Competition Drive Pressure

[777 MECHANIC]

Whats the easiest way to take a drive pressure reading without having a meltdown of the tubing. Was planning on using my existing EGT probe hole on the manifold.



MikeD

 

[KLockliear]

Get a fitting to go from your EGT probe size (probably 1/4NPT) to 1/4" compression. Use about 4-6 feet of 1/4" copper tubing, coiled around to hold condensation, then use a 1/4" compression to 1/8" compression union and go to the regular plasic line.



Never had a problem with that setup.

 

[777 MECHANIC]

Keith,

Did you use a boost gauge or a oil pressure gauge? I dont have a second boost gauge to use. Ive read that the exhaust pulsations hammer the gauge pretty bad. Does that make it difficult to get an accurate reading on the gauge?



MikeD

 

[KLockliear]

Nope, we run another 0-60psi boost gauge. If it's over 60psi making <40psi of boost, it's not working well.

 

[qzilla]

I will try to get you the name tomorrow, but we used a 200psi industiral gauge when we measure drive pressure.



The high psi makes the spring inside slightly stronger and helps it not appear to bounce as much. It is still going to pulse, but the larger increments should make it easier to follow.



If you are doing work on your twins I don't think a 60psi gauge will we quite big enough, it will be close. Last I heard you guys were running 80psi or something?



Also we always used a filter, like for a compressor to help keep the exhaust out of the gauge.



If you need to be really accurate I would be curious to use one of the digital gauges that had a memory. They may help you be more accurate, I have heard the digital gauge will read more towards the middle of the pulse.



Keith,



Do you guys take and average over the exhaust pulse range or what is your opinion on the most accurate way to read the gauge.

I think Pricol makes a gauge with a needle that remembers as well?



If you need help hollar I think you are kinda close.

 

[KLockliear]

We've never had a problem with bounce. We also don't do twins, so drive pressure that high doesn't really apply to us.

 

[qzilla]

on the exhaust side you never had a problem with it pulsing????

 

[KLockliear]

Nope.