opinions needed - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

uiuc240 · 10-04-2002, 08:42 AM

Some background:

My SR has the stock SMIC and the associated stock recirc-valve. It's working. But I still have a crappy idle and thought that maybe the valve is leaking (still have to build that damn leak tester and check it out).

Here's my thought:

Since I have the stock SMIC and the stock piping, I could get a BOV like the one shown below and just pop it in there. That way I could even keep it (and the pipe) when I get an FMIC kit. Sounds like a good plan to me. What do you think?

One more thing: does anyone have a SURE-FIRE way of tuning the BOV so it doesn't cause idle stumble. I know it's possible. I was just going to tighten it so there is NO air leak at idle and see what happens..... <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/notify.gif" border="0" valign="absmiddle" alt=':notify:'>

Eric

boosteds14 · 10-04-2002, 09:29 AM

sounds like a good idea but wont your vaccuum be screwed up because of the fact that the motor will need to suck air in but u will be providing it with the turbo causing less vaccuum. but thats my opinion, i believe also that it there will be no vaccuum problems because the turbo will be not spinning fast enough to push alot of air.

uiuc240 · 10-04-2002, 09:36 AM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (boosteds14 @ Oct. 04 2002,10:29)</td></tr><tr><td id="QUOTE">sounds like a good idea but wont your vaccuum be screwed up because of the fact that the motor will need to suck air in but u will be providing it with the turbo causing less vaccuum. but thats my opinion, i believe also that it there will be no vaccuum problems because the turbo will be not spinning fast enough to push alot of air.</td></tr></table><span id='postcolor'>
Wha???

Wow that was so confusing.  I don't think vacuum should be a problem if I set it up right.  It should not be open at idle.  And the turbo is not spooled at idle.  I should see the same vacuum I see now...or better, hopefully.  Right now, vacuum is good everywhere BUT idle.  I think it might be a leaky stock recirc valve or something.  Not sure.

So I think I'm gonna do it.  Cap the old one, put in a nice new one.  Better response, better venting, looks good under the hood, sounds good when boosting <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt='

'>

Eric

boosteds14 · 10-04-2002, 10:31 AM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (uiuc240 @ Oct. 04 2002,12:36)</td></tr><tr><td id="QUOTE"></span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (boosteds14 @ Oct. 04 2002,10:29)</td></tr><tr><td id="QUOTE">sounds like a good idea but wont your vaccuum be screwed up because of the fact that the motor will need to suck air in but u will be providing it with the turbo causing less vaccuum. but thats my opinion, i believe also that it there will be no vaccuum problems because the turbo will be not spinning fast enough to push alot of air.</td></tr></table><span id='postcolor'>
Wha???

Wow that was so confusing. I don't think vacuum should be a problem if I set it up right. It should not be open at idle. And the turbo is not spooled at idle. I should see the same vacuum I see now...or better, hopefully. Right now, vacuum is good everywhere BUT idle. I think it might be a leaky stock recirc valve or something. Not sure.

So I think I'm gonna do it. Cap the old one, put in a nice new one. Better response, better venting, looks good under the hood, sounds good when boosting <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt='

'>

Eric</td></tr></table><span id='postcolor'>
ya i just read my post. I AM AN IDIOT
i dont know what i was thinking
must be still hurting from the club last night.
im half asleep right now

SORRY

time to boil the water for some coffee

uiuc240 · 10-04-2002, 10:41 AM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (boosteds14 @ Oct. 04 2002,11:31)</td></tr><tr><td id="QUOTE">ya i just read my post. I AM AN IDIOT
i dont know what i was thinking
must be still hurting from the club last night.
im half asleep right now

SORRY

time to boil the water for some coffee</td></tr></table><span id='postcolor'>
<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt='

'>  <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/tounge.gif" border="0" valign="absmiddle" alt='

'>  <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt='

'>  <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/hehe.gif" border="0" valign="absmiddle" alt=':hehe:'>

Awesome.  Glad you had fun.  I was up until two doing research for some papers I have to write this weekend (one on the affects of the intercom on post-war suburban homes and the other on a house for Mr. Baker designed by William Drummond in Chicago).  Sounds fun, eh?  I think a club sounds better.

I'm drinking coffee too.  Mmmmm.

