Does Altitude affect MAP pressure at WOT?
Thread Starter
Joined: Jun 2004
Posts: 1,501
Likes: 7
From: Ft. Irwin, California (But Virginia is home)
Does Altitude affect MAP pressure at WOT? Been adjusting the tune on my car since I moved from Germany to California.
In short, car would reach MAP values of 100 (and sometimes 105) when WOT in Germany. Average temp was in the 60's and PA was 400-1000'
Here in California the highest MAP value I've seen on my VE table at WOT is 96.7. Average temp is 100 degrees and PA is 1800-3000'
Only change I've made in the last year was removing my stock manifolds and reinstalling LT headers.
So.... is the PA and temp difference affecting the MAP values at WOT, or is it an indication of another problem?
$0.02 appreciated
In short, car would reach MAP values of 100 (and sometimes 105) when WOT in Germany. Average temp was in the 60's and PA was 400-1000'
Here in California the highest MAP value I've seen on my VE table at WOT is 96.7. Average temp is 100 degrees and PA is 1800-3000'
Only change I've made in the last year was removing my stock manifolds and reinstalling LT headers.
So.... is the PA and temp difference affecting the MAP values at WOT, or is it an indication of another problem?
$0.02 appreciated
The higher up you go the less dense the air is........so there is less air pressure in turn the MAP shows less Kpa.
To the pcm 90-100+Kpa is WOT
When you get into 2bar+ each extra bar enables you to fine tune for higher boost pressures for fueling and timing.
To the pcm 90-100+Kpa is WOT
When you get into 2bar+ each extra bar enables you to fine tune for higher boost pressures for fueling and timing.
With engine off, key open, use a scanner to see MAP readings.
The value you see with engine off is the highest you could possibly see at WOT
You are fortunate, I can only get 85 KPa at WOT here, 5000 ft altitude (1500 m)
The value you see with engine off is the highest you could possibly see at WOT
You are fortunate, I can only get 85 KPa at WOT here, 5000 ft altitude (1500 m)
Thread Starter
Joined: Jun 2004
Posts: 1,501
Likes: 7
From: Ft. Irwin, California (But Virginia is home)
Whenever I'm checking that I do the key on, engine off check of MAP to see what the current max MAP is. MAP is basically atmospheric pressure so it is affected by altitude and also if you're in a high or low barometric pressure zone that day. What is max one day may be a few kPa higher or lower the next. The "standard" is at sea level with average baro and I think it's 102.6 kPa. In Michigan at 900' my normal is about 99-101 kPa
