openinverter forum

As noted over on the master event list, I will be taking Shocking Chevy on Hot Rod Magazine Drag Week for the 3rd year in a row.

For those who don't know, Drag Week is the originator and (in my view) still the standard for "Drag-and-Drive" events. Competitors must make a pass each day for 5 days, at 4 race tracks (starting and ending at the same track). We must drive our vehicles from track to track following a prescribed route, with no support whatsoever. Just you, a co-driver if you bring one, and the tools and spare parts you have on board (or in a small trailer towed by the race vehicle). The kings of the event compete in Unlimited Class, where they will take 3000+ HP promods and run in the low 6s in the quarter mile, and drive approximately 1000 miles on public roads over 4 days. In (nearly all) classes, you win by setting the lowest average ET over the course of the week. Just finishing the event is considered a significant accomplishment, and typically about 1/3 of participants do not make it to the end of the event.

This year, Drag Week is in Maryland and Pennsylvania, beginning September 14th. Full schedule below.

HOT ROD DRAG WEEK 2025 PRESENTED BY GEAR VENDORS SCHEDULE
Sunday, Sept. 14 – Tech Inspection, Registration, Test ‘N’ Tune, Maryland International Raceway (Budds Creek, Maryland)
Monday, Sept. 15 – Day 1 Racing, Maryland International Raceway (Budds Creek, Maryland)
Tuesday, Sept. 16 – Day 2 Racing, Numidia Dragway (Numidia, Pennsylvania)
Wednesday, Sept. 17 – Day 3 Racing, Maple Grove Raceway (Reading, Pennsylvania)
Thursday, Sept. 18 – Day 4 Racing, Cecil County Dragway (Rising Sun, Maryland)
Friday, Sept. 19 – Day 5 Racing (Finals), Maryland International Raceway (Budds Creek, Maryland)

We don't yet know what routes they'll send us on, but I will try my best to post here once we are given that information. If you're in the area, let me know, or try to come out and check out the event. I believe there will be at least two EV conversions running this year, including a DC powered El Camino. Since we're both slower than 9.99sec, the only class we fit in is Street Machine Eliminator. Unlike the other classes decided purely on average ET, in SME, the average seeds a 32 car field that runs a bracket race on day 5. Last year there were 100+ cars in SME, and the cut off to make the 32 car field was around 10.9sec. I'm hoping to get Shocking down into the 10s this year, with the ultimate goal of qualifying for the field.

Like last year, I have 3 goals:
1) Finish the event
2) Run in the 10s
2b) Qualify for the SME field
3) Sleep at least 3 hours each night.

I'll do my best to update this thread throughout the event, but things can get hectic (see goal 3 above) so I make no promises.

Good luck!

I'm very close to Reading PA and I wish I had the ability to take the day off! be warned, charging in that part of PA is a little rough so definitely try and plan a route via plugshare or similar. are you on Chademo or CCS?

How do you drive a Pro Mod on public roads, surely they can't get them registered and street legal .... can they?

I've watched each yr with great interest and a deep seated desire to actually participate in one of these Drag Week events ..... I'd even buy an MG XPower, just to do the event, modified with two Zombie inverter boards, one for each motor.

For the dial in time on in street class, is it the best time you have run, or if you qualify, can you dial in the qualifying cut off time?

T1 Terry

ScythianNite wrote: ↑Sat Sep 06, 2025 4:22 am I'm very close to Reading PA and I wish I had the ability to take the day off! be warned, charging in that part of PA is a little rough so definitely try and plan a route via plugshare or similar. are you on Chademo or CCS?

Yeah, I use Plugshare to find what I can along the route they give us. In past years I only had CHAdeMO, but I have CCS working this year which is exciting.

Compared to parts of last year (rural Michigan) and 2023 (NC, TN, SC), PA is positively covered with charging, but I am a little concerned about topping off before going to Numidia and Maple Grove, the nearest charger is 10-15 miles from each, so I'll probably need to find power at the track to get the SOC up, or just run my generator (but that's very slow).

T1Terry wrote: ↑Sat Sep 06, 2025 7:43 am How do you drive a Pro Mod on public roads, surely they can't get them registered and street legal .... can they?

All vehicles must be registered, insured, and demonstrate that they have headlights, taillights, brake lights, turn signals, a horn, and at least 1 mirror.

My understanding is that some use an OEM firewall with VIN and then a composite body, or they register the composite body as a replica or street rod. But either way the top dogs in Unlimited are full SFI 25.3 tube chassis, with all the power in the world. There's also Ultimate Iron, which is similarly unlimited in terms of chassis and powertrain, but the body must be stock exterior dimensions, and only the front clip, doors, and decklid may be replaced with composite panels. Tom Bailey shows a lot of his Unlimited cars (Sick Seconds and Sick Seconds 2.0) on his Youtube channel. Alex Taylor showed basically the entire build of her Ultimate Iron class 55 Chevy on her Youtube channel. Now I wonder what it would look like if someone built an Ultimate Iron car based on parts from a Plaid...? stay tuned, someone just might.

