# Your JR Dragster ET



## toysdoneright (Feb 20, 2012)

I've only been doing electric JR dragster racing for a year. We however have raced the alcohol powered ones for 6 yrs. I was hoping to step up our ETs this year.I don't want to reinvent the wheel and was hoping some more experienced NHRA or NEDRA legal racers would like to share how fast and how they did it. This was our set up and ETs for 2011 The car is a 2005 Half Scale [old outlaw car] The motor is a Mars ME1003 The controller was a ALLTRAX 7245 The battery's are 7- AGI 18ah jumper pack battery's The best ET was 11.02 We want to run 7.90 @85 mph and this is what I was thinking of trying The same car The same motor {Mars said it was tested to 5000 rpm with burst of 8000 rpm] The controller would be a Kelly KDH 14600 or a KDH 14800 The same battery's would be the same just add more 120 to 144 volt What do you think ? What did you do? How fast did you go? Please don't slam me because your smarter than I am Lets all learn together Remember you might be dumb on things I can help you with


----------



## major (Apr 4, 2008)

toysdoneright said:


> I've only been doing electric JR dragster racing for a year. We however have raced the alcohol powered ones for 6 yrs. I was hoping to step up our ETs this year.I don't want to reinvent the wheel and was hoping some more experienced NHRA or NEDRA legal racers would like to share how fast and how they did it. This was our set up and ETs for 2011 The car is a 2005 Half Scale [old outlaw car] The motor is a Mars ME1003 The controller was a ALLTRAX 7245 The battery's are 7- AGI 18ah jumper pack battery's The best ET was 11.02 We want to run 7.90 @85 mph and this is what I was thinking of trying The same car The same motor {Mars said it was tested to 5000 rpm with burst of 8000 rpm] The controller would be a Kelly KDH 14600 or a KDH 14800 The same battery's would be the same just add more 120 to 144 volt What do you think ? What did you do? How fast did you go? Please don't slam me because your smarter than I am Lets all learn together Remember you might be dumb on things I can help you with


Hi toys,

I'm not sure if Chip has a time slip yet or not. I'm thinkin' the dragster he built has potential to be really quick. Hopefully he'll chime in. http://www.diyelectriccar.com/forums/showpost.php?p=268482&postcount=69

major


----------



## casey.mynott (Sep 29, 2011)

Hey toysdoneright,

We are currently building a Junior Dragster, electric of course! Netgain Impluse 9, Zilla 1K LV, and 144 volt nominal, 1200 amp capable lithium modules. Should be pretty impressive! Below is a response from EV racing guru Shawn Lawless about this very topic. Hope it helps!
;D

Casey

*From Lawless.....*

_*CHASSIS:*_

_*Half Scale builds excellent chassis available with or without certification. I do not regret buying the OBS chassis from them. I was able to "bolt-on" all of the EV components without structurally changing the chassis in any way.*_

_*DRIVE SYSTEM:*_

_*If you want to "WIN" by beating the Jr. bracket competition and nailing the ET and/or holding speed right at the legal limit then I would use a PM motor such as Motenergy, Perm, LMC, or Agni with a 4 Q controller such as Kelly, OR an AC system like Bryan Hall sells with Curtis control. This will allow exact control of the motor rpm and torque and allow a consistency and repeatability that the alcohol guys can't match.*_

_*With Tara's OBS I took the approach a bit differently. I wanted something that could blow any ICE Jr. off the track at any time. To achieve this I used an old fashion tweaked GE 7.5" series motor and a Zilla 1K, with the option to install a 2K in a few minutes if I had to. Even though the Zilla speed limiter was not meant for EXACT speed control, the car is extremely consistent. With an 87 volt A123 pack and current set to 1000 amps, the car pulls decent off the line and is very close to the 8.90 ET and 85 MPH top speed limitation every time down the track. Knowing that with a few changes that it can run in the 6's at well over 100 MPH leaves a very good feeling inside. When we ran 10.16 @ 129 during testing, the drives system wasn't even straining. At 100+ lbs, the GE motor is heavy, more than twice that of TWO LMC's. You can save 50-70 lbs by going a different route. If you want to go "Outlaw 330" racing where times of 4.10 in the 330 are allowed, I would use this setup.*_

