HI

I am going to get a downpipe but have been concerned about overboost problems, as my car already has a Pettit intake and cat back system on it. I am interested for engine safety not increased performance.

I have been told that the Pettit downpipe comes with a kit that restricts the orafice (opening) to make the pipe flow like the stock pre-cat (when new) and thereby eliminate the risk of high boost. Does anybody have experience with these? Do other downpipes have this option?

Thanks
Greg

 

Some people make one out of sheet metal using tin snips and install it between the DP and main cat flanges. You can always do the "poor man's boost controller" or swap out the pills to limit boost while you save for an ECU/PFC, if that's your goal.

 

My Pettit SS d/p came only with the new "pill" (aka Holley carb jet)
to put into the vacuum/pressure hose. No sort of restrictor plate.....