You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!
vacumn.. i constantly get about -20 for my vacumn reading. someone said it could be cause i have a cracked seal.??? im all confused. i thought -20 vacumn was normal??? what is normal and what does it all mean.. thanks
20 inHG is normal? I've gotton 15 inHG ever since I got my boost gauge. I got my gauge when I had about 5k miles on this engine. I think that was about 5 or 6 months ago. My FD doesn't seem to have as much power as when I first got it, but that may just be me being paranoid. Should I be worried about anything?
I get ~14psi @750 RPM with Pettit Intake, PFS- IC,DP,MP,CB. Runs fine. 20psi is GREAT for modded, and normal for stock. I've never seen that much.
~Tom
There have been numerous conversations on this topic. You might be able to find some by searching the forum. 18/20 is usually for a non-ported motor while 14/15 is for a ported motor .... usually. I get 14/15 on a ported motor with 3 mm apex seals.
uh oh.. i thought i was getting good readings. @ idle i get 15-16 vacuum. and then cruising w/o the pedal on the gas peddle. i get about 20. Is this correct or is there problem with my readings?!
__________________
-='93 BB Touring=-
*Fashion DP
*Efini Y-pipe
*Trust Catback
*Apexi Power FC w/ Controller
*Intake
*Midpipe
*GT Style Spoiler
*Autometer Boost/ AF gauge
*Silicon Hoses
*Pioneer 7" LCD w/ CD player
I have a street ported motor w/ 3mm apex seals, and @ idle my vacuum readings are at 15. This is normal right? as my motor get older will the vacuum readings get higher? or lower?
__________________
93 RX7 Silver w/ Re Amemiya body kit and Mazdaspeed wing. Street ported w/ 3mm apex seals. Blue printed turbo's, XS front mount I.C, Fluidyne radiator, Crane hI-6 ,ported wastegate, big bore throttle body and A.C/P.S removal. Autometer race guages, Cusco fuel pump, front and rear strut brace, EFI PMS, 12.1 best 1/4 mile
It also depends on you idle I think. I know that at around 750rpms my vacume is about 15 but at 900 or so rpms its closer to 20. You vacume will change with rpms so unless we all have the same idle I think we're comparing apples to oranges.
Here is my vacume readings:
750rpm - 15
about 900 rpm - 20
driving and take foot off gas - 20
The car runs real strong and has a rock solid smooth idle
Later,
__________________
STEPHEN
1995 RX7 with a few goodies
412rwhp and 125mph traps on pump gas driven daily with BNR stage 3 twins
Originally posted by SPOautos It also depends on you idle I think. I know that at around 750rpms my vacume is about 15 but at 900 or so rpms its closer to 20. You vacume will change with rpms so unless we all have the same idle I think we're comparing apples to oranges.
Here is my vacume readings:
750rpm - 15
about 900 rpm - 20
driving and take foot off gas - 20
The car runs real strong and has a rock solid smooth idle
Later,
Yup, vacuum is definately affected by your idle. My idle is set at around 850 and I get around 16 and it increases as I get closer to 1000 rpm. Once you go past a certain rpm, I think around 1000 rpm, the vacuum will then start to decrease.
On my old engine with 74000 miles on it (with intake, dp, and cb) I got a 16-18 vacuum reading. Dave at KDR told me with my new street-ported engine I would see around 15 and as it broke in I should see 18. I've seen 19-21 reading at about 750 rpms and it wasn't dropped any and I'm around 1000 miles - not bad - hope I can keep that kind of reading though