Unitronic IC + bi-cooler?

[Mk7Matt]

Anybody running a bi-cooler with their Unitronic IC? I don’t like how much my iats are increasing over a 3-4 pull and am wondering if a bi-cooler would help?

I’m also wondering if anybody has run a bi-cooler with a Unitronic turbo discharge pipe? If I end up going this route I hope the hoses will work with the turbo discharge pipe.

 

[Diggs24]

Did you quit using meth?

 

[Mk7Matt]

Did you quit using meth?

Yeah. I’m glad I had the fail safe gauge. There had been times where the pump said it was pumping yet I saw no flow and got out of the pull. Finally got an open circuit error from the controller and trying to trouble shoot it with no luck so I pulled it the system out.

I’m going to check the continuity of the wires in the harness this weekend. If I can find a broken wire I may go ahead and reinstall it.

I should have just done fueling

 

[Diggs24]

I don’t think another IC will help. Will add more restriction and you are out of WG already.

 

[GTI_Owner]

I don’t think another IC will help. Will add more restriction and you are out of WG already.

The opposite will occur, the additional passages for air to flow through will decrease the restriction.

OP, it should help, adding more surface area and mass to dump heat into during a pull should keep the IAT from rising as quickly.

 

[jimlloyd40]

The opposite will occur, the additional passages for air to flow through will decrease the restriction.

OP, it should help, adding more surface area and mass to dump heat into during a pull should keep the IAT from rising as quickly.

How can additional passages reduce restriction? The more passages the more restriction.

 

[GTI_Owner]

How can additional passages reduce restriction? The more passages the more restriction.

As an analogy, if you have a single 3" exhaust vs a dual 3" exhaust, the single will have more back pressure / restriction.

 

[OBP]

Did you retain the factory air diverters? You would have had to trim them, but you should have put them back in.

 

[jimlloyd40]

As an analogy, if you have a single 3" exhaust vs a dual 3" exhaust, the single will have more back pressure / restriction.

That's not a very good analogy. The exhaust has either one or two passages whereas the intercoolers have dozens of small passages.

 

[GTI_Owner]

That's not a very good analogy. The exhaust has either one or two passages whereas the intercoolers have dozens of small passages.

It is a good analogy, you don't understand the way air velocity affects pressure drop which might be why you think it is not a good analogy.

The Unitronic has 24 charge air rows, when it is combined with a bicooler the extra core adds around 10-12 additional charge air rows. There's now 36 passageways for air to flow through. This allows the air to flow through at lower velocity; the volumetric flow rate is the same in the two cases. The slower air velocity through any individual passageway reduces the pressure drop (Here's another analogy, a car experiences less drag force at 60 mph versus 120 mph. The same is happening inside the core as the charge air velocity decreases.) An additional benefit of the slower travel is more time to get heat out of the charge air and into the cores.

 

[Diggs24]

ok Jeff....

 

[jimlloyd40]

Wonder why when I installed a much larger FMIC on a Veloster Turbo there was so much pressure drop that I had to get retuned to turn boost up?

 

[GTI_Owner]

Wonder why when I installed a much larger FMIC on a Veloster Turbo there was so much pressure drop that I had to get retuned to turn boost up?

If there was more pressure drop with the larger IC it could have had less area across the passages, or the internal fins might have obstructed more of the passages. That would help with cooling but hurt airflow. Hard to say when all that is known is that you swapped ICs and saw more pressure drop.

In the example being asked about here, it started with one core and a second is added in parallel. Why do you think the additional core will result in more resistance to the airflow?

 

[Mk7Matt]

I don’t think another IC will help. Will add more restriction and you are out of WG already.

I’m good on wg duty; stilling at 27-30% after it opens.

 

[Mk7Matt]

Did you retain the factory air diverters? You would have had to trim them, but you should have put them back in.

Yes i still have them.