4" exhaust

[RUQWKNF27]

Heres mine!! At first I made my own with a race magnum an 4" bends but this one looks better. has the traditional factory buick cut on the tip..

 

[RUQWKNF27]

2

 

[RUQWKNF27]

3

 

[thunderace31]

2

This looks like a huge bottle neck to me right at the end of the DP not good for performance Other wise a nice set up

 

[BlackMetal]

This looks like a huge bottle neck to me right at the end of the DP not good for performance Other wise a nice set up

Well unless you're running a 4"DP or bigger, there's always going to be a bottle-neck in the system.

 

[Underboost]

Whats the most CFM a Hooker 2.5 System can flow? Low 11's - High 10's? Does anyone know?

 

[JayC]

I think the Hooker system starts becoming a restriction around the mid 11 area because of the mufflers. If you replace them with something that flows better, it's probably good into the 10s.

 

[Underboost]

I think the Hooker system starts becoming a restriction around the mid 11 area because of the mufflers. If you replace them with something that flows better, it's probably good into the 10s.

Thanks

 

[thunderace31]

Thats why you need to do a 4" DP when you go to a 4" exasut
RJC has them

 

[Fuelie600]

Well unless you're running a 4"DP or bigger, there's always going to be a bottle-neck in the system.

Going from smaller to larger is not a problem as long as the transition taper is smooth. Larger than 4" into 4" or smaller will create a bottle neck. Brian

 

[Alky V6]

You want to keep any transition tapers to 14 degrees included or less, to maintain a smooth flow. Any higher angles invite turbulence, which restricts flow.

 

[thunderace31]

correct me if I am wrong here but wouldnt a 4" onto a 3" DP be a waist in the sence that the exaust will all ready be pushed into the smaller tube and then when released into a larger tube will slow down do to more space to fill causeing some sort of BP ??
Maybe im off my rocker again lol

 

[J-B Racing]

Hey Joe, We must have run into each other ar Napierville, but I can't remember. I hang with a group of Dodge boys from the states( '68 Charger 9.96, '70 Superbee 11.20's, '67 Cuda 10.60's ). Anyhow, I believe you gained from changing out the Fowmaster mufflers, or in the change of design. I know a 4" is more than enough for most guys, but like you, my Jet Hot coated Kenne Bell 3" single rusted from the inside out after 14 years. I decided then, I would build an exhaust that would not rust, would not restrict down to the 8's, and would look and sound as good as it gets. After much brain picking ( alot of brains in the TR family ),this is what I came up with and i'm very pleased. I'm expecting 9's this year, so this is probably overkill, but it certainly won't ever hinder me, and in another 20 years, my son can put whatever he wants on it. Brian

Yes Brian....we have met a few times at Napierville. I also will try to get the darn Bitxh in the 9`s..but with work and 3 boys to please. Time for myself is hard to come by. Hope to see you there. or let me know when you will be going...

Later
Joe

 

[Alky V6]

correct me if I am wrong here but wouldnt a 4" onto a 3" DP be a waist in the sence that the exaust will all ready be pushed into the smaller tube and then when released into a larger tube will slow down do to more space to fill causeing some sort of BP ??
Maybe im off my rocker again lol

If the taper is correct at the transition, no extra back pressure is caused by the transition.

Flow resistance is a function of tubing diameter AND tubing length AND bends.
A 15 foot length of 3" diameter piping will have more flow resistance than a 15 foot length of tubing with 5' of it being 3" ID and the rest being 4" ID.

 

[RUQWKNF27]

It works well.. I have not a 4" DP so yes there has to be a bottle neck some where... DUUURRR

 

[XxDarkSidexX]

It works well..

is that aluminum piping? Im refer'ing to post dp pipe to be exact. BTW I think Don said it best, tubing flow is a combination of length, size and bends. Ill keep that 14 degrees a bend limit in my notes DON! EVERY lil tid bit helps, and I again wanna say Thanks.

darkside

 

[Alky V6]

is that aluminum piping? Im refer'ing to post dp pipe to be exact. BTW I think Don said it best, tubing flow is a combination of length, size and bends. Ill keep that 14 degrees a bend limit in my notes DON! EVERY lil tid bit helps, and I again wanna say Thanks.

darkside

Mark, the 14 degrees refers to the included angles of the walls for a tapered cone. When you are transitioning from one pipe diameter to another, you should use a cone. The wall of the cone should not be angled more than 7 degrees or 14 degrees included (measuring 2 sides of the cone together, 180 degrees from each other). It is a basic truth of flow dynamics that if you exceed this max angle, turbulence develops and turbulence causes flow restriction in a pipe.

 

[XxDarkSidexX]

I see, looks like I misread again. Thanks for the correction. I might try a new exhaust style n muffler soon. Just working out the small things, such as flow and fit first Im still looking for a 3" to 4" cone shapped transition. The most popular style it seems for this transition just not a cone shape so its pretty hard to find. And reading, then thinking about your basic explaination of flow(the 15' idea), I would assume that a dual 3" exhaust, though it carries more bends and adds more weight VS a single shot. I would have to run a huge 4"+ maybe even a 5" single shot in order to match the flow capability of a dual 3", does this sound right? I was thinking of using the magnaflow 3" y pipe with dual 3" outlets from a single 3" inlet, then going ahead and doing my own 3" dual exhaust. Just ideas floating around though, I havn't gone out and bought an exhaust flow book yet, but I will when I get my MIG

darkside