_*BATTERIES:*_

_*As good as the A123 cells are and have been, there are better power sources available now for drag racing. The Flight Power packs that we have tested that are similar to Black Current's, are very impressive. They weigh nothing, are at almost 100% power out of the box, don't heat up, and have very little voltage sag. If you want to keep the nominal voltage low, that feature is very important. My 87 volt A123 pack drops down below 50 on a hard run. I am confident that a 48 volt car built with the Flight Power cells could run right at 8.90 and 85 MPH all day long. *_

_*DRIVER:*_

_*If you want set records - Someone who is "Hammer down" and always comes back asking for "More Power". A car this light can post incredible 60' times if you are willing to push it to the edge of traction and control. They don't keep records for Jr's in the 60' column, YET, but it has been discussed before as a way to compete while keeping inherent danger at a minimum.*_

_*If you want to win brackets - Someone who is calm, reasoning, and a perfectionist. The car will dead consistent. The race will be won or lost by the driver at the tree.*_

_*Hope this helps,*_

_*Shawn*_




toysdoneright said:


> I've only been doing electric JR dragster racing for a year. We however have raced the alcohol powered ones for 6 yrs. I was hoping to step up our ETs this year.I don't want to reinvent the wheel and was hoping some more experienced NHRA or NEDRA legal racers would like to share how fast and how they did it. This was our set up and ETs for 2011 The car is a 2005 Half Scale [old outlaw car] The motor is a Mars ME1003 The controller was a ALLTRAX 7245 The battery's are 7- AGI 18ah jumper pack battery's The best ET was 11.02 We want to run 7.90 @85 mph and this is what I was thinking of trying The same car The same motor {Mars said it was tested to 5000 rpm with burst of 8000 rpm] The controller would be a Kelly KDH 14600 or a KDH 14800 The same battery's would be the same just add more 120 to 144 volt What do you think ? What did you do? How fast did you go? Please don't slam me because your smarter than I am Lets all learn together Remember you might be dumb on things I can help you with


----------



## toysdoneright (Feb 20, 2012)

casey.mynott said:


> Hey toysdoneright,
> 
> We are currently building a Junior Dragster, electric of course! Netgain Impluse 9, Zilla 1K LV, and 144 volt nominal, 1200 amp capable lithium modules. Should be pretty impressive! Below is a response from EV racing guru Shawn Lawless about this very topic. Hope it helps!
> ;D
> ...


Thanks Very impressive set up ! I wish I understood the battery's better that's why I stuck to simple gel battery's I can only learn so much at a time Remember It's only my second year with electric. I called Shawn a year ago he really helped me. We talked a lot about the mars motor He said not to go much past 120 volt we could have problems Question for you How much you think its going to weigh when your ready to race ? Good drivers are made not found My son won the western conference finals in 2010 for the 12 yr old's and my daughter was Iowa state Jr dragster champ for the same yr


----------



## jr dragster (Oct 11, 2010)

You ran a little quicker than we did ,best run 11.40 at 59.57.We ran exact same set up as you,we used 6 18ah batteries weight was 350 pounds without driver{mild steel car}Im going to put lithium in, the battery pack is 82 pounds so with lithium we should loss 40-60 pounds Just cant decide to what kind to go with r/c type,headway or the A123 pouch cells.Have to get on it first race 90 days away.I think the battery pack will be to heavy at 144 volts on lead to give you a real gain .50 pounds =1/2sec or so.Keep us posted on your results and we can compare and see what works the best.


----------



## toysdoneright (Feb 20, 2012)

jr dragster said:


> You ran a little quicker than we did ,best run 11.40 at 59.57.We ran exact same set up as you,we used 6 18ah batteries weight was 350 pounds without driver{mild steel car}Im going to put lithium in, the battery pack is 82 pounds so with lithium we should loss 40-60 pounds Just cant decide to what kind to go with r/c type,headway or the A123 pouch cells.Have to get on it first race 90 days away.I think the battery pack will be to heavy at 144 volts on lead to give you a real gain .50 pounds =1/2sec or so.Keep us posted on your results and we can compare and see what works the best.


