ITB setup startup - removed idle stabilizer - ok?
01-15-2019, 03:24 AM
#16
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01-15-2019, 03:41 AM
#17
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Jonas, very crudely I used a micrometer slid down the itb mouth to measure the throttle plate deflection for initial setup. If the car is not street driven then you may be ok without an ICV? Just set the throttle plates for a fast idle and call it good? I’m not sure what others have done..
My setup courtesy of Alex P uses bmw itbs with the vacuum passages cast in place.
My setup courtesy of Alex P uses bmw itbs with the vacuum passages cast in place.
There are very many multi-cylinder engines having no ICV out there so why should it not work? The throttle plates have to be synchronized. Set the throttles for good idle when engine has reached operating temperature. The only problem I can see is the idle rpm cold will probably not be the same as when engine is warmed up. Here is how they do it for a bike.
Åke
https://pastframe.wordpress.com/2014...nchronization/
Some additional info.
http://www.compsystems.com.au/index....whole-ls-range
Åke
https://pastframe.wordpress.com/2014...nchronization/
Some additional info.
http://www.compsystems.com.au/index....whole-ls-range
/Jonas
01-15-2019, 10:46 AM
#18
Chronic Tool Dropper
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In fact you don’t want any “one way air connectors”. Pulses at each port need to balance some to make the throttle stop adjustment a little less sensitive. Retain the check valve at the brake booster and you’ll be golden. Getting the tip-in response perfect will be your challenge, as you try to get all the throttles to move off their stops at exactly the same time. I’ve done this with a collection of various flow detectors like Uni-Syn, but often end up with a couple vacuum hoses to listen above the throttles as I adjust. It’s tedious but worthwhile.
01-15-2019, 10:52 AM
#19
01-15-2019, 12:14 PM
#20
Drifting
01-15-2019, 03:52 PM
#21
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In fact you don’t want any “one way air connectors”. Pulses at each port need to balance some to make the throttle stop adjustment a little less sensitive. Retain the check valve at the brake booster and you’ll be golden. Getting the tip-in response perfect will be your challenge, as you try to get all the throttles to move off their stops at exactly the same time. I’ve done this with a collection of various flow detectors like Uni-Syn, but often end up with a couple vacuum hoses to listen above the throttles as I adjust. It’s tedious but worthwhile.
I think they alreade start moving at the same time but they really need to be aligned. So if I put the ICV near b booster with hose and also a hose from ”after MAF” but before ITBs” it should work ?
01-15-2019, 03:56 PM
#23
The IAC needs to be able to pump filtered air into the throttle bodies after the butterflies.
01-15-2019, 11:54 PM
#24
Chronic Tool Dropper
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In fact you don’t want any “one way air connectors”. Pulses at each port need to balance some to make the throttle stop adjustment a little less sensitive. Retain the check valve at the brake booster and you’ll be golden. Getting the tip-in response perfect will be your challenge, as you try to get all the throttles to move off their stops at exactly the same time. I’ve done this with a collection of various flow detectors like Uni-Syn, but often end up with a couple vacuum hoses to listen above the throttles as I adjust. It’s tedious but worthwhile.
Yes to the questions.
Allowing post-MAF air to pass into the "vacuum manifold" will work. The vacuum manifold has a hose from below each throttle, with no restrictions or check valves. It will have the IAC line, and the hose from the brake booster, so all eight cylinders can draw air out of the booster as well as from the IAC. Reminder: 1/4" or 6mm ID individual hoses/fittings will be almost equal the flow available through a 12mm from booster and another from the IAC at the same time. It should work.
01-16-2019, 04:36 AM
#25
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Yes to the questions.
Allowing post-MAF air to pass into the "vacuum manifold" will work. The vacuum manifold has a hose from below each throttle, with no restrictions or check valves. It will have the IAC line, and the hose from the brake booster, so all eight cylinders can draw air out of the booster as well as from the IAC. Reminder: 1/4" or 6mm ID individual hoses/fittings will be almost equal the flow available through a 12mm from booster and another from the IAC at the same time. It should work.
Allowing post-MAF air to pass into the "vacuum manifold" will work. The vacuum manifold has a hose from below each throttle, with no restrictions or check valves. It will have the IAC line, and the hose from the brake booster, so all eight cylinders can draw air out of the booster as well as from the IAC. Reminder: 1/4" or 6mm ID individual hoses/fittings will be almost equal the flow available through a 12mm from booster and another from the IAC at the same time. It should work.