Phenolic Spacer Development for VQ35s
#802
Ahhh. Then I was wrong; I keep getting hung up on vehicles not using fuel trims for open loop operation. Whatever metric is used to define load (MAP, MAF, or a calculated/correlated value) is calibrated beyond normal operating parameters (VE). Eventually this ability will run out as peak MAF/MAP voltage or injector duty cycle is achieved.
#803
To my understanding it's a simple formula to determine load as far as these ECU's are concerned: (X) MAF sensor voltage + (Y) Engine speed = (Z) Injector pulse width. The only way the a/f would change is if the target open loop a/f ratio at that particular load cell is different; otherwise it should remain the same.
#804
Many vehicles don't use fuel trim feedback to modify base fuel delivery tables, or increase fuel delivery even if more air is measured. Based on Aaron's posts, it seems the Maxima's ecu falls into this category. As such, the fuel trims (or calibration method) will keep constant closed loop AFR, but will not accommodate air flow increases at/near WOT. The AFR changes are likely not significant as calibrations generally run rich at/near WOT to cool and protect the catalyst(s).
Nissan ECU's do not carry an 'AFR target' but a base injection pulse width for a certain cell value in open loop. Hence why using a Z32 air flow meter requires a complete retune as it is not trying to maintaina certain AFRs but a base injection pulse for a given amount of air.
Once a change is made to the induction or exhaust system, the volumetric efficiency of the engine will change allowing the engine to run more ignition advance(choked up exhaust promotes more exhaust valve heat and hence more detonation prone etc so reduced timing as an example) but by offering a colder and denser air, the knock retard map is likely to allow more timing with the benefit being that a stronger induction can be generated on the next intake stroke due to a thorough combustion from more timing and denser oxygen air on the just emptying exhaust stroke leaves more vacuum inside the bore, which increases volumetric efficiency
Narrow band O2 sensors are just not accurate enough for open loop AFR control
#807
Nearly all OBDII vehicles require short and long term fuel trims(for emissions compliance testing) which is why often an 'ECU reset' will make the car feel quicker for a few days until fuel trims kill power again by adding too much fuel or retarding timing etc to take into account engine wear, poor O2 sensor output etc.
Nissan ECU's do not carry an 'AFR target' but a base injection pulse width for a certain cell value in open loop. Hence why using a Z32 air flow meter requires a complete retune as it is not trying to maintaina certain AFRs but a base injection pulse for a given amount of air.
When changing to another MAF (Z32, etc.) a new calibration is necessary as the new MAF's correlation of voltage to air flow is different. Consequently, this correlation must be 'taught' to the ECU as the original base map references MAF voltage and will no longer provide the correct AFR.
Once a change is made to the induction or exhaust system, the volumetric efficiency of the engine will change allowing the engine to run more ignition advance(choked up exhaust promotes more exhaust valve heat and hence more detonation prone etc so reduced timing as an example) but by offering a colder and denser air, the knock retard map is likely to allow more timing with the benefit being that a stronger induction can be generated on the next intake stroke due to a thorough combustion from more timing and denser oxygen air on the just emptying exhaust stroke leaves more vacuum inside the bore, which increases volumetric efficiency
Yup, that is why most vehicles use 'wideband' primary oxygen sensors.
Last edited by 2slow; 10-11-2009 at 05:45 PM.
#808
To my understanding it's a simple formula to determine load as far as these ECU's are concerned: (X) MAF sensor voltage + (Y) Engine speed = (Z) Injector pulse width. The only way the a/f would change is if the target open loop a/f ratio at that particular load cell is different; otherwise it should remain the same.
#809
free bump
free bump
I'm having someone else install this was just thinking of worst case scenarios, and say something like that happened as in pbn85's case. What would be the consequences of this? Just short term? or long term?
Im just curious, I would hope my fav shop could handle this.
I have these in my living room by the way. Can't Wait !
Scottwax or anyone who has paid a shop- Do you remember what you ended up paying additionally in your sparkplug+spacer change?
Thanks for sending me an email about this. With the details you gave me, it seems that they applied too much RTV, which squeezes out in the airflow and also impedes the injector spray pattern. But in order to do this, you have to be pretty careless with the application of RTV and not read the instructions. If you just put a large bead of RTV around each intake spacer, the majority of it will squeeze out in the intake port. The best way to apply the RTV is to put a tiny pea sized amount on the tip of your finger and smear a consistent and thin layer of RTV around the intake port. Then when you stick the spacer onto the manifold, push down as hard as you can in a straight manner and if you see a ton of RTV squeeze out, you'll know you applied too much. You can wipe the excess off or remove it, clean it, and reapply.