Eric

uiuc240 · 10-04-2002, 07:10 PM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (James @ Oct. 04 2002,7:13)</td></tr><tr><td id="QUOTE">Here is my fresh opinion:
If you're having a stumbling idle with the stock setup already --->I would highly doubt that using a aftermarket vented BOV is going to solve this. Either with your guess that it's a leaky stock setup or going the aftermarket route you'll always have some quirky idle, unless.......
Isn't it well documented that an S-AFC can be used as a band-aid to cure idle problems on aftermarket vented BOV's?
So you could always go that route.
And the procedure you asked about IIRC is screw the adjuster until you just start to hear hissing- then back out a turn and lock it up.</td></tr></table><span id='postcolor'>
Well, the idle isn't "stumbling"...it's just rough...or bubbly.  It's gotten better.  It just doesn't like 800 rpm.  1000 rpm is much better...but that's a bit high.  I'm thinking part of it may be a small exhaust leak too.

One note:  The S-AFC is a good idea, but OUT of the question.  A $400 band-aid?<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'>  I don't think so.  I'd get a JWT ECU before shelling out the cash for that crap.  Phooey.

Eric

particleeffect · 10-04-2002, 08:28 PM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (uiuc240 @ Oct. 04 2002,8:10)</td></tr><tr><td id="QUOTE">One note: The S-AFC is a good idea, but OUT of the question. A $400 band-aid?<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'> I don't think so. I'd get a JWT ECU before shelling out the cash for that crap. Phooey.

Eric</td></tr></table><span id='postcolor'>
i've been wondering about this.  i assume the jwt ecu is preset for a certain boost and such.  but would it be worth it to have if you're still running an a/f controller?  say you also had a boost controller and detuned you'r boost and a/f for daily driving and then as you bring the boost up a bit for the track, you can properly ajust the a/f ratio..  or is the jwt ecu just a better ecu to be running an a/f controller with?

uiuc240 · 10-04-2002, 09:59 PM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (particleeffect @ Oct. 04 2002,9:28)</td></tr><tr><td id="QUOTE">i've been wondering about this. i assume the jwt ecu is preset for a certain boost and such. but would it be worth it to have if you're still running an a/f controller? say you also had a boost controller and detuned you'r boost and a/f for daily driving and then as you bring the boost up a bit for the track, you can properly ajust the a/f ratio.. or is the jwt ecu just a better ecu to be running an a/f controller with?</td></tr></table><span id='postcolor'>
The JWT has maps that go farther than the stock maps, yes.  But the main thing here is that with the JWT ECU, you can tell them what MAFS/turbo/injectors/etc. you have and they can do their best to set something up for the flow and power characteristics you have.  In all honesty, I'll probably skip that and make the jump to something more programmable...that's a long way down the road.  I just don't see the point in getting an S-AFC just so I can use the "dec-air" function for my soon-to-be atmospheric BOV.  I do like the fact that I would be able to control 550cc injectors and a Z32 MAF, but I don't need those now anyway.  I'm still running the stock T25.  I'm just going to get the BOV and pop it in there and PFfffftttt all over town <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt='

'>

Eric

uiuc240 · 10-04-2002, 11:27 PM

I guess I was just looking for someone to say:

"Dumbass, you're wasting your money, the stock recirc valve is fine...save your cash for something worthwhile."

You know, a reality check.

But on the other hand, I think this was just my way of saying "look at what I'm getting."  <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt='

'>

Eric

particleeffect · 10-05-2002, 01:07 AM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (uiuc240 @ Oct. 05 2002,12:27)</td></tr><tr><td id="QUOTE">I guess I was just looking for someone to say:

"Dumbass, you're wasting your money, the stock recirc valve is fine...save your cash for something worthwhile."

You know, a reality check.

But on the other hand, I think this was just my way of saying "look at what I'm getting." <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt='

'>

Eric</td></tr></table><span id='postcolor'>
hehe, and thnx for the answer.

10-04-2002, 08:42 AM	#1
uiuc240 Nissanaholic! Join Date: Apr 2002 Location: Naperville, IL Age: 46 Posts: 2,093 Trader Rating: (0) Feedback Score: 0 reviews	Some background: My SR has the stock SMIC and the associated stock recirc-valve. It's working. But I still have a crappy idle and thought that maybe the valve is leaking (still have to build that damn leak tester and check it out). Here's my thought: Since I have the stock SMIC and the stock piping, I could get a BOV like the one shown below and just pop it in there. That way I could even keep it (and the pipe) when I get an FMIC kit. Sounds like a good plan to me. What do you think? One more thing: does anyone have a SURE-FIRE way of tuning the BOV so it doesn't cause idle stumble. I know it's possible. I was just going to tighten it so there is NO air leak at idle and see what happens..... <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/notify.gif" border="0" valign="absmiddle" alt=':notify:'> Eric __________________ 2002 Mazda Protege5 1989 S13 w/SR20DET (sold)

