I just got my Kooks Headers from JDM and high flow cats and mid pipes put on this wk-end. What a sound!....its awesome! It does seem like its pulling harder too....It better be for the $1300 I forked out for it!

 

Do you have before and after Dynos ???

I've wondered what the difference would be and what the
HP per Dollar spent would be.

 

No, I don't have any dyno results. It's actually probably not worth $1300 but its a good mod...just EXPENSIVE.

 

Where is it that our trucks start to benefit from aftermarket exhaust? Below 12.50's?

 

Well I wish I could scan & post my sheets, but I can't.
sorry if it gets long winded, since the first run after exh., down shifted and was scraped, I'm comparing new 2nd pull #s(which are about 14hp&25 tq. lower than 1st pulls according to my previous 2 times on same dyno) to old 1st pull#s. Also the new #s are heat soaked (45 min drive in 85* and straight onto dyno) old had min. 1/2 hour cooldown 53* out.
also these are SAE corrected #s so air temp shouldn't make a differance but the heat soaked part does.
Before#s
peak 374.4 hp@4600stayed in the 370hp range from4400-4800rpm
peak tq. 466.8@3800rpm stayed in460 range from 3400-4000 rpm
New #s
389.9 hp@4700 rpm stayed in 380 range from 4400-5300 rpm
473.9 tq. @4000 rpm stayed in 470 range from 3800-4000 rpm
worst case gain "on mine" 15.5 hp & 7.1 lb ft tq. ( if compared to previous best 2nd pull) 29.7 hp & 32.8 tq
overall stayed ABOVE old hp from 4300-5400rpm, and tq. from 3700-4100rpm
so without question it comes on a little sooner and carries deeper
I have to get back to the track someday
Mods are
JDM tuned flip chip, 4lb lower, PHP extrued honed upper plenum,single blade tb, elec. fan, Cobra R waterpump, 170* therm. JLP cold air& thunder tube, kooks lts., hi flo cats& mid pipes, silver bullet, FTVB, 58" t bars, 2" drop shackles, PSP line lock kit, JDM driveshaft loop,

 

So it sounds like I should have made some HP with my mods.....Any more replys on this??

 

Silver 2002
I always heard the factory exh. was good for 500 hp, but never heard if that was flywheel or RWHP, so I figured it was going to be needed before I could go much further anyway, if it was flywheel hp. figuring a 20% loss to rear wheels, it would be there with almost any of the mods left, so I'd get it out of the way now and not worry about exh. restriction in the way of future mods
sound is awesome and nothing but compliments "from car people" and the higher dollar mod is out of the way, Now for the ported blower

 

On my stock engine, the headers worked nicely:

 

That looks like pretty nice improvements for a stock motor. I would think I should get more with my mods....but I don't know for sure.