Stock exhaust manifolds

[supragod98]

Anyone know at what power level they should be replaced? Also what about having the stock one ported? How much power will ported ones hold up to before becoming a major restriction? One last thing anyone know who ports them?
Thanks in advance

 

[nastynivek]

Good question. I've been wondering the same thing, as I didn't want to purchase headers and have them not make a power difference. Hope someone gives some experienced insight into this one.

 

[Derek@Amazon]

not sure but i think i can bust out an 11 on mine with my upper only...


but honestly ive thought about it ALOT but after installing a set i wont be doing it unless i have to or i get on HELL of a deal on them. ill prolly just do a high flow mid pipe and cat back

 

[supragod98]

Anyone got any input?

 

[LIGHTNING LARRY]

I pulled an easy 473 rwhp with stock manifolds. :thumbsup:

Unless you're running a built motor and lots of boost I feel they are a waste of big $$$.

 

[2004SVTLightnin]

Umm, I really dont remember there name, but there was someone on here who did a built motor and was around 500-550 RWHP with stock exhaust, did LT's with high flow cats and jumped up to 620-630RWHP. I think they did something other than just exhaust, but the stock was restricting badly!

 

[brucewrs]

I would'nt waste my money on headers.From what I have read on here and other boards,they dont make much of a difference. Getting rid of the rear cats and putting on high flow cats help a little.

 

[Nvr_Spds]

Umm, I really dont remember there name, but there was someone on here who did a built motor and was around 500-550 RWHP with stock exhaust, did LT's with high flow cats and jumped up to 620-630RWHP. I think they did something other than just exhaust, but the stock was restricting badly!

Was it Camcojb?

 

[203Cree]

Was it Camcojb?

I was gonna say the same thing. Look on his website, it give the results.

 

[Jesse@MBRP]

My stockers are ported...made a decent difference

 

[2004SVTLightnin]

Was it Camcojb?

yes it was......thanks!

 

[Derek2001]

I have a set of kooks longtubes on my truck. I really dont see the problem with install, i think it took me like 8hrs on my back. The absolute worst part of the entire job is removing the stock componants. As for power increases, i cant tell you, as i've only dyno'd one time, and that was fully modded. I do know that they add more under the curve than ppl pay attention to, i wasnt looking to pick up peak hp or anything. Plus i thought they'd be beneficial when i go to a 6lb lower. Then again, they'll be even more beneficial when i go built here in a year or so.

 

[supragod98]

Jesse,

who ported yours? Did you do a dyno comparison and get #'s? If so please post them.

 

[camcojb]

yes it was......thanks!

Yes it was me. I stuck with the stock exhaust as long as I could. Maxed out at 578 rwhp and 597 rwtq. Added the full exhaust (Dynatech headers, high flow cats, and Bassani cat-back) and with no other changes and 1 psi less boost made 621.5 rwhp and 708.7 rwtq.

So if you're at the high boost lots of mods level it's a huge difference. But at 450 rwhp or the difference is much less.

Jody

 

[Lightning28307]

THe headers helped me tremendously I didn't have it dynoed befor but I know that I pick up alot of power with the headers and it was on my stock block. For those that have asked before unsure of new motors horspower and torque still in "THE BREAK IN PERIOD"

If I had it to do all over again I would buy the headers if I had the cash, just because then I have them a, and b my truck sounds mean as cat piss

 

[Jesse@MBRP]

Jesse,

who ported yours? Did you do a dyno comparison and get #'s? If so please post them.[/QUOTEt]

The guy who ported my heads...they did a good job and it made a pretty noticable improvement on the low end of things