Topic: Anti reversion chamber fab (Read 25603 times)

mandrel-bends · « **Reply #30 on:** April 28, 2010, 07:53:14 PM »

Dave - the 550i is a 4.8L v8 that is rated for like 350 hp and the m5 and the m6 have the same engine. I would be very interested to know what his mods were to get 50 horse. I know of quite a few people who are getting 500 wheel with just bolt on mods, so he is definitely in the right neighborhood.

I was also thinking about installing those anti reversion cones first thing in the exhaust right after the pre-cat. I may test that as well.

The system is getting dyno'd on friday at psi. Should see some interesting results. The video of the original dyno is here:

2006 BMW E60 M5 on the dyno at PSI

mandrel-bends · « **Reply #31 on:** April 29, 2010, 10:48:26 PM »

Ready for testing.

Stock H-pipe w/ Resonator (deleted)

ratcityrex · « **Reply #32 on:** April 30, 2010, 12:02:54 AM »

SEX!

mandrel-bends · « **Reply #33 on:** April 30, 2010, 02:11:33 PM »

So the new #s are in: 411HP/368TQ vs 406HP/362 from the previous best. All stock cats, Stock intake, etc. Not too shabby.

So at this point we've just deleted the rear resonator, added twin anti reversion chambers, and replaced the stock h-pipe with a dual merge collector x-pipe.

Next up were going to add (2) more anti-reversion chambers right after the discharge of the headers and replace the twin stock catalytic converters with a set of resonators.

3" version for right after the headers: (Exhaust goes 3" down to 2.5" through catalytic converters currently)

mandrel-bends · « **Reply #34 on:** May 05, 2010, 12:30:20 PM »

A pic of the reversion chamber after putting ~200 miles on it. Notice the back of the chamber is highly discolored from heat versus the front of the chamber. Good sign they are working properly.

Starting on section 1 today. Removing stock catalytic converters and replacing them with resonators. Adding an additional larger anti-reversion chamber right after the header.

mandrel-bends · « **Reply #35 on:** May 05, 2010, 02:43:50 PM »

Resonator is going to be a squeeze. We are using some 3" ID x 4" OD 18" case resonators from magnaflow. Straight flow design. Have to wack off the ends to make it fit.

Location of front anti-reversion chamber.

mandrel-bends · « **Reply #36 on:** May 05, 2010, 04:40:01 PM »

Side by side with stock and new piece.

Fab

Joseph Davis · « **Reply #37 on:** May 05, 2010, 04:50:19 PM »

Quote from: mandrel-bends on May 05, 2010, 12:30:20 PM

A pic of the reversion chamber after putting ~200 miles on it. Notice the back of the chamber is highly discolored from heat versus the front of the chamber. Good sign they are working properly.

Devil's advocate here. If they were working, meaning that there was a predisposition to reversion, then wouldn't the front of the chamber become discolored from the latent heat in the exhaust that tries to backflow, but is not allowed to?

bigdaddyvtec · « **Reply #38 on:** May 05, 2010, 04:55:55 PM »

Being the rear reducer cone is discolored from heat due to backpressure???

mandrel-bends · « **Reply #39 on:** May 05, 2010, 05:06:48 PM »

I was thinking it was showing a higher pressure at the outlet from the back pressure generated inside the chamber (and hence high temperature) zone at the re-entry point to the chamber. I know if we were to take out the entry tube on the inlet side (which was precisely calculated for length & ID based on the the patent) the entire case will turn the same color but it wont be anywhere near that dark. Anybody know how these things are supposed to work?

92CXyD · « **Reply #40 on:** May 05, 2010, 05:14:33 PM »

I suspect the discoloration is due to a restriction of flow when the pressure wave fronts slow down and an higher pressure wave (behind the first) slams into it.

In other words the the exhaust stream is not moving at the same speed from beginning to end and slowing down.

I believe you want to keep the tapper angle at 10deg or less one size to the next. $:-\$

mandrel-bends · « **Reply #41 on:** May 05, 2010, 05:17:17 PM »

According to the patent 20 degree was acceptable. 10 degrees would be a huge taper, but it is something to test. We are using a 20 degree die for our forms.

mandrel-bends · « **Reply #42 on:** May 05, 2010, 05:21:50 PM »

I can make some small ones if anybody has a header project they want to do some dyno testing with before and after. Free of charge if you can provide verifiable results.

