Low KPa at WOT
Thread Starter
Heel & Toe
Joined: Jun 2017
Posts: 15
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Low KPa at WOT
I've been having trouble with an airflow restriction on my C5z (228/232 cam, 1 3/4 long tubes). I dyno'd it with a KN filter and zip tie mod and it made strong torque (405 ft-Lb) but choked up top with a map of 91KPa at ~6k rpm with an atmospheric pressure of 98 KPa. I put a vararam on with stock air bridge and did some logging on the street and map improved to 94 KPa at ~6k again at 98Kpa atmospheric. Obviously there is still a restriction somewhere...stock air bridge? MAF housing? Throttle body? Let me know what yall think.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Do you have ANY CATs or PUP CATs???? Maybe clogged if they are in place..
MAF could be putting out bad data??
Run it without a filter for a test...
Is the Throttle blade showing full open at full throttle/full load?/
BC
MAF could be putting out bad data??
Run it without a filter for a test...
Is the Throttle blade showing full open at full throttle/full load?/
BC
Melting Slicks
Joined: Feb 2001
Posts: 2,804
Likes: 358
From: Northville, MI
Did you dyno it in 4th gear? It is possible that that you are running out of air at the dyno. When driving down the street more air is to the engine bay or on the frontal area. Heat and humidity are other factors along with the tune in the PCM.
