# Shock Therapy Racing's golf cart based dragster.........



## TerryH (Jun 9, 2012)

We run custom motors built using the stock golf cart motor cases. We turn these motors nearly 10,000 rpms in the lights.



And here are some of my favorite photos of the completed cart.......











The best pass with the AGM’s was 8.29 @ 80.00. Changing to the LiPo has yielded a best of 6.59 @ 97.57. We currently hold the NEDRA DR/B 1/8th mile record. We could not back up the [email protected] run but we hope to go quicker and faster than our current record of 6.68 @ 84.57 very soon!!! Thanks so much for checking out our project!!

Terry


----------



## major (Apr 4, 2008)

Congratulations. Well done


----------



## TerryH (Jun 9, 2012)

major said:


> Congratulations. Well done


Thank you, Jeff! It's come a very long way since we started. Feels good to finally be getting a handle on how to make it run.


----------



## Karter2 (Nov 17, 2011)

Well done ..on the build and the results !
How much have you had to rework the transmission/axle ??
It must be dealing with a ton of torque now.
Good to see you have seen the "light" and switched to LiPo.
Attempting to break records whilst dragging a few hundred pounds of lead down the track just doesnt make sense !
..But.. i do think every golf kart should have to carry a full set of clubs onboard !! )


----------



## TerryH (Jun 9, 2012)

Karter2 said:


> Well done ..on the build and the results !
> How much have you had to rework the transmission/axle ??
> It must be dealing with a ton of torque now.
> Good to see you have seen the "light" and switched to LiPo.
> ...


Thanks!! Beleive it or not, the rear end is a completely stock Graziano golf cart rear end with the spider gears blocked. They are obviously very tough. We haven't hurt anything in the rear end yet but I have 2 complete spares just in case. BTW....I don't even own a golf club.


----------



## John Metric (Feb 26, 2009)

TerryH said:


> BTW....I don't even own a golf club.


Congratulations Terry, the project looks super professional and safety looks to be well thought about. 
We are happy to have helped with the record. DC Plasma's cells are still pretty strong eh?

I think you should take in a round of golf at least one time. Just to say you have. You could of course use your cart to drive around the course, if anything, just for the photo op.


----------



## TerryH (Jun 9, 2012)

John Metric said:


> Congratulations Terry, the project looks super professional and safety looks to be well thought about.
> We are happy to have helped with the record. DC Plasma's cells are still pretty strong eh?
> 
> I think you should take in a round of golf at least one time. Just to say you have. You could of course use your cart to drive around the course, if anything, just for the photo op.


Thank you for all of your help, John!!! DC Plasma's cells certainly have plenty of punch left!! One of these days I am going to take the carts to the golf course just for the photo op and to see the reaction of the real golfers.


----------



## TerryH (Jun 9, 2012)

Let's just say it was an interesting weekend of testing for us at Ozark Raceway Park.....



Check out the video here....

https://www.youtube.com/watch?feature=player_embedded&v=TUDX5MmulF0


----------



## major (Apr 4, 2008)

I'm glad you're O.K. Been thinkin' about wheelie bars?


----------



## TerryH (Jun 9, 2012)

major said:


> I'm glad you're O.K. Been thinkin' about wheelie bars?


Well, I am now. It never ever had the front end more than a couple of inches off the track before that pass.


----------



## Yabert (Feb 7, 2010)

NICE! 
I wish you a successful implementation of wheelie bars 

Quick question: It appear that your little motor only have one brush per pole (only four brushes total) and I'm highly interested to know how many amps you push in those little brushes (how many motor amps is set the Zilla?)
Thanks


----------



## frodus (Apr 12, 2008)

Front page of Yahoo.com today:
https://autos.yahoo.com/blogs/motor...turn-a-wheelie-into-a-backflip-154310628.html


----------



## major (Apr 4, 2008)

TerryH said:


> It never ever had the front end more than a couple of inches off the track before that pass.


On that note: Did you turn up the juice to 11 before you made that run? Any chance you collected data from the Zilla for it? I'm just wondering why it flipped assuming you were running just like previous passes. Think maybe the Zilla latched on or something and passed full-on current at the launch instead of limiting it to the set point? Or do you usually get some wheel slip and the tires stuck this time?

