We all know how formidable the Hellcats can be on the drag strip and on cruising out on the highway. But, what in the world possesses a person to believe that a HC Challenger can be a half-way decent autocross car? Well, a lot of it is in the numbers and below the surface - plus a little risk management.
I am going to break this down based on my experience, the numbers, and a little educated guesstimation.
My experience:
I've driven nothing but big over-powered American cars throughout my autocross "career". I've never raced a small car with a short wheel base and balanced power. Nope, just good old mullet machines - some way worse than others.
'91 Z28 with a really warmed up TPI 305 with a 5 speed on three different brand tires and a completely blown suspension.
'02 B4C (police Z28) with eBay lowering springs on shot factory orange shocks with Sumiturdmo hockey pucks.
Some days it doesn't go your way:
'87 Buick Turbo T with lots of suspension work and running 315/35R17 Nitto NT05Rs out back.
And some days it does go your way:
I have yet to get my wagon out (most of the running gear came out of my wife's B4C).
The point here is that over a decade you gain a lot of experience racing any car, but learning how to handle a crappy chassis well before progressively moving up to a better car/parts pays dividends in the long run. You absolutely could step into a built car and run decent, but you will never really know your limitations. So, having confidence in autocrossing a big car like the Challenger is not an absurd proposal for me.
By the numbers:
As I mentioned previously I had considered a 2015 Z28 (
https://www.caranddriver.com/chevrolet/camaro-z-28/specs) which is very comparable to the widebody Challenger (
https://www.caranddriver.com/dodge/challenger-srt-srt-hellcat/specs) in length, wheel base, width, track width, tire width (not compound, easily rectified) etc. Obviously the weight, CG, and suspension configurations are going to differ - but, how much in the hands of a relative novice is not enough to worry about when you run for fun in club racing. If it bugs you that much you are either a real race car driver or an asshat racing spec sheets - in either case the Z28 or HC are not the car for you so move on with your life.
Spring rates, sway bars, and shock design are a big deal in managing a tubby machine. Dodge gets this with their factory suspension tuning. Note the change between the standard HC and the Scat Pack widebody spring rates in the back - there was obviously something to be gained there (especially compensating for the SPWB's hollow sway bars; lighter yes but offering a lower rate). Keep in mind that the SPWB has less sprung mass to control so the HCs big spring/big bar vs. SPWB big spring/biggish bar combo is probably nullified in this situation. Note, there are no comparable lap times offered up by Dodge between the HCWB and SPWB for a reason - the difference is marginal at best.
I've been in touch with the dealership responsible for my order and sent them my desired suspension settings to be changed prior to me taking possession. Front -1.5* camber, 9.5* caster, .25* total toe in and rear -0.5 camber and 0* total toe. These settings are within the factory acceptable ranges and will make the most of the suspension in a stock configuration - which is a requirement to avoid taking points penalties in my class (more on this in a minute).
The lot I currently race in has the capability to reach speeds of about 60 mph in very short bursts - meaning that this is a "first gear" track in a stock M6 HC. The manual transmission comes in handy as autocross can leave an auto searching or with contemporary short geared transmissions choosing the closest gear. Ideally, I'd have some 4.10s and dump it in second.
Risk management 101:
This brings me to why the Challenger HC is a good choice (despite a few inherent compromises) for autocross. SCCA classes the Challenger HC as F Street (which coincidently is where my Buick started before the mods) - in my local club the Challenger HC becomes D+12; for the sake of comparison the SPWB is classed as B Street (2015 Z28 is A Street) which is a huge hit when you see what it is up against. The trouble is that being remotely competitive was always a challenge in my Buick as the mods pushed it into A or Prepared classes and it... I... got tromped. So think about it, the Challenger HC sits square on 305 tires, 700hp (overkill), modern adjustable suspension aaaaaand I can still pull 400lbs out of the car. You can see the other cars it stacks up against here:
https://www.scca.com/downloads/45362-2019-04-11-street-category-by-manufacturer/download it is a hilarious dumping ground of cars. Most of which never show up - so it is mostly Civics and Miatas - so it becomes a driver's race. A few minor mods would only move the HC up a class - I've done the math and it won't be worth it for a while; and if I am successful, the club rules will get rewritten.
Fast is smooth, smooth is fast. Even on a rhino.
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