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moosejaw · 08-12-2001, 11:53 PM

Lets see...

Addressing the lean condition at idle. Do you have a low temp thermostat? Is the motor getting completely warmed up?

Do you have hard starts with the 36# injectors?

Ok, the HKS is big which is good. I believe it is similar in size and adjustability to the Vortech race unit. You didn't say specifically if the bypass routed back the blower inlet. It is important that the air isn't dumped out.

You can adjust the bypass to be more compatible with your cruising rpm and vacuum. Loosen the locknut and turn the adjust screw in. This will change the opening point of the valve to be "more vacuum". Lets say it is set at 4" HG. You can adjust it in to say 8" HG. Now the valve will close more quickly when loading. Since your idle vacuum is about 10" HG this could be a help. The best way to set the valve is with a hand vacuum pump. There is a limit to how far you can adjust these valves. Verify the stroke on the valve when complete, it should stroke the same distance before and after adjusting. Adjusting to far will jam the diaphragm and keep the valve from fully opening.

Operational Note: The bypass needs to open when at high rpm with the throttle closed or part closed. This is where the blower makes a ton of air flow and pressure. With out a means to relieve this airflow the blower will "overload" and possibly kick the belt off or damage the drive gears, with your cogged setup. Ever notice how much vacuum the motor pulls when decelerating from rpm? It will pull 20-25" HG sometimes. This is when the bypass earns it money. Lots of rpm with a shut throttle is when blower belts get destroyed.

The point here is the setpoint change from 4" to say even 11" is not a big deal (as long as the valve does open) because the conditions stated above are when the bypass is really needed. I had an early Vortech s trim on my 92 f250 and they didn't even give me a bypass with that kit! Truth is it never threw a belt but you could feel the surge sometimes after racing it.

Mike

------------------
Live near St.Louis?
Check out Mustang Muscle and Dyno in High Ridge, MO
Check out my ride.

08-12-2001, 11:53 PM	#13
moosejaw Registered Member Join Date: Apr 1999 Location: St.Louis,MO Posts: 274	Lets see... Addressing the lean condition at idle. Do you have a low temp thermostat? Is the motor getting completely warmed up? Do you have hard starts with the 36# injectors? Ok, the HKS is big which is good. I believe it is similar in size and adjustability to the Vortech race unit. You didn't say specifically if the bypass routed back the blower inlet. It is important that the air isn't dumped out. You can adjust the bypass to be more compatible with your cruising rpm and vacuum. Loosen the locknut and turn the adjust screw in. This will change the opening point of the valve to be "more vacuum". Lets say it is set at 4" HG. You can adjust it in to say 8" HG. Now the valve will close more quickly when loading. Since your idle vacuum is about 10" HG this could be a help. The best way to set the valve is with a hand vacuum pump. There is a limit to how far you can adjust these valves. Verify the stroke on the valve when complete, it should stroke the same distance before and after adjusting. Adjusting to far will jam the diaphragm and keep the valve from fully opening. Operational Note: The bypass needs to open when at high rpm with the throttle closed or part closed. This is where the blower makes a ton of air flow and pressure. With out a means to relieve this airflow the blower will "overload" and possibly kick the belt off or damage the drive gears, with your cogged setup. Ever notice how much vacuum the motor pulls when decelerating from rpm? It will pull 20-25" HG sometimes. This is when the bypass earns it money. Lots of rpm with a shut throttle is when blower belts get destroyed. The point here is the setpoint change from 4" to say even 11" is not a big deal (as long as the valve does open) because the conditions stated above are when the bypass is really needed. I had an early Vortech s trim on my 92 f250 and they didn't even give me a bypass with that kit! Truth is it never threw a belt but you could feel the surge sometimes after racing it. Mike ------------------ Live near St.Louis? Check out Mustang Muscle and Dyno in High Ridge, MO Check out my ride.