Amazing O2 housing

[MNGSX]

Originally posted by ItsStockOfficer
If you raise exhaust manifold pressure, boost goes up.

Ah so manifold pressure is the only thing that matters.. Quick stick a potato (watermellon for ricers) in your tailpipe we need manifold pressure stat....


It is the CFM flow thru the turbine that propels the turbine wheel. The best way to monitor the turbo is via a turbo tach. I might find the tech I'm looking for and post it. Then again I think you might not read all of that either.

3 inch makes more power then 2.5. And 3 inch leaves a ton of room for a wg tube. Hahns been doing it for 8 years....RNR has over 800 on the market that do it great.

Oh yes hahn.... The times list is just full of HRC turbos. I think I saw a single digit et guy the other day running a HRC t3/t4 secret turbo.. NOT!!!!

RNR's sh&t looks like my first welds some 14yrs ago back in HS shop class. I can make their sh7t look like the sh*t it is, my welds are all on par with what FP's metal fab guys can create.

Unlike RNR FP just does'nt sit back and copy everyone else. If they say a 2.5" works the same it works the same. I also have alot more faith in what people with engineering degrees have told me. Like a garret engineer and people at FP. They have 100x the credibility and experience over anyone here who is disagreeing with me. IMHO that is all the matters. If some of you don't get it that is ok because I think it probably is't the only thing you cannot comprehend.

 

[jdmawd]

Originally posted by MNGSX
FP just does'nt sit back and copy everyone else. If they say a 2.5" works the same it works the same. I also have alot more faith in what people with engineering degrees have told me. Like a garret engineer and people at FP. They have 100x the credibility and experience over anyone here who is disagreeing with me.

Good point lets look at what Brian at forced performance has to say about this topic.

Originally posted by sleestack

The 3" O2 housings I build are designed mainly with maximum flow in mind (long gentle radius) where the 2.5" are designed with best fit in mind.the main concern is fitment. Making it so it bolts up int he exact same orientation and angle that a stock O2 housing would.

I guess this debate is done.




Later.

 

[ItsStockOfficer]

Originally posted by MNGSX
Ah so manifold pressure is the only thing that matters.. Quick stick a potato (watermellon for ricers) in your tailpipe we need manifold pressure stat....


It is the CFM flow thru the turbine that propels the turbine wheel. The best way to monitor the turbo is via a turbo tach. I might find the tech I'm looking for and post it. Then again I think you might not read all of that either.



Oh yes hahn.... The times list is just full of HRC turbos. I think I saw a single digit et guy the other day running a HRC t3/t4 secret turbo.. NOT!!!!

RNR's sh&t looks like my first welds some 14yrs ago back in HS shop class. I can make their sh7t look like the sh*t it is, my welds are all on par with what FP's metal fab guys can create.

Unlike RNR FP just does'nt sit back and copy everyone else. If they say a 2.5" works the same it works the same. I also have alot more faith in what people with engineering degrees have told me. Like a garret engineer and people at FP. They have 100x the credibility and experience over anyone here who is disagreeing with me. IMHO that is all the matters. If some of you don't get it that is ok because I think it probably is't the only thing you cannot comprehend.

More proof of your idiocy. please, cal FP and tell me what they say about 3 inch o2 housings instead of sticking words in his mouth.

Mike W at RRE said "Of course a fast car needs a 3 inch o2 housing, but there a pain to make"

 

[MNGSX]

Originally posted by jdmawd
Good point lets look at what Brian at forced performance has to say about this topic.




I guess this debate is done.

Yes it is I win...

With his flagship turbos the FP30's what does he do?


He starts out at about 2.5" with a V band clamp on the FP30 and uses a gentle long radius for maximum flow. It may have been convenient to use the clamp and that diameter but it is also much closer in keeping with what turbo engineers have found in testing to be the best outlet shape.

Also keep in mind with bolt on mitsu flange o2 housings designed for all normal downpipes I am sure he will say that 2.5" and 3" are equal since there is'nt anyway to match a regular downpipe with any other angle.

Therefore his 3" non direct fit wide radius o2 housing beats the bolt on 2.5" which has a tighter radius.

