Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: Ed_RX7 on August 24, 2005, 11:06:39 AM

Title: mad boost problem on single
Post by: Ed_RX7 on August 24, 2005, 11:06:39 AM
low boost was originally set at 14psi and high at 19 psi. I have a profec b 2 controller. Not sure what caused it but now I cannot control the bost at all. when on low it boosts to 16 psi no more and on high it goes up to 20psi......just cant figure....checked the hoses and all seem fine. i even turned off the controller and boosted  and it still went to just below 16 psi???? :confused: ...I can turn the set and gain right down to two and it will still boost to 16 psi but as soon as change ti high it will still boost to 19-20 psi........totally baffled


Ed calling MAX.............or anyone :(
Title: mad boost problem on single
Post by: maximtaylor on August 24, 2005, 11:25:26 AM
You\'ve turned the wheel (number flashes), then pressed the wheel (stops flashing) to reduce the main gain, right?
Title: mad boost problem on single
Post by: maximtaylor on August 24, 2005, 11:26:51 AM
Do the peak readings on the boost controller and your boost gauge match up ok?
Title: mad boost problem on single
Post by: Ed_RX7 on August 24, 2005, 12:16:32 PM
yep max.....made sure it was set correctly and boost gauge and profec are out by about .3-.5 psi......it has alwas been like that though....I always go off the profec though!!!
Title: mad boost problem on single
Post by: maximtaylor on August 24, 2005, 12:40:04 PM
Is it holding that level of boost, or just peaking up to the high point?
Title: mad boost problem on single
Post by: Ed_RX7 on August 24, 2005, 12:57:08 PM
seems to be holding.......
Title: mad boost problem on single
Post by: Ed_RX7 on August 24, 2005, 12:57:42 PM
max pm me your number if its easier

cheers

ed
Title: mad boost problem on single
Post by: antnicuk on August 24, 2005, 03:34:55 PM
I know you said you checked the pipes but it sounds like there is a very slight leak. If its doing with the unit off then i would have thought its not the profec itself.  Have you checked the vacume pipe connection to the side of the w/g,  you could have a leak there that you may not find until you put pressure through it. Also, it could be a slight hole/tear in the diapham,  might be worth checking as if it gets worse, it could kill your engine.
Title: mad boost problem on single
Post by: Ed_RX7 on August 24, 2005, 03:47:27 PM
i\'ll try and pull teh pipe going to the side of the wastegate on sun and check that. otherwise i can only think its the wastegate...maybe the spring is stuck or something?
Title: mad boost problem on single
Post by: Ed_RX7 on September 11, 2005, 11:39:32 AM
decided to change the wastegate and at the same time  vent my wastegate to atmos\' ....boost is now holding low down 15PSI.....:-)  but I cant get high boost any higher than 17psi?????? ...that is with the profec b at 75% on the SET setting......

Could the fact  that the temporary blockoff plate  ( that blocks of the remaining pipe that goes into the downpipe) that I made up is not sitting right and there is a slight blow??????......( it was just temporary...gonna get a proper one made up on WED)


Would this afftect high boost?