Mugen MTX-4
03-23-2007, 06:09 AM
#7861
Originally Posted by rmdhawaii
The forum does have search capabilities within a thread. There is a wealth of information here if you're willing to spend some time digging for it. Just type in "ackerman" (yes, with just one "n", because it is often misspelled) and see what other people have to say about it..
03-23-2007, 06:33 AM
#7862
LCG battery plate
i found this battery plate in LHS, just install n take some photo.
before :
before :
03-23-2007, 06:35 AM
#7863
after :
03-23-2007, 06:44 AM
#7864
and more :
03-23-2007, 06:57 AM
#7865
Nice part.......open bottom? Looks like the skyline part. Thats the skyline chassis?
03-23-2007, 07:23 AM
#7866
Originally Posted by rcfoolz
Nice part.......open bottom? Looks like the skyline part. Thats the skyline chassis?
03-23-2007, 12:16 PM
#7867
Originally Posted by ruicortez
I have one doubt about rear roll center that I haven't found any anwser in this thread:
If I remove the upright spacers from the rear block suspension this will lower rear roll center, right?
If I remove the upright spacers from the rear block suspension this will lower rear roll center, right?
When you lower the inner pivot point of the rear a-arm this lowers the roll center=more roll =more grip
Raising the inner pivot point does the opposite. I believe the MTX-4 data base has this info wrong.
This info was reference from the hudy set-up book.
03-23-2007, 12:47 PM
#7868
Originally Posted by rcfoolz
I've been working on getting CG down in the car and a few weeks ago, I had hinted at this little prodject on my MTX-4. After careful consideration, I've decided to show it here and allow you all to see it, I'm sure that shortly afterwords someone will start producing it, and if so, just send me some free parts 
The whole idea was to get the weight as low as I could in the car. This started out by first having to lower the batteries down as far as i could. This was done by making a carbon fiber "TUB" for them. The batteries are .2mm from going through the carbon fiber. This lowered the batteries down over 2mm from stock. That left the fuel tank way above the batteries. This lead me to look at the whole deck. The room I had under the servo's was about 1.4mm. I took 1mm of this out buy cutting a 3mm upper deck then milling the mounting points on the bottom side 1mm. This dropped everything attatched 1mm. Then I used a low-profile Futaba 9550 servo (half height) and used the lowest servo mount in the kit, and used 2mm of shimms to drop it down even farther. From the stock servo mount, I dropped it a total of 5mm! (1 from the deck, 2 from the mount, 2 from shims). Next was the fuel tank. Looking close at the tank and the chassis, I had to mill the chassis out where the bottom of the tank fits between the middle bulkhead. The middle bulkhead had to be trimmed 3mm where the tank rests on it and the 4mm chassis had to have an aditional 2mm milled from the area where the tanks sits. I could have cut the area out completely, but didn't want to expose the fuel tank to the ground. This made the fuel tank come down 4mm total!
The whole idea was to get the weight as low as I could in the car. This started out by first having to lower the batteries down as far as i could. This was done by making a carbon fiber "TUB" for them. The batteries are .2mm from going through the carbon fiber. This lowered the batteries down over 2mm from stock. That left the fuel tank way above the batteries. This lead me to look at the whole deck. The room I had under the servo's was about 1.4mm. I took 1mm of this out buy cutting a 3mm upper deck then milling the mounting points on the bottom side 1mm. This dropped everything attatched 1mm. Then I used a low-profile Futaba 9550 servo (half height) and used the lowest servo mount in the kit, and used 2mm of shimms to drop it down even farther. From the stock servo mount, I dropped it a total of 5mm! (1 from the deck, 2 from the mount, 2 from shims). Next was the fuel tank. Looking close at the tank and the chassis, I had to mill the chassis out where the bottom of the tank fits between the middle bulkhead. The middle bulkhead had to be trimmed 3mm where the tank rests on it and the 4mm chassis had to have an aditional 2mm milled from the area where the tanks sits. I could have cut the area out completely, but didn't want to expose the fuel tank to the ground. This made the fuel tank come down 4mm total!Don't quote me on this I'm just thinking out loud.
