Not Divided Mod

[jibberishballr]

I was reading this thread and wondering if it works. It doesnt seem like it would be that hard to do at home. Anyone have any expierence with this.

Heres a link to what im talkin about:

http://www.dsmtuners.com/forums/showpost.php?p=50427715&postcount=20

Also i realize you cant run external once you do this.

 

[kenamond]

I was reading this thread and wondering if it works. It doesnt seem like it would be that hard to do at home. Anyone have any expierence with this.

Heres a link to what im talkin about:

http://www.dsmtuners.com/forums/showpost.php?p=50427715&postcount=20

Also i realize you cant run external once you do this.

Seems like the WG flow would run interference on the turbine exit flow. If the evo3 flapper doesn't open all the way, it will send all of the exhaust into the stream of the turbine exit making that exit "look" smaller to the exiting turbine gasses, so it would act like you had a smaller exhaust. But that's my guess; I don't know if it would hinder performance or not.

I still don't understand why someone doesn't just put a better actuator on the evo3 which opens the flapper all the way and has enough spring force to hold a larger flapper closed at high boost.

 

[jibberishballr]

Seems like the WG flow would run interference on the turbine exit flow. If the evo3 flapper doesn't open all the way, it will send all of the exhaust into the stream of the turbine exit making that exit "look" smaller to the exiting turbine gasses, so it would act like you had a smaller exhaust. But that's my guess; I don't know if it would hinder performance or not.

I still don't understand why someone doesn't just put a better actuator on the evo3 which opens the flapper all the way and has enough spring force to hold a larger flapper closed at high boost.

I think one of the vendors does sell a flapper that opens all the way and holds at higher boost. I was reading about it in these forums. But as for your theory it may be true but i was wondering if anyone had expierienced the non divided mod.

 

[MyBeatGSX]

Its one of the stupidest ideas I've ever heard. People that are stuck with undivided housings stock, usually try to make them divided or do anything possible to aid wastegate and turbine flow. We're blessed with a very nice divided housing and divided discharge (the O2 housing), why on earth would you want to get rid of that? The backpressure and turbulence created by non-divided housings is enormous. It hurts wastegate flow and turbine discharge flow. That equals less power and slower spool.

The idea is equivalent to stopping boost creep by installing a restrictive exhaust. Or "helping" turbine flow by clipping.



On a side note refering to kenamond's post. Does anyone know the explaination for whyyyyyyyy MHI wastegates don't open a full 90*? And somehow people wonder why we're so plauged with boost creep problems.

 

[kenamond]

On a side note refering to kenamond's post. Does anyone know the explaination for whyyyyyyyy MHI wastegates don't open a full 90*? And somehow people wonder why we're so plauged with boost creep problems.

I know I can feel the love. I could hypothesize, but at this point, I'd rather you just politely tell us.

 

[MyBeatGSX]

I think you misread that. I was seriously asking if anyone knew why, not implying that I did know why. Its a complete mystery to me, I see no benefit in it....

 

[kenamond]

I think you misread that. I was seriously asking if anyone knew why, not implying that I did know why. Its a complete mystery to me, I see no benefit in it....

Ooops. Okay. Sorry. It's funny, because you and read your post two ways and get COMPLETELY different things out of it: one innocent and one arrogant/snotty/rude.

Seems like you need a spring with more preload to hold the flapper shut at higher boost. And you need a larger diaphragm to overcome the higher preload in the spring so that it gets transferred to the actuator arm. Also, the diaphragm has to be able to compress the already preloaded spring far enough to turn the level. And the whole mechanism has to have enough room to displace far enough to turn the lever 90*.

I'm not sure what these things look like inside so I'm gonna go look for WGA design pictures. Then I can think about how to handle the longer throw.

 

[jibberishballr]

So im thinking im not gonna do this mod...
Also as for boost creep, by doin porting the wastegate 02 area, will i solve most boost creep? Im goin to do other porting, just wonder what is the most effective?