T1Terry wrote: ↑Sat Sep 06, 2025 7:43 am I've watched each yr with great interest and a deep seated desire to actually participate in one of these Drag Week events ..... I'd even buy an MG XPower, just to do the event, modified with two Zombie inverter boards, one for each motor.

Do it. Do it. Do it. No seriously, these are immensely difficult but also immensely awesome events. Everyone should put their builds to the test.

T1Terry wrote: ↑Sat Sep 06, 2025 7:43 am For the dial in time on in street class, is it the best time you have run, or if you qualify, can you dial in the qualifying cut off time?

So for SME, the dial in for the bracket race is 0.1 quicker than your average for the week. So a 10.123 average would have a dial of 10.023. UNLESS, your average is 10.100 or quicker, in which case the dial is 10.000 (because quicker would require a cert'd cage).

It would be a very big undertaking for me, I live in Australia, getting the car there would be only half the challenge, getting it legal to drive on US roads would be something I'd have to investigate, and do it all before I'm too old to actually attempt such a mammoth effort.

I doubt there would ever be anything like that in Australia, we have the tracks, but getting race cars on the road would be a very big challenge ..... maybe the car on a trailer between tracks where the car would not be road legal, or just limited to road legal cars ..... simply getting an EV that is not a factory production on a race track over here is a pipe dream at the moment ......

T1 Terry

T1Terry wrote: ↑Sun Sep 07, 2025 6:22 am I doubt there would ever be anything like that in Australia, we have the tracks, but getting race cars on the road would be a very big challenge ..... maybe the car on a trailer between tracks where the car would not be road legal, or just limited to road legal cars ..... simply getting an EV that is not a factory production on a race track over here is a pipe dream at the moment ......

Yeah, I've heard your rules are super strict.

There have been a couple drag-and-drives down under - but I understand that its tough for y'all to do.

T1Terry wrote: ↑Sun Sep 07, 2025 6:22 am It would be a very big undertaking for me, I live in Australia, getting the car there would be only half the challenge, getting it legal to drive on US roads would be something I'd have to investigate, and do it all before I'm too old to actually attempt such a mammoth effort.

Historically there have been a few crazy Aussies that come over for Drag Week, but I know it's a big undertaking. I do know that its been a mix of shipping cars over and buying a car here - including the legendary Chevelle that was bought out of a field and had a couple turbos stuck through the hood in the days before Drag Week.

Was just about to post on your Project thread asking how things were getting on before finding this post!

Do you think you've got the car in a good place this year?

Good luck

Well I'm fully registered and we are started on day 1! (Photos from last night) we have 3 EVs this year, me, a DC motored Elcamino, and a Lucid Sapphire.

Routes are here: https://www.hotrod.com/events/hot-rod-d ... tes-inside

Aragorn wrote: ↑Mon Sep 15, 2025 10:57 am Do you think you've got the car in a good place this year?

I think that the car is finally what I thought it was from the start. Not perfect, but my goal is to put it in the 10s this week. The charging systems seem to all be functioning (even if the AC charging is still hacked together) and I mostly know what I'm doing.

Just watched the Lucid do a 9.8 sec pass with a launch that looked more like he was leaving church ..... How does Jeff Lutz run a 5.9 second pro-mod on the street between events .... US road laws are certainly different to Australian road law .....

Looking forward to watching your progress this yr, may the race gods be with you

T1 Terry

Well I'm back home from Drag Week, having completed the event for the 3rd year in a row. I'll have more to share when I'm less tired, and when I've gone through my GoPro footage and pieced together a video.

Overall, the event was good. I averaged 11.5866sec @ 113.272MPH over the course of the week, with a best time of 11.439sec @ 114.81MPH. On Thursday, I had the opportunity to run the other EV conversion (an ElCamino with dual Warp9s), creating the first ever all-EV pass in Drag Week history. He ran 11.1 and I ran 11.4, but I nearly beat him (lost by 0.05) because I tree-d the daylights out of him (0.3 to 0.6). Full timeslip below. I'm 193R in the left lane. I fought the tune all week. A tune that worked perfectly fine in street tuning would cause the LDU desat fault when I tried to launch it on track, immediately on launch. I believe this was due to the extra traction preventing any wheel slip and thus causing a harder current spike. Unfortunately, one of the things I didn't get done before drag week was adding a laptop mount so I could data log, and they were strictly enforcing "no unsecured laptops" after an incident Monday. I ended up backing off the power (by dropping fslipmax) to get it to go down cleanly so I could get on the road each day.

