Heat soak

[destineal]

What are the symptoms of intercooler heatsoak? just reduced performance?

 

[black daliha]

Good question, I wonderd that myself. It makes sence its just reduced power but im wondering if there is some bad driveability involved.

 

[BOOSTR]

Turbobygarret.com has a turbo tech section full of good information.

What is intercooler heat soak?
Heat soak is when the intercooler can't dissipate the heat that it absorbs from the turbo fast enough. When an intercooler can't cool the charge air by removing the heat from it, it loses its effectiveness. This explains why turbo cars tend to run slower or have slightly less power when the weather is warm.

 

[Spiced MSP]

^^^bingo!!!

 

[black daliha]

makes sence meth injection lol

 

[CHIQLES]

I moved my AIT to the cold pipe and after driveing for a while then parking then driveing the outside air was 48 but the air to the throttle was 90...heat soak.but after driveing for fiv minutes i was back down to 70..

 

[destineal]

So PSI is not influenced?

 

[Bassmachine]

Short answer yes the higher the psi you have the more heat you will be putting out.

 

[HighSpeed]

I think he was wondering about the psi during heat soak, like if the turbo will change what psi it will be pushing.

If that was what destineal was asking then you still have wg pressure, but your car will be a slug. Heatsoak sucks, especially in a car that isn't extremely fast to begin with. Usually the timing gets a crap pulled out of it to fight detonation.

 

[b6gtxawd]

dont mean to thred jack here but what can we do to try and prevent this heat soak?? im sure there are alot of msp owners like me that when you first get in your car(specially me right now, living in bc with -4 temps in the morning) it runs like a champ with more power then i know what to do with, then 15 minutes later feels like iv lost 20 hp..... is this just issues with the intercooler or could it be an issure with the SRI sucking in all the hot engine bay air?

destineal do you have a sri or a cai??

 

[Carlinator]

So PSI is not influenced?

PSI stays the same, but it's a bit more complicated. Basically, air expands when it heats up; if it's inside a container (like, say, an intake pipe) this causes it to exert greater pressure than it would at lower temperature. Although the air has expanded to take up greater volume, it also exerts higher pressure as if it had been compressed instead. This means that 7 psi at 95 degrees represents a lower mass of air than 7 psi at 70 degrees. The actual mass of the air is key here, since the amount of power you make is directly tied to the amount of fuel you can burn, which in turn is limited by the mass of air you take in. Since you aren't taking in as much air, you can't burn as much fuel, hence the car loses power if the intake charge gets hot, as it does with IC heatsoak.

The only real options are to increase boost as temp rises, add meth injection or, you know, get an intercooler setup that doesn't suck ass.

 

[jdwk]

Another thing to note is that since the intercooler cools down the compressed air from the turbo, you actually lose a couple PSI of pressure. If you were to measure the pressure on your hot side it would be a couple PSI higher than the cold side.

A CAI definitely helps. Our cars are so perfectly setup for it with that hole and nice little compartment it's almost a crime not get a CAI.

All cars are effected by temperature equally, and heat soak isn't just a turbo phenomenon. Go to a drag strip sometime you'll most likely see NA guys putting bags of ice on their intake manifolds in between runs.

 

[destineal]

I think he was wondering about the psi during heat soak, like if the turbo will change what psi it will be pushing.

If that was what destineal was asking then you still have wg pressure, but your car will be a slug. Heatsoak sucks, especially in a car that isn't extremely fast to begin with. Usually the timing gets a crap pulled out of it to fight detonation.

Correct. The reason I was asking was because after I changed my spark plug, I was beating the s*** out of my car and it was pulling harder than it had in a while. After a while of going up and down the street my boost gauge was reading 3 psi at WOT.

 

[719prottege]

heat soak shouldnt really affect your psi that much destineal. i would check for boost leaks... i know my car is a beast when i start driving it in the morning, or when it just starts to warm up on a cold day. after being parked in the cold, i will hit 7-9psi, and have practically no lag. but after driving, only about 5-6psi and a lot of lag.. but im also pretty sure my cats are effed on my car....

 

[destineal]

gotcha

 

[HighSpeed]

yeah if you are reading only 3 psi, you either have a boost leak, bad boost gauge signal/gauge, or a failing turbo. My guess is one of the first two that i mentioned. GL