R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric Off-Road

Reply
 
Thread Tools Search this Thread
Old 12-27-2005, 04:24 PM   #46
Tech Fanatic
 
SavageSYNTH25's Avatar
 
Join Date: Aug 2005
Location: Charlotte, NC
Posts: 794
Send a message via AIM to SavageSYNTH25
Default

Does your local track have a website, or a forum? Ours does and guys post setups all the time that work well.

It's been a while since i've worked on a K-Car, and a little bit longer than that since I've driven one, but the new 777's look pretty nice. Everyone I've talked to says that "Famous Kyosho Push" is gone.......
SavageSYNTH25 is offline   Reply With Quote
Old 12-28-2005, 06:26 AM   #47
Tech Addict
 
downunder23's Avatar
 
Join Date: Oct 2005
Posts: 618
Cool

savagsynth25: yeah that is true because after cleaning and retightening everything and re mounting the cvd on its diff mount cured the problem i was just seeing if any of you guys knew so i had some back up on my thoughts about that fact of the front not loaded and the rear slips because the front is slipping etc by the way the diffs work alls well now except (my bad) i jumped it and ruined the survo horn gear, even after replacing with that of another servo i still cant get full left steer consistantly so i need a new servo any one got advise on the top servoes im interested in high torque as high as possible i guess and speed.
also as far as my engine is concerned i seem to have got it going better than i have been in the past but as soon as i took it to the track i ran into some probs like my servo was 1 and my radio throttle not responding when i accelerate it started to delay response time in the after noon so it may just be near flat reciever batteries.
also my engine seemed to have a little trouble with glow plug which i think may be the problem all together its not getting constant and consistant spark or glow for the engine to keep running i say this because after replacing plug due to non glow or spark to kick it over and it would stop some times when i removed the plug ignitor so it seems i could do all the tunning in the world but it just won't stay going even after running it round the track few laps and coming to a stop due to the fense being the way(no reverse) it would stall when idling so um my thinking is toward the glow plug not glowing and i am thinking toward the fact that too much fuel is making this happen im not sure but it was definately a glow plug problem towards the end of the day as i said before it would cut out after i removed the ignitor.

things that make you go hmmmm.
regards.......................Aaron.
downunder23 is offline   Reply With Quote
Old 12-28-2005, 06:39 AM   #48
Tech Addict
 
downunder23's Avatar
 
Join Date: Oct 2005
Posts: 618
Talking

also due to being on a dusty track traction is quiet hard to achieve so its like a non stop rally type of drive on this track and alot of the time i seem to have too much steering and the rear floats alot on corners. any tips on how to narrow that loose rear traction and have more centralised turning insted of full backend whipp any suggestions on how i should set up is much welcomed keeping in mind its a off-road tight,jumpy dirt with gravel surfacing like bmx tracks (very loose) with a 30 mtr straight. rally skills needed which i would obtain but cant get the damn thing to run for full run time of fuel tank capacity or more. so far the most i have gone is about 1/2 tank and i run into some sort of a problem.sorry guys but the damn thing just dont wanna stay goin please help me.






ive been asked if you ever take no for an answer.
and i tell them yes but its more like no!....no!......please!....nooooo.
downunder23 is offline   Reply With Quote
Old 12-28-2005, 09:46 PM   #49
Tech Fanatic
 
SavageSYNTH25's Avatar
 
Join Date: Aug 2005
Location: Charlotte, NC
Posts: 794
Send a message via AIM to SavageSYNTH25
Default

Got a few more questions, eh? No problem, I'll try to answer them. About your steering servo, I would suggest an Airtronics (or Sanwa in your neck of the woods) 94258. That's a great high tourque servo.

Yes, it seems your plug is bad. If you have the engine going, but you remove the igniter and it stalls, you have a bad plug. Replace with a nice cool plug to start with. Make sure everything is charged up before your next run as well, a dead receiver pack doesnt help much!!!!!

As for the rear end looping out: Run no camber in the front (wheels vertical), and a little positive camber in the rear (1 deg. out) to offset the front, and run some toe-in in the front to counterbalance the suspension settings. Also, try using some stiffer clutch springs to slow down clutch response so it doesn't snap so hard.