Im just curious, I would hope my fav shop could handle this.
I have these in my living room by the way. Can't Wait !
Scottwax or anyone who has paid a shop- Do you remember what you ended up paying additionally in your sparkplug+spacer change?
#810
I paid a mechanic for this work... if I back out the cost of a new VC, and guess how much to back off for the extra work involved because of the rear VC being trashed and having to clean oil out of the spark plug tubes (damn 5.5 gen covers)... I think the specific cost was around $250.
That's the best guess I can give from my experience.
Worth it? Yes sir, it was.
That's the best guess I can give from my experience.
Worth it? Yes sir, it was.
#811
free bump
I'm having someone else install this was just thinking of worst case scenarios, and say something like that happened as in pbn85's case. What would be the consequences of this? Just short term? or long term?
Im just curious, I would hope my fav shop could handle this.
I have these in my living room by the way. Can't Wait !
Scottwax or anyone who has paid a shop- Do you remember what you ended up paying additionally in your sparkplug+spacer change?
I'm having someone else install this was just thinking of worst case scenarios, and say something like that happened as in pbn85's case. What would be the consequences of this? Just short term? or long term?
Im just curious, I would hope my fav shop could handle this.
I have these in my living room by the way. Can't Wait !
Scottwax or anyone who has paid a shop- Do you remember what you ended up paying additionally in your sparkplug+spacer change?
The estimated labor time to install the Spacers is 2-3 hours. Do not let a shop charge you for more than 3 hours. But if they are replacing the valve cover or spark plugs at the same time, then labor will be increased slightly.
Most fair quotes I've seen to have these Spacers installed range from $150 to $245. While speaking with one of my customers recently, he was happy with the customer service at one performance shop in South Florida that installed the Spacers for $190 labor. I think this is a very fair price, especially considering they appear to build some pretty nice race cars there.
#813
#814
free bump for a great product/company
I can't read the install directions that come with the spacers right now so I dont know if they answer this question.
What type of RTV Silicone Sealent should be used for the spacers? It seems like there are many types.
If it is not specified in the directions which it probably is. I need to inform the guy doing the install. As of now all I have to tell him is to keep all old parts.
Thanks.
What type of RTV Silicone Sealent should be used for the spacers? It seems like there are many types.
If it is not specified in the directions which it probably is. I need to inform the guy doing the install. As of now all I have to tell him is to keep all old parts.
Thanks.
#815
I can't read the install directions that come with the spacers right now so I dont know if they answer this question.
What type of RTV Silicone Sealent should be used for the spacers? It seems like there are many types.
If it is not specified in the directions which it probably is. I need to inform the guy doing the install. As of now all I have to tell him is to keep all old parts.
Thanks.
What type of RTV Silicone Sealent should be used for the spacers? It seems like there are many types.
If it is not specified in the directions which it probably is. I need to inform the guy doing the install. As of now all I have to tell him is to keep all old parts.
Thanks.
BTW here's the PDF of the instructions: http://nwpengineering.com/VQ35DE_FWD_Instructions.pdf
Just saw that the instructions call for black RTV
Tools/Materials Needed: Basic
Metric Socket set, Basic Metric
Open-Ended Wrench set, Metric
Allen Wrench set, Pliers,
Flathead and Phillips
screwdriver, Torque Wrench, E 8
External T o r x Socket (optional),
Permatex Ultra Black RTV
Silicone Gasket Maker (598B) or
1 Minute Gasket (25229), Shop
Vacuum for removing dirt in
engine valley
Metric Socket set, Basic Metric
Open-Ended Wrench set, Metric
Allen Wrench set, Pliers,
Flathead and Phillips
screwdriver, Torque Wrench, E 8
External T o r x Socket (optional),
Permatex Ultra Black RTV
Silicone Gasket Maker (598B) or
1 Minute Gasket (25229), Shop
Vacuum for removing dirt in
engine valley
Last edited by Froggmann; 03-31-2011 at 09:37 AM.
#816
I used standard Permetex Blue RTV. No Leaks. The biggest thing to keep in mind is to allow the RTV to get a little tacky (Spread then wait a minute or two) before putting that part on the engine. Also you need to use a super thin layer of RTV. Too much and it either makes a mess or causes an air pocket that causes a vacuum leak.
