ICRAZY6

iTrader: (68)

Just a quick run down of the car first. 390 Iron block, massaged 317 heads, Fast 90/90, Brute Speed boost cam, D1sc with 3.7 pulley, 7.65 crank pulley (10-13lbs) 4L65, 3600 stall, 3.70 gears in a Fab 9". Puts almost 700hp/ 650tq down to the tires. I'm currently running pacesetter headers 1 3/4" and Magnaflow exhaust. Just wondering if there's something to be had with getting larger headers vs a pulley swap and tune? What's everyone running for headers right now?

stevieturbo

IMO new headers would not yield as much power per $$$ as a smaller pulley and retune.

Blown06

iTrader: (32)

I can't say for sure......but I'd say there is power to be had. Even more so if you do above and add more boost.

slow trap

iTrader: (22)

i would think a pulley swap/tune would be much more beneficial than bigger headers. and also that magnaflow catback probably needs changed out along with headers when you decide to squeeze out some more power.a set of 1 7/8 or 2" along with duals or a single 3 1/2 or 4" would be quite a chunk of $ but a better exhaust setup will obviously help.

handyandy496

iTrader: (9)

Just researched this before getting my 1-7/8 headers. Seems that on a dyno on a stock ls1 1-3/4 bace line going to 1-7/8 produces 3-4 horses and torque and another 2hp for 2" tubes. Not a lot of hp per dollar. lol. lots of really fast cars running 1-3/4 tubes.

ezzlez28

iTrader: (21)

Not an apples to apples comparison, but last fall I finished my heads/cam stock bottom end car. Exhaust was: 1 3/4" Stainless works (2.5" collectors), catted y-pipe (2.5") thru the SLP Dual/Dual. Over the winter I swapped to 1 7/8" Kooks (old version, not revised 3" collectors) to a offroad x-pipe (3") dumped before the axle thru Borla XR1's.

Entire exhaust was changed, resulted in an average gain of 12-15 RWHP and 15rwtq across the board. I would get that exhaust opened up, larger headers, and get rid of the y-pipe.

stevieturbo

Exactly my point. How much did that 15hp cost in $$$ ? And more than likely the gains were down to either removal of the cats, or the retune...or a bit of both ( assuming you did retune after )

ezzlez28

iTrader: (21)

Bought the headers and x-pipe for ~800 bucks shipped (used). Sold my stainless works and cats for 550. So not much. Most of the gain was from y-pipe to x-pipe, and the larger collectors. They were high flow cats (random technology). You can get the TSP 1 7/8" stainless headers for a great price, and go from there. I think it would be worth it. You're pushing a lot more air through your motor than I am.

After the change, the tuner was able to throw another degree of timing as well. Huge pick-up. 20+ rwtq peak and 20+ rwhp peak.

ezzlez28

iTrader: (21)

And I don't disagree on the smaller pulley & retune, but mine as well do it one shot.

ICRAZY6

iTrader: (68)

I'm leaning toward the pulley swap and re-tune with the possibility of a touch of meth/water to keep temps down. That would keep cost down to about $600 apposed to $2000 for kooks headers and dual exhaust.