Completed Project My 98 super charged EX

[delexploder]

Nice

 

[2000StreetRod]

upshift control?

Once you determine upshift control I'll be happy to use your results. You probably remember that my WOT upshifts were at a much lower RPM than what I entered in my tune. Just another calibration constant that doesn't work according to how it is designed.

 

[4pointslow]

Transmission

I would be happy to share anything you need with you but my stuff may not work with yours since I have a slightly different calibration and some other stuff like 4.88 gears. But just say the word and I will email or post it, whatever works best. You will have to be more specific though, I don't know exactly what you meant by Upshift Control. lol.

Got to love this tuning stuff!

 

[4pointslow]

Internet

My internet is half fast(Half [MENTION=127576]ss[/MENTION]ed).I have really slow upload speeds. I am trying to upload a couple more videos to youtube but I have DSL internet. I want FIOS but it is not available in my area right now. 44 minutes remaining. lol.

 

[2000StreetRod]

upshift example

I noticed in a datalog that the 1st to 2nd WOT upshift occurred at 5721 rpm and 49.5 mph even though the Trans WOT Shift 12 was set at 5850 rpm and Trans Shift Schedule 12 for TP > 700 was set at 66 mph. According to the Trans WOT Shift description the PCM commands the shift when the earliest condition is satisfied. There's a caution that since the shift takes some time the specified rpm or mph will be exceeded. However, in my case neither was even reached. I've read that mph is usually more accurate than rpm but neither of mine is accurate even though I've entered the correct axle ratio, drive ratio, tire revs per mile, and the axle ratio switch is set to 0.

 

[4pointslow]

Transmission

Did you change your N/V in your tune?

 

[4pointslow]

Video skipping second gear

Transmission not shifting into 2nd


Transmission shifting correctly

 

[2000StreetRod]

stock value

Did you change your N/V in your tune?

No, it's still the stock value (43). Tomorrow I'll calculate the correct value and compare it to the stock value to see if that explains the error. Tnx!

 

[vroomzoomboom]

And what?

E.T. and mph!!! lol
and 15 lbs of boost?! i am very surprised that motor has lasted as long as it has

 

[delexploder]

Time to stroke and get some BOB or BOA heads

 

[4pointslow]

Et

E.T. and mph!!! lol
and 15 lbs of boost?! i am very surprised that motor has lasted as long as it has

E.T. was posted in the pictures of the datalogs. I edited them to add MPH.
Boost is 16lbs.

I expected a .5 slower than 12.9 1/4 mile time due to the hot weather. Seeing the 13.20's was a surprise. After my appointment on May27th to have the exhaust work done, I will be off for a week so I should have some more track time if it doesn't rain.

 

[4pointslow]

heads

Time to stroke and get some BOB or BOA heads

What are BOB and BOA heads?

Supersix Motorsports has some nice cylinder heads. Things is I wont put $2,000.00 heads on unless the pistons/rods are upgraded, I would hate for a piston to break from detonation or other unsuspected problem and have the pieces smash up the cylinder heads ruining them. Otherwise I would have them on already.

 

[delexploder]

The dohc setup from the cosworth 2.9, there's a few threads on here somewhere, super six bottom end with the dohc and all your other stuff would be sick,

 

[4pointslow]

Dual overhead cams

I saw those threads, very interesting designs!
Someday I may actually build a motor for this truck.

 

[4pointslow]

Share

Share a Coke with your Explorer.
I heard you can even clean battery terminals with a can of coke.
My battery terminals don't get dirty though, Optima battery.

 

[4pointslow]

Exhaust Back Pressure Testing @ WOT

In preparation for some exhaust work I am having done,
I decided to do an exhaust backpressure test at WOT to see where it is now.
According to some information from FORD, backpressure should be no higher than 3 at Idle and 8 at WOT.

I removed the wideband O2 sensor and installed the back pressure tester fitting into the exhaust.
With the hose run into the vehicle, I placed the gauge on the dash and wedged it there.
I was supprised to see a little over 10 psi exhaust back pressure. Can't wait to see how it is after the exhuast work is done.

