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Old 07-05-2007, 12:38 PM   #4351
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Yea, 7 minutes sounds about right for the Mach 427. If you want better fuel economy you need to get a .21. The OS V-spec and VG are suppose to get exceptional runtime.
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Old 07-05-2007, 01:16 PM   #4352
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With my VG in my 8ight, I average 10-12 minutes of race/run time.
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Old 07-05-2007, 01:59 PM   #4353
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Originally Posted by boo-car View Post
I am new to Nitro, and have the RTR car.

If I want to start over tuning from factory settings, what's the proper way to do this? For factory settings, both high and low speed are 2.5 turns 'out', but 'out' from what starting point? Do I turn them 'in' until I start to feel a change in the amount of restistance to turning, or until they stop moving altogether with low torque (i.e. not trying to tighten them like a structural screw, just twisting lightly with the fingers until it will no longer move with this amount of light pressure). I notice when turning in there is a point where it gets slightly harder to turn before its stops.

Also, after break-in, how much 'off' are the the 2.5/2.5 factory settings? Way off, or is it just minor tweaks? I've tried to have others help me on this front, but my engine seems to chug fuel the current settings (maybe I can run 7 minutes on a tank), and it still seems to get a little too hot. The settings aren't even close to factory, from the changes that have been made. I live in the New England area with pretty much normal elevation and temps in the sommer in the high 70's/low 80's, I know engine tuning is affected by the environment, but this will be what I am mostly running in for the near future.

Thanks in advance for any help.
Where do you run in New England?Maybe if you shoot me a PM I can try and help you and stuff. ttyl.
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Old 07-05-2007, 01:59 PM   #4354
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Quote:
Originally Posted by boo-car View Post
I am new to Nitro, and have the RTR car.

If I want to start over tuning from factory settings, what's the proper way to do this? For factory settings, both high and low speed are 2.5 turns 'out', but 'out' from what starting point? Do I turn them 'in' until I start to feel a change in the amount of restistance to turning, or until they stop moving altogether with low torque (i.e. not trying to tighten them like a structural screw, just twisting lightly with the fingers until it will no longer move with this amount of light pressure). I notice when turning in there is a point where it gets slightly harder to turn before its stops.

Also, after break-in, how much 'off' are the the 2.5/2.5 factory settings? Way off, or is it just minor tweaks? I've tried to have others help me on this front, but my engine seems to chug fuel the current settings (maybe I can run 7 minutes on a tank), and it still seems to get a little too hot. The settings aren't even close to factory, from the changes that have been made. I live in the New England area with pretty much normal elevation and temps in the sommer in the high 70's/low 80's, I know engine tuning is affected by the environment, but this will be what I am mostly running in for the near future.

Thanks in advance for any help.
BOOCAR-Where do you run in New England?Maybe if you shoot me a PM I can try and help you and stuff. ttyl.
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Old 07-05-2007, 05:14 PM   #4355
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Originally Posted by R40Victim View Post
With my VG in my 8ight, I average 10-12 minutes of race/run time.
Damn, I need a 21. My 427 will only go 8min at best. Mostly in the 7:20 range with safe tune. To get 8min it runs hot but fast. I never thought about going over 10 with these buggies.
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Old 07-05-2007, 05:39 PM   #4356
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I think that I may have gotten to the root of my problem. I put in the MC-59 glow plug and returned to the factory settings. It started, idled and ran fine for break in. It was running very rich, good smoke from the pipe and a fair amount raw fuel coming from it as well. I ran it around going from idle to 1/3 throttle intermittently. After about 4 minutes I checked the temp which was right at 250 and I immediately covered the exhaust to shut it down. I then went to remove the air filter and noticed that the carb was loose, I could spin it around with my fingers. Am I correct to think that it could suck enough air to get it hot while appearing to be overly rich?
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Old 07-05-2007, 05:55 PM   #4357
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I run an old Novarossi 3 port. The thing rips pretty good according to most people that watch my car. Unfortunately it makes only 5:30 runtime on my large home track. I have literally flamed while crossing the line in qualifiers. And trust me, the tune is fine, the thing rips pretty good And even with that I still manage to do quite well in the expert class. So basically what I'm saying is that 7:30 and 8:00 is fine. Don't go buy a new engine JUST for the fuel mileage IMHO.
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Old 07-05-2007, 06:14 PM   #4358
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We get 9 minutes of runtime with our Mach .28 in the Losi 8t. (similar to the .427) It has a bigger fuel tank but as long as we make 7 1/2 minutes for a 30 minute main we're happy. I did make a carb restrictor for it also. We had a p5x in till it sucked dirt, it was getting 10 minutes.