The other thing that comes to mind is you said you car shimmies thru the turn. That leads me to believe is that you chassis is not rolling very much but your lower COG is keeping your car planted. I believe this would help an electric car more than a nitro car just because of the traction of carpet and slower speeds of electric. I'm not sure with this set-up that your car is the fastest it can be thru the turns. The other point is you still have the engine that stills sits very high on the chassis. I believe a nitro car still needs a little more distance between the COG and the roll center to offset the weight of the engine that sits up high(This is your tuning option).
I hope this post did not come off as a slam; that was not my intent I just wanted you to see your idea from a different angle. And I hate to say.I believe some of your ideas will make it to some company's production model.
The things you have done to your car are quite amazing. Keep it up you might start a revolution!!!
03-23-2007, 01:07 PM
#7869
lil-bump: What are you throught on the Team XRAY NT1? That is were most of my inspiration for lowering the CG comes from.
http://www.teamxray.com
http://www.teamxray.com
03-23-2007, 01:52 PM
#7870
Originally Posted by lil-bump
This is pretty interesting stuff you've done to your car. In my mind you have turn a nitro car into a somewhat of an electric car. Electric chassis have a very low center of gravity. My question is how has this changed your roll center. If reasoning holds true you have probally raised your roll center(your roll center is closer to the COG)
Don't quote me on this I'm just thinking out loud.
The other thing that comes to mind is you said you car shimmies thru the turn. That leads me to believe is that you chassis is not rolling very much but your lower COG is keeping your car planted. I believe this would help an electric car more than a nitro car just because of the traction of carpet and slower speeds of electric. I'm not sure with this set-up that your car is the fastest it can be thru the turns. The other point is you still have the engine that stills sits very high on the chassis. I believe a nitro car still needs a little more distance between the COG and the roll center to offset the weight of the engine that sits up high(This is your tuning option).
I hope this post did not come off as a slam; that was not my intent I just wanted you to see your idea from a different angle. And I hate to say.I believe some of your ideas will make it to some company's production model.
The things you have done to your car are quite amazing. Keep it up you might start a revolution!!!
Don't quote me on this I'm just thinking out loud.
The other thing that comes to mind is you said you car shimmies thru the turn. That leads me to believe is that you chassis is not rolling very much but your lower COG is keeping your car planted. I believe this would help an electric car more than a nitro car just because of the traction of carpet and slower speeds of electric. I'm not sure with this set-up that your car is the fastest it can be thru the turns. The other point is you still have the engine that stills sits very high on the chassis. I believe a nitro car still needs a little more distance between the COG and the roll center to offset the weight of the engine that sits up high(This is your tuning option).
I hope this post did not come off as a slam; that was not my intent I just wanted you to see your idea from a different angle. And I hate to say.I believe some of your ideas will make it to some company's production model.
The things you have done to your car are quite amazing. Keep it up you might start a revolution!!!
As for the car doing the shimmies, it is a very positive feel when the car does this. I can put it just about anywhere I want on the track and hold a lot more speed than before. Unfortunatly, I hadn't had the use of the left eye since I did most of the mods and my driving isn't what it was. By the region 4 race, I hope to have the last few mods done and tested.
Oh, not a slam, just a way of looking at it. even though I had done these at the Winternats, This is the only time I got to drive the car at 100%. Since then, I've not been able to run all out. And the last race, I ran the car with a rear broken A-arm for 18 of the 20 min. The only way it would turn right was to use the brakes and slide the rear end around, if not, the car was like a dumptruck on ice. When in the staights, I was dog-tracking and wanted to hook left, but I think that the reason the car still did good enough to drive was that the lower CG.
Thank you for the input. It makes me think of a way to test the car out more.
03-23-2007, 02:19 PM
#7871
Originally Posted by rmdhawaii
lil-bump: What are you throught on the Team XRAY NT1? That is were most of my inspiration for lowering the CG comes from.
http://www.teamxray.com
http://www.teamxray.com
I believe the Nt1 has further modification to the chassis which are not easily seen by the naked eye which lowered the COG gravity but also lowers the roll center. Don't get me wrong I believe a lower center of gravity is a good thing but I don't believe in it if it hampers my ability to move the roll center.
03-23-2007, 02:23 PM
#7872
Originally Posted by lil-bump
I really have not had a chance to see the Nt1 in action yet. The nitro season in my parts has not started yet. But I would like to see the suspension geometry.
