Is it possible to loose 1and a half to 2 psi of boost from a ... say 40 degree temp rise, or is temperature irrelevent?.... 86 gn mostly stock went from 19 psi to 17 ... i checked all the hoses and glanced at the vacume lines,,,, but more inspection is needed it still spikes to 20psi or even 21 for a sec then drops down to 17 tnx for your input eric smith
so you know there is no knock and i have the red 93 chip i run enough octain just incase that answer came up
Not sure about temp changes causing boost changes, but the spike could be caused by an exhaust leak ahead of the turbo. Check for header leaks (i.e. cracked header) and at the connections from the header to crossover and header to turbo. It may be tough. Sometimes the smallest leak can cause the spike...so small that unless you have real good ears, you may not even hear it. Good luck.
well i found the problem ....good tip for some. the intercooler had shifted and the tubes were not lined up corectly, now most of the time this cant happen, but i had mine mounted differently because a year ago i had found the mount was holding the innercooler in a possition that made the piping line up incorrectly causing bad turbulance in the system. So to cure i had changed the mounts and added new, fernco with steel connectors, there like the stoks but have a steel band around the outside to make them very ridged, forcing the tubing to line up right. when i 1st did that last year I gained 3 tenths and almost 4 mph!!! (while gaining boost,hence the loss when It moved back this year) I will be working on a better mount that will hold better have a g1 and good luck.... I suggest if you have not gone though you innercooler sytem,, that you check them out to see if they line up good... think how much hp you get when just porting a head... and compare it to to 2in. pipes missing allingment bye (in my case) 1 forth of an inch....