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The 196mph LSR 1970 Cadillac Coupe de Kill – Caddy Powered And Homebuilt!

(Just about a month ago we ran this feature on Sean Mote’s wild turbocharged Caddy. Well, it went viral and was viewed by seemingly half of the gearhead world. It quickly jumped into our top 10 most viewed items so here it is again!) We love guys like Ohio’s Sean Mote. Dudes that are undaunted at simply blazing a trail into the hot-rodding wilderness because they want to be true to who they are and their own tastes. We may bash on guys who are over-the-top brand-loyal honks, but that’s not Sean. Sean is just a dude who has loved Cadillacs, hot-rodded Cadillacs and dreamed about Cadillacs forever, so when it was time for him to make something go really fast, he stuck with who he was, physics, common sense, and the laws of nature be damned. He’s the man. This is his 1970 Cadillac Coupe de Ville, which we personally saw run over 186mph at the Wilmington Mile earlier this summer. Power comes from a 500ci Cadillac engine with MegaSquirt EFI, and a 106mm Precision turbo. How much power does it make? Well, the same mill with a smaller 90mm turbo and a blow through carb made 788hp and 770 ft/lb of torque spinning a stock crankshaft. But we’re getting ahead of ourselves. Take a look at this thing! It makes you smile to see it sitting still, but let us assure you that when the monster is making nearly 180mph and is at full bellow, you’ll burst into the kind of maniacal laughter that only car guys know when they are watching something awesome beyond words.

So how did this all happen? “This whole car is just a series of bad decisions,” the self effacing Mote told us during the time we chatted him up. He loves to take cracks at himself and his abilities, but there’s major irony in that. He built this car, like all of it. The cage? Sean. The fiberglass hood and front bumper? Made them with friends. Turbo plumbing? Hand fabricated by him. Mustang Fox-body adapted front suspension? That too. Of course, the thing didn’t spring forth from the womb like this and as most hot rods are, the machine has been an evolutionary process of improvements and refinements over the years. If you can refine a bazooka that is.

Sean bought the car from a junkyard in Ohio where it had been sitting out front for ages. The vehicle had been set on fire at some point and the interior was completely charred. Since this was a Cadillac that had been set on fire we asked Sean if someone was in it when the thing erupted and he confirmed that he found no human remains when rehabbing the inside. That was a happy ending. Using another 1970 Coupe de Ville as a daily driver, Sean set this car to the side for a while until the Ohio winters, road salt, and old age killed his primary Caddy. At the time this actual car was put on the road it was a menage of red, green, and rust colored body panels. “The thing kind of looked like a giant Christmas tree,” Sean said. “I built a mild naturally aspirated 500 for it and with steel wheels, a full interior and all, it would go 13.50s at 105 at the drag strip.”

Sean became interested in turbocharging and spent a fair amount of time doing research and trying to figure out what he’d need to feed the 500 and boost the car safely. In 2003 he gave the car a makeover. That’s when the black paint you see in these photos was slathered all over it and that’s also when he stepped up the motor program. Adding a set of aluminum Potter Performance high port cylinder heads, the blow through carb, and a 90mm Precision turbo, the car became a true terror, dipping into the 10-second zone at the strip. It has gone as quick as 10.90 at 127mph in the quarter mile. That’s not to say that Sean hasn’t gone through his fair share of parts over the time he’s owned this car. “I’ve blown up lots of stuff over the years,” Mote said. “At one time, I had 15-20 blocks in my barn. I still have 5-6 spares now.” He didn’t kill all of those, but certainly, a healthy few met their end getting hammered on. “The big problem with these engines when you start making some serious power with them is that by the end of a drag racing season, the main caps are walking and stuff,” Sean said.

2005 would see massive changes for the car. In order to try and get some of the weight balanced better, Sean decided to move the engine some nine inches back in the engine bay. In doing so, he had to move the turbo, which he actually mounted inside the car, behind the driver’s area. He then looked at the front suspension and this is where his fabrication talents (acquired after working as a millwright for years) came in along with his creativity. Mote figured he would use Fox body Mustang front suspension components…all of them. He was planning on using the upper and lower control arms, struts, you name it. The problem was that the struts were going to be hanging out of the hood by four inches when he was done, so Sean went hybrid on the deal. There’s Mustang lower control arms, adjustable circle track upper control arms, RideTech airbags on all four corners, Mustang spindles, a Mustang rack and pinion, and the cappers are the Mustang Cobra 13″ rotors and matching calipers. Obviously, none of this stuff bolted on and all of it required tweaking and touching and modifying. It all looks just about factory fresh to us and it works. “I was worried about how the car would act at high speed because of the homebuilt suspension up front, but it drives really well, even at more than 175mph,” Mote said (almost proudly, which is saying a lot for this guy).

