More Airflow and Balanced EGTs from Cosmo Intake
Thread Starter
Joined: Jan 2008
Posts: 438
Likes: 5
From: Ft Worth, Tx
Did a little testing tonight. Looks like the elbow has evened out the EGTs a little bit. Both tests were done with the Rear Secondary Injector trimmed +4%.
Pre-Elbow:
Rotor 1 - 1777 deg. F
Rotor 2 - 1803 deg. F
Difference - 26 deg F.
Post-Elbow:
Rotor 1 - 1783 deg. F
Rotor 2 - 1799 deg. F
Difference - 16 deg. F
These are by no means earth shattering results, and the main issue is probably the unequal length runners in the lower intake manifold. But, the elbow should also help even out the water/methanol distribution on the AI system I'm installing.
Pre-Elbow
Post-Elbow
Pre-Elbow:
Rotor 1 - 1777 deg. F
Rotor 2 - 1803 deg. F
Difference - 26 deg F.
Post-Elbow:
Rotor 1 - 1783 deg. F
Rotor 2 - 1799 deg. F
Difference - 16 deg. F
These are by no means earth shattering results, and the main issue is probably the unequal length runners in the lower intake manifold. But, the elbow should also help even out the water/methanol distribution on the AI system I'm installing.
Pre-Elbow
Post-Elbow
I think that you'll end up finding out that the factory shaped throttle body and throttle body tube is the issue. This is why I build my upper intake manifolds with a round throttle body. It allows for a more even flow through the pipe. Mazda aimed for extremely crisp throttle control and keeping velocity to a maximum. In the aftermarket world we tend to make up for this in other ways (open ended statement). Your divider will certainly reduce the problem but will not ever eliminate the root. I can't give away all my secrets but I'll gladly point out the main flaws for you to either entertain or continue testing.
Remember oxygen has weight to it so it is subject to g-forces when making turns in pipes/runners. Run some more boost and I think you'll see an increasing variance that will show up as a progressive not linear curve...
Remember oxygen has weight to it so it is subject to g-forces when making turns in pipes/runners. Run some more boost and I think you'll see an increasing variance that will show up as a progressive not linear curve...
What you should do is get rid of that throttlebody and use a FD unit. I cut mine open but did it a little differently. These pics weren't the final product, it was such a pain in the ***, I don't think I would ever do that again in my life. Haven't finished the car yet so I don't have any results...
Thread Starter
Joined: Jan 2008
Posts: 438
Likes: 5
From: Ft Worth, Tx
Finally got the intake done. If everything holds together at next weekends drag races, we'll take the car to the dyno for some before and after manifold comparisons.
