SRI issue
07-24-2010, 08:42 AM
#1
SRI issue
Last year i installed a stillen intake on my car. The stillen intake does not delete the PCV box and the flex tube behind it. So yesterday i decided to go down to pep boys and pick up one of those chrome 6 inch tubes to delete the PCV box and flex tube so the air would go straight to the throttle body. Installation went smoothly and i placed one of those little filters on the valve cover where the PCV hose goes.
So now for the test drive, the car sounds much louder and i think better. The issue i am having is when the car hits 4800rpms to about 5500 rpms there feels like a lag, which i dont understand. I figured deleting the PCV box i would better air flow into the IM. Now, my car is not tuned, and i did not try the air idle relearn afterwards.
Has anyone else ever experienced this before?
So now for the test drive, the car sounds much louder and i think better. The issue i am having is when the car hits 4800rpms to about 5500 rpms there feels like a lag, which i dont understand. I figured deleting the PCV box i would better air flow into the IM. Now, my car is not tuned, and i did not try the air idle relearn afterwards.
Has anyone else ever experienced this before?
07-24-2010, 09:34 AM
#5
The Stillen intake is not the problem. Several org members are using the Stillen, JWT, and/or generic intake adapters that use the venturi design and have obtained nice gains from it.
Also, the "PVC box" is known as a Helmholtz resonator. It is there to reduce intake sound, and oddly enough, it assists with low end torque.
You are having other issues non-related. I would check for air leaks. And what is this "flex tube" your are referring to? If it's what I think it is, that is more than likely your problem. Causes unwanted turbulence.
Pics?
Also, the "PVC box" is known as a Helmholtz resonator. It is there to reduce intake sound, and oddly enough, it assists with low end torque.
You are having other issues non-related. I would check for air leaks. And what is this "flex tube" your are referring to? If it's what I think it is, that is more than likely your problem. Causes unwanted turbulence.
Pics?
07-24-2010, 10:14 AM
#8
07-24-2010, 10:26 AM
#9
The Stillen intake is not the problem. Several org members are using the Stillen, JWT, and/or generic intake adapters that use the venturi design and have obtained nice gains from it.
Also, the "PVC box" is known as a Helmholtz resonator. It is there to reduce intake sound, and oddly enough, it assists with low end torque.
You are having other issues non-related. I would check for air leaks. And what is this "flex tube" your are referring to? If it's what I think it is, that is more than likely your problem. Causes unwanted turbulence.
Pics?
Also, the "PVC box" is known as a Helmholtz resonator. It is there to reduce intake sound, and oddly enough, it assists with low end torque.
You are having other issues non-related. I would check for air leaks. And what is this "flex tube" your are referring to? If it's what I think it is, that is more than likely your problem. Causes unwanted turbulence.
Pics?
no leaks, here is what i did.
here is the flex tube i was refering to:
07-24-2010, 10:43 AM
#10
It looks like you have a solid 3" or 4" inches available to push that filter further away than you've got it here.
I like the little breather filter on the VC. Well, I like the look (very cool), although I think there are environmental reasons why you'd want to burn those oil vapors. Is there an issue with inspection? IDK.
btw, it's a nice thing, seeing clear quality photos.
I like the little breather filter on the VC. Well, I like the look (very cool), although I think there are environmental reasons why you'd want to burn those oil vapors. Is there an issue with inspection? IDK.
btw, it's a nice thing, seeing clear quality photos.
07-24-2010, 03:45 PM
#14
nismopc has the most sense in this thread.
Removing the breather lets unmetered air in, thus creating a lean condition under no load/vacuum (idle). I've noticed this more so because I'm AT, since sparks didn't notice it very much. Search PCV on this forum and you'll see this has come up before. I ran a breather filter on my VC for years, and I'm back to having a line that goes post MAF now.
The stock Helmholtz helps with power delivery as well as throttle tip in. Myself and many others have seen this in dynos. The extra noise only nets 1-2 whp, and does not deliver power as smoothly, as noted by your feeling if the mid RPM band lag/loss/dip, basically it's not worth the noise.
The Stillen/JWT, IMO is the best intake for this car/engine.
FWIW, I have a JWT intake with my 3" MAF set-up and I found a way and made it a point to incorporate the Helmholtz as well.
Cripes I need to clean my engine bay.
Removing the breather lets unmetered air in, thus creating a lean condition under no load/vacuum (idle). I've noticed this more so because I'm AT, since sparks didn't notice it very much. Search PCV on this forum and you'll see this has come up before. I ran a breather filter on my VC for years, and I'm back to having a line that goes post MAF now.
