3.1/6# lower= 15.2PSI????

[04gtstang]

My car has always seemed to make low boost for the pulley, and now after throwing on the 3.10 upper + snub idler, thats all the car sees in 60* weather. I logged it the other night and it went to 15.2 and almost immediatly started falling and then by 6K RPM had dropped to 12.4.

Does this seem normal? I was under the impresion this combo would make 16PSI or so....and I was hoping it wouldnt bleed off so darn fast.

BTW in 3X* weather I saw 15.6PSI peak once...so no the factory MAP sensor isnt pegging. Actual voltage from the sensor is around 4.7V on the adverage day.

I also went to the track with my half finished tune this past wednesday (11.0 A/F and seeing 17*s timing) and the car ran like crap. 12.5 @ 115 with granny shifting and no burnout. I was just wanting to check the trap. First run was a 12.4 @ 105 missing 4th. 1/8 trap was down from 95MPH with the 6# lower only, to 90/91MPH now.
Old tune was 12.0 A/F and 22*s...car was tuned for 91 octane (previous owner), but I run 93 so im sure it had a little more left in the tune. Ran time in sig.

You guys think adding 4-5*s timing and leaning her out is going to put me up to where I should be? IE mid 11s @ 121 or so?

Thanks!

 

[TrickStang37]

i think your old tune was pretty aggressive for 93 octane. with 91, it was VERY aggressive/borderline. your not ported, are you? your probably creating too much heat if your not.

 

[SicStang03]

I see nothing wrong here... If you are not ported you should be happy with the times you ran considering you didn't burnout and you granny shifted

 

[CobraBob]

Max boost with any upper/lower configuration will vary depending on your other mods. You're going to see less boost, for example, with an O/R mid-pipe vs. one with a catted mid-pipe. Intakes will vary the boost a bit as well. The key is making more power with less boost. Meaning if Cobra A is making 490rwhp with 16 lbs. of boost and Cobra B is making the same 490rwhp with 15 lbs. of boost, Cobra B is more efficient. Assuming, of course, the dyno's are setup nearly identical.

 

[Silverboost]

list all your mods and post up the dyno sheet. Adding more timing will definitely help out with power. check your boost bypass adjustment to make sure you are not bleeding off any of your boost.

 

[04gtstang]

Good idea about the boost bypass, ill check that today.

I plan on having the timing up to about 21-22*s peak and 17*s or so mid range and maybe a hair less below 2000RPM. I checked half the plugs a little after I got it and there were zero signs of detonation....even with 91 winter blend the car was fine and previous owner ran a 12.4 @ 117 in it. I guess this is just one of those cars that LOVES timing.

Mod list_
Bassani O/R X
Bassani Catback
Self ported plenum
SCT BA-2600 MAF
Fuel pump wiring upgrade
Amazon racing CAI (just an 9?inch air filter...12 inch S&B on the way)
Billet flow snub idler
Motorcraft plugs (the IX style thats one step colder than TR6IXs)
Steeda 3.10 upper
Metco 6# lower

I have a few little things done that I wont mention, but thats the just of it.

Nope im not ported.