Page 1 of 3
Some random questions about boost on SRT.
Posted: Mon Jul 30, 2007 2:44 pm
by MyNeonSaysHi
Ok I got some questions that I have been needing to get off of my chest and been to much of a puss to ask so here we go:
1. I bought a used AGP Wastegate on SRTforums from one of the "Oldtimers". He said it was the old skool version and the only difference is that it doesn't say AGP on it and doesn't ahve the bling silver. This is what it looks like..

He said it was working fine when he took it off, because he was returning back to stock to sell his SRT. Let me know if that is indeed a AGP Wastegate because I really can't tell.

I got it for $70 shipped.
I mainly got this piece because a friend of mine also has an 04 SRT-4 and he has the Kinetic Wastegate on his bone stock SRT-4 except for Injen SRI and rice plate. He did the vac-line mod. (Whatever that is) So the wastegate is not controlled by the computer and he got rid of most the the vac lines on the solenoid pack. He said once in a while he gets a code and he just takes out the relay and puts it back in, code is gone. But anyways, he took me for a ride in it, and man..it pulls a bit harder than mine. I saw his gauge and he was spiking at 18 psi because he had adjusted it etc by turning the screws on the wastegate.
With all this said, is that all I need to do? I read the FAQ's on MPX and if you are running more boost it says you need an aftermarket BOV to help relieve the pressure, is this necessary?
2. I would like to get an aftermarket BOV like a Greddy Type S or HKS SS but I am not sure if they mount where your stock BOV is? Or do you have to get a UPP with a welded flange to use a aftermarket BOV. I see little connector things that go in between the UPP so you can moutn an aftermarket BOV. Whats the benefit of having a aftermarket BOV mounted right there on the cold side UPP than having it right by the turbo?
3. Will I need manual boost controller to up the boost?
4. Will I need a Stage 1 PCM to run higher boost?
5. How much boost can a stock SRT run without hurting it?
Let me know if my friend is doing anything wrong, because I want to be able to keep up with him and push a bit more power before I dyno it again this fall. Any advice would be great.
Posted: Tue Jul 31, 2007 5:24 am
by dysphagia
1. everything seems to be in order.
2. an after market bov is absolutely not needed if you are on the stock turbo. most UHP/BOV kits come with a block-off plate for the stock surge valve. there are a few bov's the go right on the turbo like the stocker i.e. boombas. but if thats the route you're gonna go you might as well just get the mopar conversion plate.
3. no the wastegate will control the boost
4. no you can just pull and cap the red vac line to hide the boost from the stage 0 computer.
5. 17-18lbs is the max on stock fuel.
Posted: Tue Jul 31, 2007 10:36 am
by MoxHair
dysphagia wrote:1. everything seems to be in order.
2. an after market bov is absolutely not needed if you are on the stock turbo. most UHP/BOV kits come with a block-off plate for the stock surge valve. there are a few bov's the go right on the turbo like the stocker i.e. boombas. but if thats the route you're gonna go you might as well just get the mopar conversion plate.
3. no the wastegate will control the boost
4. no you can just pull and cap the red vac line to hide the boost from the stage 0 computer.
5. 17-18lbs is the max on stock fuel.
ditto
Posted: Tue Jul 31, 2007 12:14 pm
by MyNeonSaysHi
Thanks alot! I was looking at different BOV's online and there was one that goes in the stock location. Its made by Forge. I could of sworn I heard bad things about this... Is it just like the rice plate/boomba one, any differences? Damn, so getting a nice BOV will be pretty pricey since I will have to get a block off plate and a hardpipe.
So do I need an aftermarket BOV if I am running more boost? Would a boomba or forge be fine if I am running 16-17 lbs?
Posted: Tue Jul 31, 2007 3:32 pm
by dysphagia
the stocker is good to 25+ pounds (the same one is used on the stage 3 turbo as well) i wouldn't recommend ether forge or boomba, if you just want the bov sound get a mopar atmospheric conversion. if it is installed correctly it will hold 25+ lbs as the stock surge valve is used.
Posted: Tue Jul 31, 2007 3:40 pm
by OB
Hey dysphagia, you probably know the answer to this question. myneonsayshi asked this in one of his threads awhile back and I didnt see if anyone came up with the answer. What causes a BOV to have that on/off shuttering sound? I see a lot of cars in videos have those and I personally think they sound pretty sick. An SRT at school had one like that and it sounds awesome. What causes that and which BOV's make the sound?
Posted: Tue Jul 31, 2007 3:59 pm
by MyNeonSaysHi
Good read from mpx site:
To quickly summarize why turbocharged SRT-4’s have blow off valves – the turbochargers internal fins spin at nearly 30-50,000 RPMs. When the turbocharger is building full boost, it continues to build boost after you release the throttle. Therefore, when the turbocharger is pressurizing the engine and you release the boost, the throttle body closes and the air that the turbo is pressurizing rushes to the blow off valve. Without the blow off valve, the air that’s coming from the turbocharger will ram into the throttle body that’s closed and then rush back into the spinning wheels of the turbocharger. That can cause damage to the throttle body and to the turbochargers compressor fins. So, when you release the throttle to either come to a stop or if you are changing gears the blow off valve opens by a vacuum signal connected to either the intake manifold or the turbo and releases the compressed air into the atmosphere.
