Mustang GT NOT making 412HP

[Versa-Tech]

Ok, so a few things need to happen now

 

They need to put a Cam on that same dyno and see what happens

No need. The cam timing maps can be adjusted electronically now.

[fordmantpw]

No need. The cam timing maps can be adjusted electronically now.

 

I think he meant Camaro...to compare the two directly on the same dyno and not from one dyno to another.

[FoMoCobra]

I just hope this thing can put the power to the ground. That is going to be the determining factor.

Once I see the 0-60 numbers come in, I'll finally be able to decide on whether I go with a bargain basement V6 at 23K or pony up an additional 10K for a track pack GT.

 

Six banger is such a bargain... OTOH 430hp+ aint no joke

 

hmm...

[jpd80]

They've made an error in calculations,

 

the new 6-speed manual is not 1:1 in 4th gear

[theDuff]

They've made an error in calculations,

 

the new 6-speed manual is not 1:1 in 4th gear

 

This is a comment from the article. The poster at least sounds like he knows what he's talking about. I'm sure it will still be a point of contention though.

 

The Dynojet itself doesn't care what gear the car's in. Remember, there's a final drive gear reduction after the transmission, which further alters the wheelspeed - engine speed relationship beyond what the transmission does, so there's nothing magical about 1:1.

 

In fact, dynoing in a gear that's 1:1 usually results in a hair less (yes, less) driveline loss as its a more (the most) efficient ratio in the gearbox. That's why a lot of dyno operators like the 1:1 ratio. Plus, when using an inertia dyno like a Dynojet, higher gear ratios have a lower rate of acceleration, so less power is soaked up in accelerating the rotating masses, which further props the numbers up.

 

Higher gears do tend to result in higher tire losses since the wheelspeed is higher... at this point all you're doing is trading off one loss mechanism for another. Generally, though, what I've seen come out in the wash is that on an inertia dyno, higher gears will result in higher numbers than lower gears.

 

Furthermore, higher gears also load the engine for a longer duration, requiring more cooldown, plus put more heat stress on driven tires. As the dyno operator, I don't like either of those things.

 

I can't wait to see what 1/4 mile times Evan Smith gets!!!

[akirby]

One quick question,

The new 6-speed manual transmission, they say 4th gear is 1:1, is that true?

 

Google says

 

1st: 3.66

2nd: 2.43

3rd: 1.69

4th: 1.32

5th: 1.00

6th: 0.65

Final drive: 3.31:1

 

But again - regardless of the transmission gear, the power still has to go through the differential at 3:31:1 so you're never actually measuring 1:1 at the rear wheels anyway.

[RichardJensen]

Horsepower doesn't depend on gearing anyway.

 

Torque is multiplied by gearing that proportionally reduces wheel RPM, balancing out the HP equation.

 

(T * RPM)/5252 = hp. An increase in torque reduces the RPM by a proportional amount, thus the top number in the equation doesn't change, regardless of gearing.

[jpvbs]

Does anyone know what rwhp numbers stock SS Camaros are putting down these days?

[timmm55]

Does anyone know what rwhp numbers stock SS Camaros are putting down these days?

 

364 according to this one.

http://www.camaro5.com/forums/showthread.php?t=16158

[timmm55]

Some comments from the Camaro board:

 

 

Yes, but how will they respond to the Coyote V8?

 

http://blogs.insideline.com/straight...ang-gt-50.html

 

If that dyno number holds up on customer cars, GM has just been massively owned by the Blue Oval Boyz again.

 

 

Never fear...the LS-V8 is not the "be-all and end-all" of SBC. "Stay tuned..."

 

this car is still going to take the lead just because of the styling.. its much better tan the mustang

 

^Agreed. Personally I think for many people the styling will be a big seller. Sure the engine is a big thing but I don't know I just feel like styling would have more influence. Just my opinion don't flame me for it lol. But I feel like that since Ford did this with the Mustang that GM should do something to one up them. Sure do a little to the engine but I think that they need to do a little shaving on the weight and tweak the suspension just a little ya know nothing major but from what I've read, Mustang handling is preferred by most magazines. But then again I feel like they always put too much pressure on the Camaro that it needs to be superb but yeah just my opinion again.

