Diesel Place banner

Status
Not open for further replies.
1 - 13 of 13 Posts

·
Registered
Joined
·
443 Posts
Discussion Starter #1
Do you pull the pipe that connects from the back of the turbo, to the flange where the exhaust pipe really begins. Im talking the flange that is right in front of you when you pull the plastic inner fender. I want to pull that pipe off so i can braze in a bung to screw in my Probe for the EGT. I was planning on doing this about an inch or 2 into the pipe. (As close to, but after the turbo, as possible). There is also 2 heat shields to contend with, which i have no idea how to pull out either.

I messed with it for about an hour and a half, and now I figure instead of wasting time trying to figure it out myself, that i would ask some people that might have actually done it a time or two. What do you guys think, what am i overlooking that would allow me to pull this stuff out easily? :think:

Thanks for the help. :cool:
 

·
Premium Member
Joined
·
20,561 Posts
DOnt bother with a post turbo EGT gauge... drill and tap the passenger side exhaust manifold..
 

·
Registered
Joined
·
5,255 Posts
Ditto.
Idle the engine while drilling and tapping, it'll blow the chips right out.

When people here are talking about EGTs, they are referring to pre-turbo, right on the spot we're talking about... right on the #7 exhaust port.
 

·
Registered
Joined
·
544 Posts
I took the manifold off to drill and tap. It took 20 mins. longer and no chance of chips going through the turbo.
 

·
Registered
Joined
·
443 Posts
Discussion Starter #6
Well i would feel more confortable with a post turbo, reason being if the sensor does fail, which i know is like 1 in a million chance, it'll blow out the exhaust and not into the turbo.

What is/are the reasons for drilling the manifold besides making it a simple istall? :D
 

·
Registered
Joined
·
6,504 Posts
Not only a simple install, but more accurate and timely reading of EGT. The amount of heat loss in the turbo is variable, then there's the time delay for a "hot" cylinder to get through the turbo (and be blended with the other gases) before you can read/respond. You're not really monitoring EGTs to protect the turbo, you're monitoring EGTs to protect your piston, valves and heads. Monitoring post-turbo is kind of like waiting until you get smoke out of the tailpipe.
 

·
Registered
Joined
·
53 Posts
I know a few people that run two pyro's one post and one pre turbo. They say it helps with the temp. monitoring, in different case's.
 

·
Registered
Joined
·
2,386 Posts
Removing the downpipe isn't easy. Go outside and scrape all your knuckles on the pavement until they are bloody. Then, go to your toolbox, take out all your wrenches and throw them out the door at the dog (while cussing loudly). This will give you an idea what you will feel like after wrestling that tight SOB for 2 hours.
 

·
Registered
Joined
·
6,504 Posts
I know a few people that run two pyros (me included) in the manifolds. I already had my Isspro in the passenger manifold driving my A-pillar gauge when I upgraded my Juice to the Attitude, so I put the Attitude pyro into the driver's side. Now that I'm starting to fool around with EFI Live, I just may go to a marine dual EGT gauge in the A-pillar.
 

·
Registered
Joined
·
1,371 Posts
Funny, I just run one pyrometer and when it is pegged @ 1600 I figure I should get out of the throttle!;)
 

·
Registered
Joined
·
5,255 Posts
Well i would feel more confortable with a post turbo, reason being if the sensor does fail, which i know is like 1 in a million chance, it'll blow out the exhaust and not into the turbo.
More like one in a billion.... it's a tube, that's all it is, and it's inserted from the outside. If it fails, it's going to be blown into your wheel well, not the turbo.
What is/are the reasons for drilling the manifold besides making it a simple istall? :D
More accurate, instantaneous temp change with respect to engine loading.
You'll have a "good" number to compare with "everyone else"... what'll happen post-turbo is you'll post that you were at only 1100 towing 15k up a 6% grade and someone will call BS, when in fact you MAY be dangerously high pre-turbo.
Likewise, you'll read that max recommended temp for short periods (seconds) is 1600, and they'll run at 1200 all day... you may be on the high side but not realize it. ALL temp references posted on the forums assume the probe is mounted in the manifold off of #7.

On the high side, it lets you know how hot the cylinder is getting... not how how the tailpipe is. On the low side, if you are one of the guys that's anal about letting the temp get down to 300^ before shutting off, it gives you an accurate indication of the temperature of the gasses that are flowing INTO the turbo, not out.

Ya, with the VVT, post-turbo temps can fluctuate wildly.
 

·
Registered
Joined
·
1,311 Posts
PV=nRT, this simple equation states that temperature is directly proportional to pressure, my point being that pre-turbo there is much more pressure than post turbo, thus the temperature is higher. This is were you want your sensor, or dont bother.
 
1 - 13 of 13 Posts
Status
Not open for further replies.
Top