10-04-2002, 09:29 AM	#2
boosteds14 Zilvia.net Advertiser Join Date: Jan 2002 Location: CIPmotorsports Age: 43 Posts: 1,612 Trader Rating: (0) Feedback Score: 0 reviews	sounds like a good idea but wont your vaccuum be screwed up because of the fact that the motor will need to suck air in but u will be providing it with the turbo causing less vaccuum. but thats my opinion, i believe also that it there will be no vaccuum problems because the turbo will be not spinning fast enough to push alot of air. __________________ 240SXONE www.240SXMOTORING.com --- One Stop Shop for Your Nissan 240sx

10-04-2002, 09:36 AM	#3
uiuc240 Nissanaholic! Join Date: Apr 2002 Location: Naperville, IL Age: 46 Posts: 2,093 Trader Rating: (0) Feedback Score: 0 reviews	</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (boosteds14 @ Oct. 04 2002,10:29)</td></tr><tr><td id="QUOTE">sounds like a good idea but wont your vaccuum be screwed up because of the fact that the motor will need to suck air in but u will be providing it with the turbo causing less vaccuum. but thats my opinion, i believe also that it there will be no vaccuum problems because the turbo will be not spinning fast enough to push alot of air.</td></tr></table><span id='postcolor'> Wha??? Wow that was so confusing.  I don't think vacuum should be a problem if I set it up right.  It should not be open at idle.  And the turbo is not spooled at idle.  I should see the same vacuum I see now...or better, hopefully.  Right now, vacuum is good everywhere BUT idle.  I think it might be a leaky stock recirc valve or something.  Not sure. So I think I'm gonna do it.  Cap the old one, put in a nice new one.  Better response, better venting, looks good under the hood, sounds good when boosting <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=''> Eric __________________ 2002 Mazda Protege5 1989 S13 w/SR20DET (sold)

10-04-2002, 10:31 AM	#4
boosteds14 Zilvia.net Advertiser Join Date: Jan 2002 Location: CIPmotorsports Age: 43 Posts: 1,612 Trader Rating: (0) Feedback Score: 0 reviews	</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (uiuc240 @ Oct. 04 2002,12:36)</td></tr><tr><td id="QUOTE"></span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (boosteds14 @ Oct. 04 2002,10:29)</td></tr><tr><td id="QUOTE">sounds like a good idea but wont your vaccuum be screwed up because of the fact that the motor will need to suck air in but u will be providing it with the turbo causing less vaccuum. but thats my opinion, i believe also that it there will be no vaccuum problems because the turbo will be not spinning fast enough to push alot of air.</td></tr></table><span id='postcolor'> Wha??? Wow that was so confusing. I don't think vacuum should be a problem if I set it up right. It should not be open at idle. And the turbo is not spooled at idle. I should see the same vacuum I see now...or better, hopefully. Right now, vacuum is good everywhere BUT idle. I think it might be a leaky stock recirc valve or something. Not sure. So I think I'm gonna do it. Cap the old one, put in a nice new one. Better response, better venting, looks good under the hood, sounds good when boosting <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=''> Eric</td></tr></table><span id='postcolor'> ya i just read my post. I AM AN IDIOT i dont know what i was thinking must be still hurting from the club last night. im half asleep right now SORRY time to boil the water for some coffee __________________ 240SXONE www.240SXMOTORING.com --- One Stop Shop for Your Nissan 240sx

10-04-2002, 10:41 AM	#5
uiuc240 Nissanaholic! Join Date: Apr 2002 Location: Naperville, IL Age: 46 Posts: 2,093 Trader Rating: (0) Feedback Score: 0 reviews	</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (boosteds14 @ Oct. 04 2002,11:31)</td></tr><tr><td id="QUOTE">ya i just read my post. I AM AN IDIOT i dont know what i was thinking must be still hurting from the club last night. im half asleep right now SORRY time to boil the water for some coffee</td></tr></table><span id='postcolor'> <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=''>  <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/tounge.gif" border="0" valign="absmiddle" alt=''>  <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=''>  <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/hehe.gif" border="0" valign="absmiddle" alt=':hehe:'> Awesome.  Glad you had fun.  I was up until two doing research for some papers I have to write this weekend (one on the affects of the intercom on post-war suburban homes and the other on a house for Mr. Baker designed by William Drummond in Chicago).  Sounds fun, eh?  I think a club sounds better. I'm drinking coffee too.  Mmmmm. Eric __________________ 2002 Mazda Protege5 1989 S13 w/SR20DET (sold)