With the same radius with a tapered diameter outflows a 3" non tapered dimeter. It depends on if you are compairing a o2 replacement to work with all down pipes vs one for a specific downpipe. Yes a 3' o2 is better than a 2.5" especially when it starts at 2.5" and tapers to 3"

 

[ItsStockOfficer]

Actually, you lose, and I have been linking this thread to my friends, who are faster on pump gas then you will ever be on race gas(and that includes me), as proof of how idiotic DSMtalkers are.

Keep your w/g power theories to yourself and STFU.

 

[MNGSX]

Originally posted by ItsStockOfficer
Actually, you lose, and I have been linking this thread to my friends, who are faster on pump gas then you will ever be on race gas(and that includes me), as proof of how idiotic DSMtalkers are.

Keep your w/g power theories to yourself and STFU.

Listen punkass b8tch.

#1 This is'nt DSMtalk

#2 What does linking to your freinds have to do with the scientific aspects of a debate over o2 housing design let alone winning the debate.

#3 Ohhh you just barely went under 12sec I am so scared. Especially considering how many people have managed to run well into the 10s on race gas with a 56trim.

#4 I'm not running race gas. Its alcohol. It's been done before. by Aniel P and others. With 10sec ET's FWIW.

 

[i550]

Originally posted by MNGSX
As for proving the potential power gains I dont have the kind of budget or free time to do my own back to back dyno test with different wastegates.

I would expect someone building a car such as yours with all of the custom fabrication, specialty clutches, one off engines with titanium rods, and who knows what else could justify a little time and money invested into R&D.

Many of your posts indicate a desire to maximize everything. I often wonder if you'll ever finish the car with all of your ideas that will require a substantial budget and free time to complete.

 

[ItsStockOfficer]

Im running right around 12 flat on 91 octane and full weight, and your POS car is never going to run, You remind me alot of Manny...

And your still so wrong about your wg theory its ####ing hilarious, and everyone luaghs at how you changes you reasoning ever post.

And tuners and Talk are the same shit.

 

[MNGSX]

Originally posted by i550
I would expect someone building a car such as yours with all of the custom fabrication, specialty clutches, one off engines with titanium rods, and who knows what else could justify a little time and money invested into R&D.

Many of your posts indicate a desire to maximize everything. I often wonder if you'll ever finish the car with all of your ideas that will require a substantial budget and free time to complete.

You are right that it takes alot of time. Also it is in storage. I don't know if you have seen what many years of driving on MN winter roads does to cars or not. I'm not really in a hurry and rolling in something right now which I don't care if it rusts, gets keyed or backed into. Which has all happened this winter. No road rash and time to build it right.

The kind of equipment and money required to back to back dyno just one component like an o2 housing is'nt something I can do.

Nobody else wanted to do ti rods so I'll just go with forged steel rods. I thought that if we had enough people together the price would be less crazy.

I don't have my own dyno. I do have alot of welding gear, tons of power and hand tools and many machinist friends. Much of what I can't do at home I can do at work or a friends shop.

I don't know if too many seriously built DSMs are ever really finished. They just keep evolving. It will be "finished" enough to run at the local strip as soon as it is the time of year here where we can do that sort of thing again. Maybe a month after that the other block will go in..

 

[MNGSX]

Originally posted by ItsStockOfficer
Im running right around 12 flat on 91 octane and full weight, and your POS car is never going to run, You remind me alot of Manny...

And your still so wrong about your wg theory its ####ing hilarious, and everyone luaghs at how you changes you reasoning ever post.

And tuners and Talk are the same shit.

HA HA HA HA HA HA HA
at how you changes you reasoning ever post

Originally posted by ItsStockOfficer
at how you changes you reasoning ever post

Get hooked on MF'N phonics dude you need it.

The car does run. I just look all the salt on the icy road and wait for it to melt.

 

[ItsStockOfficer]

I tell you why your tech is wrong and you attack my english. Everyone knows who to listen to.

 

[jdmawd]

Originally posted by coltboostin
And for the turbulance comment, tell that to the people who have swiched to this unit form a ported Evo III O2 elbo and full 2.5 inch peices, and gained .2-.3 in the 1/4 mile and a couple miles an hour

This is all the data i care about. However bench tech is fun to read. Anyone with a large turbo should look into this o2 I had one very similar with my PTE 50 trim.



Later.

 

[hostile]

Colt: where is the proof of people gaining two tenths with this housing over one like the Victory housing?

That is 20hp...

 

[sidoze]

That wasnt fun to read, I dont exactly know anything about o2 housings, but I bet if I did MNGSX would probably argue with me too.