 

[kenamond]

So im thinking im not gonna do this mod...
Also as for boost creep, by doin porting the wastegate 02 area, will i solve most boost creep? Im goin to do other porting, just wonder what is the most effective?

Have you read this tech article?

I can refer you to others that I've written that have clearer pictures, but that one and the threads it links to go into the gory details.

 

[jibberishballr]

Have you read this tech article?

I can refer you to others that I've written that have clearer pictures, but that one and the threads it links to go into the gory details.

Ive read it, i was just wondering which porting effects boost creep the most. I plan on porting everything. Also any clearer pictures woudl be appreciated.

 

[kenamond]

Ive read it, i was just wondering which porting effects boost creep the most. I plan on porting everything. Also any clearer pictures woudl be appreciated.

Here's one of my posts about porting.

Are you going with an evo3 or what? Nevermind, just looked at your modlist.

 

[jibberishballr]

Here's one of my posts about porting.

Are you going with an evo3 or what? Nevermind, just looked at your modlist.

Yes i have one. Installin it Saturday and would like to port it before it goes in. Haha im the one who brought that thread u just gave me back to life. So im guessing the turbine inlet is more important for solving creep. Maybe the wastegate flapper opening fully. Maybe thats my real question. Which one helps solving creep more. The wastegate flapper opening 90 degrees or porting the turbine inlet?

 

[kenamond]

Yes i have one. Installin it Saturday and would like to port it before it goes in.

From what oldman and others have said, you really need to port the entrance to the WG passage in the turbine inlet bigtime. The other porting is also going to be needed, but the WG entrance seemed to be the key in that tech article. Keep in mind that there are people saying the flapper doesn't open all the way, and I'm not sure if all evo3s have the same WGA problem, and maybe the porting won't help you if yours doesn't open enough.

Port it and find out!

 

[MrBoxx]

There is a way to make the wastegate flapper open more than it currently does. What's required is moving the post on the wastegate flapper arm closer to the pivot point. The wastegate actuator arm will still move the same distance, but the shorter radius of the flapper arm's movement will cause the flapper to open wider. This can be done by welding another post onto the flapper arm halfway down, or thereabouts, between the stock post and the pivot point.

 

[jibberishballr]

There is a way to make the wastegate flapper open more than it currently does. What's required is moving the post on the wastegate flapper arm closer to the pivot point. The wastegate actuator arm will still move the same distance, but the shorter radius of the flapper arm's movement will cause the flapper to open wider. This can be done by welding another post onto the flapper arm halfway down, or thereabouts, between the stock post and the pivot point.

Interesting. Ive never heard that before. Id like to see if this works but think i am just going to port because of all the success from what ive seen.

Thanks for all the help guys!

 

[keymaster]

Or you can go to www.dpconcepts.com, and get a boost creep elimination kit, which moves the post on the WG arm closer to the pivot point, without have to weld anything.

 

[MrBoxx]

I just threw out welding a new post on as an example. You could also drill a hole in the flat part of the flapper arm, insert a small cotter pin bolt through from the back and attach the wastegate arm to that. There are probably countless other ways to do it.

 

[DGajre777]

Its one of the stupidest ideas I've ever heard. People that are stuck with undivided housings stock, usually try to make them divided or do anything possible to aid wastegate and turbine flow. We're blessed with a very nice divided housing and divided discharge (the O2 housing), why on earth would you want to get rid of that? The backpressure and turbulence created by non-divided housings is enormous.

PTE turbos have an option undivided housings. It is their recommended way to prevent boost creep on their bigger turbos without having to go external. Dave from www.dejonpowerhouse.com also told me that porting the Dual BB 5061RE is not necessary.

I'm letting people know it IS an option. This is right on www.dejonpowerhouse.com website, click on turbochargers.com and scroll down to EVO III 16G.
"Divider Removed - We found this PTE trick of removing the divider between the turbine outlet chamber and the Waste-gate outlet chamber works on the 16g to eliminate boost creep - $49"

If you want, I'll be glad to send Dave an e-mail to find out about backpressure and turbulence created by non-divided housings on EVO III 16G turbos.