 

 

The old saying is there is no replacement for displacement... ;-)

[blksn8k2]

The only dyno test that would really mean anything would be to run a Mustang GT, a Camaro SS and a Challenger SRT8 back to back on the same dyno on the same day under the same conditions. My guess is some rag like MT will be doing just that if they haven't already. Should be interesting...

[Fgts]

Too bad the 5.0 is only in a Mustang..... :rolleyes:

Edited March 26, 2010 by Fgts

[jpd80]

Too bad the 5.0 is only in a Mustang..... :rolleyes:

 

In Falcon as of July or maybe August/September...:shades:

Edited March 26, 2010 by jpd80

[atvman]

This is a comment from the article. The poster at least sounds like he knows what he's talking about. I'm sure it will still be a point of contention though.

 

 

 

I can't wait to see what 1/4 mile times Evan Smith gets!!!

There's a difference between sounding like you know what you're talking about and actually knowing what you're talking about. The author of the Edmunds article replied back to him.

Edited March 26, 2010 by atvman

[goinbroke2]

You guys make me laugh. As one who HAS run an engine dyno and have assisted at many chassis dyno runs...what the guy who runs dyno's said is correct.

It also works on an engine dyno, if you change your rate of acceleration, the hp will change as more torque is used to accelerate the rotating mass.

 

 

Example, SBF 900rpm/min rate max 300hp at 5500rpm

600 rpm/min rate max 305hp at 5500rpm

Light rotating assembly so their isn't much difference over all power but the torque curve would be higher/sooner the slower you rev

 

521BBF 900rpm/min max 550hp at 5500rpm

600 rpm/min rate max 580hp at 5500rpm

Heavy rotating assembly so their is massive difference in hp. The torque chart will be REALLY impressive probably showing 50-75lb ft difference in some spots

 

Since dyno's only measure torque and the hp is a mathematical equation (you guys knew that right?) the biggest difference you will see though is the torque chart which will be WAY higher the slower you accelerate the engine because it can "load" better.

(saw this with a 455 which had 58lb's/34hp more on the dyno but slower on the strip, to account for the difference, changed to a looser converter and geared higher keeping the engine under load longer per gear/accelerating the engine closer to the 600rpm/min like the dyno was. car picked up 3/10's if I remember correctly)

 

As far as dyno chassis go, you can "fool" the dyno into reporting anything you want. An example is a chev 1 ton 4x4 with a built 454/t400 4.86gears and 39" tires. It was something like 290hp. (it was less than 300)Then we switched to street tires (I forget 245/75/16's or around there) and it jumped to 410hp. This change was in the time it took to swap tires.

Yes you always dyno in 4th gear or whatever gear is 1:1. The reason is that if you don't, the results will be swayed either up or down depending on overall gearing. The lower the gear, the slower the dyno speeds up which records lower hp. If you could increase the chassis dyno loading ability (you can't, it's a set weight to match the dyno combo) then you could make use of the slower wheel speeds and increased torque. But since you can't, all it registers is a slower overall hp number even though the initial bump will be higher. The same goes for overdrive, the less torque available makes the dyno spin up slower which shows as less hp.

 

The only place or the perfect trade-off point is 1:1. Higher robs the engine of torque (like accelerating in high gear on the highway) and lower gearing (more torque) can't be utilized by current chassis dyno's.

 

There is a reason engine dyno's are not "mass acceleration" machines and instead are "brake load induced".

 

All dyno runs are supposed to be "corrected" to certain values or it doesn't mean anything. example; you run an engine at 8am and it's 350hp barometer reads 29.00

Then you swap cams and the engine shows 355hp at 1pm and barometer of 29.9. Did the cam increase or decrease power? The magazines will congratulate the cam company giving the extra 5hp but in reality the engine lost power because if it was corrected you would see the same cam before would of made 360hp with that much barometric pressure! And that's not going into humidity or room temp/engine oil temp/coolant temp/oil level etc etc which all effect hp. Everything has to be corrected and preferably run on the same dyno by the same operator.