BTW here's the PDF of the instructions: http://nwpengineering.com/VQ35DE_FWD_Instructions.pdf
Just saw that the instructions call for black RTV
BTW here's the PDF of the instructions: http://nwpengineering.com/VQ35DE_FWD_Instructions.pdf
Just saw that the instructions call for black RTV
#817
Blue RTV will work as well. But Black RTV is recommended.
As Froggmann already mentioned, a thin layer is all that is needed. Most people apply way too much and it gets messy and squeezes out of the intake port and can slightly hinder airflow. I would suggest to make sure the Spacers are wiped clean and the intake manifold surface is clean and free of gouges. Once the mating surfaces are clean, all that is needed is a paper thin layer of RTV around each intake port of the Spacer. Do this to both sides of every Spacer.
I recommend to apply a marble sized amount of RTV on the tip of your index finger and smear it smoothly around each port on the Spacer. Make sure it's a consistent and smooth layer of RTV. If the layer is thicker than poster board paper, then it's too thick and you'll probably see it squeeze out once you torque everything down.
Also, once you have RTV on both sides of the Spacer, you will want to stick the Spacer directly on the manifold. Push it firmly straight down and leave it. Do not let it slide laterally once it's stuck to the manifold.
I love the 1 Minute Gasket made by Permatex. It's much easier to apply. I cut the nozzle very small and apply a TINY bead around each intake port. Then I go back with my finger and smear it around the port. I will wipe the excess RTV off my finger from time to time. Again, a consistent, beautiful paper thin layer of RTV is all that is needed.
As Froggmann already mentioned, a thin layer is all that is needed. Most people apply way too much and it gets messy and squeezes out of the intake port and can slightly hinder airflow. I would suggest to make sure the Spacers are wiped clean and the intake manifold surface is clean and free of gouges. Once the mating surfaces are clean, all that is needed is a paper thin layer of RTV around each intake port of the Spacer. Do this to both sides of every Spacer.
I recommend to apply a marble sized amount of RTV on the tip of your index finger and smear it smoothly around each port on the Spacer. Make sure it's a consistent and smooth layer of RTV. If the layer is thicker than poster board paper, then it's too thick and you'll probably see it squeeze out once you torque everything down.
Also, once you have RTV on both sides of the Spacer, you will want to stick the Spacer directly on the manifold. Push it firmly straight down and leave it. Do not let it slide laterally once it's stuck to the manifold.
I love the 1 Minute Gasket made by Permatex. It's much easier to apply. I cut the nozzle very small and apply a TINY bead around each intake port. Then I go back with my finger and smear it around the port. I will wipe the excess RTV off my finger from time to time. Again, a consistent, beautiful paper thin layer of RTV is all that is needed.
#819
#821
Just installed mine today and now have every single bolt on plus DW 440cc injectors and 255lph. Called and asked why there we're two spacers for the LIM. LMAO. I've never taken off the LIM didn't really think before calling haha. I did apply more RTV than needed but I torqued everything down and cleaned the ports before sealing everything up. I don't really notice any sound change but my car is loud as hell up front with intake and headers. No leaks. Butt dyno felt great.
Overall I'm more than satisfied with the results and the spacers and bolts looked great. Highly recommend this mod. Now need a tune and JWT stage 2 cams and I'll be done modding this thing.
Overall I'm more than satisfied with the results and the spacers and bolts looked great. Highly recommend this mod. Now need a tune and JWT stage 2 cams and I'll be done modding this thing.
#823
#824
Just installed mine today and now have every single bolt on plus DW 440cc injectors and 255lph. Called and asked why there we're two spacers for the LIM. LMAO. I've never taken off the LIM didn't really think before calling haha. I did apply more RTV than needed but I torqued everything down and cleaned the ports before sealing everything up. I don't really notice any sound change but my car is loud as hell up front with intake and headers. No leaks. Butt dyno felt great.
Overall I'm more than satisfied with the results and the spacers and bolts looked great. Highly recommend this mod. Now need a tune and JWT stage 2 cams and I'll be done modding this thing.
Overall I'm more than satisfied with the results and the spacers and bolts looked great. Highly recommend this mod. Now need a tune and JWT stage 2 cams and I'll be done modding this thing.
Also, a tune would be a great thing to do right away. You'll notice a pretty decent gain from leaning out the AFR and advancing ignition timing.
