I wanted to give everyone an update on a successful tune by Andre Terranova on my 05 Mustang with an auto tranny. We originally tuned my 05 with the ProCharger on 8/4 with a 6# pulley with yielded 404 rwhp and 357rwtq - with a smooth 12.2:1 A/F - over 11 runs to get this. This landed me a 12.33 @113 MPH in the Qtr.

As of 10/19, we got back on the dyno with the 9# pulley and the MAF.ia. We made 3 pulls in an hour and called it a day. The results were 462rwhp, 398rwtq and a very smooth 11.9:1 A/F. 1/4 miles stats to come soon...

Andre did a fantastic job and I highly recommend him to anyone.

FYI. If you back calculate the drive train loss of 18%, this is about 560 engine hp

[attachmentid=36598]

-Bryan

 

Thats easily an 11.5 second car with traction.

-Dan

 

Very impressive

The Boss Hog

 

Thanks guys. We shall see how much, if any, it helps the 1/4 miles times and MPH

-Bryan

 

Sorry, Bryan, but HP figures just don't work that way, and this is a VERY common misconception.

First off--congratulations on the great HP figures at the rear wheels! I hope that transmission can live with them!! Why? Because MY car is an automatic too!!

Now, let's discuss why using percentages to calculate crankshaft HP is not even remotely close to being accurate:

Powertrain losses can ONLY be calculated from a baseline; i.e.: we know what a specific engine is rated at the flywheel, and we can measure the power at the rear wheels.

For example, let's use the 5.0 Mustang:

From the factory, it was rated at 225HP at the crank, and in many cases put 175HP to 195HP to the rear wheels.

That equals a HP loss, when measured as a PERCENTAGE of between 14% and 23%.

NOW--let's use just a generic example--let's say that we have an engine that makes 250HP at the crank and puts 200 to the rear wheels.

That's a 20% loss, but when we add parts that increase the HP level to, say, 400HP at the crank, the driveline is NOT going to increase the amount of HP that it absorbs.

In other words, it isn't going to be NOW "only" putting 320HP to the rear wheels--it will put what the drivetrain ORIGINALLY ABSORBED, which in this example was 50HP, so IN REALITY, it will put down 350HP to the rear wheels.

It's just plain and simple--the increase in crankshaft HP does NOT cause a corresponding increase in drivetrain power absorption.

Therefore the ONLY way to get a somewhat accurate evaluation of how much power is being absorbed by the drivetrain (and therefore, allow a calculation of how much HP is actually being produced at the crankshaft), you have to have a baseline figure before modifications from which to draw.

I see that in most cases, our cars are putting anywhere from 260HP-275HP to the rear wheels, which means that *IF* the engine HP rating is correct, the actual driveline HP loss is in the neighborhood of 25HP to 40HP.

 

OK, point take stonecoldtx. However, in this case I do have a baseline for my car. With a stock engine, I started at 232rwhp on the "base" 300 engine hp.

But you are right, who cares what the engine hp may be, I still have 460+ at the wheels :P lol

-Bryan

 

And that's an AWESOME figure, too!!

 

 

I hope you used an SCT tuner

If you don't have drag radials, get some!

 

SCT 'Custom' tunes all the way

As for the tires, I currently run 285 Nitto 555r's and soon to try some wider rubber - 305/45 555r's.

-Bryan

 

I would like to offer a different opinion. It really depends on what you are using to measure the loss. The common inertia dyno is really measuring the acceleration the drum. The driveline loss is made up of several factors including friction and rotational inertia. It takes more power to accelate a given amount of rotational inertia at a faster rate, which in turn shows up as more driveline loss. This effect is minimized by having the rotational inertia of the drum very large compared to the rotational inertia of the driveline, but it is still there.

Bottom line is actual driveline loss (measured in hp on an inertial type dyno) does increase, at least to some extent, as engine horsepower increases. A steady rpm, load type dyno is not subject to this effect.

The Boss Hog . . . . . .just my opinion

 

Get to the track NOW Bryan!

We need new track times bro!

 

Well, I'd have to disagree with you on that, and what I've previously stated aren't opinions, they're facts based upon solid principles of physics . . .

The amount of power put to the wheels, or the associated "loss" or "absorption" from the driveline is unaffected by the machine on which it is tested.

The drums of which you speak aren't part of the car . . . the HP loss from the crankshaft to the rear wheels is going to reach it's maximum amount, regardless of what machine the rear wheels are sitting upon, and that maximum "loss" or "absorption" is never going to increase just because the engine makes more power than it did previously.

Therefore, put another way, it is still going to only "lose" that specific amount of power. As I said above--there are many principles of physics at play here that dictate this.

Now, as to whether it is accurately MEASURED by the device, that's another story, and I think you may be confusing that aspect with the true driveline power loss or absorption that occurs from the flywheel through the rear (or front, however the case may be) tire patches.

 

So anyway...Bryan, hows the tranny holding up? Have you put in a looser converter yet?

 

tranny seems to have no strain. I have 6 passes on the qtr with the 404rwhp and now 14 dyno runs. The tranny sometimes has some blow out of fluid, but only on had HARD runs .

My Tuner, Andre, wants me to Braket Race it on the 29th at the "Clash of the Titans". I am highly considering it. It if holds up to a full day of ball-outs racing, I will be impressed.

-Bryan

 

I suggest you re-read Newton's Second law of Motion . . .

Quote:

Originally posted by stonecoldtx@October 20, 2005, 3:29 PM

The amount of power put to the wheels, or the associated "loss" or "absorption" from the driveline is unaffected by the machine on which it is tested.

Quoted post

. . . see explaination of effect of Rotational Inertia. It applies to the rotating parts of the driveline as well as the drum.

Quote:

Originally posted by stonecoldtx@October 20, 2005, 3:29 PM

The drums of which you speak aren't part of the car . . .

Quoted post

. . . . I don't believe I said it was.

<!--QuoteBegin-stonecoldtx@October 20, 2005, 3:29 PM

..., and I think you may be confusing that aspect with the true driveline power loss or absorption that occurs from the flywheel through the rear (or front, however the case may be) tire patches.

Quoted post

[/quote]

Everybody is entitled to their own opinion.


The Boss Hog

PS: ever wonder how those underdrive pulley systems work?

 

Hi, Boss Hog--

You are indeed entitled to your opinion, but responding with proof as to the facts would be inappropriate in this thread.

Thus, I'd be happy to continue this discussion offline through PM's, so I am sending you a PM to that effect.



Bryan--

I have some questions about your transmission and/or tune:

What kind of increases in line pressure have you made in your tune (or do you know)?

On the shifts, is the "Torque Management" turned off, or in some way reduced?

Any changes to the actual transmission or components?

 

congrats on the numbers Bryan. i can not wait to hear about your 1/4 mile times. the clash of the titans would be the ultimate test.

 

I am using a tranny tune from SCT that has increased line pressures, etc. for extremely hard shifts from 1-2, 2-3, 3-4 and 4-5. All bark hard except 4-5 as you can imagine why It also has higher RPM and MPH shift points, for low, mid and high throttle position.

I believe the "Torque Management" is 100% off.

No other tranny mods at this time ... but I am intrested in some once they are more readily available at a reasonable price. A looser converter is soon to come though.

Per my Tuner, Andre:


-Bryan