Jared,
It appears to me you are under the impression I am measuring boost prior to the intercooler. My measurement is actually after the intercooler and in the plenum prior to the butterfly. I agree the closer to the intake the better and at that manifold would also allow the measurement of vacuum. I will attempt this weekend to tap the previous location I used, the same place in Stacy’s picture, and get a measurement there using my digital pressure sensor. I’ll report my comparison findings. My guess is that the recorded pressure numbers will not be all that different. (within 10-15%)
<<< My point with this is that you might consider that the issue is not the fuel pump. And, as you know, running lean is scary.>>>
I am considering everything. So far it appears I am running lean however I just did a Mustang 4 wheel dyno and one run was rich while the other two were lean. I would like to get a reading from the Durametric and PIWIS to see what the O2 sensors are seeing. I’m working on that.
<<<99 is a brassy guy. He does make statements as if they are facts.>>>
I have no problem with this, just include documentation or substantiate them.
<<< Regardless, your numbers are crazy high. Understand that.>>>
The dyno comparison was only to compare the 3.8 pulley to the 3.6 pulley. I am aware you can get a dyno to say pretty much anything you want it to by fudging numbers. I make no claims as to the accuracy of this dyno or the numbers it shows. (I took the forward drive shaft off for these 2-wheel drive runs.)
Having said that, I just finished a 4-wheel drive Mustang dyno and those numbers were 404HP and 308 ft lbs. TQ.
Here are the 3 AFRs recorded.


Not sure why one of them is so different. More research is in order.

Walt

 

Gotcha. Makes more sense now. Seems like I had something happen that made the car seemingly sporadically run rich or lean...

I'll think on it and hopefully will recall.

Those numbers look good now, so far. Now we just need to get your AFR consistent.

 

Is your diverter valve black plastic or aluminum?

 

Black plastic

 

More information.

Ehrin and I just tapped the pressure gauge into the vacuum line behind the throttle plate and recorded new numbers from that position. The pressure gauge indicated a vacuum until the engine was accelerating. . (At idle we recorded -9.7 PSI.) The max boost recorded from this new sensor position was 6.1 PSI and I believe that is a valid max number. (A spike of 7.0- 7.6 was recorded.) We previously saw 4.5-4.7 PSI at this same location with the larger Pulley so comparing the new 3.6 inch pulley to the previous 3.8 inch pulley we saw an increase of 1.4-1.6 PSI. (That is in line with Vortech’s claim of a 1-2 PSI increase with a one step down pulley size replacement.
When comparing the max psi numbers from the post intercooler plenum of 7.3 at redline and 6.1 from the location behind the throttle plate there is a difference of 1.2 PSI or a 16% difference. Ehrin and I previously guessed there would be a difference of 10-15%)
I believe this behind the throttle plate, location is a better and more accurate place to put the pressure sensor in that it will record engine vacuum as well as boost pressure more indicative of what the engine is seeing.
That’s all for now.

Walt

 

This is sounding BETTER...!
So let's assume your car stock would have dyno'd at 301 RWHP(according to Porsche claim of 355 BHP) and you now are showing 404 RWHP so that means you are making 17.1 RWHP/ psi of boost....
I was reading on the internet on a few forums and it seems,and this being very general,that 1 PSI of boost equals 10-15 RWHP so you are doing really well!
CONGRATS!

Stacy

 

Stacy,
I don't care too much about the numbers but more about the driveability and actual power however irt the 404HP number that was not a rwhp but a awhp. (all wheel horse power) since there is a loss in the front wheel drive also that must be factored in also, correct? I guess a way to get that number would be to take the fwd shaft out and re-run on the Mustang. Not sure that's worth the expense though.
Anyone know a factor to use to figure out flywheel hp when given 4 wheel drive dyno numbers?
Walt

 

That makes the numbers even better!


Stacy

 

This is all extremely interesting to me from a technical perspective, but I am also curious in how all these numbers work on the blacktop. Hopefully none of you are too "snob" to do a 1/4 mile run? Or use a g-meter to pull 0-60, 60-100, and 0-100 times?
CATTMAN

 

Getting these times are tough between cars......I have a hard time launching my car and hammering shifts(hate doing it) and also we will all shift diferently... so what I do is use my Durametric program(as it has a time table on it)...3rd gear from 3000 RPM to redline....this way we can compare the info/times there.
I do use an old G-tech and the same piece of road to do my runs as well.....

But Cattman I will do my best for you when I can.....

Stacy

 

How could this thread just die? I want more info, debate, and answers. What happened to 2006's pulley swap, is he still running the 3.6, and is he running lean? Did he make changes to a smaller pulley, or did he go back to the 3.8? Did he ever sort why his AFR's were so varied?

Come back and let us know, 2006.
CATTMAN

 

[quote=Cattman;2670558]How could this thread just die? I want more info, debate, and answers. What happened to 2006's pulley swap, is he still running the 3.6, and is he running lean? Did he make changes to a smaller pulley, or did he go back to the 3.8? Did he ever sort why his AFR's were so varied?

Come back and let us know, 2006.

John,
please tell me you didnt revive this thread! LOL I just put the popcorn in and I might take the day off for this thread ROFL

Jim

 

ughh,this thread drives me nuts. i nominate the guy with the 'secrets' and no real help attitude as most annoying of the year. plus it is doubly annoying how no one calls him on it for fear that he won't reveal his 'secrets' to them some point in the future. Either really help or don't post anything!

 

Cattman,

Sorry I just noticed your questions.
I am still running the smaller pulley and have not had any issues with the car. I have driven over 1,500 miles thus far. As for the AFR's, I don't know what the actual numbers are. One dyno had lean numbers and another one did not. So I continue to drive it like I always have.
I would probably pursue it more but just bought a 06 Cayenne Turbo S so that is getting most of my attention for the moment. I'll revisit the C4S later this year.