#825
Thank you. I'm glad you are happy. That's good that you wiped down the ports before bolting everything back up. You don't want RTV squeezing out and hindering airflow. If your mating surfaces on the manifold and Spacers are clean, all you need is a paper thin layer of RTV to make a good seal.
Also, a tune would be a great thing to do right away. You'll notice a pretty decent gain from leaning out the AFR and advancing ignition timing.
Also, a tune would be a great thing to do right away. You'll notice a pretty decent gain from leaning out the AFR and advancing ignition timing.
Aaron, is there a way to only order all the bolts/studs that come with the spacer kit. And about how much?
#826
Please let me know if you have any more questions.
#827
Yes, all the hardware for the VQ35DE Maxima Thermal Intake Spacer Kit is $15.00 plus $6 shipping via 2-3 day Priority Mail. You may place your order anytime by sending a Paypal payment to sales@nwpengineering.com. Please be sure to mark the payment as "Goods" and specify the correct shipping address. Do not include your shipping address in the message box.
Please let me know if you have any more questions.
Please let me know if you have any more questions.
Be on the lookout funds sent.
#829
Thank you. I have received your payment. I'm sorry I haven't contacted you earlier. I recently had a very close family member die this past weekend and things have been hectic.
But everyone's orders will ship within the next day or two. You will receive an email with package information soon. Thank you for your business!
Thank you. And good job to you too on reading through this huge thread. Please let me know if there is anything I can do or if you have any questions.
But everyone's orders will ship within the next day or two. You will receive an email with package information soon. Thank you for your business!
Thank you. And good job to you too on reading through this huge thread. Please let me know if there is anything I can do or if you have any questions.
#830
Thank you. I have received your payment. I'm sorry I haven't contacted you earlier. I recently had a very close family member die this past weekend and things have been hectic.
But everyone's orders will ship within the next day or two. You will receive an email with package information soon. Thank you for your business!
Thank you. And good job to you too on reading through this huge thread. Please let me know if there is anything I can do or if you have any questions.
But everyone's orders will ship within the next day or two. You will receive an email with package information soon. Thank you for your business!
Thank you. And good job to you too on reading through this huge thread. Please let me know if there is anything I can do or if you have any questions.
Appreciate the hardware. I'm glad the tb bypass nozel was included, because I forgot all about doing that.
Spacers are in 7hrs later (basically didn't have a good seal first time and had to take apart and redo, so it was like doing job twice).
I thought I saw this somewhere but can't remember. ?? Since car fired right up and no chk engine light or idle issues... Do I need to do any of the relearns?
Last edited by 7speed; 08-08-2011 at 01:33 PM.
#831
Hope everything is better for you and the family.
Appreciate the hardware. I'm glad the tb bypass nozel was included, because I forgot all about doing that.
Spacers are in 7hrs later (basically didn't have a good seal first time and had to take apart and redo, so it was like doing job twice).
I thought I saw this somewhere, but since car fired right up and no chk engine light or idle issues. Do I need to do any of the relearns?
Appreciate the hardware. I'm glad the tb bypass nozel was included, because I forgot all about doing that.
Spacers are in 7hrs later (basically didn't have a good seal first time and had to take apart and redo, so it was like doing job twice).
I thought I saw this somewhere, but since car fired right up and no chk engine light or idle issues. Do I need to do any of the relearns?
#832
Hope everything is better for you and the family.
Appreciate the hardware. I'm glad the tb bypass nozel was included, because I forgot all about doing that.
Spacers are in 7hrs later (basically didn't have a good seal first time and had to take apart and redo, so it was like doing job twice).
I thought I saw this somewhere but can't remember. ?? Since car fired right up and no chk engine light or idle issues... Do I need to do any of the relearns?
Appreciate the hardware. I'm glad the tb bypass nozel was included, because I forgot all about doing that.
Spacers are in 7hrs later (basically didn't have a good seal first time and had to take apart and redo, so it was like doing job twice).
I thought I saw this somewhere but can't remember. ?? Since car fired right up and no chk engine light or idle issues... Do I need to do any of the relearns?
You don't have to do any of the procedures if your car is running properly. I've never had to do any of them on any of the installs I've done. But, like Unklejoe said, it won't hurt to do the procedure. Even if you just want to practice them, go ahead and feel free. The Idle Air Volume Learning procedure can be tricky to get the timing right. If you are not within a 1 second accuracy with your timing, then it probably won't work.
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