Turns out I probably didn't help my launch issue by running a higher tire pressure. On Friday, I finally went and talked with the Mickey Thompson folks that were onsite, and learned that, for a drag radial like I run, increasing tire pressure actually increases traction, up to the point that the tire is so hard it acts solid. So my issue may have been less the glue on the track, more the tire pressure. Likely some combination of both. I only experimented with this on my single Friday run, where I dropped the pressure and put a tiny amount of fslipmax back in, and it held and launched cleanly. Ran a similar time as Thursday, but I think Thursdays track had a bit more slope to it. I'm hoping to get to a track locally in the next month so I can get the tune fully sorted out, and put the thing in the 10s.

The drives were tough, but overall went well. FOCCCI performed nearly flawlessly, though apparently there's an issue with the SWTCH network. Due to time constraints, I don't have logs, and there is a chance that it was network side, but I tried multiple SWTCH chargers with no success. Fortunately, those occurred when I had backup options to charge. I did have one physical breakdown, a bad pothole broke my right rear coilover mount at around 9:30pm on the first night, but fortunately someone on the facebook group was able to bring me the bolt I needed. The next day I bought 4 spares, so that won't be an issue in the future. We had lots of windy mountain roads, and one night of driving in the rain, but overall the drives went well. I actually got real sleep most nights.

Total route miles: 660
Total miles I traveled: 735 (from the end of tech on day 0 to the pits after my last run of the week)

It was an absolute blast having multiple EVs on the event. It makes it much more fun when you can commiserate about issues with someone that speaks the same language, and running against each other was the highlight of the week. I'll close with this for now: if you're in the US and considering doing a Drag-and-Drive style event, I wholeheartedly encourage it, and offer any help I can provide you to get your car and yourself ready. Come and join the madness!

Watched hrs and hrs of the Motor trend live feed, but not live, you can't do 4 x sp live and I didn't want to lose the will to live Saw a number of the stumble starts and guessed it was a traction/current spike issue ..... is there a work around for that?

T1 Terry

T1Terry wrote: ↑Mon Sep 22, 2025 11:06 am Saw a number of the stumble starts and guessed it was a traction/current spike issue ..... is there a work around for that?

So far the work-around has been to pull power by lowering fslipmax. I think that I may be able to get a bit back by lowering tire pressure, or possibly by switching to slicks entirely. The fault is basically built in protection in the Tesla gate drivers, so there's no overriding (probably a good thing for my wallet at least). I've also considered a completely new approach to the tune. My tune is based on Jon Volk's originally, and he has a car that would give a bit of wheelslip. I have a car with 900 lbs of batteries between the driver and the rear axle, right on top of the suspension pickup points. I may need to find a setup that lets me ramp in power better, and then pour it on down track. But I do love the hard launch so for now, the goal is to find a combination of slight wheel slip/tire wrinkle and power/ramping settings that will give me a clean but hard launch. I really need a full test-and-tune day, and there's just not a good opportunity for that on DW. I meant to get to one all summer but stuff kept getting in the way.

It certainly lights them up out of the water ...... the lower tyre pressure might help, but avoiding turning the tyre inside the rim becomes an issue, but the tyre people might have answers for that and an idea just how low the pressure can go without destroying the sidewalls or spinning the rims.

I had a motorbike, a 750 Norton Commando, that I swapped the rear wheel for a Honda 450 wheel so I could get a better top speed ratio ...... the wider tyre and changed ratio caused the torque to turn the tyre inside the rim and tore the valve stem out of the tube .... resulting in a trip up the bitumen and 3 mths growing flesh back and learning to use my hand again after the nerves were repaired ..... not a desirable thing to repeat .....

T1 Terry

T1Terry wrote: ↑Tue Sep 23, 2025 5:46 am the lower tyre pressure might help, but avoiding turning the tyre inside the rim becomes an issue, but the tyre people might have answers for that and an idea just how low the pressure can go without destroying the sidewalls or spinning the rims.

Yeah the Mickey Thompson folks were also quick to recommend marking the tire at the valve stem location to monitor slippage - haven't done that yet. The current radials are tubeless, but if I switch to slicks those will likely have tubes.

Did you ever investigate the Current Control firmware? That looked really promising for pushing big power... Not sure if theres much active development though.

Aragorn wrote: ↑Thu Sep 25, 2025 8:36 am Did you ever investigate the Current Control firmware? That looked really promising for pushing big power... Not sure if theres much active development though.

I'm currently running fw5.35

Sorry, i meant this:

viewtopic.php?t=3086

Seemed like a clever approach to get more accurate control over motor current and enabling the envelope to be pushed.

Aragorn wrote: ↑Wed Oct 01, 2025 9:02 am Sorry, i meant this:

viewtopic.php?t=3086

Seemed like a clever approach to get more accurate control over motor current and enabling the envelope to be pushed.

I have not tried anything beyond the standard OI firmware. I'll have to read through that thread and get caught up.

My Drag Week video is up! Check it out here:

Brilliant work mate.

Alibro wrote: ↑Tue Oct 07, 2025 2:52 pm Brilliant work mate.

Thanks!