I believe the Nt1 has further modification to the chassis which are not easily seen by the naked eye which lowered the COG gravity but also lowers the roll center. Don't get me wrong I believe a lower center of gravity is a good thing but I don't believe in it if it hampers my ability to move the roll center.
I believe the Nt1 has further modification to the chassis which are not easily seen by the naked eye which lowered the COG gravity but also lowers the roll center. Don't get me wrong I believe a lower center of gravity is a good thing but I don't believe in it if it hampers my ability to move the roll center.
03-23-2007, 02:31 PM
#7873
Originally Posted by rcfoolz
Roll center and Center of Gravity being the two main forces of cars. I had a lot of thought about doing this and you are right in the area of the motors. But just receintly, engine makers have started making engines with more wieght lower in them, helping with CG. The Ninja 12 has a lower CG than most. With Electric cars dealing with high bite conditions like carpet, the tracks that we run nitro on are also high bite. On occasion, I run smaller, technical tracks, and I have modifications for adjustments to handle the small technical tracks. I hadn't had discussed these adjustments in detail, but a shortened wheel base by up to 4mm, a lower than lowest stock front inner upper A-arm, giving a very quick direction change mixed with less caster, helps get through those technical sections. My car actualy feels a lot like my 12th scale. Very forgiving too when I get it out of shape, easy to recover. I've done some work to the rear of the car too, on advice of a friend, A lower than stock upper camber link on the inner and outter by as much as 3mm in both locations. This gives a very adjustable roll center.
As for the car doing the shimmies, it is a very positive feel when the car does this. I can put it just about anywhere I want on the track and hold a lot more speed than before. Unfortunatly, I hadn't had the use of the left eye since I did most of the mods and my driving isn't what it was. By the region 4 race, I hope to have the last few mods done and tested.
Oh, not a slam, just a way of looking at it. even though I had done these at the Winternats, This is the only time I got to drive the car at 100%. Since then, I've not been able to run all out. And the last race, I ran the car with a rear broken A-arm for 18 of the 20 min. The only way it would turn right was to use the brakes and slide the rear end around, if not, the car was like a dumptruck on ice. When in the staights, I was dog-tracking and wanted to hook left, but I think that the reason the car still did good enough to drive was that the lower CG.
Thank you for the input. It makes me think of a way to test the car out more.
As for the car doing the shimmies, it is a very positive feel when the car does this. I can put it just about anywhere I want on the track and hold a lot more speed than before. Unfortunatly, I hadn't had the use of the left eye since I did most of the mods and my driving isn't what it was. By the region 4 race, I hope to have the last few mods done and tested.
Oh, not a slam, just a way of looking at it. even though I had done these at the Winternats, This is the only time I got to drive the car at 100%. Since then, I've not been able to run all out. And the last race, I ran the car with a rear broken A-arm for 18 of the 20 min. The only way it would turn right was to use the brakes and slide the rear end around, if not, the car was like a dumptruck on ice. When in the staights, I was dog-tracking and wanted to hook left, but I think that the reason the car still did good enough to drive was that the lower CG.
Thank you for the input. It makes me think of a way to test the car out more.
Well mr Rcfoolz
I believe you're headed in the right direction. I see you have planned your mods out very carefully. I made a commitment this year to better understand the geomotry of rc car chassis and how it effects handling . I'm no expert
I'm still learning. I wish you all the luck in the world. Keep us posted on your progress. Shop some of your ideas to the car manufactures.
BTW When you pass me in turn #2 try not too get much smoke and oil on my body
Race you later
03-23-2007, 04:46 PM
#7874
clutch bell bearings
How have the stock 5x8 clutch bell bearings been holding up in the mtx-4.
I have not had a chance to run my car on a regular basis yet. I'm thinking of up grading to ceramic clutch bell bearings. Any feedback would be greatly appreciated
I have not had a chance to run my car on a regular basis yet. I'm thinking of up grading to ceramic clutch bell bearings. Any feedback would be greatly appreciated
03-23-2007, 04:53 PM
#7875
I've ran both, ceramic and steel. They both last about the same. I now buy the 5.x8 steel bearings 50 at a time. Thats enough to last about a year.