as she likes a fast idle until she hits 200* or so.
>
> I had an intermittant bog off the line I couldn't tune out, and I think
this
> was partially due to the softer springs (clutch engaging when engine was
at
> low RPM and producing very little useable power) After changing to the
> 1.0mm springs, I haven't had a single bog off the line in six or so tanks.
> Wheelies are gone for some reason or another with the stiffer springs,
which
> I don't really mind as I was really mashing my bodies up quickly and they
> were getting kind of annoying.
>
> I stuck with the original, stock shoes, which still look brand new after 5
> gallons of fuel! I just sanded the glaze off em' and roughed up the
> clutchbell a bit before reassembley. I'm seriously considering grabbing a
> Sportwerks .26, 7-port motor for the Sav over the winter as I have one in
my
> Mayhem ST and it is insanely powerful, VERY reliable, and holds a tune
like
> you wouldn't believe. I also like the Sportwerks starting system much
> better than HPI's rotostart. As soon as Sportwerks comes out with a MT
I'll
> be the first in line to buy one. They started with buggies, then ST's,
the
> next logical step is a MT!
>
> Doc
>
Nice, thanks for the info, I'll look into it..

I find it weird though that you now cant wheelie considering you have more
off line punch. You haven't changed your springs or shock oil to different
types by any chance??

I haven't had a chance to do anything to my Savage for the last 3 weeks as
I've been busy with other stuff and its been raining heaps on the w/e's.
When I do get a chance I plan to do some more tuning, it isn't running as
well as it could so keen to sort it...

Cheers Dre

[\Doc\]

"Dre" <blah@somewhere.com> wrote in message
news:434b1a96$1@patrick.nettas.net...

> Nice, thanks for the info, I'll look into it.

Well worth the $4.49 I paid!

> I find it weird though that you now cant wheelie considering you have more
> off line punch. You haven't changed your springs or shock oil to
> different
> types by any chance??

Nope, everything else is the same per way of setup. I agree, it is weird.
It takes off just as fast as it used to, the front end just stays put, which
is rather nice actually! Maybe she's starting to get tired after 5 gallons
of fuel? Seems to run just as strong as it always has.

> I haven't had a chance to do anything to my Savage for the last 3 weeks as
> I've been busy with other stuff and its been raining heaps on the w/e's.
> When I do get a chance I plan to do some more tuning, it isn't running as
> well as it could so keen to sort it...

You have the K-4.6 right? Is it as finnicky to tune as the S-25? I have
been fighting with my S-25 since I bought it, and while it runs well, it has
never run as well as it "should." Every now and then I'll get 2-3 minutes
of insane performance, then it's back to where it usually runs with no
explanation as to why!

Doc

[\Doc\]

"Dre" <blah@somewhere.com> wrote in message
news:434c442b$1@patrick.nettas.net...

> This paragraph:
>
> " I find with cold plugs during break-in, the tendency to overlean the HSN
> while
>> compensating for a super-rich LSN is really easy. With a hot plug, no
>> matter how rich the idle is, it tends to burn it all off when you hit the
>> gas and allow for a more realistic HSN setting."
>
> is exactly what happened to me last time I ran it. Except I didn't put a
> hotter plug in there to find out. (plugs in there now, but I haven't
> tested
> it yet)
>
> You just nailed it right on the head :) I think I might take her out
> tonight and see what I can come up with.
>
> Funny, the plug I replaced the HPI cold one with was an OS A5! (great
> minds
> think alike eh :)

Just make sure you leave her tuned a bit rich with the hot plug if you end
up using an A3 for initial tuning as it'll reduce the tendency towards
detonation. Once you switch from A3 (hot) to A5 (medium cold) you'll have
to lean a bit further as well. My method for break-in and tuning pretty
much any new nitro motor is thus:

