2GNT.com Forums - Printer friendly page, topic ID #8824 -

Go back to previous topic
Forum name	4G63 Tech
Topic subject	boost drops as soon as it hits max psi....
Topic URL	http://forums.2gnt.com/dcboard.php?az=show_topic&forum=67&topic_id=8824
8824, boost drops as soon as it hits max psi.... Posted by All4thaN0okie, Dec-31-69 06:00 PM OK.. I've been having this problem for a while now, but always attributed it to my leaking 1g BOV. Now I've replaced that with a Greddy type s. The car will boost normally to around 18-20 psi, as soon as it hits 18-20 psi the boost will drop all the way down to almost 0. I have checked for boost leaks and there are none (checked past 25 psi). I have no idea what else could be causing my boost to drop all the way down, other than maybe my wastegate opening and staying open? Any and all help is appreciated, as always guys. Mod list- EVOIII16G, walbro 250, FIC 550s, greddy type s, apexi cat back 3", K&N, UICP, stock IC
8825, RE: boost drops as soon as it hits max psi.... Posted by Jeff_99gs, Dec-31-69 06:00 PM Originally posted by All4thaN0okie other than maybe my wastegate opening and staying open? Sounds like your wastegate is sticking open for some reason. I have heard of that happening before. The hinge on the wastegate arm might be rusty or otherwise stuck. Does it still spool as fast as it always did?
8826, RE: boost drops as soon as it hits max psi.... Posted by All4thaN0okie, Dec-31-69 06:00 PM i'm hitting around 20 psi at about 3200rpm... i think thats pretty good for not having a downpipe... any way to fix the wastegate?
8827, RE: boost drops as soon as it hits max psi.... Posted by PowerEclipses, Dec-31-69 06:00 PM Originally posted by All4thaN0okie i'm hitting around 20 psi at about 3200rpm... i think thats pretty good for not having a downpipe... any way to fix the wastegate? internal? external? depends sometimes if its bent you can bend it back
8828, RE: boost drops as soon as it hits max psi.... Posted by All4thaN0okie, Dec-31-69 06:00 PM its an internal wastegate... stock evoIII 16G also.. the wastegate arm is not bent or rusted as far as i can see... looks the same as it does in my sig....
8829, RE: boost drops as soon as it hits max psi.... Posted by Jeff_99gs, Dec-31-69 06:00 PM Woah no downpipe? Are you running with no exhaust, or do you mean no aftermarket downpipe?
8830, RE: boost drops as soon as it hits max psi.... Posted by All4thaN0okie, Dec-31-69 06:00 PM lol.. i meant it's stock... not aftermarket...
8831, RE: boost drops as soon as it hits max psi.... Posted by Vandy420a, Dec-31-69 06:00 PM how do you guys see max boost at 3200 rpm, esp. with a stock downpipe?!?!? I"m looking more at 3800... sounds to me like the wastegate is sticking shut, then slammign open and staying that way. Check the cotter pin---remove it and move the wastegate by hand to see if its sticky...very easy to do as you install a larger downpipie }( Are you ported/polished? What size flapper? there may be some carbon gunk in there...
8832, RE: boost drops as soon as it hits max psi.... Posted by All4thaN0okie, Dec-31-69 06:00 PM not ported not polished turbo is a stock evo III.... and only MAYBE 5000 miles on turbo... i'll check the wategate for movement though.. thanks for all of your suggestions :)
8833, RE: boost drops as soon as it hits max psi.... Posted by Uberingram, Dec-31-69 06:00 PM Sounds like the wastegate to me too. Common problem for stock SRT's when the stocker internal wastegate is failing.
8834, RE: boost drops as soon as it hits max psi.... Posted by All4thaN0okie, Dec-31-69 06:00 PM very interesting Uber.... maybe its time to go external }(

^{I generated this page in 0.014013051986694 seconds, executing 7 queries.}