Now, regarding the SRT-4 blow off valve, the stock blow off valve is built into the turbocharger manifold and is very quiet, and hard to see in the engine bay. That’s why some SRT-4 owners who have never owned a turbocharged vehicle before, who expect to hear a loud whish between shifts or don’t see a blow off valve may at first think their car doesn’t have a blow off valve. The factory has done a great job at minimizing the BOV “whoosh” noise by designing an air intake system that’s very quiet.
So, now that you own a turbocharged vehicle you may be thinking to yourself, do I need an aftermarket blow off valve ? Here's the answer to your question.
Do you plan on going to a higher boost level ?
Do you want to have the “whoosh” noise between gears or when you release the throttle ?
If you answered yes to either of these questions, then a aftermarket blow off valve will work fine for you.
You'll find the aftermarket BOV is really important when you start running higher boost pressures as the stock BOV does not have a strong enough spring to keep it closed at higher boost pressures. Therefore, if you use the factory BOV with higher boost pressures (ie, 18PSI or so) youll notice that the boost pressure will fluctuate and your power levels will not be smooth on the dyno as the stock BOV will open and close repeatedly with higher boost. A aftermarket BOV like the Hks BOV, TurboXS, or GReddy BOV can hold boost pressures up to 35-40 PSI, therefore being the only BOV youll need for the life of your car.
Just to let you know, the Mopar BOV conversion piece that we sell for about $70 is a plate that mounts under your stock BOV, and channels the air through the plate. Therefore it makes a traditional aftermarket BOV but at a much cheaper cost. Please do not confuse this piece with a aftermarket BOV piece, as it still uses your stock BOV, and so if you plan on running higher boost levels youll still have a basic stock BOV if you install this piece and it will still open under higher boost levels.
Therefore, the mopar BOV piece is great if you are running below 18PSI or so but if you plan on going higher or are at a higher boost level you should get one of the Hks, GReddy or TurboXS BOV.
Also, whenever you install a aftermarket intake system on your SRT-4, especially the aluminum tube types, they will generally resonate the noises from the factory BOV much more. You'll hear a slight fluttering noise whenever you release the throttle under low boost, and you'll hear more of the BOV whoosh whenever your in positive boost pressure or switching gears fast under boost. So don’t be alarmed if you install an intake system and you hear more of the BOV flutter or whoosh noises afterwards. Its normal.
I am kind of mad, because I had the Mopar piece and I sold it, it came with the car uninstalled with no gasket.
I think I am gonna go with this:
http://turboneonstore.com/customer/prod ... t=3&page=1
Sounds good too!
http://youtube.com/watch?v=uaFdQRD1m8Q
The Greddy Type S is nice also, but I don't want to spend an arm and a leg with hardpipes and such.
Posted: Tue Jul 31, 2007 8:51 pm
by hansken_yo
I'm sitting here reading this and wonder why I'm getting so much fluttering and whoosh sounds from my car and they answer it right at the end... CAI.
Nice... Good read yo!!!! THanks!
Posted: Tue Jul 31, 2007 9:52 pm
by dysphagia
MyNeonSaysHi wrote:Good read from mpx site:
To quickly summarize why turbocharged SRT-4’s have blow off valves – the turbochargers internal fins spin at nearly 30-50,000 RPMs. When the turbocharger is building full boost, it continues to build boost after you release the throttle. Therefore, when the turbocharger is pressurizing the engine and you release the boost, the throttle body closes and the air that the turbo is pressurizing rushes to the blow off valve. Without the blow off valve, the air that’s coming from the turbocharger will ram into the throttle body that’s closed and then rush back into the spinning wheels of the turbocharger. That can cause damage to the throttle body and to the turbochargers compressor fins. So, when you release the throttle to either come to a stop or if you are changing gears the blow off valve opens by a vacuum signal connected to either the intake manifold or the turbo and releases the compressed air into the atmosphere.
Now, regarding the SRT-4 blow off valve, the stock blow off valve is built into the turbocharger manifold and is very quiet, and hard to see in the engine bay. That’s why some SRT-4 owners who have never owned a turbocharged vehicle before, who expect to hear a loud whish between shifts or don’t see a blow off valve may at first think their car doesn’t have a blow off valve. The factory has done a great job at minimizing the BOV “whoosh” noise by designing an air intake system that’s very quiet.
