High speed buggy project......

[IBJAMMIN]

Ive been away awhile and was looking around for info on the Mamba MMM esc and saw your post.

I have some advice for you I was going to do this about a year ago with the XLB but decided the cost of electronics was to high at the time and my RC18B was fast enough for me at 93mph on 4s curently working on a 5s setup along with a 3s scalpel for speed cars.


Aero wise the buggy body is the best way to go it's a lot like an indy car with the buggy rear wing and adding a front wing it will allow you to control how much down force the car has and keep it on the ground at high speeds with the smallest frontal profile on the RC18 I tried a few full bodies and found they were all slower then the buggy body?

Tires? I would highly recomened Jaco foams for the Tmaxx they are the largest foam tire and wheel avalable for MT's and should work great on the XLB dont waste your time with glued beads they fail around 60mph beadlock wheels are much better at holding the bead on at high speeds.

Shocks? I found instead of using spacers under the pistons to lower the car using springs instead softens the top out of the shock and improves handling and stability at high speeds.

Chassis flex? The XLB needs a lot of help in this area pick it up and twist the front and rear of the car in oposit direction's for high speed stabilty you need to eliminate this flex.

Motor and ESC?
Duel 15 series Neu's with MMM ESC'c on 6s should be enough torque to get you to a 100mph plus?

Radio? check out the Worlds fastest RC thread for extending the range on your radio system.
http://forums.radiocontrolzone.com/s...d.php?t=239623




Good luck I think a 100mph is very doable with the XLB. :)

Originally Posted by jzemaxx

Well those that PM'ed me here is the project I am working on. Thanks to guys like Aqwut, Lutach, BrianG and others I have gotten ideas off of some of their builds. I bought a XLB a few weeks back and decided to go full tilt on it.....

Shooting for 100mph on it.....

The setup will consist of:

2 X Turnigy HV's
2 X 1527's
4 X 6S lipo's

I will keep this post up to date as I start to try to fit all this crap under the buggy body....lol

Still haven't figured out how to mount both 1527's on the single spur...but I will come up with something.....I think

[lutach]

The front wing is a nice idea. I did that on my buggy. You can find the picture of it here: http://www.rc-monster.com/forum/show...00&postcount=8

[jzemaxx]

Yeah I am looking at something now. 100mph in a 1/7th scale, 15-18lbs and 17" wheelbase buggy is asking alot as it is.....lol. The little purpose built speed cars with aero built bodies and 1/4" off the ground is alot easier. I think this will turn out to be more difficult then I anticipated. I don't really know if the wing will hurt or help. Since the car is so large a large wing like that would create huge amounts of drag. If it were a small 1/12 or 1/10 scale touring car it probably would be less amplified. I think I am just going to remove all the wings, and attach a difuser under the flat pan chassis like a Formula 1 car and use the air underneath to help pull the car down at speed.

[IBJAMMIN]

F1 cars use wings to keep it on the groung there is no ground effects used anymore in F1? the old cars used tunnels or ground effects under the car to create vacume to suck the car to the ground along with wings.

defusers are used to control turbulance under the car witch reduces drag used without wings or a high downforce body under acceleration and weight transfer the front of the car will lift and stack the air under the car inducing a flip?

The scale of the car does not matter the same aero dynamic prinipals apply be it 1/18,1/7 or full scale the main difference is weight and the power or torque it takes to overcome the aero drag and weight diferences as the scale size increases.

[jzemaxx]

Originally Posted by IBJAMMIN

F1 cars use wings to keep it on the groung there is no ground effects used anymore in F1? the old cars used tunnels or ground effects under the car to create vacume to suck the car to the ground along with wings.

defusers are used to control turbulance under the car witch reduces drag used without wings or a high downforce body under acceleration and weight transfer the front of the car will lift and stack the air under the car inducing a flip?

The scale of the car does not matter the same aero dynamic prinipals apply be it 1/18,1/7 or full scale the main difference is weight and the power or torque it takes to overcome the aero drag and weight diferences as the scale size increases.

The principals are the same for all scales yes, but the drag is not. Smaller object takes alot less power to push through the air all things being equal. As the scale gets larger the frontal area increases, which can be independant of the weight. Also I don't plan to use any ground effects....

