The Sledgehammer - Shooting for 1,000hp

Here's the first video out of Monday's dyno tests - we tested the new 100mm vs the old 75mm TB:

The electric turbo test is next. And yes, I stayed up way to late to finish editing the thing - I make poor choices. I'll be dead at work tomorrow. Or in five hours. Which is when I have to be there. Whatever.

Enjoy!
 
I've had an opportunity to pull up my dyno session from the Whipple. We're only about 12 rwhp off the power level that got the car in the 9's. Of course, I did tweak it a bit over time, but we're right in the same ballpark. It also appears, but this is a bit harder to confirm, that we weren't pushing through the converter as hard.

I've been thinking about it, and the car was on the dyno for 4 hours and had 8 pulls in total. The whole time, the header collectors are about an inch away from the transmission pan on both sides, just cooking the fluid. Since there's really no airflow (Ray's fan is a bit anemic), that's likely the difference. We'll have to take it to the track and see what it does. Before with the Whipple, I had different (shorter) headers on the car and the pipes were not nearly as close to the transmission pan. On top of that, that was a different Dynojet that was only about 15 miles away, not 100.
 
I watched the vid... a few times. You said the potentiometer was set to about 90-95%
Is anything past that,a point of diminishing returns? Given the voltage drop, I would say that is a major weak point in power delivery.
Did you already shorten the run of cables?

The heat may be a factor, it's easy to test with some wrap or making an AL shield.

When do you start the spool up
 
Yeah, I should have clarified that better in the video - I had it set just under 100% (datalog actually shows 97%) for the first pull only. After that it was set to 100% and left there for the rest of the pulls. That 3% did actually make a difference - peak boost went from 5.9 psi to 6.7 psi. I've shortened the cables as much as I could; at this point most of the voltage drop is coming from the batteries - I can always add a second set of LTO cells in parallel - I actually have enough cells on hand to do that.

The heat is definitely a factor in the converter losses. I'll be installing a trans temp gauge, although I probably wouldn't be able to replicate the dyno conditions anywhere short of the dyno (running at 140 mph without the 140 mph airflow...)
 
Hi Alex this is a really cool project, I followed you over here from Yellowbullet. I have a couple of questions I hope you don't mind me asking. I've read up on these forums and I can't find the answers. Do you have any idea what the whole setup weighs from the motor to the batteries including wiring and batteries? I'm guessing 150 pounds or so...? Also approximately how many passes can you get at full boost out of the batteries as you intend to run them?
Thanks!
 
Thanks for joining! It's new tech, but I do believe it has a very bright future - and not just with fire, lol.

The current head unit probably weighs under 20 lbs (I've never weighed it, it's a guess - the motor is about 5 lbs); I have weighed the battery packs and they're about 60 lbs. However, I'm using LTO cells for safety and current capacity; you could use LiPos - an equivalent LiPo pack would weigh about 20 lbs and be physically a lot smaller, but it would also be a bit more dangerous and more sensitive to temperature (but it would also be cheaper). There are about 25lbs of cables (if you have a shorter car or are willing to put stuff in different places, that could go down as well), and the controller box & ESC weigh maybe 10 lbs combined, if that. So the current setup is about 115 lbs on the high side. Probably closer to 105 lbs in reality, but you could shave an easy 40lbs off of that.

On our dyno tests, we got 4 pulls with no real dropoff in boost. So figure at least 3 dragstrip passes; though with the on-board charging, you could run all day.

Hope this helps.
 
No thank you for the info! Like I said man I'm very intrigued. What are your plans for onboard charging? I'm curious about charging those batteries vs parasitic drag from engine driven alternators (or the like) to charge them back in a time effective manner. Thanks!
 
The control box has a charger built into it. It draws 30 amps from the car's electrical system while charging. The optimal configuration would be to use high-current regenerative charging (during braking), but that's realistically not feasible for me to implement - that would best be done being integral to the trans. Here's the control box video:

 
I don't think I'm going to the track this weekend - we're supposed to have bad thunderstorms tomorrow, and then on Saturday my local tracks are running events that don't work for me - one is an 1/8 mile nostalgia race, and the other is a no-prep grudge race, at a track that had a shooting last month. This is why we can't have nice things. I don't feel great about going to that track anymore after going there for 30 years. Considering I got now radial slicks mounted today (and they caused some minor damage to my Bogart wheels - :mad:), I don't think this is the weekend.

Besides which, I'd like to make things more "complete" - I'd like to install the trans temp gauge, new voltmeter (which involves 3d printing a new console panel - I love the fact that I can just make some changes and print a new one), touch up a 1/2" scratch in the paint (I know how it got there, all I'll say is: :mad::mad:) and properly finish up the battery pack mounting brackets. I've been burning too much midnight oil lately at the expense of my health, too.

In a nutshell, too much :mad: and not enough :). I think it's best to heed the will of the Fates (google "norns").

Norns.jpg
 
We went to the track last night. Good news and bad news. The good news is we went 10.2 at over 131 mph with the sledgehammer; from a naturally aspirated pass of 12.5 @ 111.75 mph. Which is awesome. A gain of 20mph and dropping 2.3 seconds is huge. The bad news is the converter's definitely hurt - most likely the sprag is gone, but could be the input tube to the pump has spun. Which would also explain the slip/lower than expected dyno numbers.

The arduino code also bit us - at 100% on the pot, the sledgehammer would just shut off after a little over 4 seconds. The ESC datalog shows the "input request" - i.e. input signal - would literally go from 100% to zero after just over 4 seconds. In order to get a clean pass, I had to set the pot to less than 100%. I haven't pulled the datalog from ESC yet to know what it was actually set to.

I'll post more details later; but in a nutshell, this is easily 9 second power. Maybe mid 9's once everything's sorted on good air day (density altitude varied from 1,400 feet to over 2,000 feet last night), with meth injection. We saw peak boost of 8 psi, btw.
 
Unfortunately, we lost a few posts in this thread thanks the the ruzzian hack. But things are coming along; if you follow my youtube channel, you'll know I'm also working on moving, which involves building a barndominium on the Texas coast. Here's where I was a couple of weeks ago:


As for the car and electric turbo, the new torque converter is installed, the engine is back in the car and just a few things left before she'll be running again (upper intake & radiator, mainly). Then I can re-install the Sledgehammer with the meth injection setup and take it back to the dyno.

EngineBayEngineIn.jpg
 
We finally made it back to the dyno yesterday. It was an interesting day to say the least. The converter, running n/a, LOST 40 rwhp, but locked up harder and turned 6 more mph on the dyno. And when all was said and done, we made a good bit more power with the Sledgehammer in ~90 degree heat - running meth and a coated volute. Here's an SAE corrected dyno chart showing our best N/A and Sledghammer pulls from last time and from yesterday:

DynoComparoLastYearThisYear.jpg

The only changes were - new torque converter, line 2 line coated volute, AEM meth injection. Green line - last year's best n/a pull; purple line - yesterday's best n/a pull; red line - last year's best Sledgehammer pull; blue line - this year's best Sledgehammer pull.
 
Here's a graph of torque (though keep in mind this is a glide, so I don't know how meaningful this is):

DynoComparoLastYearThisYearTorque.jpg
 
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