Oscar Mayer Wienermobiles hit the track for the Wienie 500 as part of the Carb Day schedule at Indianapolis Motor Speedway and created some exciting action on track. My immediate thought as a racing mechanic was that I could see a way to win that race with the right set of modifications and adjustments, and I’ve decided to share my master plan to build a faster Wienermobile.
Each Wienermobile is built on a modified version of the Isuzu NPR-HD, which features a 6.6-liter Chevrolet L8T V8 engine that is rated for 350 horsepower and 425 pound-feet of torque. This engine is backed by an 8-speed 8L90 transmission. This is the first step in our grand plan to build the fastest racing Wienermobile. The easy items here are swapping the intake manifold and throwing on some headers, and giving it a tune that is more in line with a crate L8T to boost output to over 400 horsepower and increase speed for those straightaways at Indy.
That 8L90 will get hot under racing conditions, so the first move there is to install a transmission fluid thermal bypass valve in order to maximize flow to and from the transmission cooler in order to keep the transmission in an optimal shift state.
Once we’re putting down some better power, we’ll need to start looking underneath the chassis to improve handling and braking. The Wienermobile is equipped with 19.5-inch commercial steel wheels that are wrapped in 225/70R-19.5 commercial tires. These wheels are fairly heavy, and the tires are typically designed with a pretty hard compound and tread that is suited for dry and wet conditions. We can swap those wheels to 17×9 super singles, which will allow us to install performance-oriented tires.
We’ll want to keep a high load rating due to the weight of the Wienermobile but we can still find an ultra-high performance tire in that load range with a shorter and stiffer sidewall to not only offer a better compound for race track traction but also help to lower the ride height in order to optimize handling even further.
The Wienermobile is equipped with leaf springs, which limits upgrade options, but an easy change that we can complete is swapping to parabolic springs. The standard leaf springs on the Wienermobile feature a traditional leaf spring pack that causes the stacked leaf springs to slide against each other which results in friction. This type of friction results in internal resistance which is not present in something like a coil spring. A parabolic spring features a more stretched out shape which prevents this type of friction and results in a progressive spring that is much closer to the compliance levels of a coil spring. This type of spring upgrade would allow our Wienermobile to corner significantly better than our competitors.
Spring upgrades could be assisted by air suspension products that are already available on the market, or the possibility of working with a vendor like King Shocks which offers suspension kits for this chassis already. These suspension kits are typically focused on raising ride height for things like camper conversions, so the shocks would need to be customized for lowering, but they would offer far more adjustability as most of these shocks offer at least compression adjustment. These upgrades can be accompanied by camber and caster kits, which are available for this chassis in order to fine-tune the setup to be optimized for the layout at Indianapolis Motor Speedway.
Our Wienermobile can only go as fast as the brakes are able to slow down in the turns, but fortunately it is already equipped with a sizable 14.3 by 1.65 inch front rotor that offers a lot of thermal capacity but also a lot of weight so we’ll want to step down to the 11.5-inch rotor found on the standard non-HD Isuzu NPR to drop some weight on the front corners.
Our main focus when it comes to braking will be the brake pads, as we’ll want to have an appropriate compound handy when and if we do need the brakes. The Wienermobile uses a brake pad shape that is shared with the Isuzu Elf and Chevrolet Tiltmaster that isn’t found on other vehicles, so we’ll have to go to a custom build here with a company like Carbotech that can take a specific brake pad shape and apply one of their racing compounds. Once we’ve upgraded the pads we’ll also want to use some matching brake fluid in order to complete the package. As the race is short enough to basically be a qualifying run, we’ll want to pull those pads back so that the rotors can spin freely until we absolutely need to apply the brakes.
CFD study of the Wienermobile.
Courtesy of Dan Mather from Digital Engines. https://t.co/jh1R6zfEqh pic.twitter.com/hVBeJOKCBR
— Bozi Tatarevic (@BoziTatarevic) May 23, 2025
In order to take advantage of our other upgrades, we’ll want to make sure that aerodynamics are appropriately optimized, and as a first step, we’ll want to fold in the mirror to reduce drag on the sides of our Wienermobile. We’ll be so far out front that we won’t need to even look at those. The top of the hot dog, where the windshield glass meets the fiberglass skin is also another high-pressure area, and depending on what the rules allow here, we can start with basics like taping the transition or going as far as filling and sanding it in order to make it completely smooth. Since the Wienie 500 is only a two-lap race at Indianapolis Motor Speedway, we can also partially tape that lower grille in order to redirect some of the airflow.
Adding a splitter at the front of the bun and a spoiler at the rear of the bun could significantly improve downforce if allowed by the rules with a focus on the rear as the transition at the front where the hot dog meets the bun traps a decent amount of air which likely shifts the downforce percentage more towards the front.
We’ll also want to maximize our steering feel to take advantage of these modifications, so we’ll want to dig into the steering system and adjust the worm gear in order to make the steering as tight as possible. We’ll also want to adjust the tie rod ends in order to optimize the toe for left-hand turns.
Once all of our changes are completed, we’ll need to adjust our setup in order to optimize cross weight of the Wienermobile along with other setup adjustments before we put it out on track where it will surely gain more than a few tenths on the competition.
If we do this right, the competition will have a hard time catching up, and it’ll be our hotdoggers enjoying some milk (mustard?) and kissing the bricks.
A core memory for me as a kid was pulling up to the Kroger on the west side of Indianapolis with my mom and sister in the late 90’s, and seeing the Wienermobile sitting out front. I actually got to go up in it, and left with a Hot Wheels diecast of the Wienermobile, which my own toddler plays with to this day.
Despite it not being a “real” race, it was still a lot of fun to watch! Those wieners on wheels hold a special place in my heart.