 

[2000StreetRod]

back pressures

Thanks for posting Ford's range and your current maximum and minimum back pressures. I wish that I would have had the capability of measuring mine before and after replacing my exhaust system. It's not surprising that with forced induction your max value is greater than Ford's. I suspect that your stock cats provide the greatest restriction. Second is probably the small diameter of the short radius bends at the bottom of the downpipes before the cats.

According to one review the valve in my Dynomax VT muffler begins to open when the back pressure exceeds 0.29 psi and 100 scfm, and is fully open at 0.74 psi and 500 scfm.

 

[4pointslow]

Exhaust vs HP

I take no credit for this information, I did not make it up. I just figured out how to use it. It may or may not be correct.

I have found some interesting statements about exhaust flow and horsepower.

1. Straight pipe is said to flow 115 CFM per square inch of area
2. To avoid exhaust restriction the exhaust pipe should flow 2.2 CFM per horsepower. (I am assuming crankshaft HP)

These statements may not apply to all vehicles under all conditions, but they are interesting.
The statements are used with this formula.
The area of a pipe X 115 CFM / 2.2 CFM = Horsepower that the exhaust pipes can support.

(1/2 x True Pipe ID) ² x 3.14 = Area of pipe
To find area of exhaust pipe you need to know the thickness of the pipe wall.
16 gauge is .065
There are 2 walls for a total of .13
Subtract that from the pipe diameter.
2.5 inch OD - .13 = 2.37 ID

2.37 x .5 = 1.185 (half of pipe ID)
1.185 x 1.185 = 1.404225 (squared)
1.404225 x 3.14 = 4.4092665 (Pie'd) lol.
Area of 2.5 inch pipe with .065 thick walls = 4.4092665

(4.4092665 x 115) / 2.2 = 230.4843852272727 HP
Rounded 230 HP per 2.5 inch exhaust pipe per side.
Duals with 2.5 inch pipes should be good for 460HP


The below numbers would be with .065 wall thickness
So if my math is correct.

3 inch can handle 337HP per side
676 HP Total with duals

2.5 inch can handle 230 HP per side
460 HP Total per side

2.25 inch can handle 184 HP per side
368 HP Total with duals

2 inch can handle 143HP per side
286 HP Total with duals

I last tested my truck on the dyno a while back with 290 HP at the wheels when I was running 13.34, at the crank maybe 350HP according to 20% drivetrain loss.
Now with water meth running 12.9. I have not been able to test on the dyno but.... online calculators...
Maybe 380 HP at the crank.
Remember it takes 75 HP to drive the GT500 supercharger.
380+75= 455HP at Crankshaft.
Kind of puts things in perspective.
Wednesday I drop my truck off at the exhaust shop.

 

[CDW6212R]

I take no credit for this information, I did not make it up. I just figured out how to use it. It may or may not be correct.

I have found some interesting statements about exhaust flow and horsepower.

1. Straight pipe is said to flow 115 CFM per square inch of area
2. To avoid exhaust restriction the exhaust pipe should flow 2.2 CFM per horsepower. (I am assuming crankshaft HP)

These statements may not apply to all vehicles under all conditions, but they are interesting.
The statements are used with this formula.
The area of a pipe X 115 CFM / 2.2 CFM = Horsepower that the exhaust pipes can support.

(1/2 x True Pipe ID) ² x 3.14 = Area of pipe
To find area of exhaust pipe you need to know the thickness of the pipe wall.
16 gauge is .065
There are 2 walls for a total of .13
Subtract that from the pipe diameter.
2.5 inch OD - .13 = 2.37 ID

2.37 x .5 = 1.185 (half of pipe ID)
1.185 x 1.185 = 1.404225 (squared)
1.404225 x 3.14 = 4.4092665 (Pie'd) lol.
Area of 2.5 inch pipe with .065 thick walls = 4.4092665

(4.4092665 x 115) / 2.2 = 230.4843852272727 HP
Rounded 230 HP per 2.5 inch exhaust pipe per side.
Duals with 2.5 inch pipes should be good for 460HP


The below numbers would be with .065 wall thickness
So if my math is correct.