10-04-2002, 07:10 PM	#6
uiuc240 Nissanaholic! Join Date: Apr 2002 Location: Naperville, IL Age: 46 Posts: 2,093 Trader Rating: (0) Feedback Score: 0 reviews	</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (James @ Oct. 04 2002,7:13)</td></tr><tr><td id="QUOTE">Here is my fresh opinion: If you're having a stumbling idle with the stock setup already --->I would highly doubt that using a aftermarket vented BOV is going to solve this. Either with your guess that it's a leaky stock setup or going the aftermarket route you'll always have some quirky idle, unless....... Isn't it well documented that an S-AFC can be used as a band-aid to cure idle problems on aftermarket vented BOV's? So you could always go that route. And the procedure you asked about IIRC is screw the adjuster until you just start to hear hissing- then back out a turn and lock it up.</td></tr></table><span id='postcolor'> Well, the idle isn't "stumbling"...it's just rough...or bubbly.  It's gotten better.  It just doesn't like 800 rpm.  1000 rpm is much better...but that's a bit high.  I'm thinking part of it may be a small exhaust leak too. One note:  The S-AFC is a good idea, but OUT of the question.  A $400 band-aid?<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'>  I don't think so.  I'd get a JWT ECU before shelling out the cash for that crap.  Phooey. Eric __________________ 2002 Mazda Protege5 1989 S13 w/SR20DET (sold)

10-04-2002, 08:28 PM	#7
particleeffect Join Date: Sep 2002 Posts: 27 Trader Rating: (0) Feedback Score: 0 reviews	</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (uiuc240 @ Oct. 04 2002,8:10)</td></tr><tr><td id="QUOTE">One note: The S-AFC is a good idea, but OUT of the question. A $400 band-aid?<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'> I don't think so. I'd get a JWT ECU before shelling out the cash for that crap. Phooey. Eric</td></tr></table><span id='postcolor'> i've been wondering about this.  i assume the jwt ecu is preset for a certain boost and such.  but would it be worth it to have if you're still running an a/f controller?  say you also had a boost controller and detuned you'r boost and a/f for daily driving and then as you bring the boost up a bit for the track, you can properly ajust the a/f ratio..  or is the jwt ecu just a better ecu to be running an a/f controller with? __________________ it doesn't need to work tomorrow, it just needs to win today.

10-04-2002, 09:59 PM	#8
uiuc240 Nissanaholic! Join Date: Apr 2002 Location: Naperville, IL Age: 46 Posts: 2,093 Trader Rating: (0) Feedback Score: 0 reviews	</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (particleeffect @ Oct. 04 2002,9:28)</td></tr><tr><td id="QUOTE">i've been wondering about this. i assume the jwt ecu is preset for a certain boost and such. but would it be worth it to have if you're still running an a/f controller? say you also had a boost controller and detuned you'r boost and a/f for daily driving and then as you bring the boost up a bit for the track, you can properly ajust the a/f ratio.. or is the jwt ecu just a better ecu to be running an a/f controller with?</td></tr></table><span id='postcolor'> The JWT has maps that go farther than the stock maps, yes.  But the main thing here is that with the JWT ECU, you can tell them what MAFS/turbo/injectors/etc. you have and they can do their best to set something up for the flow and power characteristics you have.  In all honesty, I'll probably skip that and make the jump to something more programmable...that's a long way down the road.  I just don't see the point in getting an S-AFC just so I can use the "dec-air" function for my soon-to-be atmospheric BOV.  I do like the fact that I would be able to control 550cc injectors and a Z32 MAF, but I don't need those now anyway.  I'm still running the stock T25.  I'm just going to get the BOV and pop it in there and PFfffftttt all over town <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=''> Eric __________________ 2002 Mazda Protege5 1989 S13 w/SR20DET (sold)

10-04-2002, 11:27 PM	#9
uiuc240 Nissanaholic! Join Date: Apr 2002 Location: Naperville, IL Age: 46 Posts: 2,093 Trader Rating: (0) Feedback Score: 0 reviews	I guess I was just looking for someone to say: "Dumbass, you're wasting your money, the stock recirc valve is fine...save your cash for something worthwhile." You know, a reality check. But on the other hand, I think this was just my way of saying "look at what I'm getting."  <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=''> Eric __________________ 2002 Mazda Protege5 1989 S13 w/SR20DET (sold)

10-05-2002, 01:07 AM	#10
particleeffect Join Date: Sep 2002 Posts: 27 Trader Rating: (0) Feedback Score: 0 reviews	</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (uiuc240 @ Oct. 05 2002,12:27)</td></tr><tr><td id="QUOTE">I guess I was just looking for someone to say: "Dumbass, you're wasting your money, the stock recirc valve is fine...save your cash for something worthwhile." You know, a reality check. But on the other hand, I think this was just my way of saying "look at what I'm getting." <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=''> Eric</td></tr></table><span id='postcolor'> hehe, and thnx for the answer. __________________ it doesn't need to work tomorrow, it just needs to win today.