There is a new system that is being sold at www.a-1performance.com It is a dual tail pipe, cat back system, but I'm worried that I might lose some low end, so I want to know what y'all think. It is a 3 inch pipe going from the cat to the muffler which then exits into two 2 1/2 inch pipes which exit on both sides of the license plate. Will this be too much loss of backpressure or will it be just right? It is being sold for 259.95 so it's not a half bad deal either.

 

I don't think backpressure is the issue. Lower backpressure is better. I think the problem with too large of an exhaust is gas velocity. If the exhaust is moving too slowly thought the system (which would happen if it's too large) scavenging isn't as good and torque is lost. For max horsepower, Flowmaster recommends a 2 1/2" single exhaust for the size and HP of the 4.2L. I forgot what the correct dual pipe size is. I went with a single 2 1/2 and didn't lose any torque. Actually, I think I gained all over.

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Danny
'98 F-150 Std., RC, SB, 4x2, 4.2L, 5-sp, 3.08, AC, speed control, rear slider
with Syntec engine oil, MTL trans fluid, Edelbrock shocks, 50 Series Flowmaster, K&N with airbox mod, electric radiator fan

 

Just moving post to top of page to try and get more repsonces.

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Finally, the day has come! I am now the proud driver of BIG RED! '99 S/C, 4.2, 5 spd, XLT, Bright Red Clearcoat, Medium Graphite, Cast Aluminum wheels, Lund bug shield, Limo tinting, Pendaliner, Infinity References all around, (amp in process), (subs for x-mas), (Dynomax Cat back coming), (if product released, will aquire Airaid, "HINT HINT EVERGREEN!")

 

charles f.,

I got the same system on my truck and had A-1 install it for me. For about $10.00 dollars less than the ad. price. But to me it gained more toruqe than the stock exhaust. It sounds like a V6 when going throw the gears. But it does have a good sound sitting at the light. I had bells put on the tips by the way.