Heck of a sight  You're a star now


----------



## dedlast (Aug 17, 2013)

major said:


> On that note: Did you turn up the juice to 11 before you made that run? Any chance you collected data from the Zilla for it? I'm just wondering why it flipped assuming you were running just like previous passes. Think maybe the Zilla latched on or something and passed full-on current at the launch instead of limiting it to the set point? Or do you usually get some wheel slip and the tires stuck this time?
> 
> Heck of a sight  You're a star now


In the video he explains that they had to change motors, and the one they put in was a "torque monster". He had actually turned down the current, but apparently not far enough. With the wheelie bars, he won't have to (as much). 

B


----------



## samwichse (Jan 28, 2012)

Hey, you made the Yahoo News front page!

https://autos.yahoo.com/blogs/motor...turn-a-wheelie-into-a-backflip-154310628.html


----------



## Karter2 (Nov 17, 2011)

Sam...3 posts up above ^^^


----------



## TerryH (Jun 9, 2012)

Yabert said:


> NICE!
> I wish you a successful implementation of wheelie bars
> 
> Quick question: It appear that your little motor only have one brush per pole (only four brushes total) and I'm highly interested to know how many amps you push in those little brushes (how many motor amps is set the Zilla?)
> Thanks


The short answer to how amany amps is to many.  the NEDRA record runs were made on a 4 brush motor with the Z2 set to 2000 amps and 169 volts. We have sucessfully killed the brushes in all of our 4 brush motors with that amount of current. Have some 8 brush motors in the works now. We'll have them before next month's race.


----------



## TerryH (Jun 9, 2012)

major said:


> On that note: Did you turn up the juice to 11 before you made that run? Any chance you collected data from the Zilla for it? I'm just wondering why it flipped assuming you were running just like previous passes. Think maybe the Zilla latched on or something and passed full-on current at the launch instead of limiting it to the set point? Or do you usually get some wheel slip and the tires stuck this time?
> 
> Heck of a sight  You're a star now


No data from the Zilla. I don't currently have any way to collect the DAQ files except for my lap top and it's impossible to make a pass with it in the cart. I had the Z2 set to 2000 amps and 150 volts on the previous pass when we killed the brushes. The motor that flipped the cart is a 51 bar vs the 37 bars that we usually run. The 51 bar has 8 brushes. I ran it with the old AGM's and it had a ton of torque but wouldn't turn the rpm that we were looking for. The cart had pulled the front tires a few inches off the track with this motor in it before and I wanted to make sure that it didn't pull a big wheelie. With that in mind I knew that I should not go to the line with the Zilla on kill like had been so I turned the amps down to 1500 and the volts up to 190 hoping to get some top end rpm. I also put an additional 1 pound of air in the slicks thinking that it would just spin the tires. Apparetly I was wrong.  

Another factor was the nostalgia AA/FA altered were supposed to be the "show" at the track that night and they had sprayed who knows how many gallons of traction compound the entire length of the track. I had no clue how sticky it was until I climbed out and discovered I was walking on fly paper.


----------



## TerryH (Jun 9, 2012)

frodus said:


> Front page of Yahoo.com today:
> https://autos.yahoo.com/blogs/motor...turn-a-wheelie-into-a-backflip-154310628.html


It's been a crazy week for sure. I could have never dreamed that anything like this would have happened. Many automotive sites across the net such as bangshift.com, Power Block TV, Speed Society etc... have picked it up. Great exposure for EV drag racing and electrics in general and I've had a lot of fun with it for sure. I'm acutally going to be on the MotoIQ radio podcast tonight as well. I'm honestly dumbfounded by it all.


----------



## piotrsko (Dec 9, 2007)

First time I've ever heard anybody complaining about too much traction


----------



## TerryH (Jun 9, 2012)

piotrsko said:


> First time I've ever heard anybody complaining about too much traction


Lol....touche'.


----------



## TerryH (Jun 9, 2012)

Problem solved.


----------



## TerryH (Jun 9, 2012)

Got our junk back together just in time for the Mickey Thompson Shootout last weekend. Made a couple of low power passes to build a little confidence in the driver and the driver's wife.  Then we turned it up and had some fun. Dew was falling big time at Ozark Raceway Park on Saturday night but we still managed 5 passes in the 6's and the 90's. Best of 6.71 @ 96.22 With the cart sideways at the hit spinning the tires. Felt good to be back at the track though. 