[jzemaxx]

New updates on mods done. Car is now SLAMMED to the ground, wing modified for high speed passes and front bumper modified with radius curved deflector for high speed. Soon to have some video passes

[lutach]

Originally Posted by jzemaxx

New updates on mods done. Car is now SLAMMED to the ground, wing modified for high speed passes and front bumper modified with radius curved deflector for high speed. Soon to have some video passes

Wow. That looks awesome. Looks like it's going 100mph just standing there. Can't wait to see some vids of it.

[jzemaxx]

Alright guys after talking to Neu I ordered 2 1527's a while back in case I do twins or single and also a 2215 is coming. So now its time to figure out where the heck to fit the crap. The goal that had said to try to achieve was 140mph. I don't think its possbile, but I'm willing to try and I have been wrong before. The tires of course will be foam now since NO way the HPI's will stay together much past 80 as is now.

[MetalMan]

You must be made of money or something... That's gotta be at least $1000 in motors. But the results of them should be very interesting!

[jzemaxx]

I'm just asking to see if its possbile to even reach 140 and what kind of watts is needed. Heck the record is 134.4mph and that's with a purpose built RC that looks like a spaceship and is lightweight. This heavy and big monster buggy with a buggy body that is not aerodynamic can't be easy to reach those speeds...lol

[lutach]

I will take some pictures tomorrow of what will be the body for my propose built speed car. The body will have the famous tear drop design. I will also be designing a very nice active system to keep my car on the ground. The only problem is finding the time to do all of this .

[jzemaxx]

Yeah I am trying to avoid purpose built body's and such. I think a buggy body isn't "bad", but its not the best either. But its cool when you can go fast with a regular body and such.

[IBJAMMIN]

A 100mph should be very doable with a 1/7 scale car and a single motor with off the shelf parts higher speeds are posible but at a much higher cost IE custom chassis and running gear to trim as much weight as posible custom spur and pinion gears duel motors ect.

Tires I found some foams awhile ago at towwer hobbies made by Jaco for the Tmaxx there the largest dia foams I have seen but I dont know if they are still avalable?

Layout wise I found in my CRT conv everything fit and was ballanced running the 1515 motor forward and duel packs in the back? pic 1

On my CRT.5 conv I tied the motor mount into the battery mount that runs from the front of the chassis to the rear pic 2 I found this eliminated just about all the chassis flex and made the car alot more stable at speed vers a friends CRT.5 with a std motor mount? If you can incorporate a mount like this in the XTM with it's exessive chassis flex it will help keep the car going in a straight line at speed.

Weight? get rid of as much weight as you can my CRT weighs in at just a little over 11lbs RTR with 2 8000mah packs you should be able to come in under 13-14lbs RTR?

Just a few things to think about when you are laying everything out.

BTW What KV 1527 motors did you end up getting?

[jzemaxx]

Originally Posted by IBJAMMIN

A 100mph should be very doable with a 1/7 scale car and a single motor with off the shelf parts higher speeds are posible but at a much higher cost IE custom chassis and running gear to trim as much weight as posible custom spur and pinion gears duel motors ect.

Tires I found some foams awhile ago at towwer hobbies made by Jaco for the Tmaxx there the largest dia foams I have seen but I dont know if they are still avalable?

Layout wise I found in my CRT conv everything fit and was ballanced running the 1515 motor forward and duel packs in the back? pic 1

On my CRT.5 conv I tied the motor mount into the battery mount that runs from the front of the chassis to the rear pic 2 I found this eliminated just about all the chassis flex and made the car alot more stable at speed vers a friends CRT.5 with a std motor mount? If you can incorporate a mount like this in the XTM with it's exessive chassis flex it will help keep the car going in a straight line at speed.

Weight? get rid of as much weight as you can my CRT weighs in at just a little over 11lbs RTR with 2 8000mah packs you should be able to come in under 13-14lbs RTR?

Just a few things to think about when you are laying everything out.

BTW What KV 1527 motors did you end up getting?

Running 2 1.5D's. Will be running 12S through each motor.....so both will be spinning WAY over RPM's.....probably not good , but I will try it.