The stock Helmholtz helps with power delivery as well as throttle tip in. Myself and many others have seen this in dynos. The extra noise only nets 1-2 whp, and does not deliver power as smoothly, as noted by your feeling if the mid RPM band lag/loss/dip, basically it's not worth the noise.
The Stillen/JWT, IMO is the best intake for this car/engine.
FWIW, I have a JWT intake with my 3" MAF set-up and I found a way and made it a point to incorporate the Helmholtz as well.
Cripes I need to clean my engine bay.
Last edited by NmexMAX; 07-24-2010 at 03:53 PM.
07-24-2010, 07:07 PM
#15
Originally Posted by NmexMAX
nismopc has the most sense in this thread.
Originally Posted by NmexMAX
Cripes I need to clean my engine bay.
07-24-2010, 08:18 PM
#16
nismopc has the most sense in this thread.
Removing the breather lets unmetered air in, thus creating a lean condition under no load/vacuum (idle). I've noticed this more so because I'm AT, since sparks didn't notice it very much. Search PCV on this forum and you'll see this has come up before. I ran a breather filter on my VC for years, and I'm back to having a line that goes post MAF now.
The stock Helmholtz helps with power delivery as well as throttle tip in. Myself and many others have seen this in dynos. The extra noise only nets 1-2 whp, and does not deliver power as smoothly, as noted by your feeling if the mid RPM band lag/loss/dip, basically it's not worth the noise.
The Stillen/JWT, IMO is the best intake for this car/engine.
FWIW, I have a JWT intake with my 3" MAF set-up and I found a way and made it a point to incorporate the Helmholtz as well.
Cripes I need to clean my engine bay.
Removing the breather lets unmetered air in, thus creating a lean condition under no load/vacuum (idle). I've noticed this more so because I'm AT, since sparks didn't notice it very much. Search PCV on this forum and you'll see this has come up before. I ran a breather filter on my VC for years, and I'm back to having a line that goes post MAF now.
The stock Helmholtz helps with power delivery as well as throttle tip in. Myself and many others have seen this in dynos. The extra noise only nets 1-2 whp, and does not deliver power as smoothly, as noted by your feeling if the mid RPM band lag/loss/dip, basically it's not worth the noise.
The Stillen/JWT, IMO is the best intake for this car/engine.
FWIW, I have a JWT intake with my 3" MAF set-up and I found a way and made it a point to incorporate the Helmholtz as well.
Cripes I need to clean my engine bay.
I thought about placing some jet engine DANGER decals near the intake to prevent anyone from getting injested into my engine.....LOL!!!!!!
07-24-2010, 08:28 PM
#17
This is a reason why i love forums, within 12 hours i have all my answers. Thank you all, i decided to put the helmholtz unit back on. So now i might have a random intake piece for sale lol. The only thing i might do is try to extend the stillen intake a bit further to get it away from the heat.
07-24-2010, 08:46 PM
#19
This is a reason why i love forums, within 12 hours i have all my answers. Thank you all, i decided to put the helmholtz unit back on. So now i might have a random intake piece for sale lol. The only thing i might do is try to extend the stillen intake a bit further to get it away from the heat.
07-25-2010, 07:49 AM
#20
nismopc has the most sense in this thread.
Removing the breather lets unmetered air in, thus creating a lean condition under no load/vacuum (idle). I've noticed this more so because I'm AT, since sparks didn't notice it very much. Search PCV on this forum and you'll see this has come up before. I ran a breather filter on my VC for years, and I'm back to having a line that goes post MAF now.
The stock Helmholtz helps with power delivery as well as throttle tip in. Myself and many others have seen this in dynos. The extra noise only nets 1-2 whp, and does not deliver power as smoothly, as noted by your feeling if the mid RPM band lag/loss/dip, basically it's not worth the noise.
The Stillen/JWT, IMO is the best intake for this car/engine.
FWIW, I have a JWT intake with my 3" MAF set-up and I found a way and made it a point to incorporate the Helmholtz as well.
Cripes I need to clean my engine bay.
Removing the breather lets unmetered air in, thus creating a lean condition under no load/vacuum (idle). I've noticed this more so because I'm AT, since sparks didn't notice it very much. Search PCV on this forum and you'll see this has come up before. I ran a breather filter on my VC for years, and I'm back to having a line that goes post MAF now.
The stock Helmholtz helps with power delivery as well as throttle tip in. Myself and many others have seen this in dynos. The extra noise only nets 1-2 whp, and does not deliver power as smoothly, as noted by your feeling if the mid RPM band lag/loss/dip, basically it's not worth the noise.
The Stillen/JWT, IMO is the best intake for this car/engine.