Also, I was next to one on Interstate 65 a few months back, and it was going at least 70, so these are definitely not governed at 60 like the announcer stated.
Imagine if NPR bought Isuzu. Then they’d be selling the NPR-Isuzu NPR. At least if they bought that, they’d also be able to get Bill Kurtis as their spokesman, in between making calls to listener voicemails and arm wrestling Peter Sagal.
6.6 Diesel swap, run the suckers on Fry Grease and make sure they have hot dog cannons out back for extra boost and to get dogs out tot he stands as necessary
My employer builds box trucks/flatbeds on Isuzu NPRs. Most of what we use are diesel, but I get a few gassers. It’s no slouch! They will get up and scoot. Especially as a bare chassis before the box gets put on (assuming you can get traction). I’ve surprised many people at stoplights!
Am I the only one that wished it were an actual race, and not a staged event? I mean, I know they aren’t going to let them race super hard, but come on, it was so fake. Ruined what could have been fun.
Whenever they decide to replace the current Weinermobiles, they should do a demolition derby.
Yeah, it was fun for the kids to watch Friday evening, but you could definitely tell it was staged.
I’d love to know what happened when the smoke poured out of one of them. Was that staged, or did it actually overheat?
Hated the narrowed passing space with all those random vehicles taking up nearly half the width of the track near the finish line. I’d guess it was fake if only cuz that smoking wiener still caught up with the rest of the pack and finished the race.
Does the existence of the weinermobile mean someone somewhere is still producing 1994 Grand Am headlights?
The spicy mustard adds 50hp. Pepperoncini adds another 75 but is only legal within Illinois state lines.
An additional 3 points awarded to vehicles baring the bumper sticker “My Other Car is a Sandwich”.
Are you implying a hot dog is not a sandwich?
It’s a scooter/motorcycle situation.
Slaw adds 75 hp
Sauerkraut gives you the largest performance boost but you also have to deal with a Teutonic maintenance schedule, so it’s a bit of a wash.
Franfurtgnugen
Forget these scripted races with big Weiner bucks I want to see a brat 500.
I quite enjoyed the race. There were many puns, as expected, however I didn’t hear one ketchup (catch up) pun which is okay if these were brats but it is the #1 hot dog condiment.
On the mods I wonder if it would be better to just dump as much weight on the brakes use the banked corners to bleed of enough speed to keep from rolling the dog over and then use the extra height for speed coming out of the turn? Also I wonder how much extra speed a good wax job might bring?
I’m assuming the “body” is fiberglass either sand it down to almost nothing or if you are really crazy and have time and money build a aluminum or carbon fiber body. Then make a mustard bottle splitter for the front to help with that buffeting.
I get an almost Jag XKE vibe from the lower part of their bodies.
In the “Nice Wiener” photo, I noticed how the windshield wipers were parked on opposite sides. That stirred up some almost Jason-level questions in my mind. Were these fabricated at the same time, or by the same people? Was there an aerodynamic advantage to one side or the other?
I’m sure the whole thing was scripted and choreographed. It’s not like there going to do NASCAR level PITT maneuvers and damage what I imagine is very expensive bodywork.
And I enjoyed that there were a few mildly racy inuendoes thrown in the commentary. And also, a lot of cheesy Dad joke level puns that kind of land with a thud.
All in all, a pretty brilliant PR stunt. And thank you, Bozi, for a thoroughly entertaining article.
All of your modifications sound like a lot of money to spend to get to squirt some crappy mustard on essentially, co-workers.
The trick is driving a slow car fast.
I think almost anybody can figure out how to make one faster.
That instantly ruins it.
They should ideally all be the same.
No wheelies.
Perfect! Just add a bumper sticker between the exhausts that says “You’re Listening to NPR” and we’re done.
Can someone explain this? Is it a valve that diverts to a second, larger diameter set of pipes or hoses once the tranny warms up?
Just turbocharge it and call it a day.
Use better mustard.
But you’re NOT using ketchup to fill any gaps/seams, right? That’d be doubly problematic.
If this were a NASCAR race that overheating wienermobile would have caused a caution and three green/white/checker attempts.
Spilling coolant on the track could have resulted in some slippery wienermobiles.
Weinermobile…”high load rating”…
“hot dog meets the bun”…
“tight as possible”…
“hard time”
Ha ha ha ha ha…this article is GOLD!
“No ifs, ands or buns.”
Performance-enhanced wieners. Not what I expected to be reading about this Friday night. But it’s the perfect nightcap.
I always try to chase the hard hitting stories.
And no Cialis or Viagra cross-promotions. Amaze-balls.
So you would keep the automatic transmission ?
I’d think a dog box would be appropriate .
Appropriate suggestion.
Especially that 8L!
It didn’t cut the mustard, and Ford gave up on their version after a year, and everyone I’ve met with the GM one complains that it hunts for gears, shifts too soon, and is just an all around brat.
To be frank, I would just swap it for an Allison or Eaton.
Great piece!
I thought going too fast is the opposite of what people generally applaud in weiners.
Usually it’s not the speed that’s the issue directly, but it often leads to a blowout forcing you to retire early.
Ah. Here come the comments I was expecting.
I don’t think those mods would really cut the mustard.
Are you hopped up on sauerkraut? The rest of the field will be playing ketchup, while the drivers relish a victory. That’s the highest condiment I can give these mods. Provided they’re legal, of course. Secret sauce or not, this hot wiener has to be kosher, or it’ll get bunned.
You brat, using up all the buns.
Almost true, frankly.
No points this was very slawpy Mechjaz.
I’m sure secret sauce would be an illegal race modification resulting in leek points and causing the team to cry wondering how they can ketchup on points. Probably no bigger slawt drop since the Ford Mustard scandal where they were caught substituting grey poopon for the required frenches brand mustard