Bozi Tatarevic Profile picture
I run in front of race cars professionally and create motorsport content. Champion Racing Mechanic | Writer @RoadandTrack | Presenter | Dessert Fan
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Oct 1 12 tweets 5 min read
Listening to Actions Detrimental and feel like @dennyhamlin might need a whiteboard for a technical explainers to @jareddallen and @TravisRockhold.

Here is a good illustration to add to his explanation on why Xfinity cars can get close and pass but Cup cars can't. Image If you look at the car when they're far apart, you can see how the air comes off the spoiler of the leading car and and also how the following car can get air under the splitter. The cars will be somewhat comparable in how they perform in these situations. Image
Aug 21 10 tweets 4 min read
I do not see a way that having the lifter system installed could have any impact on the right rear droop so I don't believe that it played any role in the LaJoie flip.

Calling it an air jack is incorrect as this is a lifter system that can temporarily increase damper length. I know that the air jack terminology was used on the segment segment in the show but it is incorrect and will cause confusion if people keep repeating it. It's best to refer to it as a damper lift system or shock lift system..
Aug 12 9 tweets 4 min read
There have been a lot of opinions on the moves by Austin Dillon on the last lap but best way to analyze them is to look at the actual data so let's dig into his last two laps in a quick thread.

Orange = Lap 407
Blue = Lap 408 In order to get an understanding of what we're looking at we'll start with Dillon's moment of impact with Logano.

If you look on the chart on the right you'll see that Dillon was moving at 105.2 mph and had 30.9 degrees of steering to the left at the moment marked. Image
Mar 3 9 tweets 4 min read
The right front wheel on the No. 17 was not fully tight which resulted in the wheel riding at an angle on the hub and eventually snapping. Let’s dig into how that happens.
During a tire change, the wheel has holes on the back of it that need to seat on drive pins that are on the center of the hub around the snout. Image
Feb 11 8 tweets 4 min read
Ever wonder what all those buttons and knobs on a race car's steering wheel do?

The steering wheels in our Lexus RC F GT3s have a over a dozen functions and are the command center for our drivers. Let's dig into some of them and how they're used during a race. A photo looking at the steering wheel and dashboard of the Lexus RC F GT3. The top of the steering wheel features three knobs:

TCS: Sets the level of traction control intervention.

GEAR: Sets the mapping for the gearbox and adjusts throttle blip.

ENG: Sets how the car responds to throttle input dependent on a driver’s preference and conditions Image
May 9, 2023 5 tweets 2 min read
Checking out some pit lane stats for Trucks at Kansas and just like in Cup, having that first pit stall is an advantage for driver time on pit lane.

Having an open in or out also appears to be an advantage.

Here are top 15 drivers based on average pit lane time: Image An experienced driver in the first pit stall can be a huge advantage. The gap from 1st to 2nd is 0.74 seconds but the gap from 2nd to 3rd is only 0.01 seconds.

5th place is over a second behind best.
15th place is over two seconds behind best. Image
May 9, 2023 6 tweets 3 min read
Looking at average driver time on pit lane during the Darlington race last year and out of the 10 fastest drivers only one didn't have an opening either going in or coming out of their pit stall.

The first stall has a huge advantage but openings are helpful even down the line. Image Those top 10 fastest drivers on pit lane from last years Darlington spring race marked on the pit stall chart. Image
May 8, 2023 11 tweets 4 min read
Here is a comparison of a legal splitter stay versus the illegal one that resulted in a penalty for the No. 3 car based on the photos released by NASCAR.

You can see the two nuts that are bonded to the turnbuckle which resulted in the penalty. Image There appears to be epoxy applied at these two joints in order to bond the nuts to the turnbuckle. This would allow the nuts and turnbuckle to move as one assembly instead of having the nuts jam against the turnbuckle to hold it in place. Image
May 7, 2023 4 tweets 2 min read
Hamlin versus Larson lap time differentials during the race so far.

