I have Never seen z rated off road tires. I will probably pick up a set of BFG for my next desert run , since my current Coopers are only Q rated at 99.
Sponsored
Sponsored
- First Name
- Min
- Joined
- Jan 31, 2022
- Threads
- 37
- Messages
- 615
- Reaction score
- 917
- Location
- Denver, CO
- Vehicle(s)
- 2019 Ford Mustang, 2023 Ford Bronco
- Your Bronco Model
- Badlands
I was over exaggerating lol these bricks won't ever reach that speed
Even BRaptors (governor at 120mph) are equipped with BFG K02 which has an R rating (106mph) so yeah BFG should suffice.
Agreed. I have zero doubt my 2dr 2.7 could surpass 125 without a limiter also.
- First Name
- Jared
- Joined
- Feb 20, 2023
- Threads
- 45
- Messages
- 6,536
- Reaction score
- 12,568
- Location
- Denton, TX
- Vehicle(s)
- 2023 2dr Badsquatch
- Your Bronco Model
- Badlands
I did 75mph once in my 8" lifted '82 Ford F-250 with the gimpy steering, granny four on the floor, and leaking master cylinder. We almost died (that truck had many problems!). Also, that one time in the rain on the overpass, or turning the corner when we almost took out the mailbox/tree/random parked car, or when... 
Sponsored
Whipple Stage 1 Raises it to 120 mph limit. So far I chickened out at 112.....
Go to know. I’ve held mine at its limits off road many times. 5” lift and 37” definitely makes 101mph a little more of a challenge.Whipple Stage 1 Raises it to 120 mph limit. So far I chickened out at 112.....
- First Name
- Cliff
- Joined
- Nov 15, 2021
- Threads
- 4
- Messages
- 1,382
- Reaction score
- 2,435
- Location
- San Angelo
- Vehicle(s)
- Bronco
- Your Bronco Model
- Wildtrak
Curious to know what the drag coefficient is on the Bronco specifically.
I've had it to 107 with a steady 20mph quartering headwind, accelerated just fine up to the limiter.
Mine is certainly not a poster child for low drag, high speed, or even fuel efficiency.
I had to use both Cd and frontal area to calculate top speed (obviously). I'm pretty sure I couldn't find either for the Raptor but found Cd for a non Raptor and then did a very rough calculation of the frontal area or increase in frontal area. I can let you know the numbers I used later when in front of my laptop.
- First Name
- Cliff
- Joined
- Nov 15, 2021
- Threads
- 4
- Messages
- 1,382
- Reaction score
- 2,435
- Location
- San Angelo
- Vehicle(s)
- Bronco
- Your Bronco Model
- Wildtrak
Sure, no rush, just curious what kind of values you were running.
Sponsored
- Banned
- #102
Those YJ leaf springs are very nerve wracking at higher speeds for sure lol. My old 04 TJ was lifted on 3 inch BDS suspension lift and anything above 90 was no go territory with terrible handling, terrible wind noise, etc
I’m far from an expert in aerodynamics, but just looking at other vehicle measurements, I feel that frontal area is a very high estimate
I brought this up in a different post a while ago, and while maybe not exactly the same, the frontal area of an H2 hummer is only 26.5
Last edited:
- First Name
- Cliff
- Joined
- Nov 15, 2021
- Threads
- 4
- Messages
- 1,382
- Reaction score
- 2,435
- Location
- San Angelo
- Vehicle(s)
- Bronco
- Your Bronco Model
- Wildtrak
Gotcha, so you were factoring it for the Raptor then?
My guess would put a 2dr Bronco somewhere between 25 and 28, and the 4dr at 28-32, just loosely basing it off figures for similar vehicles such as the XJ, TJ, and JK 2/4dr, but one of the problems here is that those figures are based off stock vehicles with stock suspensions. Lift any of those vehicles, add bigger tires, and frontal area will naturally increase due to the tires and drivetrain being more exposed to the air. That's why you'll see such a variation in mpg between the tiny tire 2dr broncos and 4dr sasquatch broncos. Cd is a little trickier, as the Bronco should have an equal to or better Cd than any Wrangler on the road today simply due to its more aerodynamic a-arm setup with superior body aero considerations than a new Jeep would have. Just to put it in perspective, the difference between a hard and soft top on a Wrangler changes cd by only .03 but frontal area increases by .5sqft, so the relationship between the two is also important. Coincidentally, .55 is the Cd for an older TJ, so I'd probably place a 2dr Bronco a little lower, maybe at .45 or so.
38sqft would be where you'd land if you took the height and width, roughly 41.5sqft depending on the source of those measurements, and split the difference between a generic frontal area multiplier of .85 for typical passenger cars and 1.00 for trucks, around .9-ish. It's a fair estimate and rule of thumb for basic efficiency comparisons between vehicles, and that factors in wetted area for a typical length that you'd see as well as all the other nitpicky stuff (cars being shorter and less undercarriage exposed, trucks being longer with a draggy bed and whatnot). But when you start calculating drag limited top speed, it really does need to be super precise, and those figures seem a bit high to me. But that's just my own ballpark estimate and what I've observed in practice, as I certainly don't have accurate numbers for any of it. I doubt any of us could provide an actual figure for a drag limited top speed on a Bronco without wind tunnel data anyway.
My figures are estimates. Both though will be significantly different than for a 4dr Wildtrak. Using 0.5 and 36 yield a top speed of 132.
Sponsored