Just try your best to get the engine going good, play with the chassis to get a little more grip, and if you have any more trouble, let us know.

Thanks!!!!!!!
SavageSYNTH25 is offline   Reply With Quote
Old 12-31-2005, 03:59 AM   #50
Tech Addict
 
downunder23's Avatar
 
Join Date: Oct 2005
Posts: 618
Default

savage: i ended up getting a high torque ( twice that of my original) whith netal gears so thats my steering prob sorted and i am getting closer to getting my engine running well just a quick question about that is what does it mean when the car makes that struggling sound when its on the verge of top end it seems to be struggling for air it does this with least smoke so i am guessing it is a lean high end needle mixture i think i have the bottom setting sorted now its just consistancy ang best throttle all the way through to top end performans (im getting the hang of it) i also bought a venom micro temp so i can tune to temp now any advice on specific temps to aim for etc.
i recall a temp of 240-260 degrees but is that celcius or farenheight.
thanks alot youve been great help couple more weeks of practice ill have the car set up great. regards................Aaron
downunder23 is offline   Reply With Quote
Old 12-31-2005, 07:44 AM   #51
Tech Fanatic
 
SavageSYNTH25's Avatar
 
Join Date: Aug 2005
Location: Charlotte, NC
Posts: 794
Send a message via AIM to SavageSYNTH25
Default

Your top end performance is more than likely a little lean.

If, all of a sudden, it starts to sputter and try to stall, you have a lean top end tune. (maybe the temperature was warmer since the last time you ran it?) and can probably be tweaked by just richening the WOT 1/4-1/2. You usually have to re-tune the car even when the weather changes [u]slightly[u]. So when you are running your car, and you hear a lean "squeal", or a bottom or top end "bog", then you know why!

I would hope that your engine would never run 260 Celcius, that would be somewhere in the high 300 range in Farenheit??? Just joking. Your engine can safely run at any temperature from 190-275. Always try to keep temps over 200, but under 250 if at all possible. Some engines run better at different temperatures though, so when you "temp tune", that is just a baseline setting. I have a small block Sirio engine that runs best at about 190-205 all day, but then again, I have an OS big block that won't run well until the temps get up to about 250-280. Try to tune your engine until the temps are in the low 200 deg range [u]CONSISTENTLY[u], and then tweak the needles based on what you see and hear (smoke, sounds) after you "temp tune".


Just so you know, all the temps I listed are in Farenheit.


Thanks!!!!!!
SavageSYNTH25 is offline   Reply With Quote
Old 12-31-2005, 05:41 PM   #52
Tech Addict
 
downunder23's Avatar
 
Join Date: Oct 2005
Posts: 618
Default

yeah thanks savage i didnt think an engine would last on 200-250 celcius.
so looks as if i tune in farenheit then my mini temp guage from venom can tune in both so yeah is all good.
ill be able to tune it anywhere any time any temp any day so thanks.
oh and hows your xb8 for sale going? i would make you an offer but it seems a little out of my price range, im looking for a spare parts source if you know of any buggs or cheap spares sources lmk............regards........Aaron.
got new tyres the other day called badlands from proline what tyres do you know of that are great for off-road dirt gravel loose stuff badlands will be good for this hows those x patterned tyres go?
downunder23 is offline   Reply With Quote
Old 12-31-2005, 05:46 PM   #53
Tech Addict
 
downunder23's Avatar
 
Join Date: Oct 2005
Posts: 618
Default

oh yeah and savage whats the rule of pro race engines and their idle speed i heard that race engines do not idle ?
================================================== ========
downunder23 is offline   Reply With Quote
Old 12-31-2005, 06:49 PM   #54
Tech Rookie
 
Join Date: Dec 2005
Location: Many, Louisiana
Posts: 5
Default NEED HELP REMOVING CARB ON HPI 25

I recently purchased a used hpi savage with a 25 on it. I need to know how to get the carb off. Can anybody tell me how to do this? I removed the one screw that seemed to be holding and it still won't pull off. Should it pull off easy or is there some kind of tool I need to get it off with? I am new to nitro!! HELP!!!!!!!!!!!
rc_racer61 is offline   Reply With Quote
Old 12-31-2005, 07:53 PM   #55
Tech Fanatic
 
SavageSYNTH25's Avatar
 
Join Date: Aug 2005
Location: Charlotte, NC
Posts: 794
Send a message via AIM to SavageSYNTH25
Default

downunder: I'm selling one of my backup buggies, I assume you looked at it? It is going well, I'm getting all kinds of offers.