The internet has a weird way of empowering people, if you were standing face to face with sean (I mean "itsstockofficer") I dont know that you would exactly argue with him the way you have and said the same things you did MNGSX.

I dont exactly see you out there running 12.2 on a 2.0 60" on shitty gas with a full weight car on a cheap 50 trim either. When you get to the track you'll understand how hard that really is, I know I'll never be a good 60" away from 11s.

Now I know why 90% of the veterans stick to the email lists, wouldn't you be frustrated too if some noob tried to tell you how to do something you've been doing for 10 years?

 

[MNGSX]

Originally posted by sidoze
That wasnt fun to read, I dont exactly know anything about o2 housings, but I bet if I did MNGSX would probably argue with me too.

I don't argue for arguement sake. I have always considered you to be playing with a full deck. Therefore I will leave my comments towards that at just that

Originally posted by sidoze


The internet has a weird way of empowering people, if you were standing face to face with sean (I mean "itsstockofficer") I dont know that you would exactly argue with him the way you have and said the same things you did MNGSX.

Please, In uniform have gone toe to toe in real life with alot worse.

Originally posted by sidoze

I dont exactly see you out there running 12.2 on a 2.0 60" on shitty gas with a full weight car on a cheap 50 trim either.

I have gone alot faster than 12.2 without a turbo and a measly holley 4bbl on pump gas back in the day. A guy I work with now has a full weight regular cab dodge 3500 that runs 12.1 on shitty diesel fuel :laugh:

Originally posted by sidoze
Now I know why 90% of the veterans stick to the email lists, wouldn't you be frustrated too if some noob tried to tell you how to do something you've been doing for 10 years?

A noob... You don't know who you are talking about do you? That's ok I like to keep it that way on the net.

Ever play with this software?

http://www.fluent.com/solutions/automotive/exhaust.htm

I have. Aint no way I'll afford my own copy but it was fun to play with the keyboard a while.

Anyway.

A bigger pipe connecting the same two points will do so using a tighter radius. FACT. Now if you can move one point farther away like the downpipe flange you can use a more gradual radius. Since were talking about a bolt on product that is not applicable.

Secondly a 20g has a 1.93" exducer. Why mounting about 1" bigger pipe and bending it sharper seems like a good idea to some is beyond me.

Third... Well I'll quote someone highly educated and experienced. I have plenty of education but not this much. This has probably been around most every gearhead forum and mailing list by now. That does'nt discredit anything. In fact it reinforces the truth that listening to the people that designed and created the turbo components and produced them from nothing but raw stock is probably a good idea.

The following excerpts are from Jay Kavanaugh, a turbosystems engineer at Garret, responding to a thread on www.impreza.net regarding exhaust design and exhaust theory:
“Howdy,

This thread was brought to my attention by a friend of mine in hopes of shedding some light on the issue of exhaust size selection for turbocharged vehicles. Most of the facts have been covered already. FWIW I'm an turbocharger development engineer for Garrett Engine Boosting Systems.

N/A cars: As most of you know, the design of turbo exhaust systems runs counter to exhaust design for n/a vehicles. N/A cars utilize exhaust velocity (not backpressure) in the collector to aid in scavenging other cylinders during the blowdown process. It just so happens that to get the appropriate velocity, you have to squeeze down the diameter of the discharge of the collector (aka the exhaust), which also induces backpressure. The backpressure is an undesirable byproduct of the desire to have a certain degree of exhaust velocity. Go too big, and you lose velocity and its associated beneficial scavenging effect. Too small and the backpressure skyrockets, more than offsetting any gain made by scavenging. There is a happy medium here.

For turbo cars, you throw all that out the window. You want the exhaust velocity to be high upstream of the turbine (i.e. in the header). You'll notice that primaries of turbo headers are smaller diameter than those of an n/a car of two-thirds the horsepower. The idea is to get the exhaust velocity up quickly, to get the turbo spooling as early as possible. Here, getting the boost up early is a much more effective way to torque than playing with tuned primary lengths and scavenging. The scavenging effects are small compared to what you'd get if you just got boost sooner instead. You have a turbo; you want boost. Just don't go so small on the header's primary diameter that you choke off the high end.