Rex
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Old 07-05-2007, 06:36 PM   #4359
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Originally Posted by 22Racer View Post
We get 9 minutes of runtime with our Mach .28 in the Losi 8t. (similar to the .427) It has a bigger fuel tank but as long as we make 7 1/2 minutes for a 30 minute main we're happy. I did make a carb restrictor for it also. We had a p5x in till it sucked dirt, it was getting 10 minutes.

Rex
How did you make a restrictor? I'd be interested in that. These motors have too much power for the 8. IMHO. Well, too much for the way I drive.
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Old 07-05-2007, 06:51 PM   #4360
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you can use the carb body off of a sportwerks .21 that uses restrictors, your slide/high speed needle will work in the sportwerks carb body so all you have to get is the carb body and restrictors. i did it when i raced the mach .26 on my lst.
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Old 07-05-2007, 07:17 PM   #4361
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Ok. Thanks. That's sounds too simple. I should have tried it a long time ago.
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Old 07-05-2007, 07:58 PM   #4362
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Quote:
Originally Posted by R40Victim View Post
With my VG in my 8ight, I average 10-12 minutes of race/run time.
All I got out of my VG was a un-tunable pile that would flame out on every extended run and get about 6-7 minutes/tank at best. Ran awesome for 5 minute quals, but haven't finished a main with it yet.

Oh well, my new Novarossi 3 port will run 8 and 1/2 minutes tuned a little rich and is a much smoother engine.
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Old 07-06-2007, 03:53 AM   #4363
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Hi Trebor,

Thanks for the offer.

I live in Milford MA. I race about every three weeks or so at RC Excitement. I'll probably be there to race electric next Thursday and was planning to go a little early to try to tweak the tuning on the 8ight's engine so it would be ready the next Sunday that I go. Don't know if this is around where you are. Time is kind of tight with me w/family and all, so I've been a little slow getting the hang of Nitro tuning thing.

Shawn
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Old 07-06-2007, 07:35 PM   #4364
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I run the VG in my sons SP2, it has been an awesome engine, in fact I bought another.

With the tower specials I get in the mail it is $135 to my door usually, how can you beat that!!!

We are getting 9 minutes of runtime on high bite and 10 and a few seconds on looser tracks. It is super smooth, but not bad for power on the bottom, the only place it is a little weak is up top trying to carry gearing down the straight. Where this motor really shines, small straights or loose tracks. We are running a JP3 pipe on it and he is having a blast with it, never DNF'd except one time his mechanice didn't have the battery charged...oops.

Bad gas car, dumping during the mains! LOL


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Old 07-06-2007, 08:22 PM   #4365
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As much as my VG has torqued me off, I've wanted to skip it across the concrete or beat it to death with a sledge hammer

However, with all the good luck everyone else has had with theirs, I'm going to tear it down, seal everything up really tight and try it out in a different car around the end of August I figure I'll reset the needles and try a different plug (either the R-5 or another brand in place of the #8) and hope for better luck then.

It always seems to be after about 8-9 minutes I have problems (and yes it's after it's been refueled). Would an air leak issue affect it then or would it more likely be a tuning/glow plug issue? It's always temped under 255, but that was with a DuraTrax gun...I don't know if I trust it completely, so I bought a O'Donnel to go with the Novarossi after watching it temp consistent with my buddies $250 gun.
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