Needle valve as boost controller
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Burning Brakes
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I've been doing some thinking (a dangerous pastime), and I was wondering about using a needle valve as a boost controller.
I'm certainly open to comments or corrections.
I have the APE Stage II chipset and a shimmed wastegate. AFAIK, the APE chips are designed to be run with a jetted banjo bolt as a method of boost control / enhancement.
The chips are mapped based on this, assumign that there will be some drop off in boost at high RPM. There is a belief that using a standard MBC is bad because it holds boost constant at high revs, rather than dropping off.
The jet in the banjo bolt seems to act as a restrictor to slow the rate of increase of pressure, and by adjusting the orifice, you can set your boost.
The kit was already installed in my car, but I understand they supply multiple jets so you can tailor it for your particular car / WG.
A needle valve is really just an adjustable orifice, so my thinking is by replacing the jet wwith a needle valve, you actually have a continuously variable orifice that should allow for more precise tunign while still keeping with the same "concept" and overall behaviuour that the chips are deisgned for.
HAs anyone tried this ?
I'm certainly open to comments or corrections.
I have the APE Stage II chipset and a shimmed wastegate. AFAIK, the APE chips are designed to be run with a jetted banjo bolt as a method of boost control / enhancement.
The chips are mapped based on this, assumign that there will be some drop off in boost at high RPM. There is a belief that using a standard MBC is bad because it holds boost constant at high revs, rather than dropping off.
The jet in the banjo bolt seems to act as a restrictor to slow the rate of increase of pressure, and by adjusting the orifice, you can set your boost.
The kit was already installed in my car, but I understand they supply multiple jets so you can tailor it for your particular car / WG.
A needle valve is really just an adjustable orifice, so my thinking is by replacing the jet wwith a needle valve, you actually have a continuously variable orifice that should allow for more precise tunign while still keeping with the same "concept" and overall behaviuour that the chips are deisgned for.
HAs anyone tried this ?
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There is a belief that using a standard MBC is bad because it holds boost constant at high revs, rather than dropping off.
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Burning Brakes
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Yes, but apparently the APE chips aren't mapped for it, and that's why people have issues with them running a bit lean at high RPM's.
Please don't suggest that I get new chips.
Please don't suggest that I get new chips.
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Hey I have been running a needle valve on my 86 turbo since last march. I got ape stage 2 chips and the guy never gave me the banjo insert so i had no choise since ape didnt want to sell me the jets seperately. It works perfectly, i just turned it up till it was a hair before 2 on the stock gauge and in the 1 year ive had it like this no problems no over boost nothing. I retained the cv tho.