PRESSURE ADJUSTER

[dlaing]

Keep in mind that if you increase the total hose length or inside diameter, that will increase the volume within the hose. Adding a pressure gauge will also increase volume. Any increase in volume will delay the response time for a given size "nipple". As the vacuum suddenly increases, the gas in the hoses and regulator has to flow through the nipple to relieve its pressure. The more gas there is, the longer it takes.

A good solution would be to use hose with a smaller Inner Diameter.

Maybe it would be helpful to only use the right cylinder for vacuum reference???

I don't see any drawback.

[raz]

A good solution would be to use hose with a smaller Inner Diameter.

Maybe it would be helpful to only use the right cylinder for vacuum reference???

I don't see any drawback.

That would not result in damping, would it? I think there should be a tight obstacle and then wider again. Also, because our damping will slow down response a bit, I thought connecting both cylinders would help a little against that.

Though maybe this slowdown is not an issue at all. My Carbtune has much tighter dampers than 0.030" if I remember correctly, and the response on the gauge is immediate. The hoses after the dampers are much longer than in this application.

[dlaing]

No, I don't think it would not result in damping or dampening.

In fact it might transmit more of the fluctuations that we might want to dampen.

I think having a fine orifice dampen the oscillation would be more beneficial, than the very slight delay that it would cause. How much would it delay it, maybe one firing cycle at high rpms???? The delay probably would not be noticeable.

With my TwinMax I added extra restrictors (infinitely adjustable plastic things) to dampen it even more than the stock brass fittings.

I never noticed any delay in response to throttle changes.

[Dan M]

Hi Ratch,

 

I think you may have missed my earlier question, as copied below. I'm interested in correlation your results with the location of hour hose connection, as follows:

 

"Are the "intake "recovery canister/balance" barbs" you mention the ones on the intake manifold used for throttle synch? If not, then little change should be expected, if connected where there would be very little vacuum created. Moreover, if connected to the airbox, the variation in absolute pressure would be opposite that of the intake manifold, and provide a reverse signal to the regulator."

 

Thanks, John

 

 

The vacuum is created and lost instantaneously with throttle plate movement. The smaller the diameter of the tubing the faster the response. The chamber where the diaphragm resides inside the regulator is very small so very little "flow" is needed to actuate it. True, if there was several feet of large diameter hose it would delay action, but only on the closing of the throttle when the vacuum is being applied, when the throttle is opened the vacuum will fall off instantly regardless of hose size.

Connecting to the air box would give the same result as leaving it disconnected. I haven't taken the time to test how much vacuum is needed to overcome the spring in this particular regulator but an educated guess would be at least 10 inHg, likely up to 15. The air box gets nowhere near this.