FWIW, I have a JWT intake with my 3" MAF set-up and I found a way and made it a point to incorporate the Helmholtz as well.
Cripes I need to clean my engine bay.
07-25-2010, 08:36 AM
#21
Although not mentioned, engines are designed to operate with negative pressure inside the crank case...specifically at higher rpm's. This helps to seal the rings and aid in maintaining compression as well as reducing blowby. So, by installing that filter (aside from any environmental gloom and doom), you are preventing your engine from running as efficiently and placing additional strain on your rings/engine. The PVC/recirculating system is NOT just about oil vapors and emissions.
Seems like pretty much all the older nissan guys run a breather...just sayin.
Chris wrote a post that speaks to conventional wisdom, but Korn reps for the "older nissan guys". Alliances in conflict.
07-25-2010, 10:20 AM
#23
Ok, here's my intake question. If you could get ONE 3" I.D. Pipe with breather and MAF plugs built right in, wouldn't that be best?? I don't think I've seen that... Everyone always has filter/stack -> MAF housing -> coupler -> pipe w/ breather plug -> TB...... What if we could just have filter/stack -> 3" I.D. Pipe with plugs for MAF & Breather hose -> TB??? It seems to me that if someone somehow made this, there'd be a big market for it here on the org. Wouldn't it reduce intake turbulence due to having fewer joints/edges? Just my thoughts... 
07-25-2010, 11:51 AM
#24
Although not mentioned, engines are designed to operate with negative pressure inside the crank case...specifically at higher rpm's. This helps to seal the rings and aid in maintaining compression as well as reducing blowby. So, by installing that filter (aside from any environmental gloom and doom), you are preventing your engine from running as efficiently and placing additional strain on your rings/engine. The PVC/recirculating system is NOT just about oil vapors and emissions.
that's the same thing I was taught....as well!
07-25-2010, 01:25 PM
#25
It's obvious that it must be better for a lot of applications. I think it's importance is being overblown.
07-25-2010, 03:13 PM
#28
It's pretty easy to see how this can let metered air escape. With the stock setup, once the air passes through the MAF, it has only one place to go in the end, and that's out the exhaust. It is a sealed system. Now if the breather hose was before the MAF from the factory, then it wouldn't make a difference.
This is similar to when people put atmospheric blow off valves on WRX's, you are letting metered air out, and the computer thinks that air is still there, so it runs rich while shifting.
Now I doubt that anyone will notice a real difference with running a breather but I chose to keep my stock Helmholtz resonator like CMax, as this is the best all around setup.
You correct, but the air that it is letting in and out has already been measured by the MAF sensor. Like I said above, if the stock hose was before the MAF, then it would not matter (not that it really matters anyway).
TB - Helmholtz Resonator - MAF - Adapter - 6" Velocity stack/AEM Dryflow
This is similar to when people put atmospheric blow off valves on WRX's, you are letting metered air out, and the computer thinks that air is still there, so it runs rich while shifting.
Now I doubt that anyone will notice a real difference with running a breather but I chose to keep my stock Helmholtz resonator like CMax, as this is the best all around setup.
TB - Helmholtz Resonator - MAF - Adapter - 6" Velocity stack/AEM Dryflow
Last edited by Unklejoe; 07-25-2010 at 03:16 PM.
07-25-2010, 03:17 PM
#29
If you leave the factory air scoop in place and have the filter installed on velocity stack @the MAF that leaves the filter right behind the incoming air from the scoop. Is that not the best way to go, having cooler air @ the filter when in motion?
07-25-2010, 03:20 PM
#30
It could help. I just took mine out to clear out the engine bay. Maybe someone has some IAT logs...
07-25-2010, 03:39 PM
#31
with all the surface area of a cone filter, i doubt that scoop does anything...its needed with the stock setup, because its all sealed
07-25-2010, 04:26 PM
#32
07-25-2010, 04:28 PM
#33
The factory scoop isn't a "scoop" in the sense that you're forcing fresh air up against the cone filter. It's just the outside air source for a closed system. Once the negative pressure is gone, I can't imagine that little slit doing anything except taking up space in the engine bay.
07-25-2010, 05:05 PM
#34
07-25-2010, 06:11 PM
#36
http://forums.maxima.org/7637839-post48.html
This poster measured the intake temp. I beleive "the little slit" does help.
This poster measured the intake temp. I beleive "the little slit" does help.
07-25-2010, 06:23 PM
#37
, I'm sure there's no stats, but from all the engine bay pics, etc I see of moderately/heavily modified cars, I can't say anyone has it hooked up.
07-25-2010, 06:28 PM
#38