So, now that you own a turbocharged vehicle you may be thinking to yourself, do I need an aftermarket blow off valve ? Here's the answer to your question.
Do you plan on going to a higher boost level ?
Do you want to have the “whoosh” noise between gears or when you release the throttle ?
If you answered yes to either of these questions, then a aftermarket blow off valve will work fine for you.
You'll find the aftermarket BOV is really important when you start running higher boost pressures as the stock BOV does not have a strong enough spring to keep it closed at higher boost pressures. Therefore, if you use the factory BOV with higher boost pressures (ie, 18PSI or so) youll notice that the boost pressure will fluctuate and your power levels will not be smooth on the dyno as the stock BOV will open and close repeatedly with higher boost. A aftermarket BOV like the Hks BOV, TurboXS, or GReddy BOV can hold boost pressures up to 35-40 PSI, therefore being the only BOV youll need for the life of your car.
Just to let you know, the Mopar BOV conversion piece that we sell for about $70 is a plate that mounts under your stock BOV, and channels the air through the plate. Therefore it makes a traditional aftermarket BOV but at a much cheaper cost. Please do not confuse this piece with a aftermarket BOV piece, as it still uses your stock BOV, and so if you plan on running higher boost levels youll still have a basic stock BOV if you install this piece and it will still open under higher boost levels.
Therefore, the mopar BOV piece is great if you are running below 18PSI or so but if you plan on going higher or are at a higher boost level you should get one of the Hks, GReddy or TurboXS BOV.
Also, whenever you install a aftermarket intake system on your SRT-4, especially the aluminum tube types, they will generally resonate the noises from the factory BOV much more. You'll hear a slight fluttering noise whenever you release the throttle under low boost, and you'll hear more of the BOV whoosh whenever your in positive boost pressure or switching gears fast under boost. So don’t be alarmed if you install an intake system and you hear more of the BOV flutter or whoosh noises afterwards. Its normal.
I am kind of mad, because I had the Mopar piece and I sold it, it came with the car uninstalled with no gasket.
I think I am gonna go with this:
http://turboneonstore.com/customer/prod ... t=3&page=1
Sounds good too!
http://youtube.com/watch?v=uaFdQRD1m8Q
The Greddy Type S is nice also, but I don't want to spend an arm and a leg with hardpipes and such.
not to be a dick or anything but MPx uses that more or less just to sell aftermarket bov's. take it from me, my stocker+mopar conversion held 28lbs in boost leak tests and 23 on the street with no problems. my mopar conversion got sent to live on my friends turbo after i went to a turbonetics raptor. it still holds 20+psi. if you're gonna get the agp one and order it from their site agpturbo.com
OB, if you are refering to the "horse whinny" thats compressor surge, depending on the severitiy it can destroy a turbo within a few thousand miles. compressor surge(taken from above posting from MPx):"Without the blow off valve, the air that’s coming from the turbocharger will ram into the throttle body that’s closed and then rush back into the spinning wheels of the turbocharger. That can cause damage to the throttle body and to the turbochargers compressor fins."if at lower boost levels 10inhg to 5 psi the stock surge valve will have an audible surge. if it is surging at higher levels (say full boost) and not making the whoosh (venting the gases) it is doing damage.
Posted: Tue Jul 31, 2007 11:52 pm
by MyNeonSaysHi
Interesting man, very interesting. I will remember that if that ever happens to my car...
And hansken_yo, heres the complete thing fromMPX, good stuff.
http://modernperformance.com/dcx/srt4_faq.htm
Ahhh thanks dysphagia! Its only $45 bucks there. Rock on!
http://www.agpturbo.com/product.php?pro ... 271&page=1
Posted: Wed Aug 01, 2007 1:08 am
by OB
The sound im referring to is a BOV, its not surge. Ive heard it on hundreds of well built race cars so I doubt its a bad thing. It basically sounds like the BOV is opening and closes about 5 times a second. Thats the best way I can describe it. Sounds bad ass.
Posted: Wed Aug 01, 2007 1:15 am
by dysphagia
well its not possible for the bov to open that quickly, it is surge. on larger frame turbos its not as bad because they have larger shafts and bearings to take the force but on the td04 its a bad thing.
here is a vid
http://video.google.com/videoplay?docid ... &plindex=0
it is a perfect example of what i am talking about, when in higher boost the bov goes off, every other throttle jog he makes it surge at lower boost. if it were surging at high boost it would be bad
Posted: Wed Aug 01, 2007 1:23 am
by OB
Yeah thats pretty much what I was talkin about, but if its surge then why do so many nice cars I see do it? Its usually the real nice skylines and shit in the BMI videos and stuff. Why does it sound like its blowing off on and off really quickly?
Posted: Wed Aug 01, 2007 1:47 am
by hansken_yo
Quadruple post makes me think of Dejavu...
thanks for the link... I have a lot to learn about turbos.... amongst other things...

