Speed run car
 

Here is a pic of my car i'm preparing for a speed run attempt. Basically its an Evolva front and back with a custom chasis and 3 x 0.21 engines installed.

The engines are JP R03, RB Xenon and a cheapo Sirio.

The engines are interlocked with drive belts and all power the rear axle and the car is rear wheel drive only. For testing I am using standard gearing and this will give me a top speed of around 65Mph. The plan is to replace the rear drive of 20 - 48 to 32 - 32 and this will give me a theoretical top speed of 165 mph

I know of other guys building electric cars for a speed run and one other with a small turbine in.

The present speed record is recognised as 134.2mph and we all hope to beat that.

I cant let the electric boys have it all there way so thought I would pitch in for us IC guys. Wish me luck!!

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Do you think that those 1/8 scale tires are going to be able to give you enough traction?? Good luck at your speed attemps.

They will give enough traction but they might not stand the centrifugal force. Somebody told me they will blow up around 135 mph! I'll have to test them to find out

Cheers

got any pics with the body off?

you can find more pics of this car at
http://www.fastrc.blogspot.com/

Hey Ziggy are you running a solid rear end??

Yes a 1/8th solid rear end. I did a small vid of testing i did today. Istripped the middle belt again. I have ordered aluminium pulleys with steel re enforced belts 10mm wide. They should be here in a week

Here is the vid

http://www.youtube.com/watch?v=NnyDXLX0vfw

Here's my blog

http://ziggy12345-myspeedattemptcar.blogspot.com/

Cheers

Wow...that's pretty awesome. I noticed a few things that might complicate things...first of all, you might be going through side belts because you have three different types of engines, all wanting to turn at different speeds. Also what could cause a problem is the three different clutches not tuned exactly identical and three different engine tunes. Also, it's gonna be really hard to make all three two-speed transmissions shift at the same time...unless you don't plan on using it...just wanted to point that out...:blush:

I have updated the blog. i am waiting for the middle pulleys and belts to do the first medium speed run. They will be arriving in a week

I will also try and test the 40 mhz rario range with 13 cells in the TX. This should give me the range I want

Cheers

The belts arrived and I fitted the new pulleys and new 2.5mm pitch belts. After starting one engine a few revs and the belts snapped.

I figured out that the layshafts on the engines that are off are rotating and after a given rev limit the 2 peed engages and loads up the belts dramatically and snaps them.

I need to adjust the 2 speeds to come in late rand also only rev the engines when the 3 are running. I will fit the new 5mm pitch belts and try again

cheers

I would think that raising the engagement point of the 2 speeds will only make the problem worse because they will engage harder. You could run one way gears on the belt side to try and solve the problem. The only other suggestion I would have is to go to 2 engines and mate both clutch bells to the same spur gear. That way you only need one 2 speed. That would simplify your drive train consederably.

Very interesting topic.

I think if you have a 1-way pulley at each 3 main shaft on other side will gives you better in all these three engine power distributed to the rear wheel. It doesn't matter which engine engeage 2nd speed.

But one thing is the rear 1/8 tyre gives enought traction?

I think a one way bearing will do the trick. Anybody know what car uses a one way on the 2nd speed clutch?

Cheers