EDIT: I sent an e-mail to Dejon.

 

[DGajre777]

So im thinking im not gonna do this mod...
Also as for boost creep, by doin porting the wastegate 02 area, will i solve most boost creep? Im goin to do other porting, just wonder what is the most effective?

My thread was to provide information. If you were not happy with what I said, contact www.dejonpowerhouse.com to get more information. Just because one member said it is not a good idea based on theory, is not enough, in my opinion, to base your decisions on.

And since you used my post, you could have alteast told me that you started a thread on it, I missed out on all the action.

Also i realize you cant run external once you do this.

50% correct. You can't run exernal off the o2 housing once you do this. You can still run an external wastegate off the exhaust manifold.

 

[jibberishballr]

My thread was to provide information. If you were not happy with what I said, contact www.dejonpowerhouse.com to get more information. Just because one member said it is not a good idea based on theory, is not enough, in my opinion, to base your decisions on.

And since you used my post, you could have alteast told me that you started a thread on it, I missed out on all the action.

50% correct. You can't run exernal off the o2 housing once you do this. You can still run an external wastegate off the exhaust manifold.

I just have heard so many success stories of porting and not as many on the non divided thing. Id rather go the safe route.

Yea......I did pm you asking you and figured id start up a thread and hopefully youd jump in.

My fault i forgot to put off the 02.

 

[DGajre777]

I just have heard so many success stories of porting and not as many on the non divided thing. Id rather go the safe route.

This is because porting the turbo was an option long long before PTE introducted the undivided housings. Before the option was port it, if it doesn't go away, port it again, if that doesn't work, go external. Now you have the option of porting it and/or gettin an undivided housing before having to think about going external.

I'm waiting for a response from Dave Johnson at Dejontool for some more info the bad things of an undivided housing.

 

[jibberishballr]

This is because porting the turbo was an option long long before PTE introducted the undivided housings. Before the option was port it, if it doesn't go away, port it again, if that doesn't work, go external. Now you have the option of porting it and/or gettin an undivided housing before having to think about going external.

I'm waiting for a response from Dave Johnson at Dejontool for some more info the bad things of an undivided housing.

I had actually emailed him before right when you told me where you got your info. So hopefully hell email me back as well. If there werent side effects id do it in a heartbeat if it solved all creep problems. You have undivided right? Are you experienceing any creep?

 

[DGajre777]

Here is the response I got from him last night.

"Has he tried it? Probably not. When Precision turbo first came out with
their SCM series the 6152 had BAD Creep. This is their solution and it
works. Its their best selling internal gated Turbine housing. I've tried
it on their turbos and it works. A customer in Indiana, Dave Hully bought
an EVO3 16g from me with 34mm flapper door and got bad boost creep. He
made this mod at my recommendation and it worked for him. My
counter-theory is that the wastegated exhaust hits the divider wall
because its forced between the wall and flapper door, and enough volume
can't escape.

Dave Johnson, DEJON Powerhouse"

> Hello,
>
> I am a member of DSMTuners (Member name DGajre777) and I have been giving
> some information on your option for undivided housings on the EVO III 16G
> Turbo. Can you chime in or provide me with some more information in
> response to the post below?
>
> Here is the thread -
> http://www.dsmtuners.com/forums/showthread.php?p=50428401
>
> This is the response from one member -
> "Its one of the stupidest ideas I've ever heard. People that are stuck
> with undivided housings stock, usually try to make them divided or do
> anything possible to aid wastegate and turbine flow. We're blessed with a
> very nice divided housing and divided discharge (the O2 housing), why on
> earth would you want to get rid of that? The backpressure and turbulence
> created by non-divided housings is enormous. It hurts wastegate flow and
> turbine discharge flow. That equals less power and slower spool.
>
> The idea is equivalent to stopping boost creep by installing a restrictive
> exhaust. Or "helping" turbine flow by clipping. "
>
> Thanks,
> Dee.
> DSMTuners - DGajre777

I agree with his theory - "My counter-theory is that the wastegated exhaust hits the divider wall because its forced between the wall and flapper door, and enough volume can't escape." No wall, no boost creep.