You can see that that Hamlin's car rolled off the truck with a better setup but Larson's car got a lot closer after the first set of adjustments. Image Hamlin versus Larson lap times from Lap 11 to Lap 38. Image
May 7, 2023 4 tweets 2 min read
Hamlin pit stops so far.

Blue = Driver time to pit box
Red = Pit stop time in box
Orange = Driver time out of box Image The numbers. Image
Nov 28, 2022 16 tweets 6 min read
If you've ever taken a peek at engine bay of a Lexus RC F GT3 and wondered what's inside the large carbon fiber box on top, you'll be pleased to learn that it houses individual throttle bodies that are mounted to the cylinder heads of the 2UR-GSE V8 race engine. Image The carbon fiber trumpets that lead to those ITBs can be seen clearly in this side view photo from TGR. Image
Sep 6, 2022 36 tweets 10 min read
We can absolutely dig into the fire of the No. 4 at Darlington and explain some of the possibilities and contributing factors. Thread incoming. A ball of flame appears from the right front wheel opening o To understand what contributes to these fires we have to go back to one of the driver cooling fixes that were done to lower the temperature of the footwell/pedal box which is directly beside the rocker box and where the exhaust comes off the car.
May 30, 2022 14 tweets 6 min read
The No. 17 car took a wild tumble during the Coca-Cola 600 but even though the incident looked intense, the safety features of the NASCAR Next Gen appear to have worked as designed and the driver was well protected based on my brief inspection of the car last night. My thread from the incident here with some details of what was going on as it hapenned.
May 30, 2022 5 tweets 2 min read
The No. 11 boys waiting out those last couple of laps. A few minutes later.
May 30, 2022 6 tweets 2 min read
Wow. That was wild. From what I can tell, the impact from the 99 caused the upper control arm to break on the No. 17 and then as the car slid on the grass the wherl got pulled under the car because the top wasn’t being held in place.
May 29, 2022 4 tweets 2 min read
Very excited to root for my key lime pie guy @KKirkwoodRacing in the Indy 500 today. @KKirkwoodRacing Pie review in this thread.
May 27, 2022 9 tweets 3 min read
Good quote from @dblakeharris in this story as to why tires blowing out isn't always as simple tire pressure or camber and how spike loads have an impact. Image @dblakeharris I shared similar thought in my story from a couple of weeks ago. nascar.com/news-media/202… Image
May 27, 2022 10 tweets 3 min read
A lot of components on the NASCAR Next Gen car have tethers so that they stay attached to the car in case they get damaged. Here is a quick diagram with some of them labeled laid on top of a cutaway view of the chassis. Image View of the hood tethers looking up from the left front of the car. Image
Jan 12, 2022 19 tweets 7 min read
Days 2 of NASCAR Next Gen testing is rolling at Daytona.

I’m following the stream here: It is really nice of @PettyGMS to help their drivers to have a better view of the palm trees outside the track.
Jan 11, 2022 8 tweets 3 min read
Not in @DAYTONA today but will be monitoring the Next Gen test remotely and sharing my initial observations below.

My understanding is that the test will run the 510hp engine config and the 1st set of runs will be with a 7-inch spoiler and later they will test with a 6-inch. Much of the aero configuration today will be similar to what we saw at Charlotte with splitter stuffers, engine panel strakes, and diffuser skirts being employed. They are also running the half-height rub blocks today.

Jan 10, 2022 34 tweets 47 min read
We’re live with the @FollowAndretti #AllAndretti @TwitterSpaces now!

twitter.com/i/spaces/1lPKq… Image @FollowAndretti @TwitterSpaces @alanisnking @AlexanderRossi @sting_ray_robb We've just learned that @sting_ray_robb got his name partly due his parents being fans of the Corvette Stingray but also as a nod to his heritage of his family being from Stirlingshire, Scotland bringing the Sting part of the name and the Ray comes from his grandfathers.