The Challenger Drag Pak cars are not street legal. Chrysler began selling the Challenger Drag Pak cars in 2009 as incomplete vehicles to be built into drag racing cars.
Now thatâs a sophisticated suspension!
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Iâm going to say it wasnât an UPgrade of the brakes but a DOWNgrade to smaller rotors, IMHO. You can make them wider to dissipate similar amounts of heat. You can put race pads on to get more braking torque but there is no replacement for diameter!
And drag cars donât need much brake as they only make one stop at a time. Road race or oval cars slow many times per lap over the course of hours.
Brakes are one aspect and a critical one. But the suspension on the original car is also tuned to the OEM tire performance. Putting on significantly different shoes is going to seriously affect the handling IMO and that is also potentially critical. They made many changes to the suspension to accommodate the purpose of that car. Going halfway (or less) and then using it in normal driving environment may be asking for trouble, especially in the wrong handsâŠ
When I wrote that I didnât know that Chrysler was selling stripper models for drag car builds.
But you can, theoretically, downsize the brakes and end up with the same performance as stock with upgraded materials. Need to dissipate heat? Duct air from the front bumper to the rotors like they did on this racing CRX back in the 90âs:
The orange hose is the ram-air for brake cooling. You can just barely make out the matching one on the other side next to the radiator. That thing could run all day on road course tracks without cooking the brakes despite having tiny little brakes.
Then slot the rotors, install up-rated pads (R4/S if youâre driving it on the street as well as the track) and, of course, upgrade the brake fluid. Youâd be fine.
Now, where I get a little iffy on that idea is that yes, youâll end up with the same or possibly even slightly better braking performance than stock. But! If youâd kept the brakes the same size and did all those upgrades, youâd have even better braking performance.
When I mod a car for speed the first thing I do is upgrade the brakes. I view them as the most important feature on the car. I would personally never undersize brakes to fit wheels even if I could do so without downgrading the brakes, because all the junk I have to install to keep the performance the same would make the performance better if I didnât undersize.
But many cars come with different wheel/tire sizes as options. I doubt they change the suspension when they change wheel/tire sizes. Or am I wrong?
If wheel options are 17 inch or 18 inch the tire profile will be different so the wheel and tire diameter will be the same.
IMO, this is a more dramatic deviation than would be encountered switching OEM variations. That being said, relatively big changes in tires are often accompanied by other changes like going from the base model to the Sport version where itâs not just an appearance difference but something functionalâŠ
Yup, you are wrong. Putting wide low profile tires onto a base car with small stabilizer bars, spring and shock and expecting sharp handling with a good ride would disappoint you and possibly make the car dangerous.
The car would be floppy, ride hard and handle like junk. There isnât enough spring or stabilizer bar stiffness to handle the greater handling and not enough shock damping to control the heavier wheel and tire. The ABS, traction control and stability control all would need a new calibration set to optimize performance.
Same for putting squishy tall sidewall tires under a car designed for low profile, wide tires. A manufacturer would never just change the wheels and tires without optimizing everything else. Not even Chrysler.
Been there done all that in building race and track cars. Better pads, cooling hoses, slotted rotors (never, ever drilled, the rotors will crack!) and beefy f4 piston fixed calipers, all to improve braking performance and heat management. You can get more brake torque from race brake pads, sure. Thicker rotors add mass that helps you store and dissipate more heat. Larger diameter adds mass, adds cooling area and brake torque faster than just making them thicker with high friction pads.
That is part of the reason both street and race wheels keep getting bigger and bigger. I donât disagree with you that all these things help but I stick by my comments about smaller diameter rotors being downgrade.
BTW, Just got my new larger 13.8 inch rear rotors for my Mustang to match the 15 inch fronts (shown in a Large pizza box), just need the new brackets to mount the calipers
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I agree. I was saying that it is possible to shrink the rotors and not lose braking performance over stock if you upgrade all the parts, but Iâm certainly not endorsing the idea. Upgrade the parts, sure, but keep it the same size (or bigger) because why keep performance the same when you could improve it?
⊠I wish Dominos delivered car partsâŠ
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My FedEx guy wishes they did, too! Those new brake rotors were pretty dang heavy!
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The FedEx guy coming to my place doesnât mind rotors or even sets of wheel/tire combinations compared to the 25 bags of specialty sand i bought online. Twice. 
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dad and I built a 60âs van with a toronado motor/transaxle in the rear. late 70âs time frame. we used the stock 15" olds rims but there were zero low profile tires available than. we needed a 215/50/15 size which was hard to find than. G50-15? anyway, so we modified the wheel tubs and fender flares which looked ok but was more effort that we didnât really want to do. donât even ask about the toronado torsion arm suspension we used.