I have a 05 AT that got 234 RWHP on a mustang dyno on a 68 degree day.

Question is I just ordered a Copper Iso thermal 5/16 spacer, a pop charger/ztube, and a grounding kit. How many RWHP should my car go up and how much BHP should I have after these mods are installed. Pop charger says 6.5, the grounding says 3hp, and the Spacer says 11. So am I really going to be adding 20.5 RWHP or is just all just advertisement bs?

Spacer = yes.

Other two = no.

Expect 9-12 whp.

so the pop charger/ztube and grouding kit dont add jack huh?

Any other relatively cheap mods that add some good RWHP?

this car comes so tuned from factory that its hard to get a lot of power n/a

Im thinking after these mods the final ones I was gonna add were


Stillen sway bars, and maybe High flow cats?

I wonder if the cats add any power. But yea Im not looking for F/I power. Just a little more power than stock and I am set.

maybe 10hps tops

For sure Dyno it again and let us know how much it really did add!!

Depends on the forced induction route you take. If you go supercharger then add a set of headers and new midpipes. If you go turbo skip the headers, but still pickup some o/r test pipes.

Im installing the parts in May. Sometime this summer I will re dyno it and see how much I really gained.

234rwhp on a mustand dyno for a stock 5AT is very impressive. I only wish that mine can be that good.

I'm sorry that I don't have any answer for you. But soon I will. I'm trying to prove something

Im doing the same mods too. I would like to know the dyno also

They may have been unloaded numbers, so more like a dynojet

Whats unloaded #'s mean?


I heard mustang usually give lower #'s. This guy in a 05 350z with an injen exhaust and manual put up 255 RWHP that day.

Seems like my run was pretty good for an AT. I tried keeping my AC on all morning. Someone told me that keeps your car cooler and gives you higher dyno reads?

Unloaded means they do not load the dyno. They calibrate it with the weight of your car, but do not apply a load. Kinda makes it give numbers more like a dynojet.

ahh ok I have no idea if they did or not. So are you saying the #'s are inflated? that a stock 5at cant get 234? because my friend with 5 or 6 mods on his 04 5at dyno'd 238 RWHP on a dynojet. He was like it could be error that you got 234 stock.

He was expecting 210-220 RWHP stock. I dont know he probabaly is right could be an error.