Wanna know how much boost drops with heads/larger headers/+.2L of displacement?

11Sec_Lx

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I ran a boost test this morning of my old engine vs new. Note... I added a +5% overdrive lower with the new setup, which makes the results even better!

Old:
Gen 1 Aluminator
Stock heads/stock cams
BBK 1-3/4" headers
Whipple 170mm mono
VMP Gen 3R, (69mm / stock lower)
dyno pull in 4th
Max boost = 22.5lbs

New:
5.2L
Gen 2 heads (ported by Airflow Solutions/Boss 302 cams)
Stainless Power 1-7/8" headers
VMP Performance 163R
VMP Gen 3R (69mm / +5% <-- adds boost!)
Street pull in second and through 3rd into 4th. (I manually shifted from 2nd to drive once I went wot)
Max boost = 19.5lbs

Even with a +5% overdrive lower and larger throttle body, it still dropped 3lbs.

Is anyone surprised? I was hoping for this, but didn't really know, as everyone seems to go straight to larger cams where I didn't.

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slow306stang

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I always love seeing gains on an engine at this level. The engine is an air pump and you built a more efficent pump with the cubes, cams, and ported heads. The exhaust is also one of the biggest factors in a supercharged engine.
 

Riddick

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Good to see how efficient your car is moving air now. I remember back in my Cobra days adding a good set of longtubes would drop boost by 1-2 psi, same principal applies to adding cams.

Just keep an eye on those IATs if you pulley down. With your set up I don't think you have anything to worry about. Car is going to roll out!!

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11Sec_Lx

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Good to see how efficient your car is moving air now. I remember back in my Cobra days adding a good set of longtubes would drop boost by 1-2 psi, same principal applies to adding cams.

Just keep an eye on those IATs if you pulley down. With your set up I don't think you have anything to worry about. Car is going to roll out!!

Sent from my Moto Z (2) using Tapatalk
I do on the track. Not so much needed in my case on the street.

Sent from my SM-G988U using the svtperformance.com mobile app
 

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