Idle valve Idea for JRSC m45 kits
10-06-2014, 12:20 PM
#1
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Idle valve Idea for JRSC m45 kits
The long hose running from the IAC -> check valve -> intake elbow
also you think about the vaccum from the supercharger in the intake elbow were the iac valve line is tapped in
kind of a lot the Idle valve has to overcome
When we deccel we get a droop in idle, some of us almost to stall out
When i look at my data logs, the Duty cycle of the idle valve is "twitching" from open to close in idle.
Really not 100% if this is the soul reason why, but it could be possibly or at least contributing to it.
Either way, The long hose just plain gets on my nerves, its wedged in between my headlight housing and scrunched over my brake lines
My idea is to just delete the line, put a check valve directly on the Idle valve port and then a small filter
so it cant leak boost, or breath in dirty/contaminated air
Here is a stupid little picture I drew, you see the current set-up and then what I think i might try
also you think about the vaccum from the supercharger in the intake elbow were the iac valve line is tapped in
kind of a lot the Idle valve has to overcome
When we deccel we get a droop in idle, some of us almost to stall out
When i look at my data logs, the Duty cycle of the idle valve is "twitching" from open to close in idle.
Really not 100% if this is the soul reason why, but it could be possibly or at least contributing to it.
Either way, The long hose just plain gets on my nerves, its wedged in between my headlight housing and scrunched over my brake lines
My idea is to just delete the line, put a check valve directly on the Idle valve port and then a small filter
so it cant leak boost, or breath in dirty/contaminated air
Here is a stupid little picture I drew, you see the current set-up and then what I think i might try
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10-13-2014, 06:25 PM
#3
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I never had a chance to try it.
But...i posted the same thread on miata.net and found that this would only slightly help the iac valve recover, compared to just doing a dual throttle set-up.
The reason the iac fails at hard deccel with an m45 is because the valve opens back up while there is still boost, which throws it off.
When you do a dual throttle mod or a mp62 remote mount iac, you get the iac to never see boost. Thats how you fix it. And the plan that i presented still does help, and free up a little bit of room/complexity
But...i posted the same thread on miata.net and found that this would only slightly help the iac valve recover, compared to just doing a dual throttle set-up.
The reason the iac fails at hard deccel with an m45 is because the valve opens back up while there is still boost, which throws it off.
When you do a dual throttle mod or a mp62 remote mount iac, you get the iac to never see boost. Thats how you fix it. And the plan that i presented still does help, and free up a little bit of room/complexity
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01-20-2015, 10:35 PM
#9
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TDR sells them.
The dual throttle body solves the idle problems of the stock JRSC, and creates a bunch of new fun challenges.
The solution posted earlier here screws the air flow meter up.
The dual throttle body solves the idle problems of the stock JRSC, and creates a bunch of new fun challenges.
The solution posted earlier here screws the air flow meter up.
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01-23-2015, 01:43 AM
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I'm in the process of prepping my 1.8 for mounting the M45 supercharger. New timing belt & waterpump. I was thinking about mounting the voodoo box for fuel management & MSD prior to doing the SC. What's the consensus?
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01-23-2015, 09:21 AM
#13
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I would agree with the approach. You may even go one step further and do the fuel management first, timing second, SC third. That way you can hopefully isolate issues that pop up. I am not familiar with the voodoo, but if you are running tan tops at stock rail pressure on a 1.8, you will run over 80% duty cycle pretty quickly. You may want to run an aftermarket fuel pressure regulator and pressure gauge to boost your pressure. Definitely check the fuel pressure even with the stock regulator. You will certainly want wideband.
Does your SC kit have any boost upgrades?
Does your SC kit have any boost upgrades?
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01-24-2015, 02:50 PM
#19
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And it is a fuel pressure gauge, not a boost gauge 
An m45 on a 1.8 is not going to boost much more than about 4 psi. If you are at sea level you will need to supply ~30% more fuel than stock to run at 12.5 A/F. I have seen stock tan tops get wiggy after extended 90% + duty cycles, this was on a 1.6 @ ~ 7.5 psi, afr 12.1, 3 bar fuel pressure ( manifold referenced)
If you were in Denver (like me) it is only a <20% increase in duty cycle.
I would really recommend corky bell's book "supercharged" if you don't already have it. It will help you to understand the basics of fueling among other things. I have seen them used on Amazon for really cheap. It was the first book I bought when I got started, and I couldn't put it down.
An m45 on a 1.8 is not going to boost much more than about 4 psi. If you are at sea level you will need to supply ~30% more fuel than stock to run at 12.5 A/F. I have seen stock tan tops get wiggy after extended 90% + duty cycles, this was on a 1.6 @ ~ 7.5 psi, afr 12.1, 3 bar fuel pressure ( manifold referenced)
If you were in Denver (like me) it is only a <20% increase in duty cycle.
I would really recommend corky bell's book "supercharged" if you don't already have it. It will help you to understand the basics of fueling among other things. I have seen them used on Amazon for really cheap. It was the first book I bought when I got started, and I couldn't put it down.
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