Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
TDR Magazine subscribers receive more than the magazine! You also gain additional forum privileges!
Details here: TDR Privileges
Subscribe to TDR Magazine here: https://www.tdr-online.com/
Attention: TDR Forum Junkies To the point: Click this link and check out the Front Page News story(ies) where we are tracking the introduction of the 2025 Ram HD trucks.
Just thinking out loud. If You have a three inch downpipe, would four inch exhaust really do much for it. I'd think that flow would only be as good as the point of most restriction? Just a thought
You're mostly correct. Flow is only as good as the worst restriction. The exception to this is if you take into account line friction over a long distance which doesn't really apply to our pickups. If you're considering buying some kind of cat back system I wouldn't advise it. You can find a system here that will not cost anymore and is a true 4" system all the way out. It's even on sale right now
-Scott
Disclaimer: I have no professional affiliation with any companies associated with this post. Just a happy customer.
Even with a 3" downpipe, I noticed a huge difference when I installed my exhaust (4" from the downpipe back). Not so much power-wise, but EGTs are dramatically lower, and I picked up a few pounds of boost, too.
The farther the exhaust flows the more it cools which slows down the flow. The pipes getting progressively larger with length help keep the flow moving to promote better turbo spool and lower EGT's.
To help even more you can wrap the hot side of the turbo and the down pipe to here it attaches to the 4" with header wrap or heat wrap. That will help keep the heat in the exhaust and keep it moving faster till it gets to a larger area.
What I wanna know, how bout 5" from the downpipe back?????? Thats what I've been thinking out loud about lately Rip or anyone making a 5"piece that fits past the t-case in the 4wd models? I think I can build the rest, but that t-case piece... . I've heard he makes a 4" piece, but then we get into the same thing, 3"dp, 5", 4", then 5"??