I watched an ARH video that claims “Our Header kit picked up +17HP and +33RWTQ at peak and as much as 37HP and 37TQ across the mid range!”

This is with headers only. No tune. I’m on the verge of buying a set, but I thought I would ask what people have truly experienced because these numbers just seem inflated to me.

What’s your experience?

 

The car sounds better. Butt dyno doesn't register any improvements. They're best utilized with several supporting mods. I did headers, ported TB and airbox/filter. It just sounds cooler.
However, I did get a baseline run on a Mustang dyno before doing anything but haven't gone for a follow up to see if the car picked up anything at all.
They're pretty easy to change out if you have access to a lift.

 

I wish I had more to add other than I've been chasing down as much anecdotal evidence and dyno graphs as I could find for the years I've owned the c8. If you believed manufacturers, we can gain loads of power with bolt ons. But nobody's seeing more than ~30 with $4000+ of parts.

I do have a question, and I havent seen the timing tables on a c8 tune (due to that $2500 cost of admission, ugh) but it sure seems that these must be aggressively running all the timing that they can manage? the factory parts arent limiting flow that much at all (cats aside). This is seemingly further illustrated by the fact that e85 wakes them up big time, but headers, intake, etc all barely make a blip. The $300 intake on my c5 gave more rwhp gains than $4500 of premium parts on a c8, and the c8 is starting with a ~100 rwhp advantage, so the overall % is just barely there.

I swear it seems that we have two functional choices: aftermarket high flow cats and a throttle body, or going full send and leaping to aftermarket heads or ported heads/cam/intake/tb/$2500 ECU mod/tune/etc. and neither of those are cheap.

 

Those numbers were backed up by another independent facility back in 2020. The results were legit.
As an aside, that same car with almost every bolt on and weight reduction went a PB of 10.20@133 on e30 without tuning. ARH is the best header on the market.

 

I love their products but I did a back to back a few years ago on our shop R&D C8. it was worth 2 hp. On a heads/cam car it was worth 12 peak and 18 in the middle at peak tq.

 

This subject has been debated many times over. I did actually track testing with my 23 C8 coupe Z51 3LT. Car went 11.40s stock at 119. I added all the boltons to include ARH, CAI, PIM, PTB, CB, little E85 mix and DRs. Car went a consistent 10.80 at almost 126. Power is measured by trap speed, and I have not seen any C8 run 125-126mph without headers with full body weight, especially a 3LT optioned C8. I know some folks like the dyno, which is a great tool but ultimately, the drag strip confirms all results with a decent DA and track prep.