PhilStubbs · « **Reply #43 on:** May 05, 2010, 05:25:31 PM »

Makes me wish I was ready to make a set of headers for my truck. Doing an auto swap first, headers next.

Joseph Davis · « **Reply #44 on:** May 05, 2010, 05:30:39 PM »

If you want to have them tested in a turbo charger environment, where there is definite reversion both from differential pressure as well as pulsed flow (exhaust pulses bouncing off of a turbine), I'd need two in 1.75" to 2" ID. In all honesty, I think the gains in that environment would be much larger since there is a verified acoustical bounce off of the turbine wheel in all turbocharged setups, whereas NA cars can be funky voodoo and a couple inches difference in placement can either make or muddy results.

They would be fitted in the upper stretch of a paired manifold based off of a 4-2-1 header upper portion running into an Evo8 turbo. Making a traditional up pipe without the chambers is trivial fabrication, and is easy to swap out on the dyno. The power target for the vehicle is 350 whp but I'll probably max the turbo out (over 400) for a number.

This is the whole reason why I asked in the first place.

92CXyD · « **Reply #45 on:** May 05, 2010, 05:39:37 PM »

Quote from: mandrel-bends on May 05, 2010, 05:17:17 PM

According to the patent 20 degree was acceptable. 10 degrees would be a huge taper, but it is something to test. We are using a 20 degree die for our forms.

In many different publications mentioning manifold (intake and exhaust) 10deg and sometimes 11deg is always encouraged.

I see in my fluid dynamics books the angle varies with the fluid as a gas or liquid, compressible or incompressible, and what temperatures we are dealing with (total energy of mass flow of said fluid).

I'll find some links and or equations form my fluids books and let you know. ;D

turbob16hatch · « **Reply #46 on:** May 05, 2010, 05:42:35 PM »

Is there a reason your building them the way you are? As they look different from the ones hytech uses in there headers? Is it a size thing? or maybe the way your designing them?

JD: you think these would show decent results in a 550whp (mustang dyno) w/s366xl 22psi 1.9L gsr running a divided top mount? hrm...

mandrel-bends · « **Reply #47 on:** May 05, 2010, 05:51:14 PM »

Send me a drawing of what you need (package size wise - length and OD that will fit. Then we can reverse engineer it from those spec's for the desired ID). admin@mandrel-bends.com. Its definitely a good idea to test both NA and forced induction.

Quote from: Joseph Davis on May 05, 2010, 05:30:39 PM

If you want to have them tested in a turbo charger environment, where there is definite reversion both from differential pressure as well as pulsed flow (exhaust pulses bouncing off of a turbine), I'd need two in 1.75" to 2" ID. In all honesty, I think the gains in that environment would be much larger since there is a verified acoustical bounce off of the turbine wheel in all turbocharged setups, whereas NA cars can be funky voodoo and a couple inches difference in placement can either make or muddy results.

They would be fitted in the upper stretch of a paired manifold based off of a 4-2-1 header upper portion running into an Evo8 turbo. Making a traditional up pipe without the chambers is trivial fabrication, and is easy to swap out on the dyno. The power target for the vehicle is 350 whp but I'll probably max the turbo out (over 400) for a number.

This is the whole reason why I asked in the first place.

mandrel-bends · « **Reply #48 on:** May 05, 2010, 05:53:40 PM »

Hytech's look like they were optimized for manufacturing. I dont know if that is true or not, but its definitely a different model.

Quote from: turbob16hatch on May 05, 2010, 05:42:35 PM

Is there a reason your building them the way you are? As they look different from the ones hytech uses in there headers? Is it a size thing? or maybe the way your designing them?

JD: you think these would show decent results in a 550whp (mustang dyno) w/s366xl 22psi 1.9L gsr running a divided top mount? hrm...

mandrel-bends · « **Reply #49 on:** May 05, 2010, 05:55:25 PM »

You've got me there man, I'm an EE not an ME. We can try them with a 10 degree taper, it just wasn't what the patent I used specifically called for. We have 10 degree dies, they would just be 4-6" longer OAL, which would be an issue I think atleast for this vehicle.

Quote from: 92CXyD on May 05, 2010, 05:39:37 PM

Quote from: mandrel-bends on May 05, 2010, 05:17:17 PM
According to the patent 20 degree was acceptable. 10 degrees would be a huge taper, but it is something to test. We are using a 20 degree die for our forms.

In many different publications mentioning manifold (intake and exhaust) 10deg and sometimes 11deg is always encouraged.

