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Phase II boost problems

435 views 5 replies 5 participants last post by  Carl S 
#1 · (Edited)
Calibra turbo
Phase II
Reds running at 3.2 bar
IK22 Iridium’s
Wallace uprated actuator
Recent dizzy, arm and leads (rotor arm mod to remove resistor)
Cat removed

Over boost is fine have had it up to 23psi (turned it back down to 20psi). The problem I have is that after dropping to 14/15psi (bar) the boost drops further to 11psi or so. This happens at around 4K rpm, in lower gears you can feel (and see if you are lucky) the boost fluctuate and drop.

My first thought is a misfire however there is no sign of this under over boost? I tried bypassing the amal valve and turned the boost up to about 13psi, no problems. To me it feels like the ECU is messing around with the boost.

Any thoughts or ideas?

Matt
 
#3 ·
The chip was designed to drive injectors that provide a given flow rate. The reds provide this without a large increase in pressure that will limit fuel flow and fire the fuel at the back of the port. I could have kept the pressure at 3 bar however by increasing it slightly the ECU will adapt to the slightly increased flow rate. In turn this will provide a little head room at maximum load to accommodate further none boost related mods such as water injection, porting or cams ect.

I have an AFR gauge, this shows rich under all full load conditions and oscillates under partial or no load exactly as the car did whilst standard. My car also easily passed the MOT emissions test.
 
#4 · (Edited)
Just an idle thought:
could all this 'spray pattern' talk be a load of bollox from people who don't profit from the sale of these injectors? You know, "the stuff we stock is by far better, hey, we wouldn't stock it otherwise, eh?";)

Yes the spray pattern is different, but under boost this is totally theoretical. If you see how the airstream behaves when shoved under 1 bar through the ports, you'd laugh at anyone suggesting that a slightly different spray pattern makes any dam difference.

It would affect idle and off-boost mostly, but it doesn't. It's close enough.

(...or is anyone suggesting that the spray patterns of the various NOS injectors are so similar to the stock LET ones? lmao
Hint: not only are they not relatives, they are different species altogether! They still work though!)
 
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