Blow-thru setups

**forrest1** · 10-24-2002, 05:49 PM

I'm guessing that the advantage of a blow-through system over a draw-thru system is that there is no mass-air sensor to obstruct flow to the blower inlet, and you could run a really big inlet tube and air filter, so the blower would run at maximum efficiency: is this correct?

About how much extra boost would you gain over a draw-through system?

The bypass, or blowoff valve would have to go between the blower outlet and the mass air sensor, so that you can vent air before it gets metered by the mass air, right? (and you could vent it directly to the atmosphere, couldn't you, no need to blow it back into the blower inlet since it isn't metered anyway, right?

This seems like a really good idea--Are there any disadvantages to blow-through? What mass air sensors are suitable for this? --some get "confused" by air turbulence, I have heard.

Thanks!

Forrest

**root** · 10-24-2002, 10:54 PM

Forrest, you are bang on as for the advatages to blow through, it will give a little more airflow. The biggest advantage is that the meter is telling the computer a more accurate figure since it is metering after the blower. I do not think you would see a large boost increase, maybe .5 of a pound or less, but the car may run a little better.

You are also correct on the bypass, there is a user I know with that exact setup and it works great.

The blow through meters are a little harder to find on the shelf, so you may have to wait a while for one, they cost the same amount as a regular meter.

You have to buy a specific blow through, Pro-M is always a good company to deal with.

Here is a pic:

If I were in your position I would not worry about it now, if you are thinking about larger injectors, that would be the time to upgrade.

Ian