BlackGMC

iTrader: (31)

That 3mm translates into ~7% more area to flow. Soooo 7% more possible flow area seems like a worth wild mod to me.

Lucille

1. Dual 3" or possible single 4" on the exhaust at a minimum.
2. Nick Williams or NWIS 102 mm dbw throttle body
3. While the throttle body is off port the TVS intake to match the new TB.
4. Probably worth looking at. Port match the TVS lower manifold to your heads.
(From the factory- mine looked more like an upside down cathedral port than an L92 port)

ayousef

I think a dual 3" would be best and sound "exotic" in truck standards, should sound like a z06.

Blower is port matched to the head.

I dont think i will port the blower but will likely use an adapter to get the NW on

Thanks guys!

Lucille

Seems like a good way to move your intake restriction 3 inches closer to your engine - but what do I know

ayousef

Thing is the opening might be bigger than 90mm but smaller than 102, so the restriction would not be the throttle body anymore, it would be the blower opening. I understand what you mean, but I can really get alot more power by a small pulley swap if i was after every last horsepower. I just want the truck to be more efficient, no need to have a 427 restricted by a truck throttle and exhaust that belongs on a stock 5.3l truck

silver-mod-o

iTrader: (15)

If you're not going to port the opening, take the TB off, measure the hole, find a TB a hair bigger and roll with it, all you're going to the able to flow is whatever that opening is... If you're not willing to port it, youre restricted to that size.... If it's a 93-94mm go with a 95, if it's above 98'ish, go to the 100+ IMO but there's no need in dropping the cash on a high dollar throttle body working with a stock size opening.... Ever pissed head on into a hurricane?


And about the X pipe argument, were they before or after the X? Some will argue that exhaust flow is exhaust flow, but..... I've seen more than one truck lose power with an X pipe with everything else being the same in similar conditions, on the same dyno... I just don't believe the theory is all it's pumped up to be. Might make a cool sound but so does a slinky... Get what I'm sayin? Put an H pipe in to balance the banks, hell, do your X pipe if you wish but by all means that setup needs big headers and dual 3" at minimum....

AKlowriderZ71

iTrader: (22)

Big headers, big exhaust, and big throttle body. Just do it.

Look at my mod list, on a 5.3, you certainly will benefit from the investment.

A Low Dime

iTrader: (13)

There was alot more to that Mustang X pipe dyno test. It was completly perfect length. It was 3" dual piping into an x pipe, 4" coming out of the x pipe into some really nice mufflers, and again, all the piping was equal length.

The test was done open headers vs. the above mention 3" xpipe/4" exit.

livefast1

iTrader: (1)

Cutouts were before x pipe thus testing open long tubes vs. x pipe and spintech race mufflers I believe.

hog

If your headers collectors are the same diameter as your exhaust headpipes, H-pipes are a great way to "terminate" the tuning length of the collectors. The tuning effects of the collectror/headpipe diameter will continue until the exhaust pulses reach a change in pipe diameter, cats or major bends.
If your header collectors are smaller than your exhaust headpipes than the H-pipe will be less effective as a tuning device.
I suggest H-pipes to be 2/3's the diameter of the exhaust. If you're running dual 3" headpipes then run a 2" headpipes.(EDIT shoudl say, run a 2" crossover)

Try and keep the headpipe length from the header collector to the h-pipe as equal as possible. In some cases your H-pipe may not run perpendicular to the bumpers of the truck. This is what GM was trying to accomplish when GM staggered the cats in these 2 GM Vortec 350 exhausts. It would be much simpler to run pipes down each side of the truck if the fuel tank was moved.

1/2 ton L31 exhaust on left(dual 1 7/8" ipes hugely crimped down in the bends
3/4 ton L31 exhuast on right (dual 2-3/4-3") with better bends and larger cats


peace
Hog