 

Oh, another thing, gross hp is a bare engine/open headers/electic waterpump etc.

SAE net is with all accesories and exhaust installed and operating.

This occured in 1972 when 460's went from 365hp to 212hp overnight. (yes I know later they reduced compression and retarded valve timing 8 degree's)

All engines took a big dump in 72 because of this.

 

I don't know of any manufacturer who rated the stock veh's by rwhp.

The only one I've seen is firebird firehawkes built by SLP which provided a chassis dyno sheet with each car when new. (saw my buddies, kind of cool to pull the dyno sheet from the glovebox hehe)

[atvman]

The Dynojet itself doesn't care what gear the car's in. Remember, there's a final drive gear reduction after the transmission, which further alters the wheelspeed - engine speed relationship beyond what the transmission does, so there's nothing magical about 1:1.

 

In fact, dynoing in a gear that's 1:1 usually results in a hair less (yes, less) driveline loss as its a more (the most) efficient ratio in the gearbox. That's why a lot of dyno operators like the 1:1 ratio. Plus, when using an inertia dyno like a Dynojet, higher gear ratios have a lower rate of acceleration, so less power is soaked up in accelerating the rotating masses, which further props the numbers up.

 

Higher gears do tend to result in higher tire losses since the wheelspeed is higher... at this point all you're doing is trading off one loss mechanism for another. Generally, though, what I've seen come out in the wash is that on an inertia dyno, higher gears will result in higher numbers than lower gears.

 

Furthermore, higher gears also load the engine for a longer duration, requiring more cooldown, plus put more heat stress on driven tires. As the dyno operator, I don't like either of those things.

 

Jason Kavanagh - Operator of the dyno used in this test

 

This should clear up any gearing issues.

[goinbroke2]

"The Dynojet itself doesn't care what gear the car's in. Remember, there's a final drive gear reduction after the transmission, which further alters the wheelspeed - engine speed relationship beyond what the transmission does, so there's nothing magical about 1:1."

 

I understand why he said that, but it is misleading to say it that way. If you make a pass in 1st then 2nd etc, you will get all different numbers. The reason you use 1:1 is because that is the only gear you are getting direct engine torque. Any other gear either multiplies the torque going to the rear end or reduces it.

Basically, if we want to know the hp of the engine, we would like to bypass the tranny, since we can't, use whatever gear is 1:1. The fact that there is a rear gear too is redundant as every rear end is reduction geared. Yes you can alter the numbers by changing gears or tires as I said before.

 

"Higher gears do tend to result in higher tire losses since the wheelspeed is higher... at this point all you're doing is trading off one loss mechanism for another. Generally, though, what I've seen come out in the wash is that on an inertia dyno, higher gears will result in higher numbers than lower gears. "

 

Again, what he is saying is true, but a generization. Higher gears do not always show higher hp numbers as I stated previously with the 4x4 example. (bigger tires equating to higher gearing)

 

BUT..always a but..depending on the initial gear ratio, you can either get more or less power. 5:13 gears would have more torque/less tire speed than the dyno could capture resulting in lower numbers than the same car with 4:11's. But if you start with 4:11's and go to 2.50's you would lose power......unless the car was built for 2:50's in the first place!LOL!

 

Kind of like the old "took the muffler off and I lost power" Well the issue isn't that you lost power with more free flowing exhaust..it's that the free flowing exhaust caused the engine to lean out..which caused the hp loss. Sometimes you have to look beyond the obvious.

Another example is a dyno test I disputed in Carcraft because I know the guy who did the work and did the runs. After talking to Bruce Fulper of RockandRoll performance (a pontiac guru and regular in pontiac performance mag) He too was pissed because they basically made it appear HE said the heads were worth 100hp which was a patent lie. The engine (455pontiac) was built up with the usual bigger cam/headers/carb in steps. He used several cams and header combo's and at the end the choking point was the heads. When the aftermarket heads were installed the power jumped by 100hp or so. The implication was that "these heads would give 100hp, aren't they great!"

