I'm interested in what would be needed in modifications to get 400 "rated" or engine horsepower. I know a stock SRT6 is advertised at 330. I'm not a wrench head, so when someone pulls up next to me and asked how many horses I have, I'd like to give them the most commonly quoted number not a rear wheel dyno number that will seem real low to the public.

Would the Needswings CAI get it close? If not, what size pulley would reach that 400 number?

Thanks

 

The SRT6 is advertised at 330hp at the crank (engine). In actuality, it is 349hp at the crank (SRT engineers have verified that it is the same as the MB C32/SLK32 engine).
IMO - a pulley (say a 178mm ASP) and the NW CAI will get you to ~400hp at the crank.
Most SRT6s dyno at ~29Xrwhp. Figure a 15-16% driveline loss of power.
Hope that helps.

 

Check this thread out (New SC pulley for under $600 installed).
You may contact me at: danwanpen@aol.com.

 

320-330 rwhp ~ 400 "rated" horsepower, so a pulley & coild air intake should pretty much do the trick.

 

Or a good intake and an ECU tune would probably do it.

The easy way to figure it out is like this:

Original Crank HP = 349

Multiply that by .8 to determine wheel hp:
349 * .8 = 279.2

Since most of the mods list the increase in wheel hp, here's how to do the calculation in reverse:
Cold air intake adds 25 whp

divide 25 by 80, then multiply the result by 100.

25/80 * 100 = 31.25 crank hp

So, to get an SRT above 400 crank hp, you would need to add mods equivalent to 40 wheel hp. So for less than $1000, you should easily be over 400 crank hp. If you catch a group buy for both the tune and the intake, you should be able to do it for about $700. Then put the cash you save into a pulley, and you'll be aweful close to 450 crank hp.