Posted: Wed Aug 01, 2007 2:14 am
by dysphagia
you're kinda missing the point, its ok to surge on bigger turbos, but only under about 5psi, so basically if you build a little part throttle boost then its ok for it to surge. usually how stiff a bov is set is how much a turbo will surge.
Posted: Wed Aug 01, 2007 11:34 am
by MyNeonSaysHi
Ordered the AGP BOV plate.

Can't wait to install it with my AGP wastegate. Ha! Brand loyalness!
Posted: Wed Aug 01, 2007 12:31 pm
by KrackstaR
dysphagia wrote:well its not possible for the bov to open that quickly, it is surge. on larger frame turbos its not as bad because they have larger shafts and bearings to take the force but on the td04 its a bad thing.
here is a vid
http://video.google.com/videoplay?docid ... &plindex=0
it is a perfect example of what i am talking about, when in higher boost the bov goes off, every other throttle jog he makes it surge at lower boost. if it were surging at high boost it would be bad
my car does this like if im crusing 30-40 mph and i tap the gas for a sec it flutters like that or if i am at a light and i tap the pedal for a sec it flutters, but when im in on the throttle it doesnt do it at all.
Posted: Wed Aug 01, 2007 3:39 pm
by Diablo0
Same here, mine only does it when I tap the gas or are still in vacuum with the stock surge valve. In boost below 5lbs I think it also does it but I'll have to pay close attention on the way home from work today.
Posted: Wed Aug 01, 2007 10:10 pm
by dysphagia
KrackstaR wrote:dysphagia wrote:well its not possible for the bov to open that quickly, it is surge. on larger frame turbos its not as bad because they have larger shafts and bearings to take the force but on the td04 its a bad thing.
here is a vid
http://video.google.com/videoplay?docid ... &plindex=0
it is a perfect example of what i am talking about, when in higher boost the bov goes off, every other throttle jog he makes it surge at lower boost. if it were surging at high boost it would be bad
my car does this like if im crusing 30-40 mph and i tap the gas for a sec it flutters like that or if i am at a light and i tap the pedal for a sec it flutters, but when im in on the throttle it doesnt do it at all.
Diablo0 wrote:Same here, mine only does it when I tap the gas or are still in vacuum with the stock surge valve. In boost below 5lbs I think it also does it but I'll have to pay close attention on the way home from work today.
these are both normal
Posted: Wed Aug 01, 2007 10:55 pm
by pyro
Like this?
http://www.youtube.com/watch?v=uGpv5g41TIY
That sounds like some kind of resonance/turbulence! I'd say it want to get out!
Posted: Wed Aug 01, 2007 11:33 pm
by OB
Ah I see, thanks for clearing that up.
Posted: Sun Aug 05, 2007 1:11 pm
by MyNeonSaysHi
Some great info on the SRT-4 turbo:
http://www.carbide-red.com/service_manu ... manual.pdf
Under exhaust systems...
It even says raising boost will not increase power.... Thats only if you don't do it right. Haha
I am going to be installing the AGP EVM BOV plate sometime next week...hopefully. I read the How-to on SRTforums, and it seems like everyone has a hard time getting to that lower 10mm bolt and its a PITA due to the oil line (steel line) being in the way. Any tips to anyone who has taken that apart or isntalled the Mopar BOV or something similar?
Posted: Sun Aug 05, 2007 4:02 pm
by dysphagia
get a ratcheting wrench to reach the last bolt, hug the motor and reach around the back. some find it helpful to zip tie the wrench to their hand.
Posted: Sun Aug 05, 2007 5:03 pm
by OB
dysphagia wrote:get a ratcheting wrench to reach the last bolt, hug the motor and reach around the back. some find it helpful to zip tie the wrench to their hand.
Now that is hilarious

