Need real-world exhaust advise

[xm20k]

xc_hide_links_from_guests_guests_error_hide_media

 

[CalSgt]

I wondered. I also figured that would be one less thing to have to upgrade when/if the engine gets a wake up. Hopefully a major wake up.

Nothing wrong with 3" on a SBC or a BBC... It's only a factor if you're worried about it being loud.

 

[Ricko1966]

Nothing wrong with 3" on a SBC or a BBC... It's only a factor if you're worried about it being loud.

You lose exhaust velocity and scavenging if to big just like too big of primaries on headers

 

[Rustisbest]

xc_hide_links_from_guests_guests_error_hide_media

Cant argue with their results. It's not the typical crossing over right under the transmission bellhousing single exhaust either. The first 3 or 4 feet is 3" that everybody says is too big.

 

[xm20k]

Cant argue with their results. It's not the typical crossing over right under the transmission bellhousing single exhaust either. The first 3 or 4 feet is 3" that everybody says is too big.

I was surprised how well the single 3" exhaust with the straight thru muffler did on a 400+HP engine. Tells me my 3" dual setup with that style muffler was the right call as far as my build is concerned.

 

[78C10BigTen]

I’m with @Ricko1966 on this one… 3” duals is just unneeded noise on a mostly stock SBC.

I’ll add that larger pipes are more likely to drone, google said so and everything on the interweb must be true!

You must be registered for see images attach

If you’re willing to re-think your pipe size I can confirm 2.25” duals with “super turbo” cheap mufflers sound great on a stock motor with a lumpy cam and should have minimal drone.

That being said quality resonators can make a world of difference on the drone front. I put the 2.5” version of this one on my Jeep because it was almost intolerable on the highway for any amount of time. The 2.5” version costs double of the 3” one for some reason but it did cure the majority of my drone issues. Resonators alone aren’t enough to eliminate annoying exhaust, instead use them to complement mufflers that produce a tone you like.

You must be registered for see images attach

Muffler and resonator location makes a difference too, the long straight portions of tubing are the most offensive for drone. Break those long straight sections up with your mufflers and resonators if you choose to run them.

I don’t have enough time behind the wheel on my most current SB build to say these mufflers don’t drone but I haven’t really noticed them to be annoying either. They are a little loud but not droning in the cab.

It seems to turn heads when I drive down the street, maybe because they have a totally different sound than the chamber mufflers that everyone seems to run on classics and V8 trucks.

2.25” Flowmaster HP2’s with Borla 4” tips that have resonators built in.

You must be registered for see images attach

You must be registered for see images attach

I like your advice on usin rezzies... ive been toyin with ALL settings on my s10 and cant make anything what i want. I have a muff i like the sound of but no matter where i put it or what amount or kind of pipe i put on it im still dissappointed. Yes i know its a v6 and they suck to make sound but im tryin. I currently have a 2.5" thrush rattler on the y pipe with the over x member to a turn down. Yes its loud, but sounds good at idle. Im wondering if a res would make what i want. Sorry to derail the thread.

You must be registered for see images attach

 

[xm20k]

A resonator or even a glass pack/race bullet the 12-18" ones will deepen the tone of any muffler in the system that's mounted after it. Did this a lot on 4- and 6-cylinder engines that sounded too raspy.

 

[Ricko1966]

I'd rather see a real world test below 3500 rpm long tubes with 2.5" duals vs. mid length headers with 3" duals at rpms below 3500, the speeds most of these will be driven at the majority of the time. You can also make more power with a bigger cam,and a single plane, but not more power where it's needed on a driver type car. Lots of people on this forumn complain if their engine turns more than 2500 rpm for real world driving. Edit. Looks like they picked up 20hp and 30 ft lbs at 3100 rpm,more power, at a more commonly used rpm. Gave up 8 ftlbs at a peak rpm,that will rarely be used. Using a single 3" with a good muffler vs 2.5" duals.And long tubes would have brought the bottom up even more.

 

[xm20k]

I'd rather see a real world test below 3500 rpm long tubes with 2 5 duals vs. mid length headers with 3" duals at rpms below 3500, the speeds most of these will be driven at the majority of the time. You can also make more power with a bigger cam,and a single plain but not more power where it's needed.

The issue I see is anything stock under 3000 isn't really grunting against the absorber and probably won't show anything that might be considered outside of margin of error as far as a dyno is concerned.

 

[78C10BigTen]

Nothing wrong with 3" on a SBC or a BBC... It's only a factor if you're worried about it being loud.

My 78 has long tubes, true duals with no cats and flowmaster super 44s all in 3" straight back to the axle and a 90 bend turned at 45° right before the rear. Its sounds good and i like it and it gets lots of compliments but yes it drones but i dont particularly care. Also the engine is bone stock.

You must be registered for see images attach

I turned the 90s down at 45 after this...

 

[Terlingueno]

The Hooker long tube headers are the only part of my dual exhaust system that isn't original to the Sub. One of the mufflers was replaced before I owned it. Also this Sub came from the assembly plant with no cats since it was designed for leaded fuel. My most likely path is replacing everything from the headers back. Looking at 2 1/4 inch pipes and some good turbo mufflers. Stock Goodwrench 10067353 crate motor.

 

[Rustisbest]

Real world you're not gonna be driving around at low RPMs with it at WOT either. Gonna be a smaller difference at part throttle when the engine is only making 50 hp.

 

[WesN]

Headers, 2 1/2” pipe, “turbo style mufflers” and turn downs gave horrible drone at some rpm. The fix was to install a crossover pipe. I made it so it could be removed with one side so I can remove the exhaust one side at a time and don’t have to fight with the whole thing. Anyway the end result is that it is now a Pleasure to drive.

 

[73 cheySuper]

As said several times, 2.25 will work with what you have, 2.5 will work up to around 475hp. I have a 427 in my chevelle that puts out around 535hp, and I chose Borla ProXS 3 inch mufflers, but ran 3 inch to the muffler, and 2.5 tailpipes. It's perfect. A big advantage in snaking tails in and around stuff with 0 performance loss. I ran 2.5 inch front to back in my '73 K20 454, and it's putting out around 425hp.

 

[blackdot25]

For our 355 build we choose this route,

• Hedman Standard Duty Black MAXX Ceramic-Metallic Coated Mid-Length Headers
• Specs: Oval Port, 1 5/8” Primary Tubes, 16G Mild Steel, 3/8” Head Flanges, 3” Collectors, 2 ½” Reducers
• Headers connect to H-Crossover Pipe, dual Borla Mufflers with behind rear wheels exits

The Borla Mufflers were the key to eliminating the drone. Though compact in size the mufflers are made of heavy gauge steel and are 40-50 lbs each. They sound great and turn heads everywhere we travel.