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  • SN95 4.6L Mustang Tech

need help

  • Thread starter Thread starter mustang51js
  • Start date Start date Nov 29, 2009

mustang51js

New Member
Nov 13, 2009
27
0
0
Nov 29, 2009
#1
  • Nov 29, 2009
  • #1
ok so ive been working on my car all the time it seems to get it ready for the dyno, i finally got it ready and i dont know if i have another problem, so when im in nuetral and hit the gas my vacume goes from -20 to -10 real quick and back to -20. So i was thinking i have a vacume leak because it should go into boost even at idle right.So i started looking around and found my pipe going from the pass side valve cover into the tb is sucked in.Is this normal with higher boost ,i should be at 12 psi with my setup. Im wondering if i put a hard tube on it is that ok, i dont know why its doing this, and only seemed to start after i put the mondo bov on, but it couldve been doing it the whole time and i didnt notice it.I ve been having problems with the car feeling like it was being held back when i hit the gas, like someone pulling on me with a rope, the rpms go up but i dont feel the pull of the car.Would that be part of the problem, here are a couple pics i took, and also i put a steeda oil separator on the car and it didnt have any oil whatso ever in it so i removed it and still the same problem.
View attachment 237908
View attachment 237909
 

mustang51js

New Member
Nov 13, 2009
27
0
0
Nov 29, 2009
#2
  • Nov 29, 2009
  • #2
ok i put a hard tube in and took it for a ride, i cant get it past 5 psi so i geuss i have a air leak somewhere, so i got to try and find that
 

stang88j

New Member
Aug 16, 2004
45
0
0
upstate ny
Nov 29, 2009
#3
  • Nov 29, 2009
  • #3
check for belt slip
 

wmburns

SN Certified Technician
Aug 14, 2009
5,892
514
204
Houston Texas
Nov 29, 2009
#4
  • Nov 29, 2009
  • #4
First, let me comment on one thing. What year car? What SC system? What mods? None of this is mentioned in the post.

Regarding your question about boost at idle, NO.....A Supercharged car will still have vacuum at idle. An engine at idle does not need boost. Besides, it takes RPM's to make boost. It is normal to start to see positive boost starting around 2000 RPM. It should go up from there. How much and how fast will depend upon which SC you have.

The colasped line is a problem. If you have used the incorrect line, that could cause this. The line has to be strong enough to withstand a vacuum as well as the boost pressure.

Does your SC have a "valet" mode? What kind of boost levels are you seeing as the RPM's increase?

Absolutely no oil at all in the oil separator? Then IMO it is hooked up wrong or not getting any PCV flow. I just don't believe that even on a perfectly brand new motor that a small amount of oil wouldn't be trapped.
 

mustang51js

New Member
Nov 13, 2009
27
0
0
Nov 29, 2009
#5
  • Nov 29, 2009
  • #5
oh yeah its an 02 gt with v2 s-trimair to air intercooler and 3.25 pulley swap..The tube is the stock tube from the factory but i switched it to a hard tube now, i dont know if that had anything to do with the oil separator having no oil because the pass valve cover had a little oil on it from that tube sucking so hard.I put the oil separator in the middle of the 5/8th line that comes out of the drivers side valve cover and into the air intake.I did find some black powder on the sc and was told thats a sign of slippage so i'll have to do something about that, i dont hear anything and its not alot of black dust so i dont know how bad its slipping. I found a air leak in by my bov and fixed that, so now i just have to wait till i take it to the dyno and see what they can do.
 

mustang51js

New Member
Nov 13, 2009
27
0
0
Nov 29, 2009
#6
  • Nov 29, 2009
  • #6
i updated my sig and i didnt know about the boost at idle because i had my gauge hooked up to the sc at first, i changed it last week to the engine so im not used to having a vacume
 

deftsound

Please ask me how much my supercharger cost
Apr 6, 2004
945
1
39
Texas City TX
Nov 29, 2009
#7
  • Nov 29, 2009
  • #7
^ what he said, you won't generate boost at idle...
 
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