Few pics from last weekend.....







My wife making sure that I'm strapped in and ready to go...


----------



## TerryH (Jun 9, 2012)

Made a few changes to the dragster over the past few days to save some weight and hopefully improve it overall. I moved the emergency kill switch to the rear compartment which saved 8 feet of battery cable and made it much more accessible for track workers in the event they ever need it...again. 




I also removed the PC680 AGM battery that I was using to power the 12v systems and replaced it with a much smaller and lighter alarm backup battery. The new battery is 6Ah and weighs 4lbs. 



The major project was to modify the center battery compartment in the chassis so I could move the LiPo pack to it. I removed the old mounting points and fabbed a new battery tray that I welded to the existing structure.



The pack looks right at home in there. This saved 4.5 feet of battery cable which pretty much offset the weight of the battery tray so it's a win all the way around. I had the chassis centered on a jack and moved the pack until it was perfectly balanced from right to left which slightly offset the tray to the right. Having the weight of the pack centered and lower in the chassis has to be a good thing.

Here it is all wired up and ready to rock.



Pretty much looks like it grew there. 



Motor is in Cali getting a couple of tweaks. Should be back next week. Hopefully next Saturday we'll be back at it trying to find that 100mph 1/8th mile.


----------



## grip911 (Dec 14, 2011)

I noticed your bad ass kill switch in your cart. very ingenious . Do you mind if I use the same design in my porsche?


----------



## Frank (Dec 6, 2008)

Very good work Terry. PM on the way about something...


----------



## TerryH (Jun 9, 2012)

grip911 said:


> I noticed your bad ass kill switch in your cart. very ingenious . Do you mind if I use the same design in my porsche?


Thanks. I stole....er...borrowed the idea from someone else myself.


----------



## aeroscott (Jan 5, 2008)

Put a strain releaf on these connectors , more for the twisting then pulling. There is just a small leaf spring holding them in and from twisting. Some of these come with the strain releaf option.


----------



## TerryH (Jun 9, 2012)

Haven't done a very good job of updating this thread so I thought I'd do a bit of catching up. I figured out with John's help, that we weren't getting the pack charged up well enough and our balance has been a work in progress. I'm charging with a string of golf cart chargers matched to the pack so it's sticks and rocks compared to a real charger. Getting much better balance and much better voltage now.

Also got some help from Helwig Carbon which I greatly appreciate. Unfortunately we've had multiple arc outs to the poles in the head this season but hopefully have a plan in place now to move the poles out of the head to a remote location to solve that issue. 

I also added a 9" automotive fan for pack cooling and that has worked out well. 

Few pics of the changes for this year. 

New Helwig red top split brushes....







New pack cooling setup replacing the 2 computer fans I had previously. This is much better. I'm powering it with a remote 12v battery.





Also fabricated some motor cooling using 6" PVC pipe and a couple of computer blowers. The blowers blow air through the brush openings and the PVC pipe is springy enough to hold them on the motor. Works great for cooling in between rounds. 







Thanks for looking. More to come.


----------



## TerryH (Jun 9, 2012)

Little update to the look of the dragster as well. Al the cool kids have names for their cars so I had to join in. Also very proudly flying the Helwig Carbon colors! Thanks to everyone at Helwig for brush help for this season!


----------



## CFECO (Sep 15, 2015)

Hello, It's looks great! Just a thought that "Might" help...I see your rear axle is mounted solid to the chassis, If it's allowed, have you thought about a 4-bar linkage setup, like pro-stock cars have? With those you can tune the car to hook up or not. Might go faster with more amps and some tire spin, without the "Air-time"! Just a thought, have fun!


----------



## TerryH (Jun 9, 2012)

CFECO said:


> Hello, It's looks great! Just a thought that "Might" help...I see your rear axle is mounted solid to the chassis, If it's allowed, have you thought about a 4-bar linkage setup, like pro-stock cars have? With those you can tune the car to hook up or not. Might go faster with more amps and some tire spin, without the "Air-time"! Just a thought, have fun!


Thanks. Suspension is allowed but this chassis is designed to be rigid on both ends. The dead hook back flip deal was a fluke. The chassis works really well. There is just enough spin to get some nice wheel speed without spinning the tires to much. We typically run the full compliment of 2000 amps now.


