What makes our FDs so easy to creep/spike?
 

As opposed to other factory turbo charged cars like the Supra, MR2, 300ZX or 3000GT VR4?

For us it's like 2.5-3 performance mods max and then we're on the brink of blowing our motors. What about the other cars? Are they just as delicate as us or can they be modded much more before requiring an upgraded ECU or boost controller? Do they spike or creep as easliy as our cars?
-Dan

My buddie has a supra and the first thing he did was replace both cats, exhaust, and put on a intake. He has the avc fuel controler and a boost controler and thats it. He goes to the track and runs 18psi and has no issues at all. Im sure the avc helps but I dont think throwing that on our cars would make us able to do that. Im not positive but I wouldnt think so... anyway, thank you and good night!

FD's use a MAP sensor and run off of preset maps as opposed MAF sensors which add fuel based on airflow. Our cars can't compensate for greater flow. They have some compensation for temps and such, but not airflow. Second of all, boost spike is caused by the secondary turbo coming online. It's prespooled before the y-pipe opens, but sometimes it's spun too fast and causes a spike in pressure. As for boost creep, the internal wastegate is too small to bleed off enough exhaust gas when you make it free flowing with a straight through exhaust system.