No, I don't have the EVO III 16G. I'm still on the stock T25, but I do plan to get PTEs Dual Ball Bearing internal gated 50trim with an undivided housing from Dejon when I have enough supporting mods.

 

[kenamond]

Here is the response I got from him last night.

"Has he tried it? Probably not. When Precision turbo first came out with
their SCM series the 6152 had BAD Creep. This is their solution and it
works. Its their best selling internal gated Turbine housing. I've tried
it on their turbos and it works. A customer in Indiana, Dave Hully bought
an EVO3 16g from me with 34mm flapper door and got bad boost creep. He
made this mod at my recommendation and it worked for him. My
counter-theory is that the wastegated exhaust hits the divider wall
because its forced between the wall and flapper door, and enough volume
can't escape.

Dave Johnson, DEJON Powerhouse"

> Hello,
>
> I am a member of DSMTuners (Member name DGajre777) and I have been giving
> some information on your option for undivided housings on the EVO III 16G
> Turbo. Can you chime in or provide me with some more information in
> response to the post below?
>
> Here is the thread -
> http://www.dsmtuners.com/forums/showthread.php?p=50428401
>
> This is the response from one member -
> "Its one of the stupidest ideas I've ever heard. People that are stuck
> with undivided housings stock, usually try to make them divided or do
> anything possible to aid wastegate and turbine flow. We're blessed with a
> very nice divided housing and divided discharge (the O2 housing), why on
> earth would you want to get rid of that? The backpressure and turbulence
> created by non-divided housings is enormous. It hurts wastegate flow and
> turbine discharge flow. That equals less power and slower spool.
>
> The idea is equivalent to stopping boost creep by installing a restrictive
> exhaust. Or "helping" turbine flow by clipping. "
>
> Thanks,
> Dee.
> DSMTuners - DGajre777

I agree with his theory - "My counter-theory is that the wastegated exhaust hits the divider wall because its forced between the wall and flapper door, and enough volume can't escape." No wall, no boost creep.

No, I don't have the EVO III 16G. I'm still on the stock T25, but I do plan to get PTEs Dual Ball Bearing internal gated 50trim with an undivided housing from Dejon when I have enough supporting mods.

One important omission from his response was whether or not it disrupts flow at full boost. I have no doubt it will help with creep, but that has nothing to do with turbo performance. Like the other guy said, you can also fix creep by putting a 2-1/4" exhaust back on.

Keep in mind that exhaust is split between the WG and turbine outlet passages whenever you're at full boost. In otherwords, the WG flow characteristics and how they "play nice" with the turbine exit flow is VERY important, because it happens when you're asking for maximum performance.

I don't see how diverting the WG exit flow into the way of the turbine exit flow could do good. The turbine exit *was* a nice, round, smooth passage for those gasses to pass through which gives a lower restriction. Admitted, the WG has a bi*** of a time getting out that door, but once it's there, it gets merged with the turbine exit flow in a very nice way in the stock O2 housing. If you start having to share that nice round turbine exit passage with other flow, the turbine is going to have higher backpressure. This gives a lower pressure differential before and after the turbine wheel which means less torque to the compressor wheel.

I can't put numbers on it, so it might not be that bad, but nobody has compared an undivided housing with, say, an external gate on an otherwise identical setup.

Also, with regard to the WGA/flapper arm mod, if you decrease the moment arm on the lever, you get more throw, but less force on the flapper. The flappers are already getting blown open in high boost applications with the larger flapper diameter option, so you'd end up in this situation at lower boost. If you're low enough boost, then this might be the answer, but if you are past the threshold where the flapper door can't be held closed, you're not going to be able to boost as high as you want to.

I disagree that a WGA cannot be invented to open the evo3 WG all the way. I'll play with some hypothetical numbers here...

Lets say that you have a 34mm diameter WG flapper. That's 0.72 in^2 area.