----------



## TerryH (Jun 9, 2012)

Unfortunately due to some health issues I'm stuck at home after surgery and our racing season is probably over. However, we are still trying to push our racing program further and prepare for next season. I thought I'd share some of the innovations that the guys at Advanced Lift Motors have come up with for our little motors. The Helwig brushes made a huge improvement in commutation but our issues involving the arc out to the pole has actually been worse.

As I stated in an earlier post, we've gotten our red neck charging/BMS system worked out to the point that we are able to get a much better and more balanced charge now so we in essence have more power even though we are still running the same well worn modules that powered John Metric's DC Plasma Fiero. The issue we have is an arc out from the brush spring to the pole connections in the motor. In John's words we continue to attempt to pack "10 pounds of crap into a 5 pound can" with these little golf cart motors. There is so little space that convincing the current to take the path we'd like for it to take is a significant issue.

The ALM guys have been thinking outside the box or perhaps outside the can would be more appropriate. They've now eliminated or moved the internal connections to hopefully solve the internal arcing. Made an interesting looking piece for sure. I've no idea when we'll be able to put it to the test but it sure looks like it should work.


----------



## Frank (Dec 6, 2008)

Very interesting connections Terry; did you ever get a weight on the car?


----------



## TerryH (Jun 9, 2012)

Frank said:


> Very interesting connections Terry; did you ever get a weight on the car?


I haven't had it on the scales with the LiPo pack but my calculations should be pretty close. Weight without my lard butt should be right at 468 lbs so approx. 738 lbs with me. Last year we tried some passes with a 150 lb driver that resulted in a ton of wheel spin and banging the rev limiter on the Zilla on every pass. Could not produce et's as quick as it's gone with me driving but did get 101.06 mph. Apparently I am my own traction control.


----------



## TerryH (Jun 9, 2012)

We recently updated to a new battery pack from Lonestar EV Performance. Went to the track for the first time yesterday. It was a gorgeous day at Ozark Raceway Park. Didn't take long to figure out that the new battery pack has a ton more power than we've ever had. I had it turned WAY down to start....or so I thought. 1500 amps, 140 volts. We normally ran 2000 amps and 190 volts. 7.02 @ 98.27 right off the trailer. Really soft launch but it was hauling on the big end. I got too greedy on pass #2 Amps to 1800, volts to 150. It was on an incredible pass but flashed over the brushes about 400 feet. I coasted through the 1/8th mile at 6.76 @ 83.94. 4 brushes damaged. No damage to the comm. 

I changed the brushes and had Cheryl hold the throttle while I applied pressure with a dowel to get the new brushes run in. I turned it back down to 1500 amps and 140 volts where I began. Ran 6.92 @ 99.14. Added a bit more for the next pass. 1600 amps and kept the voltage at 140. That resulted in a 6.75 @ 99.84. Almost painful. That was the 5th pass we've made over 99 without getting to 100. 

1650 amps and 145 volts for pass number 5. We headed to the lanes when they were calling 5 minutes before they were closing. Once again about 400 feet I felt it flashover but it just popped and kept on pulling so I stayed in it. It popped again right in the lights. I can't hear the announcer but the safety guy at the big end came over and stuck out his hand to shake mine. 6.67 @ 101.81!! Finally after 3 years of trying and lots of dollars and a mountain of work. 

For the record...



I don't put any faith in this sort of thing but this was fun that this was in my fortune cookie after last nights Chinese food. Probably the only time a fortune cookie fortune ever actually happened to me. lol...



We'll be submitting the time slip for induction into the NEDRA's Roger Hedlund 100 mph club.


----------



## TerryH (Jun 9, 2012)

Vids of the 101.81 mph pass.

https://www.youtube.com/watch?v=bED0q5-ItUc


----------



## Frank (Dec 6, 2008)

Congratulations!


----------



## TerryH (Jun 9, 2012)

Frank said:


> Congratulations!


Thanks Frank!!!


----------



## John Metric (Feb 26, 2009)

Congratulations Terry Hatfield on joining the coveted 100mph club. Very few folks are in it.. 
That's moving.


----------



## TerryH (Jun 9, 2012)

John Metric said:


> Congratulations Terry Hatfield on joining the coveted 100mph club. Very few folks are in it..
> That's moving.


Thank you for all your help, John. Could not have done it without you.


----------

