Originally Posted by Del33t

Here's some findings, please note these were performed on a Subaru Impreza RS (non turbo):

Ok folks, I ran some numbers and here is the comparison of intake air temp before and after the TB bypass mod. The numbers were taken on 2 different days, both within 1 degree of outside air temp, 60 and 61 degrees. I measured the temp while driving to work the same route, about the same style of driving, same conditions. First graphs shows before and the second shows after the mod

Before bypass:


After bypass:


What is important is the trend, not the spikes although their behavior is also interesting. The average difference is about 15 degrees less when running with TB bypassed. The bypassed run hung between 85 and 90 degress F while the run with no bypass ran around 105 and 110 F. This difference can be felt which these numbers confirm.
The spikes in the temp are due to rapid acceleration which produces rapid heat soak in the TB. When the TB is bypassed, the spikes are lesser when compared to the other graph's counterparts, taking into account the same throttle position as which is a good indicator of how hard the engine is working.

These numbers are without the phenolic gasket which will make things even better.

Reference: http://www.rs25.com/forums/showthrea...1&page=1&pp=15

Originally Posted by swan-dogg

looks like the same trend just ten odd degrees coolerbut surely with the turbo on instead, the air temps wld be higher and the coolant have a cooling effect, or none at all.... let ,me know if i'm way off

Originally Posted by swan-dogg

i'm see-sawing sounds a bit iffy thats all, subaru, and the rest make them like that for some reason.....
is quite a noticable difference??, feels slightly more responsive...