The BadLand tires should be OK for gravel, but to be honest, there isn't a company around today that makes tires for a gravel track. The vast majority of US tracks are dirt based, and most US tire makers are catering to those tracks. You may want to look for a european company, from what I've heard, many of those tracks are composed of grass, tarmac, gravel, and even cobblestones? Like I said before, try something like a ProLine Crime Fighter, that is an all-around tire that should work ok. X Pattern tires won't work too well, unless the lugs are very tall so they dig into the gravel. When you are looking for tires, just look at the pattern and size of the lugs. Generally, you would want a large sharp lug in a forward directional pattern, for what you're racing on.


Idle speed has a lot of reliance on engine tuning. There is a guy named Mike Lackey, he races locally with me, and he runs an OS VSPEC and that engine idles so low you would think it is about to stall. On the other hand, another guy runs a Sirio Kanai II motor and that thing has a very high idle. Both are tuned properly, and run well. Each engine you find will like to idle in a different range and like to run better a little richer or leaner, that is the problem with trying to tell someone how to tune their motor. Everything varies, you know?
Race engines DO idle, but many racers set the idle very high to keep the engine from stalling during a long (45 min-1 hour) main event. Personally, I do this. For the most part, it is just to keep the engine running. Another thing to keep in mind is idle is determined by low end tune. A common mistake people make is setting the bottom artifically rich and trying to lower the idle. If the bottom is too rich, closing the idle screw will not lower the idle, only make the engine stall when the carb fully closes. That frustrates many people, but it's just one of those things you have to learn. Something that has helped me out a lot is LISTENING TO THE ENGINE AS YOU LEAN THE BOTTOM. First, set the idle gap at 1mm open. No more, no less. If the engine is idling high constantly, or idles high for a few seconds and then drops, you have a rich bottom end. Bring the engine back to idle (if it is high with a 1mm carb gap) and lean the bottom end until you hear the idle drop. That is a general tune for the bottom, but of course, that is reliant on idle as well. On the other hand, if you have your idle set right and when you bring the engine back down to a low idle and it starts to idle up after a few seconds, you need to richen the bottom and lower the idle. But like I said, engines vary, temps vary, and there is only so much I can tell you about tuning the motor.

Hope this helps!!!!!


BTW, if you want a nice race motor, look me up. Some of the local guys run motors I've modded, and I have a pretty good method of "recompressing" the motor as well.

Good Luck!!!!!!!!!!!
SavageSYNTH25 is offline   Reply With Quote
Old 12-31-2005, 07:56 PM   #56
Tech Fanatic
 
SavageSYNTH25's Avatar
 
Join Date: Aug 2005
Location: Charlotte, NC
Posts: 794
Send a message via AIM to SavageSYNTH25
Default

rc_racer61: I don't know much about the HPI motors, my knowledge base is JP engines and Novarossi based big blocks. I would suggest going to www.hpiracing.com and posting your question on their forum. They could probably tell you more than we could!