3 inch can handle 337HP per side
676 HP Total with duals

2.5 inch can handle 230 HP per side
460 HP Total per side

2.25 inch can handle 184 HP per side
368 HP Total with duals

2 inch can handle 143HP per side
286 HP Total with duals

I last tested my truck on the dyno a while back with 290 HP at the wheels when I was running 13.34, at the crank maybe 350HP according to 20% drivetrain loss.
Now with water meth running 12.9. I have not been able to test on the dyno but.... online calculators...
Maybe 380 HP at the crank.
Remember it takes 75 HP to drive the GT500 supercharger.
380+75= 455HP at Crankshaft.
Kind of puts things in perspective.
Wednesday I drop my truck off at the exhaust shop.

If that truck was producing that kind of airflow, based on those assumptions, then it would need 455HP worth of exhaust sizing. The single 3" in that posting suggests supporting 338HP.

That is of course based on throughout parts sizing being at least that 3".

From the hardcore performance forums I've seen, tons of real cars making over 350HP at the wheels, NA, virtually all have 3" dual systems. Rarely does one of those manage hit those power levels with 2.5" duals. Now of course there are tons of examples of people with blown cars making 500HP+ with anything from stock 2.5" duals to 2.5" etc. Those cars are choking off a lot of power with those exhaust sizes.

The real point I'm suggesting is that tons of people see real benefits to going to a full 3" dual exhaust.

I picked the 350RWHP level as an example, which is tough benchmark to hit with a NA 302 or 4.6 based Mustang. I also noticed people doing very well with 3" systems on mild cars, mostly real 3.0" stroke 302's with no boost. The ones worth noting like that have no losses of idle power, off idle torque etc. They can leave in 2nd and 3rd gear easily. One is a 289 in a 1965 Mustang and 7000+ rpm shift point, but I don't recall every detail of his car, exhaust etc.

The point is with actual tuning of the A/F ratio and timing, which you guys are doing, you cannot make the exhaust too big. There is nothing to gain from any back pressure(which is restriction).

I'd make it at least a true dual system given the space. There is plenty of room for dual mufflers and tail pipes(use both sides). Bringing the exhaust into one muffler only creates the bottleneck of those HP limitations. Look at the exhaust flow available at every bottleneck of the system, front to back, and the HP each can support.

 

[2000StreetRod]

Ideal gas law

. . .
1. Straight pipe is said to flow 115 CFM per square inch of area
2. To avoid exhaust restriction the exhaust pipe should flow 2.2 CFM per horsepower. . .

It would be revealing to know the pipe location for each of the above general rules (i.e. exhaust manifold primaries, exhaust manifold collectors, muffler inlet/outlet, tailpipe, etc.). Thinking of an engine as an air pump the air temperature varies significantly as it flows from the inlet, thru the engine and out the exhaust. The ideal gas law is:

PV=nRT where:

P=pressure
V=volume
n=number of moles
R=ideal gas constant
T=degrees Kelvin

Since n and R are constants then the product of P&V is directly proportional to T. In other words PV=cT where c is a constant. As the combusted gas exits the chamber via the exhaust valve the temperature rapidly decreases resulting in a corresponding decrease in the PV product. The decrease in exhaust gas temperature continues until the gas exits the tailpipe. I don't know realistic values for exhaust temperatures but lets take an example where the exhaust manifold outlet temperature is 500 deg. F and the tailpipe outlet temperature is 150 deg. F.
500 deg. F = 533 deg. K, 150 deg. F = 339 deg. K

339/533=.64

If you assume that the pressure is constant from exhaust manifold to tailpipe (not necessarily valid) then the volume (CFM) exiting the tailpipe is only 64% of the volume (CFM) exiting the exhaust manifolds. I'm under the impression that there is no tuning effect after the muffler. If the exhaust manifold outlets are only 1.75 inch dia. (2.4 sq. in. x 2 = 4.8 sq. in.) then I suspect a single 3 inch dia. (7 sq. in.) tailpipe is adequate.

Do you have stock exhaust manifolds? Do you plan to replace them?