Posted: Sun Aug 05, 2007 8:57 pm
by MyNeonSaysHi
dysphagia wrote:get a ratcheting wrench to reach the last bolt, hug the motor and reach around the back. some find it helpful to zip tie the wrench to their hand.
Yeah, I read under the how-to, to tie it to your wrist with a string.

They do that because I guess you tend to drop the wrench a bunch and it can get lost somewhere under the engine and takes forever just to find it yet get to it. I picked up a nice ratcheting gear wrench from Lowes, so I am prepared. Thanks for the tip on reaching around from the back. I plan on taking out the battery and un-doing my intake tube that leads to the turbo.
Posted: Sun Aug 05, 2007 11:45 pm
by dysphagia
also be sure to seal it with copper gasket maker, absolutely positively boost leak check after to make sure you got the seal correct.
Posted: Mon Aug 06, 2007 1:39 pm
by MyNeonSaysHi
dysphagia wrote:also be sure to seal it with copper gasket maker, absolutely positively boost leak check after to make sure you got the seal correct.
Whats the difference between the copper gasket maker and the Permatex Hylomar Gasket Dressing and Sealant? Thats what was advised to be used on Dodgeforums for the BOV on their how-to.
Posted: Mon Aug 06, 2007 4:04 pm
by dysphagia
they are both made by the same company and do basically the same thing. just a warning to you, never listen to anything said on dodgeforums, there is not a single person that knows what the hell the are talking about over there, for how-to's at least go to srtforums.
Posted: Mon Aug 06, 2007 11:58 pm
by MyNeonSaysHi
dysphagia wrote:they are both made by the same company and do basically the same thing. just a warning to you, never listen to anything said on dodgeforums, there is not a single person that knows what the hell the are talking about over there, for how-to's at least go to srtforums.

I am honestly not a member there, I just saw a link to their how-to from the SRTforums how-to.

But thanks for the heads-up about that place.

Posted: Thu Aug 09, 2007 12:53 pm
by MyNeonSaysHi
I am going to a friends house to install my wastegate, he lives about 30 or so miles away. He said to take off the heat-shield before I go. Will this hurt anything? If I drive 30 miles with out it on?