 QUESTION not judging Wouldn't you be better to go more battery's which gives you more rpm so you could gear it down to get quicker 60' times which amplify to quicker 1/8 mile times yet still run same or faster mph ? I'm so confused on battery's I just want to it to go 7.90 or quicker P.S. your weight #s are good for alcohol JRs 10# = 0.10 not sure on electric Good Luck hope we both learn something from this post [like if anyone has NHRA legally gone 7.90-Shawn Lawson has but it wasn't to weight or battery position] and what it takes to get there


----------



## nedrapr (Mar 9, 2011)

Hi Toysdoneright. I actually raced one of Shawn's Jrs, Orange Blossom in 2008. It has a 72 volt A123 battery pack made by Derek Barger. I'm short and fit in the car with no problems, except I needed help getting out. LOL. The car is a Half-Scale. I ran a 1.76 60-foot with the car, out accelerating a Tesla, off the line. Of course, the Tesla is lighter. Here's a link to the video.

http://www.youtube.com/watch?v=CFgSwuO-IKY

That was so fun. I ran it 3 times that day but Shawn has all the time slips. Shawn was more impressed with how he was able to dial in the car then how quick it could go. On one run, as soon as I got back to the pits he grabbed the timeslip out of my hand and gave me a high-five when he saw we were 1/1000 of a second away from the time he dialed the car in at! It was real fun being a member of the Lawless racing team that day! 

Late in the season, last year we finished building my son, Jake, a Junior. It has a 1K Zilla HV, 72 volts of Odyssey's and a Prestolite 7.2 inch motor custom built by motor dawg, Jim Husted. Right now it's geared to 77 mph at 3000 rpm. Jake ran a .8 reaction time first time on the track but just coasted after hitting the accelerator. As soon as his confidence builds we can post some numbers. I'm going to start off setting the battery amps real low. Get him used to that then slowly set it higher as his confidence builds.


----------



## toysdoneright (Feb 20, 2012)

jr dragster said:


> You ran a little quicker than we did ,best run 11.40 at 59.57.We ran exact same set up as you,we used 6 18ah batteries weight was 350 pounds without driver{mild steel car}Im going to put lithium in, the battery pack is 82 pounds so with lithium we should loss 40-60 pounds Just cant decide to what kind to go with r/c type,headway or the A123 pouch cells.Have to get on it first race 90 days away.I think the battery pack will be to heavy at 144 volts on lead to give you a real gain .50 pounds =1/2sec or so.Keep us posted on your results and we can compare and see what works the best.


Any chance you down loaded 1 of your runs I havent but was wondering how many max amps you pulled ?


----------



## jr dragster (Oct 11, 2010)

toysdoneright said:


> Any chance you down loaded 1 of your runs I havent but was wondering how many max amps you pulled ?


No never did was going to just never got around to .my batteries last year were only something like 267 amps.Check this out for your gearing http://www.jrdragsterplus.com/geargrndr.htm. we went with 2600 rpm last year and it was pretty close ,we geared it up last year and it went slower so went back to what we had cant remember the exact gear we ran , the book is in the trailer i will check and post it ?


----------



## tropes (Jul 24, 2011)

nedrapr said:


> http://www.youtube.com/watch?v=CFgSwuO-IKY
> 
> That was so fun. I ran it 3 times that day but Shawn has all the time slips. Shawn was more impressed with how he was able to dial in the car then how quick it could go. On one run, as soon as I got back to the pits he grabbed the timeslip out of my hand and gave me a high-five when he saw we were 1/1000 of a second away from the time he dialed the car in at! It was real fun being a member of the Lawless racing team that day!
> 
> Late in the season, last year we finished building my son, Jake, a Junior. It has a 1K Zilla HV, 72 volts of Odyssey's and a Prestolite 7.2 inch motor custom built by motor dawg, Jim Husted. Right now it's geared to 77 mph at 3000 rpm. Jake ran a .8 reaction time first time on the track but just coasted after hitting the accelerator. As soon as his confidence builds we can post some numbers. I'm going to start off setting the battery amps real low. Get him used to that then slowly set it higher as his confidence builds.


