MurrietaStang

Vacuum at idle is reading between 18 and 20. I looked at the hose connecting the whipple to the boost sensor and it was collapsed at idle (vacuum)... I'm going to switch that out for something better.

danzcool

MY gut is that you should be doing a little bit better than that. It should be sitting right at about 450, you're not too far off though. What was weather like the day of the dyno, warm/hot? Car cooled off or been idling? It's a pretty smooth curve, so you shouldn't be having any belt slip.

For comparison, after my first dyno tune with only an electric water pump and borla axle backs as "performance mods" (I know, not really much at all) mine put down 467, same pulley size/everything. A few airflow mods (jba shorties, FR 62mm throttle body) and aluminum driveshaft later it's putting down 502 at 11lbs on the 3.125 pulley. So there's room for improvement when you feel the need.

TRexGAWD

A custom dyno tune is way different than the stock FRPP tune.. The FRPP tune leaves a lot of power on the table..

GTTex08

Agreed, pretty good numbers from a stock tune!

moosestang

The boost sensor? You have an electronic boost gauge? I tried an electronic gauge and didn't like how fast it reacted and I don't think it was all that accurate. Doesn't sound like it used a vacuum hose. Mine idles with 22 inches of vacuum, drops to 25-26 on decel.

A vacuum line should not collapse, so i can only imagine how well it's holding boost.

MurrietaStang

Yeah, I have the Autometer Elite Boost/Vac gauge (5677). I like it but, I'm wondering if it's accurate. The old hose was really bad, I replaced the hose with a much better one and made sure all the connections are tight. I'm still getting the same readings though.

I still have the stock cats in but, I'm wondering if my x-pipe and axle backs allow for a better flowing exhaust which could reduce boost?

TRexGAWD

Unlikely.. headers might, but an x with stock cats shouldn't affect it.. What do you have the boost gauge hooked up to? Did it come with it's own sensor or using the MAP? piggy back map?

MurrietaStang

It came with it's own sensor, I've got one end of hose connected to it and the other connected to the top of the whipple (The same spot as the #6 post at https://mustangforums.com/forum/gt-s...ost-gauge.html).

TRexGAWD

Where do you have the sensor mounted?

MurrietaStang

Here's a picture I took today: