Pyro
#12
#13
The temperature difference between the pre and post turbo is anywhere from 200*-500*, depending on how hard you are working the engine(I drive the same road twice a week). I have had both installed on my truck and that was the average difference. So, if the post turbo reading is 1000* then the pre turbo temp could be anywhere between 1200* to 1500*, and with the melting temperature of aluminum about 1250*, there could be some damage done to the pistons.
#14
#16
The turbo takes heat out of the exhaust stream and uses it to compress intake air; it does this more when it's in its efficiency range, but beyond that it also acts as a flow restriction and you start seeing even more of a difference.
OEM applications know how much fuel and flow they're putting in at what RPM and are looking for a temperature trend to know if something is broken. Hot rod applications are doing their best to burn through the pistons and are constantly pushing turbos out of their efficiency ranges. When tuning an engine you need it before the turbo.
One in each side of the manifold isn't a bad idea by any means.
Now keep in mind that on our engines, the pyro hardly means anything for the duration of a drag or pull as long as you have tons of black smoke coming out of the exhaust. You don't really care how hot it gets; it kinda makes a difference in how fast it pegs.
OEM applications know how much fuel and flow they're putting in at what RPM and are looking for a temperature trend to know if something is broken. Hot rod applications are doing their best to burn through the pistons and are constantly pushing turbos out of their efficiency ranges. When tuning an engine you need it before the turbo.
One in each side of the manifold isn't a bad idea by any means.
Now keep in mind that on our engines, the pyro hardly means anything for the duration of a drag or pull as long as you have tons of black smoke coming out of the exhaust. You don't really care how hot it gets; it kinda makes a difference in how fast it pegs.
#18
#19
#20
So the relevant information a pyro gives on a modified first gen engine while racing or pulling is how fast it pegs. 1600 doesn't really mean much, what you really want to know is if it's hitting 1800 or 2000, how fast it gets there and how long it stays there after you get off it.
What it really is useful for is while towing or driving really fast up a hill or otherwise putting out sustained power for minutes on end, because that's how long it takes for the heat in the manifold to migrate to the cylinders. But even in that capacity it lies to you; advanced timing, better injectors or different cylinder bowls will cause more heat to be put into the cylinder than what you see on the pyro. 1250 degree EGT's with timing advanced a 1/4" is about as painful on the pistons as 1350 degree EGT's with timing at the stock levels.