Sounds like fun. I am still in the parts gathering mode (rebuilt Raptor 1200, 72 volt Lipo,rebuilt K91 motor). My little brother has never driven on a drag strip so I expect this first season to be a real learning experience.
Tropes


----------



## toysdoneright (Feb 20, 2012)

tropes said:


> Sounds like fun. I am still in the parts gathering mode (rebuilt Raptor 1200, 72 volt Lipo,rebuilt K91 motor). My little brother has never driven on a drag strip so I expect this first season to be a real learning experience.
> Tropes


Remember to watch the weight you need to be under 400#s without driver I think we were about 350# 84 volt and under 300 amp to run 12.90 1/8 mile GOOD LUCK


----------



## tropes (Jul 24, 2011)

toysdoneright said:


> Remember to watch the weight you need to be under 400#s without driver I think we were about 350# 84 volt and under 300 amp to run 12.90 1/8 mile GOOD LUCK


Thanks! So far we know the rolling chassis weighs 95 lb., the motor 60 lb. and the battery 50 lb. so I expect the total weight to be around 300 lb.


----------



## toysdoneright (Feb 20, 2012)

tropes said:


> Thanks! So far we know the rolling chassis weighs 95 lb., the motor 60 lb. and the battery 50 lb. so I expect the total weight to be around 300 lb.


Geatest part of teaching to drive -stage the car is you can talk to them while they are staging The biggest problem we had was getting the car to roll in slow enough I was told to try a resistor in throddle wire with a switch that after you stage you flip to kill so you can get a good reaction time with them seeing 3rd yellow light


----------



## tropes (Jul 24, 2011)

toysdoneright said:


> Geatest part of teaching to drive -stage the car is you can talk to them while they are staging The biggest problem we had was getting the car to roll in slow enough I was told to try a resistor in throddle wire with a switch that after you stage you flip to kill so you can get a good reaction time with them seeing 3rd yellow light


The Curtis potbox reads from 0 to 4.86 K.Ohms at full throttle so I don't know how adding a resistor would help. We'll just have to try things before we make any decisions. Jr. Dragster said he had no problems with staging. Maybe he could lend some input.


----------



## toysdoneright (Feb 20, 2012)

tropes said:


> The Curtis potbox reads from 0 to 4.86 K.Ohms at full throttle so I don't know how adding a resistor would help. We'll just have to try things before we make any decisions. Jr. Dragster said he had no problems with staging. Maybe he could lend some input.


I know i can't get the car to roll as slow and smooth as my alcohol jr [we need to put the car on the same spot with in a 1/4 of a inch for consistent reaction time[ But we only had problems with staging when we had the controller turned up on kill] Enough on that subject I'll get off my milk crate So what type of battery you going to use I'm stuck with small agm's I don't have a clue where to start otherwise


----------



## tropes (Jul 24, 2011)

toysdoneright said:


> I know i can't get the car to roll as slow and smooth as my alcohol jr [we need to put the car on the same spot with in a 1/4 of a inch for consistent reaction time[ But we only had problems with staging when we had the controller turned up on kill] Enough on that subject I'll get off my milk crate So what type of battery you going to use I'm stuck with small agm's I don't have a clue where to start otherwise


I wasn't familiar with batteries so Carl at EV Drives put me on to a fellow in California who builds an EV called a Sparrow. He sold me some Headways last October and then convinced me to trade for some Lithium Ener1 batteries that he tried in the Sparrow. He is also building the controller so I am relying on him to come up with a good combination.


----------



## toysdoneright (Feb 20, 2012)

tropes said:


> I wasn't familiar with batteries so Carl at EV Drives put me on to a fellow in California who builds an EV called a Sparrow. He sold me some Headways last October and then convinced me to trade for some Lithium Ener1 batteries that he tried in the Sparrow. He is also building the controller so I am relying on him to come up with a good combination.


Good Plan find someone to point the way As long as they don't use you


----------