Run 15psi boost with 2x backpressure gives 30psi backpressure at that door. That's 21.7lb force acting on the WG door at full boost.

Let's assume the arm on the flapper is the same length as the external lever that the WGA arm pins to. So the WGA arm has to have 21.7lb preload on the internal spring to hold the door shut at 15psi boost.

Let's put a 220lb/in spring in the WGA and precompress it 1/10" to get 22lb preload on the actuator arm. This will hold the door closed at 15psi boost.

Now let's assume that you have to push the arm out 1/2" to open the WG flapper 90*. That means that you need to apply 110lb+22lb=132lb to the spring to get it to overcome the preload and and then compress it another 1/2".

Our diaphragm is seeing 15psi at full boost, so we need to pick a diaphragm diameter that will give 154lb when 15psi is pushing on it. P=F/A, so A=F/P=132lb/15psi=8.8in^2.

And using A=0.25*pi*D^2 this means you need a diaphragm with a 3.4" diameter.

There are plenty of variables that you could play with to change things around to get a smaller diameter. I just picked some numbers and ran with them.

I've never designed one of these things, and there is probably a bit more to it, but that tells me it's possible.

 

[jibberishballr]

One important omission from his response was whether or not it disrupts flow at full boost. I have no doubt it will help with creep, but that has nothing to do with turbo performance. Like the other guy said, you can also fix creep by putting a 2-1/4" exhaust back on.

Keep in mind that exhaust is split between the WG and turbine outlet passages whenever you're at full boost. In otherwords, the WG flow characteristics and how they "play nice" with the turbine exit flow is VERY important, because it happens when you're asking for maximum performance.

I don't see how diverting the WG exit flow into the way of the turbine exit flow could do good. The turbine exit *was* a nice, round, smooth passage for those gasses to pass through which gives a lower restriction. Admitted, the WG has a bi*** of a time getting out that door, but once it's there, it gets merged with the turbine exit flow in a very nice way in the stock O2 housing. If you start having to share that nice round turbine exit passage with other flow, the turbine is going to have higher backpressure. This gives a lower pressure differential before and after the turbine wheel which means less torque to the compressor wheel.

I can't put numbers on it, so it might not be that bad, but nobody has compared an undivided housing with, say, an external gate on an otherwise identical setup.

Also, with regard to the WGA/flapper arm mod, if you decrease the moment arm on the lever, you get more throw, but less force on the flapper. The flappers are already getting blown open in high boost applications with the larger flapper diameter option, so you'd end up in this situation at lower boost. If you're low enough boost, then this might be the answer, but if you are past the threshold where the flapper door can't be held closed, you're not going to be able to boost as high as you want to.

I disagree that a WGA cannot be invented to open the evo3 WG all the way. I'll play with some hypothetical numbers here...

Lets say that you have a 34mm diameter WG flapper. That's 0.72 in^2 area.

Run 15psi boost with 2x backpressure gives 30psi backpressure at that door. That's 21.7lb force acting on the WG door at full boost.

Let's assume the arm on the flapper is the same length as the external lever that the WGA arm pins to. So the WGA arm has to have 21.7lb preload on the internal spring to hold the door shut at 15psi boost.

Let's put a 220lb/in spring in the WGA and precompress it 1/10" to get 22lb preload on the actuator arm. This will hold the door closed at 15psi boost.

Now let's assume that you have to push the arm out 1/2" to open the WG flapper 90*. That means that you need to apply 110lb+22lb=132lb to the spring to get it to overcome the preload and and then compress it another 1/2".

Our diaphragm is seeing 15psi at full boost, so we need to pick a diaphragm diameter that will give 154lb when 15psi is pushing on it. P=F/A, so A=F/P=132lb/15psi=8.8in^2.

And using A=0.25*pi*D^2 this means you need a diaphragm with a 3.4" diameter.

There are plenty of variables that you could play with to change things around to get a smaller diameter. I just picked some numbers and ran with them.

I've never designed one of these things, and there is probably a bit more to it, but that tells me it's possible.

Excellent counter post. I had to read it twice just to understand most of it...