Downstream of the turbine (aka the turboback exhaust), you want the least backpressure possible. No ifs, ands, or buts. Stick a Hoover on the tailpipe if you can. The general rule of "larger is better" (to the point of diminishing returns) of turboback exhausts is valid. Here, the idea is to minimize the pressure downstream of the turbine in order to make the most effective use of the pressure that is being generated upstream of the turbine. Remember, a turbine operates via a pressure ratio. For a given turbine inlet pressure, you will get the highest pressure ratio across the turbine when you have the lowest possible discharge pressure. This means the turbine is able to do the most amount of work possible (i.e. drive the compressor and make boost) with the available inlet pressure.

Again, less pressure downstream of the turbine is goodness. This approach minimizes the time-to-boost (maximizes boost response) and will improve engine VE throughout the rev range.
As for 2.5" vs. 3.0", the "best" turboback exhaust depends on the amount of flow, or horsepower. At 250 hp, 2.5" is fine. Going to 3" at this power level won't get you much, if anything, other than a louder exhaust note. 300 hp and you're definitely suboptimal with 2.5". For 400-450 hp, even 3" is on the small side.”
"As for the geometry of the exhaust at the turbine discharge, the most optimal configuration would be a gradual increase in diameter from the turbine's exducer to the desired exhaust diameter-- via a straight conical diffuser of 7-12° included angle (to minimize flow separation and skin friction losses) mounted right at the turbine discharge. Many turbochargers found in diesels have this diffuser section cast right into the turbine housing. A hyperbolic increase in diameter (like a trumpet snorkus) is theoretically ideal but I've never seen one in use (and doubt it would be measurably superior to a straight diffuser). The wastegate flow would be via a completely divorced (separated from the main turbine discharge flow) dumptube. Due the realities of packaging, cost, and emissions compliance this config is rarely possible on street cars. You will, however, see this type of layout on dedicated race vehicles.

A large "bellmouth" config which combines the turbine discharge and wastegate flow (without a divider between the two) is certainly better than the compromised stock routing, but not as effective as the above.

If an integrated exhaust (non-divorced wastegate flow) is required, keep the wastegate flow separate from the main turbine discharge flow for ~12-18" before reintroducing it. This will minimize the impact on turbine efficiency-- the introduction of the wastegate flow disrupts the flow field of the main turbine discharge flow.

Necking the exhaust down to a suboptimal diameter is never a good idea, but if it is necessary, doing it further downstream is better than doing it close to the turbine discharge since it will minimize the exhaust's contribution to backpressure. Better yet: don't neck down the exhaust at all.
Also, the temperature of the exhaust coming out of a cat is higher than the inlet temperature, due to the exothermic oxidation of unburned hydrocarbons in the cat. So the total heat loss (and density increase) of the gases as it travels down the exhaust is not as prominent as it seems.

Another thing to keep in mind is that cylinder scavenging takes place where the flows from separate cylinders merge (i.e. in the collector). There is no such thing as cylinder scavenging downstream of the turbine, and hence, no reason to desire high exhaust velocity here. You will only introduce unwanted backpressure.

Other things you can do (in addition to choosing an appropriate diameter) to minimize exhaust backpressure in a turboback exhaust are: avoid crush-bent tubes (use mandrel bends); avoid tight-radius turns (keep it as straight as possible); avoid step changes in diameter; avoid "cheated" radii (cuts that are non-perpendicular); use a high flow cat; use a straight-thru perforated core muffler... etc.”
"Comparing the two bellmouth designs, I've never seen either one so I can only speculate. But based on your description, and assuming neither of them have a divider wall/tongue between the turbine discharge and wg dump, I'd venture that you'd be hard pressed to measure a difference between the two. The more gradual taper intuitively appears more desirable, but it's likely that it's beyond the point of diminishing returns. Either one sounds like it will improve the wastegate's discharge coefficient over the stock config, which will constitute the single biggest difference. This will allow more control over boost creep. Neither is as optimal as the divorced wastegate flow arrangement, however.

There's more to it, though-- if a larger bellmouth is excessively large right at the turbine discharge (a large step diameter increase), there will be an unrecoverable dump loss that will contribute to backpressure. This is why a gradual increase in diameter, like the conical diffuser mentioned earlier, is desirable at the turbine discharge.