The car ran in this form for a while but it was eating up turbochargers. “The guys at Precision told me that the turbo was being over-sped and that I needed to go bigger, so that is when I went to the 106mm,” Sean told us. Initially, Mote had the huge turbo in the trunk of the car but it was slow to spool back there so he decided to move it right up front and center as it is right now. That required him to move the radiator and stuff into the trunk, which you’ll see in the photos. Sean did all of the tubing work on his own and he tells us that outside of the initial elbow out of the turbo, the exhaust is all aluminum (including the Volant mufflers) and weighs 33 lbs. That is insane and awesome.

Believe it or not, this massive car weighs “only” 4200lbs. Yes, this 1970 Coupe de Ville weighs LESS than a new Dodge Challenger! The 4,200lb empty weight is just about 1,000 lbs less than these cars weighed stock. That’s wild. A half-ton lighter than factory!

Sean has not had the car on the dyno with the EFI and larger turbo as of yet so we don’t know what the official rear wheel horsepower numbers are but those will come sometime and they’ll be large by huge. The hard working Turbo 400 that sits behind this motor deserves the Congressional Medal of Honor for standing up to all the abuse!

We’re going to give you the rest of the specs and story in the photos below….let’s take a look at this awesome Caddy!


With the RiideTech airbags dumped, this thing is ready for battle. Hunkered down doesn’t do it justice!

The massive hood and massive front bumper are fiberglass. Sean and his friends made them themselves after reading, watching YouTube videos and hanging out with a guy who builds boats. Stock hood weight = 140lbs. Glass hood = 65. Bumper went from 74lbs to 7!

Note the required roof rails and 740 Dzus fasteners holding hood.

This Caddy rolls on a 120-inch wheelbase. The rear quarters are majestically huge.

The wheels are replica Mustang FR500 pieces because the front suspension is all Mustang stuff!

The center mounted 106mm turbo moves the atmosphere out of the way as the Caddy careens down course.

This just looks like a land speed car…right? The fact it goes nearly 180 is insane.

Pure evil.

We forgot to ask how many gallons of paint were used on this monster.

Sean runs a 2.5:1 gear ratio in the car for LSR one mile racing. 3.25 for the street and strip.

The switch panel is a nice and simple way to keep things organized.

Nothing major crazy in the cockpit but the Caddy wheel is a classy touch.

Cage and racing seats are a must at over 175mph!

These doors have to weigh a couple hundred pounds each. See the control at the top of the door panel…

It is for the wipers! Bad ass.

This 500ci engine has a Bullet cam with about .620 lift a stock crank, Potter Performance high port heads, 9.5:1 compression, a Potter Performance intake manifold, K1 connecting rods, and EFI. The EFI is a MegaSquirt MS3X with FIC 2150 injectors. Sean tunes himself. The coils are Pantera Ign-1s.

Dig the cool radiator and fuel cell setup in the trunk. Radiator on bottom, cell on top. Trick!

This is a 1970 Caddy Coupe de Ville with window tabs. Just sayin’…

Big 305 wide meats in the rear necessitated a mini-tub job. Wheel tubs were stretched a few inches by Sean

Another look at rear wheel house.

Yes, those are Mustang brakes because the whole front suspension is virtually all Mustang stuff!

The engine is done spinning at about 5600 rpm according to Sean. Factory nodular iron crank is tough as nails.

The engine has been moved back some 9″ from factory!

All the tubing fab work was done by Sean himself. He’s talented.

With the air dumped you can see just how low this thing is. That’s the bottom of the fender you see in this frame.

The boost maker is a 106mm Precision turbo.

We love the fact that it is front and center. Sean did this because drag racers all started moving their turbos front and center several years ago. We dig.

There’s still an amazing amount of room under there!

Sean looked at late 1980s GM cars that had forward tilt hoods and copied their mechanism with his own design. Why? Because he rules. 100% BS approved.

The forward tilt is necessary because Sean would never get to the back of the motor with the hood opening traditionally.

Also, he can lift the hood off the car himself like this. He’d need help any other way.

We didn’t measure, but we’re pretty sure this car is about an eighth of a mile long.

Seriously, look at this thing and tell us it isn’t the meanest Caddy you’ve ever seen.

The cowl was necessary to clear the plumbing from the turbo into the intake that matches the high port heads. It looks boss.

We’re actually surprised that the turbo has not sucked the plate off the front of the car yet.

This is probably the best photo to give you a look at how gargantuan this car really is. 4200lb weight is a half-ton LESS than factory stock.

Sean cruises this car on the streets, drag races it, and LSR races it. He’s a BangShift Hall of Famer for sure.

Finally…what’s cooler than this?

Courtesy of:

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