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HybridZ

1971 240z ITB install


DuffyMahoney

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Rubber one.

 

That’s a lot of valve when just a solenoid you pop open at cold start will do a great job and can be hidden like all your other plumbing. For warm idle control you can just add a big chunk of timing to your ignition map below your target idle and take a bit out at above. Works REALLY well. just doesn’t have quite enough bump when stone cold to start without touching the throttle. Once started will idle at any temp. And since it’s just a tweak to your closed throttle timing has zero effect on the way the motor runs.   These Toyota ones have a adjustment on how much they kick up the idle too. 543874F5-E045-4F1F-A30B-4BC6339E1015.jpeg.3baac5c830f44def1c74f93573d36d9c.jpeg

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I am a little concerned about the long span you have with no bolts on your plate. Do you have a o-ring groove in the top or gasket? I would be concerned it will suck in a gasket without a groove. I have seen plenty of throttle body and intake gaskets sucked in with much closer bolt spacing and larger bolts. 

Edited by tioga
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I got pretty far on the intake. I figured out my basic plan. I also tig welded the old holes and drilled and tapped new ones. So they are centered better. 
 

I tapped all existing holes for npt plugs. I also drilled each runner to 9mm. I bought a bspt 1/4 for the stock pcv fitting. Also a 5/8 hose Barb by 3/8 npt brass for the iac. 
 

I also had my stacks turned down to fit some cheap filters. Brass or no brass? 


Tioga- I will use a gasket. Either laser cut paper or silicone stuff. 

 

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On 3/6/2020 at 6:17 PM, tioga said:

Rubber one.

 

That’s a lot of valve when just a solenoid you pop open at cold start will do a great job and can be hidden like all your other plumbing. For warm idle control you can just add a big chunk of timing to your ignition map below your target idle and take a bit out at above. Works REALLY well. just doesn’t have quite enough bump when stone cold to start without touching the throttle. Once started will idle at any temp. And since it’s just a tweak to your closed throttle timing has zero effect on the way the motor runs.   These Toyota ones have a adjustment on how much they kick up the idle too. 543874F5-E045-4F1F-A30B-4BC6339E1015.jpeg.3baac5c830f44def1c74f93573d36d9c.jpeg

The iac needs to be 5/8 ID. This Bosch is just biggie then that. 

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Well this bosch and all bosch IACs of this style let a ton of air by when closed.  Bosch said roughly 30-35%.  Which makes the butterfly's useless at idle.  My next iac will be a ford.  Which closes all the way and only lets a tiny bit of air by.  

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2 hours ago, DuffyMahoney said:

Well this bosch and all bosch IACs of this style let a ton of air by when closed.  Bosch said roughly 30-35%.  Which makes the butterfly's useless at idle.  My next iac will be a ford.  Which closes all the way and only lets a tiny bit of air by.  

 

In theory the butterfly's should be closed at idle and all of your idle air controlled by the valve. 6 butterflies slightly cracked is not a dependable metering method for the air. It can also build up gunk over time but I doubt that will ever be a problem with Mr " I can eat of my motor because it's so clean" :)

 

Yes I'm jealous . 

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3 minutes ago, Derek said:

 

In theory the butterfly's should be closed at idle and all of your idle air controlled by the valve. 6 butterflies slightly cracked is not a dependable metering method for the air. It can also build up gunk over time but I doubt that will ever be a problem with Mr " I can eat of my motor because it's so clean" :)

 

Yes I'm jealous . 

Butterfly’s on the Jenvy don’t seat well enough at full close. Spring sticks. So snapped closed doesn’t close enough. So this iac won’t work. 

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13 minutes ago, DuffyMahoney said:

Butterfly’s on the Jenvy don’t seat well enough at full close. Spring sticks. So snapped closed doesn’t close enough. So this iac won’t work. 

 

 

Yikes.  Is the Ford a PWM controlled like the Bosch? 

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Bosch also does plunger type iac valves. I can give you a few part numbers if you like. The early bmw 325 used this style. Since we are one butterfly per cylinder the tiny bit you have to keep butterflies cracked to keep from binding when shut is enough for one cylinder to idle on. One butterfly Cracked  per 6 would be insignificant. I don’t think it is a jenvey thing but a itb thing. Everything about the jenvey stuff has been extremely well made and thought out. 

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2 hours ago, DuffyMahoney said:

Butterfly’s on the Jenvy don’t seat well enough at full close. Spring sticks. So snapped closed doesn’t close enough. So this iac won’t work. 

 

Just curious, but you're saying that you couldn't get the idle down with that IACV?  You actually tried it, or you just did a calculation?

 

Seems goofy to work around a sticky throttle body blade problem, by changing IACV's.  Doesn't it?  Can't you do more work on the TB's?

 

And, more talking about stuff I don't know well, but will your single port evenly distribute the air to the cylinders?  Using an IACV  for idle control seems like a great idea.  Just wondering about the final execution.

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