i keep hearing about this coolant bypass for the throttle body what does it do and will it affect my car in a negative or positive way

 

The Coolant bypass idea is fairly popular, especially in the older muscle cars. Simply put, normally you run the engine coolant "through" the throttle body to prevent the throttle body from icing up.

Nearly every car now has a cold start valve, which is just below the throttle body- it has two lines, one in and one out. They transfer coolant which in a cold start situation, helps warm up the engine faster by warming up the air in the throttle body via the coolant. In very cold climate it can be useful, but in summer months it's of little value. The bypass mod prevents the hot coolant from passing thru the throttle body when it's hot (it helps keep it cooler), like in the summertime. Now the coolant simply goes in and out of the block w/o going thru the throttle body. This reduces temps in the intake manifold.

Some have reported increases up to 4-8hp. Hope this helps.

 

this if of motordyne's web site:

2) The second component is the throttle body Coolant Control Valve (CCV). The CCV allows you to selectively heat (or not heat) the plenum assembly. With local weather temperatures below 55'F the valve is left open. In warmer weather the valve can be closed for maximum thermal benefits.

i have mine be never installed it due to temps that rarely drop below 55

 

The whole purpose of the coolant hoses going into the throttle body is to keep the throttle body from freezing up, which can be dangerous when you're at speed. It does nothing to help warm up the car. The fluids are going to be just as cold and won't help heat anything up until everything warms up enough to heat up the coolant itself. If you live in freezing temps and need something to help warm your car up, get a block heater.

In warm to hot temps when your car is running hot, every bit of cooling helps. But since the coolant is actually very hot then, stopping the coolant from flowing through the throttle body helps reduce heat that would otherwise affect intake temps.

 

The coolant hoses go into the plenum, not the throttle body.

The amount of time the air spends in the throttle body is pretty minimal, so it's not going to pick up much heat if your TB is being warmed by coolant, and that coolant is hitting it post-radiator, so it's not nearly as warm as when it comes out of the other side of the engine.

And the CCV is warming up not only the throttle body but also the plenum (the coolant lines are connected to the plenum). With the Copper ISO upgrade, you're only warming up the throttle body (coolant goes to the Cu-ISO with a thick rubber gasket between the Cu-ISO and plenum).

Assuming you have the Aramid gasket in place (less heat soak), then
TB temps: CCV Off < Cu-ISO ≈ CCV On = No CCV < Stock
Plenum temps: CCV Off ≈ Cu-ISO << CCV On = No CCV << Stock

Running CCV Off will get you the coolest air possible entering the cylinder, but the Copper ISO option will only be slightly warmer. CCV On/No CCV will be warmer still since you're heating the plenum and TB. Of course, Stock suffers from a warmed up plenum/TB and heat soak of the entire intake system. The best scenario would be to have the Copper ISO upgrade and the Coolant Control Valve.

I went with the Copper ISO upgrade. It's very cold here in the winter, and I don't (won't) feel like popping the hood every time the temp swings above/below 50 or so. (I say won't because I'm installing my spacer this weekend).

 

I would have done this mod if I still lived in CA, being up in ND is a whole different story... See temps down to -30* and lower...