wcbcruzer

I've got the gauge for it, so I thought it would be cool to rig up a mechanical exhaust pressure gauge (aka drive pressure). So does anyone have one? I'm not a huge fan of isolators but would a fuel pressure gauge isolator work for this type of thing? Something like this:

http://cgi.ebay.com/ebaymotors/Auto-...Q5fAccessories

I see running into future problems with condensation, soot, leaks, etc. if I went with coiled copper tubing straight to the gauge.

BigErksG2

I have a gauge but not installed yet. it will be going in then i build my twins in a month or so, mainly to see where the wastagate opens and to see how efficient i can tune them to be.

Jfaulkner

I have one but I ran copper for a few feet then went back to plastic. I'm not sure about that isolator. I have no issues with leaks or condensation but I've heard that the only issue is the soot will eventually clog up the gauge. But IMO it's going to also screw up that isolator and the gauge is cheaper to replace. I've ran the same 100psi Stewart Warner impact gauge for over a year without issue.

wcbcruzer

Well that sounds good. Does your plastic tubing heat up a lot to the touch or turn black? How many feet of copper and plastic tubing are you running?

Have you noticed any memory loss symptoms lately? Maybe some carbon monoxide is making it's way past the gauge and into the cab? just kidding.

mishkaya

I have a backpressure gauge, but it is a Performax gauge, so it already has an isolator so to speak. It has been in for a couple of months now with no complaints.

Wicked500R

And what is the purpose of this "exhaust backpressure" gauge??

KLockliear

I used to run one in my truck for testing turbos. 0-60psi boost gauge (in the ashtray). I ran a 1/8" copper tube out of the manifold, coiled up about 6-feet of it in a 8" diameter loop, then used a 1/8" union and went to plastic to go into the cab. Works for a while, then you'll have to open the union and blow down the copper side as it starts to get filled up with soot. We tried 1/4" line on the copper side, but it plugged as fast or faster.

AH64ID

I have one. I have 6' of copper tubing going to a snubber then plastic tubing to the gauge on the dash... The copper line dissipates all the heat in about 3'. I do have a condensation issue so the gauge freezes when it gets cold out, but only for the first 10-20 minutes of driving. No condensation or soot getting to the gauge. I do pull the line at the gauge and blow the junk back into the manifold every month or two.

JPR Ram

This guy is a member here on DTR. Anyways, he sells a kit where you don't have to drill and tap another hole. http://www.lazarsmith.com/Gauges.html

my_samurai

whats the point??i mean no muffler why worry..sounds like a waste of money to me

mishkaya

You might be surprised to find out what your drive pressure is once you are out of the efficiency range of your turbo. It is a must with twins and a good idea on more heavily modded trucks to avoid blowing head gaskets. Ideally you want a drive pressure ratio of 1 to 1, but it's not uncommon with some setups to see a drive pressure ratio of 2 to 1 when running 50PSI or greater.

wcbcruzer

Yeah the soot is what I was afraid of. I'm thinking maybe if you put a T union with a valve at the copper to plastic connection, then you can open the valve and blow air through the line to get rid of the soot every once in a while.

Wicked500R

I you want a gauge for reading how your turbo or turbo's are performing and what's going on... Invest into an air intake temp gauge ! It's not about what comes out the exhaust... It is what your putting in that matters. I can write a long post about turbo charged air intake temperature but I'll save that for later if need be..

JPR Ram

In the link I listed above, the item comes with a soot filter.

AH64ID

You can't really filter soot, most of it is sub micron.