04 cobra Questions.

MustangChris · Aug 14, 2012

hey all.

I need some help on my terminator.
lol.

so, here are a few of my questions:
1) What vacuum do your cobras idle at? (Mines at 18 in/hg)

2) My car drops from 12 PSI to 10 PSI of boost, I was told this was a boost leak, but I was also told this is common on Eatons to do so at higher RPMs. Should I start hunting for a boost leak?

3) What is your oil PSI at? mine ranges from 30 PSI at temps to 85 PSI when cold start up. (At one point it topped my 100 PSI gauge...)

4) What are some signs of high crank case pressure on these cars?

Thanks All!
-Chris

justinschmidt1 · Aug 14, 2012

All those things sound normal, you would have oil blow by if you had excess crank case pressure

RichV · Aug 14, 2012

100psi of oil pressure??

Remember my oil pressure issues. Seems real high.

ttocs · Aug 14, 2012

sounds like your using digital gauges? I am too and every once in a while they will read some crazy peak number(high/low) either from a power surge or loss or just a dirty signal. One day I checked the peak reading on my engine temp and it said it was 586 or something crazy like that.

Dalamar · Aug 14, 2012

you could pour beer into it?

uncltrvlnmatt · Aug 14, 2012

What Justin said.

Dalamar · Aug 14, 2012

whoah, uncl Matt, what's up man!! haven't seen you for a long time. how's life.

98mstanggt · Sep 8, 2012

I think this is normal at least I've seen it a few times and I think it depends on your setup also. It could be your belt, maybe its the gauge, could be the rings etc etc I'm running 15psi with my ported 03 cobra and mine stayed at 15psi the whole pull so I'm not really sure. Make sure all your vac lines are tight mine seem to loosen/come off every now and then.

JeremyAlan · Sep 8, 2012

1) i'll check mine

2) when does the boost drop happen?

3)i've never checked mine lol

4)no clue lol i have a breather on my pass valve cover and a vac line on the driver side

98mstanggt · Sep 9, 2012

What kind of power you putting out? ^^^^

JeremyAlan · Sep 9, 2012

vermilion · Sep 9, 2012

chris, you could be a tad bit rich on the tune at idle. mine sits at 14-15hg at idle during vacuum. however, i don't use pcv system. modulars have tight clearances on their bearings but still usually 20-25 idling and 65-72ish at cruise RPMS. do you have a wideband? meter your AFR.

98mstanggt · Sep 9, 2012

JeremyAlan said:
570

O yeah, you got a thread about this on svtp. Now that I see your blower in your sig, I honestly didn't even know they could be swapped and/or that could produce those numbers.

vermilion said:
chris, you could be a tad bit rich on the tune at idle. mine sits at 14-15hg at idle during vacuum. however, i don't use pcv system. modulars have tight clearances on their bearings but still usually 20-25 idling and 65-72ish at cruise RPMS. do you have a wideband? meter your AFR.

Could be this too ^

MustangChris · Sep 9, 2012

wow. this thread came back to life. lol

anyways, the boost drops from 4,500 RPM down to 6,000 RPM (continues to drop after that, but thats when it levels off at 10 PSI again.)

it has a nice, "hump" shaped boost curve:

10PSI @ 2,750
11PSI @ 3,000
12PSI @ 3,750
12PSI @ 4,500
11PSI @ 5,000
10.5 PSI @ 5,500
10PSI @ 6,000 - 6,300
drop off (close throttle) @ ~6,400 RPM

JeremyAlan · Sep 9, 2012

Sounds like a standard m112. They all experience boost drop off.

MustangChris · Sep 9, 2012

thats gay.

also, my car stalls after a WOT run. ... ... any ideas?

MustangChris · Sep 9, 2012

vermilion said:
chris, you could be a tad bit rich on the tune at idle. mine sits at 14-15hg at idle during vacuum. however, i don't use pcv system. modulars have tight clearances on their bearings but still usually 20-25 idling and 65-72ish at cruise RPMS. do you have a wideband? meter your AFR.

i have two widebands B-)

they aren't well grounded at this time (autometer tech support thinks) so they read lean. Put the car on the dyno yesterday and it's actually running rich. lol.. . . .. .