I see in my fluid dynamics books the angle varies with the fluid as a gas or liquid, compressible or incompressible, and what temperatures we are dealing with (total energy of mass flow of said fluid).

I'll find some links and or equations form my fluids books and let you know. ;D

turbob16hatch · « **Reply #50 on:** May 05, 2010, 06:35:46 PM »

Quote from: mandrel-bends on May 05, 2010, 05:53:40 PM

Hytech's look like they were optimized for manufacturing. I dont know if that is true or not, but its definitely a different model.

Quote from: turbob16hatch on May 05, 2010, 05:42:35 PM
Is there a reason your building them the way you are? As they look different from the ones hytech uses in there headers? Is it a size thing? or maybe the way your designing them?

JD: you think these would show decent results in a 550whp (mustang dyno) w/s366xl 22psi 1.9L gsr running a divided top mount? hrm...

Ah, that makes sense.

mandrel-bends · « **Reply #51 on:** May 05, 2010, 07:51:00 PM »

All done. Ready for dyno tomorrow.

Joseph Davis · « **Reply #52 on:** May 05, 2010, 07:52:47 PM »

Quote from: turbob16hatch on May 05, 2010, 05:42:35 PM

JD: you think these would show decent results in a 550whp (mustang dyno) w/s366xl 22psi 1.9L gsr running a divided top mount? hrm...

On paper, yes. I'm positive you'd see some gains in the real world as well but there's no telling how much as that setup is already fairly optimized.

The idea behind a divided manifold is that when exhaust pulses bounce off the turbine they can't travel back up to and foul a cylinder with an already open exhaust valve, at the tail end of it's exhaust event with relatively low chamber pressure which is perfect time/place for reversion. Now, if you can catch and retain some of the pulse's exhaust mass and keep it forward of the anti-reversion chamber then you have accomplished something.

At some point (well into the boost range) a divided collector becomes "mixed" which means a steady, constant pressure builds up at the turbine and feeds it much like a normal collector turbo manifold. You still have pulsed flow in both directions, though, so still gains to be had.

I think you need to do this, Matt, but only because I like seeing your welding.

mandrel-bends · « **Reply #53 on:** May 06, 2010, 05:23:28 PM »

Dyno is in. +3HP, +18 TQ

Graph shows base line, middle section, and front in green. Total gain for first 2 sections of exhaust: +8HP, +24 TQ.

Car is still running all stock intake, ecu, and stock mufflers.

Next up: new muffler section (the muffler section of these cars is typically worth 10HP by itself).

92CXyD · « **Reply #54 on:** May 06, 2010, 05:37:55 PM »

Thats good now market this exhaust kit to the M5 owners and make some bank. ;D :yes:

mandrel-bends · « **Reply #55 on:** May 06, 2010, 06:45:11 PM »

I dont like to share my own personal toys/development with others. I'll show them how to do it, but I dont think I want to sell this stuff. But maybe down the road.

Still trying to decide if we are going to have a motec or pectel ecu installed on this thing. John can do either, but one is $8k more then other. Need the control for what is yet to come.

Whitey · « **Reply #56 on:** May 06, 2010, 07:46:36 PM »

Quote from: mandrel-bends on May 05, 2010, 05:21:50 PM

I can make some small ones if anybody has a header project they want to do some dyno testing with before and after. Free of charge if you can provide verifiable results.

I'm going to make a header for my 09' Accord to get rid of the cats and improve the Y-pipe. As you can see on the new J motors they cast the exhaust manifolds directly into the heads and put the cats right there.

I'll definitely try them out and provide results but they will be skewed becuase there's a shitton of power to uncork just getting rid of the cats and changing the merge section so it won't be an accurate results of with and without the chambers. If you want to cut a deal on piping and V-bands or something I'd be able to do a with and without the chambers dyno runs. That would give you the most accurate results of if these make a difference.

I'd probably use 2 1/4" piping

crxvtec91 · « **Reply #57 on:** May 13, 2010, 11:07:14 PM »

Quote from: mandrel-bends on May 06, 2010, 06:45:11 PM

I dont like to share my own personal toys/development with others. I'll show them how to do it, but I dont think I want to sell this stuff. But maybe down the road.

Still trying to decide if we are going to have a motec or pectel ecu installed on this thing. John can do either, but one is $8k more then other. Need the control for what is yet to come.

Hum sounds like some boost is in the works

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Author Topic: Anti reversion chamber fab (Read 25603 times)