As for primary lengths on turbo headers, it is advantageous to use equal-length primaries to time the arrival of the pulses at the turbine equally and to keep cylinder reversion balanced across all cylinders. This will improve boost response and the engine's VE. Equal-length is often difficult to achieve due to tight packaging, fabrication difficulty, and the desire to have runners of the shortest possible length.”
"Here's a worked example (simplified) of how larger exhausts help turbo cars:

Say you have a turbo operating at a turbine pressure ratio (aka expansion ratio) of 1.8:1. You have a small turboback exhaust that contributes, say, 10 psig backpressure at the turbine discharge at redline. The total backpressure seen by the engine (upstream of the turbine) in this case is:

(14.5 +10)*1.8 = 44.1 psia = 29.6 psig total backpressure

So here, the turbine contributed 19.6 psig of backpressure to the total.

Now you slap on a proper low-backpressure, big turboback exhaust. Same turbo, same boost, etc. You measure 3 psig backpressure at the turbine discharge. In this case the engine sees just 17 psig total backpressure! And the turbine's contribution to the total backpressure is reduced to 14 psig (note: this is 5.6 psig lower than its contribution in the "small turboback" case).

So in the end, the engine saw a reduction in backpressure of 12.6 psig when you swapped turbobacks in this example. This reduction in backpressure is where all the engine's VE gains come from.

This is why larger exhausts make such big gains on nearly all stock turbo cars-- the turbine compounds the downstream backpressure via its expansion ratio. This is also why bigger turbos make more power at a given boost level-- they improve engine VE by operating at lower turbine expansion ratios for a given boost level.

As you can see, the backpressure penalty of running a too-small exhaust (like 2.5" for 350 hp) will vary depending on the match. At a given power level, a smaller turbo will generally be operating at a higher turbine pressure ratio and so will actually make the engine more sensitive to the backpressure downstream of the turbine than a larger turbine/turbo would. As for output temperatures, I'm not sure I understand the question. Are you referring to compressor outlet temperatures?

The advantage to the bellmouth setup from the wg's perspective is that it allows a less torturous path for the bypassed gases to escape. This makes it more effective in bypassing gases for a given pressure differential and wg valve position. Think of it as improving the VE of the wastegate. If you have a very compromised wg discharge routing, under some conditions the wg may not be able bypass enough flow to control boost, even when wide open. So the gases go through the turbine instead of the wg, and boost creeps up.

The downside to a bellmouth is that the wg flow still dumps right into the turbine discharge. A divider wall would be beneficial here. And, as mentioned earlier, if you go too big on the bellmouth and the turbine discharge flow sees a rapid area change (regardless of whether the wg flow is being introduced there or not), you will incur a backpressure penalty right at the site of the step. This is why you want gradual area changes in your exhaust."

Hmm... Over and over again... Gradual area changes in the exhaust system.

Now why does everyone clamering to buy a bigger and bigger pipe welded over the same size port make me go "hey WTF are you guys thinking?"

 

[ItsStockOfficer]

As for 2.5" vs. 3.0", the "best" turboback exhaust depends on the amount of flow, or horsepower. At 250 hp, 2.5" is fine. Going to 3" at this power level won't get you much, if anything, other than a louder exhaust note. 300 hp and you're definitely suboptimal with 2.5". For 400-450 hp, even 3" is on the small side.”

Necking the exhaust down to a suboptimal diameter is never a good idea, but if it is necessary, doing it further downstream is better than doing it close to the turbine discharge since it will minimize the exhaust's contribution to backpressure. Better yet: don't neck down the exhaust at all.

No one here argued against gradual changes, we all agree with you. We just stated that its very difficult to do in the given space. You continually state there is no gain from 2.5 to 3 inch.

You also bring up racing different cars to compare to my times. Irrelevant...100% irrelevant. Then you bring up your friends cars...the you bring up military experiance as if it's relevant to whether you would disagree with me in person. He brought it up, not becuase I am bigger then you, but becuase I would make you look like a moron.

And the entire arguement here is your 3 pages of an external making more power at the same boost level. Thats All I argued with you about and you keep avoiding it now. Either deal with that disagreement, or shut up.

 

[sidoze]

Tyson factor?

If you'd actually been to sandiego and met the DSMers down there you'd probably consider what he has to say and actually have approached things differently, thats all Im getting at.

I'm not calling you a newb, Im just trying to figure out why everyone seems to like to fight with the socal guys lately. Thats all, I'll go back to being quiet now....