1. Yank factory plug (throw in garbage!) and pop in an OS A3.
2. Run sloppy rich at factory settings for 1 tank at idle
3. Run sloppy rich at no more than 25% constant throttle with very brief
100% throttle blips for 2-4 more tanks, heat-cycling after each tank (making
sure piston is at bottom of stroke when she flames out at empty tank and
allow to cool this way)
4. Begin leaning HSN at tank 5 until "decent" top-end performance is
reached, but NOT max RPM, you still want it smoking like a freight train at
this point, not boggy, but really smoky
5. Begin leaning LSN after HSN is roughly set until take off is rich and
smoky but not boggy
6. Yank OS A3 and pitch it, replace with OS A5
7. Dial in HSN for max RPM
8. Dial in LSN for max bottom-end punch (lean more)
9. Set idle.

If you do it right, by the time you get to #7 and #8 you're only about 1/2
turn away from pure nitro bliss! I really like the A3's as they burn hotter
than Hades and keep her lit during the super rich break-in and allow her to
reach temps high-enough for a decent heat-cycle between tanks.

Doc

[Dre]

""Doc"" <nospam@noway.com> wrote in message
news:ONWdnUFzGZknDtHeRVn-pw@adelphia.com...
>
> "Dre" <blah@somewhere.com> wrote in message
> news:434c442b$1@patrick.nettas.net...
>
> > This paragraph:
> >
> > " I find with cold plugs during break-in, the tendency to overlean the
HSN
> > while
> >> compensating for a super-rich LSN is really easy. With a hot plug, no
> >> matter how rich the idle is, it tends to burn it all off when you hit
the
> >> gas and allow for a more realistic HSN setting."
> >
> > is exactly what happened to me last time I ran it. Except I didn't put
a
> > hotter plug in there to find out. (plugs in there now, but I haven't
> > tested
> > it yet)
> >
> > You just nailed it right on the head :) I think I might take her out
> > tonight and see what I can come up with.
> >
> > Funny, the plug I replaced the HPI cold one with was an OS A5! (great
> > minds
> > think alike eh :)
>
> Just make sure you leave her tuned a bit rich with the hot plug if you end
> up using an A3 for initial tuning as it'll reduce the tendency towards
> detonation. Once you switch from A3 (hot) to A5 (medium cold) you'll have
> to lean a bit further as well. My method for break-in and tuning pretty
> much any new nitro motor is thus:
>
> 1. Yank factory plug (throw in garbage!) and pop in an OS A3.
> 2. Run sloppy rich at factory settings for 1 tank at idle
> 3. Run sloppy rich at no more than 25% constant throttle with very brief
> 100% throttle blips for 2-4 more tanks, heat-cycling after each tank
(making
> sure piston is at bottom of stroke when she flames out at empty tank and
> allow to cool this way)
> 4. Begin leaning HSN at tank 5 until "decent" top-end performance is
> reached, but NOT max RPM, you still want it smoking like a freight train
at
> this point, not boggy, but really smoky
> 5. Begin leaning LSN after HSN is roughly set until take off is rich and
> smoky but not boggy
> 6. Yank OS A3 and pitch it, replace with OS A5
> 7. Dial in HSN for max RPM
> 8. Dial in LSN for max bottom-end punch (lean more)
> 9. Set idle.
>
> If you do it right, by the time you get to #7 and #8 you're only about 1/2
> turn away from pure nitro bliss! I really like the A3's as they burn
hotter
> than Hades and keep her lit during the super rich break-in and allow her
to
> reach temps high-enough for a decent heat-cycle between tanks.
>
> Doc
>
They are some really good points there, thanks heaps for writing them out!
I follow a similar procedure but I have never considered using different
plugs.

My problem this time round was when I got to step 4, I kept leaning out for
max rpm and couldn't get there. This has worked with all my other engines,
but not this one.

Not a problem, I'm keen as mustard to have a fiddle with it tonight, if I do
get a chance (and I have enough charge in the reciever pack), I'll let you
know how I go tomorrow...

Now, to pretty much reset the carb screws and start again :)

Cheers Dre