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JFairman JFairman is offline
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Join Date: Jul 2006
Location: S. Florida
Posts: 7,222
[QUOTE=mark houghton;5274496]
Quote:
Originally Posted by 911st View Post
Then adding pressure to the boost retard side (outer) with a hand pump sould retard and bring idle rpm back down. Better to observe at the timing mark. Use a pump-up bulb from a blood pressure tester.

Then there is the solenoid on the Vac-Ret side of the double pot dist. Get rid of it....I don't have one and not really needed IMO. One less thing to worry about. QUOTE]
I have to agree with you on removing the vacuum retard delay solenoid since installing the MSD boost retard box and advancing the static timing to around 12* BTDC at idle. You just don't need it anymore.

When the idle speed timing was at the weak stock setting of 0* or TDC then that vacuum solenoind delaying the vacuum retard signal to the distributor was a help to keep the idle speed up around 1100 rpms for the first 2 minutes after a cold start.

Now at 12* BTDC at idle and a cold start in Florida, the idle speed is about 1000rpms with only the help of the cold start air bypass valve because of the advanced timing making a stronger idle and then it drops down to 800 rpms when air bypass valve and engine warms up.

Now I'm using that vacuum solenoid with a summit racing RPM switch to delay the boost signal to the WUR. It's currently set to open the solenoid at 4500rpms with a K27 7006 turbo. Works great.
Old 04-03-2010, 09:15 AM
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