I just installed a 6.0 intercooler into my obs 7.3 and I have a few questions. When I first set it up and started running my truck with just the truck empty the egts started climbing much faster then before. I also lost about 3psi of boost. But my egts wont climb above 1250 now with just the truck. Then I put the camper behind the truck and the egts came up just as fast but wont get past 1200 with my foot pegged into the floor.

My question is why doesnt the egts climb accordingly?
It seems like my trucks egts would take longer to get up to 1200, but it climbs faster, then stops like it has a ceiling.

Also why does it stop at 1250 degrees empty and 1200 with a camper?

 

Your MAP sensor is "downwind" from the intercooler. If you are losing 3PSI boost, then the intercooler is doing its job well - in a measurable way. I'll bet if you had a boost sensor before the intercooler, you would not likely see a difference. I'll explain:

The intercooler's job is to increase air density by cooling the air. Radical cooling can actually reduce the air volume, which lowers boost on the MAP sensor. With denser air hitting the intake, the combustion events behave differently - they should theoretically occur faster. Faster combustion makes for a cooler EGT under load, this is why Ford installed an intercooler on the Superduties. I am still trying to think my way through the quicker EGT climb - maybe someone can help sort that out.

 

do you have a scanner or something like Auto Enginuity?

It might help if you can read the Manifold air temp & air intake temps.

 

Thanks for the reply.

My theory on why the egts rise faster is because the intercooler is acting as a restriction in low boost/rpms situations. So the amount of air going into the intake is slightly slower/restricted. Once my boost climbs, more air is jammed through the restriction and able to allow the intercooler to properly work. Im probably wrong though.

 

It's not a restriction issue unless you installed a used and/or partially plugged IC. Please don't be offended by this question because we've all had out DUH moments (some more than others, like myself)... Any chance you left a rag in either an IC tube or nozzle?

 

No offense taken. Cant find stupid things Ive done that can easily be fixed untill someone points them out. Im almost positive theres no rags/obstructions in it. The only obstruction that could exist is on the inlet side of the ic my tube is slightly bowed in from touching the side of the front clip support.

 

Ive also noticed that my outlet side of the ic pipe. Or the passenger side return pipe is hot while in the engine compartment. Would wrapping it in some insulated tape help keep it cooler, with noticeable temp reduction?

 

Would denser air=more oxygen resulting in a better, hotter burn thus resulting in faster climb in EGT's?

 

This was my first thought too after reading the symptoms!

 

While the cooler air has less volume, it still has the same number of oxygen molecules. Less volume air going in = less compression = cooler air again. I know from experience that a faster injection cycle = cooler EGTs all around - but I don't know how this all plays out with the thermodynamics of cooler air vs. burn time.

 

When the engine is up to operating temp can you hold your hand on the passenger side CAC tube without having to let go from the heat?

The MAT temps (post intercooler) should be within 10-15 degrees of OAT or air intake temp.

 

Any luck?

We are taking the schools marching band trailers to the game. Just screwing around and thought I would do some air temperature data logging.

EGT's @ 800

 

Subscribing