Imagine a pro stock engine with stock heads on it, then replacing the stock heads with pro stock heads. Huge hp jump? OF COURSE! This isn't to say a stock engine with the same stock heads will gain the same hp by bolting on pro stock heads!

 

Anyway...you get my point. Obviously he knows what he's talking about and running a dyno, he could be generalizing for the ...less informed shall we say.

 

edit: forgot to add, carcraft said "oh I see..well we're not doing a retraction" I'll leave it to your imagination as to what he said to them and why he hasn't been in that mag since. Actually he pretty much is down on all mags as they are biased towards the current advertisers...but I digress

Edited March 26, 2010 by goinbroke2

[atvman]

I'm no dyno expert, my only experiences were when I had a car dyno tuned and when I put my bike on a dyno for craps and giggles. However, I do know that horsepower is completely independant of gearing, 1hp is 1hp regardless of what gearing is put behind it. As long as the correction factors are properly implemented, the gearing of the car shouldn't matter.

 

As far as the tire example goes, you have to keep in mind that bigger, heavier tires are going to require more power to turn. Even tread pattern can have an affect, more agressive tires typically have more rolling resistance. Granted, it should have affected it as much as you say it did, but it would still be a noticeable difference.

Edited March 26, 2010 by atvman

[Mark B. Morrow]

Some comments from the Camaro board:

 

 

I like the fourth one about the mags putting "Too much pressure on the Camaro". Like it has performance anxiety? Does it need automotive Viagra? The only pressure on the Camaro is not to have a crap interior and a Fat Ass.

[jpd80]

OK, I get it now thanks guys for clearing that up..

 

So torque and horsepower at the drive wheels in is what's really driving the car

and in regards to this test, the differential and gearbox are points where losses occur.

 

As was suggested elsewhere, it would have been nice to compare the

output of a 2010 and a 2011 GT Mustang on the same dyno and same day....

 

"The Dynojet itself doesn't care what gear the car's in. Remember, there's a final drive gear reduction after the transmission, which further alters the wheelspeed - engine speed relationship beyond what the transmission does, so there's nothing magical about 1:1."

 

 

I'm just a little curious how the power/torque read outs are derived,

from years back all readings used to be in lb ft as multiplied by gearing,

so how do modern dynos convert those raw data torque numbers into

figures that discount the torque multiplication?

Edited March 26, 2010 by jpd80

[Fgts]

I'll get blasted for it but it's a dream...

 

I think Ford should do final editions of the C/V (as a Galaxie 500) and Grand M (as a Maurader) with unique front/rear clips and police running gear with the 5.0 .

 

I hope this motor winds up in another U.S. car other then a Mustang

Edited March 27, 2010 by Fgts

[blksn8k2]

MT is weighing in with their numbers for both the GT and V-6. They are a little lower than Edmunds but still higher than Ford's "official" numbers. They are also teasing about track results...

 

http://wot.motortrend.com/6659607/auto-news/mustang-power-we-dyno-the-2011-ford-mustang-50-v-8-and-37-v-6/page2.html#comments

[jpd80]

MT is weighing in with their numbers for both the GT and V-6. They are a little lower than Edmunds but still higher than Ford's "official" numbers. They are also teasing about track results...

 

http://wot.motortren...2.html#comments

 

Hmm, MT starts teasing about Mustang results, you know it's good...

[atvman]

MT said the cars put down "outrageous numbers" at the test track. Sounds good to me.

[jpd80]

MT said the cars put down "outrageous numbers" at the test track. Sounds good to me.

Yes.....high praise from a "GM friendly" site, maybe the Camaro(s) got a hiding....

 

If so, I'd expect GM will be back with a 9 liter twin blower watchamcallit LS666

Edited March 27, 2010 by jpd80