Best of luck pulling the carb though.
SavageSYNTH25 is offline   Reply With Quote
Old 01-01-2006, 12:35 AM   #57
Tech Addict
 
downunder23's Avatar
 
Join Date: Oct 2005
Posts: 618
Default

ok savage i totally understand you and once again thankyou for being so specific its been great messaging with you i think i know all there is to know about how to go about tuning the engine now i guess its just going to take me time to learn the art of it with experience, im actually starting to think it has a hole or something in the tank because it seems to be stalling about the same time everytime at just above 1/2 a tank.
once it is below the carby fuel line outlet also do you know if what air bubbles mean in the fuel line as im trying to start it and is it ok to say have a few air bubles go through the fuel lines?


r/cracer; umm i would just check everything out on the internet site of the manufacturer or similar (a site that has info on ur particular buggy,engine).
and also check all around the engine carby for screws and make sure your throttle link is off, other than that u are on your own i have enough trouble trying to keep my car going as it is lol.
downunder23 is offline   Reply With Quote
Old 01-01-2006, 08:07 PM   #58
Tech Fanatic
 
SavageSYNTH25's Avatar
 
Join Date: Aug 2005
Location: Charlotte, NC
Posts: 794
Send a message via AIM to SavageSYNTH25
Default

downunder: If you have air bubbles, you have an air leak!!!!! Check to make sure that the fuel outlet is tight in the tank, and make sure that the fuel filter is tight. The XRAY filters loosen up after a while, and let air in. If I were you, I would go ahead and replace the tank and the fuel lines. You are running a pressure line, right? The line running from the lid to the pipe? Sometimes, you will get a few air bubbles in the line before you run the engine but when it is running, there shouldn't be any air bubbles. You obviously have a leak somewhere. Try replacing the fuel lines first, then the tank and the filter.
SavageSYNTH25 is offline   Reply With Quote
Old 01-01-2006, 10:20 PM   #59
Tech Addict
 
downunder23's Avatar
 
Join Date: Oct 2005
Posts: 618
Default

ok savage yeah i think the bubbles were only there from when i start the engine it seems to be struggling to get full fuel (no air bubles) at the start but then it seems to be fuel running after it started and yes i do have a line running from lid of tank to the ex pipe umm i may need to tighten up the air filter because there is no cable ties on them so maybe its leaking unfiltered air through the pipe of the filter also just before i checked and cleaned the fuel tank and lines under nieth the air filter there was fuel or liquid on the lines under the filter but the lines and tank seem air tight as i did a pressure test by blocking an end and blowing and no air escaped also are you sure on those temperatures because my max temp after running for about 2 mins out front just reached 320 farenheight and any richer the car sputters ( too much fuel) thats a little high temp isnt it.
are you sure its 240 -275 farenheight or celcius.
would it be better to place cable ties really tight around air filter and cut them off when i want to remove the filter. cuz as i said i have no ties on it.
downunder23 is offline   Reply With Quote
Old 01-01-2006, 10:59 PM   #60
Tech Fanatic
 
SavageSYNTH25's Avatar
 
Join Date: Aug 2005
Location: Charlotte, NC
Posts: 794
Send a message via AIM to SavageSYNTH25
Default

The zip ties really don't matter, put them on if the filter is loose on the carb body though. You want air to get in through the filter, because air has to get through to the engine.

You probably need to tighten the FUEL FILTER (the silver thing near the tank) because the XRAY filters come loose often and need to be tightened. If you don't have an air leak, then your problems sound like a plain old worn out engine. The compression may seem tight when you turn the motor over because the connecting rod may have stretched, pushing the piston up higher into the sleeve and eventually through the head. A streched rod can cause the engine to run very hot, and eventually the rod will snap, the head bolts will break, or the crank will snap. You might want to pull the backplate off of the engine and take it to your local hobby shop so they can take a look at it. Your temps are extremely high, for any engine and if you don't have an air leak then you have a bad engine.

Other than an air leak, that is the only thing I could think of. Take the clutch bell off and see if the shoes and springs are in good shape, pull the flywheel off and check the rear bearing, check that the carb is all the way down in the intake body of the crankcase, etc. and then let me know what happens.
SavageSYNTH25 is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Newbie just got a nitro buggy... need advice LSUsportsfreak Electric Off-Road 5 12-16-2005 09:31 AM
Newbie looking for advice on a nitro bubby or monster truck dmt840 Rookie Zone 2 11-01-2005 12:43 PM
Newbie who needs some advice! rcracer123 Electric On-Road 66 11-30-2002 09:48 AM
newbie - needs advice Stressed Eric Singapore R/C Racers 61 03-25-2002 08:15 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 06:16 AM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net