GT350 on the dyno!!!

tt335ci03cobra

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I don't like comparing a low number factory sc car's dyno to a mid number factory na car, especially when they have different transmissions, are more than 5 years apart(drivetrain technology has steadily improved, gotten lighter, robs less power to spin, etc).

That gt500 could have been heat sunk, still on the break in settings (like no boost), or other issues. The temps for the gt350 test were 100*, the 2010 gt500's weren't mentioned so I assume it's unknown.

In the real world, rhe gt350 won't feel soft even down low. The tr6060 has a tall spread with a 1:1 4th, and is decidedly more robust, but also mechanically heavier than a tr3160 (iirc that's the voodoos trans, probably have the name wrong.) all things told, you can't compare how real world torque or power will feel in a gt350 because of a low mustang dyno number from that 2010 gt500. I'd bet easy money that that particular gt500 could never trap as high as this gt350 in question, or run the same 1/4 mile. Weight difference is 200lbs, which is notable, but not a huge difference. The mechanical torque of the gt500 is effectively reduced a lot vs the gt350's which was intentionally geared shorter, and because of effective gearing, and general leverage, it will feel great. Think boss 302, not Mazda rx8. In short, the gt350 won't feel soft, less of being in 6th gear at 70 maybe, if even then. It's 6th is a .70, gt500's had .50's iirc.

The 350's trans has a much shorter gear spacing than the gt500's tr6060.

1:1 5th in the gt350 with very close spacing and iirc a 3.23 1st. 3.73 rear and 28" tires.

1:1 4th in the 2010 gt500 (and all really) with a 2.66 1st. 3.55 (iirc) rear and 28" tires. The 3.31 came later in the 2013's I believe.

Let's say the gt500 makes 500tq at 2000rpm and the gt350r makes 300tq there for easy math.

The effective gearing from those aforementioned numbers puts them within 15% of each other in real world calculations. There difference on paper is 66% net or 40% gross.

The voodoo will be plenty fun on the street, and will be much less prone to spinning on street tires.

Think of it like this. You can have 2000wtq, but if te wheel is 20ft tall (dump trucks), or the final drive ratio is a 2.75 and the transmission has a 2.5 1st then it's really nothing special.

Real world example, when I stepped down from 3.55's and a 26" tire to 3.08's and a 28" tire, my 920wtq (older 5.4 turbo combo) suddenly was more streetable and didn't blow the tires off at 70 anymore even in 2nd. Trap speed dropped but 1st wasn't a total spin fest (did have boost by gear as well).

When people talk about torque, they often don't realize that the entire system from transmission to drivetrain and wheels/tires themselves make a huge difference on effective torque.

Pick up some decidedly lighter rims for exams and you'll gain a small amount of power. It's not ricer math, its legitimacy physics. Same goes with lighter, stronger clutches and driveshafts. The engine is still producing the exact same hp, but less of it is lost to parasitic rotational costs.

This is in large part why ff cars routinely lose less hp to the ground than rwd, and especially awd.

Sincerely, Bill from D street.
 
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westwest888

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I'm willing to accept that we may just have to agree to disagree. My personal problem for example was a local mustang dyno (a heart breaker) that a stock mazdaspeed3 dynod 214 whp on. The speed makes 265 at the crank, that's 20% drivetrain loss from a FWD car? No way. Car put down 240 on a dynojet, which may be a little lofty at 10%, sure, but its a hell of a lot more believable. I'm willing to meet you in the middle though, that it really just does come down to each shop how accurate their dyno is. I know at the end of the day its just supposed to be a tool for measuring gains, but i feel there should at least be a general ballpark thats acceptable.

Hah ok then we've gotten to the root of the problem. You don't like the results of the test under the conditions it was performed. This is the real world and drivetrain loss isn't the only loss. Carbon buildup in the engine. Environmentally friendly fuel blends without MTBE and with 10% ethanol. Old spark plugs. Dirty air filters. Humidity, barometric pressure and air density. It's a $23,000 car new so it's not going to have the repeatability in performance of a $200,000 991 Turbo S.

Here's a dyno chart for an identical Boxster 2.7L PDK to the one I have. It makes 213 HP (within 1 HP of your Mazda rated the same at 265 factory). Surely Porsche can do a better job with drivetrain losses on the 7 speed PDK lifted from their 991 3.4L, right? It's a mid engine car with the tranny out back connected directly to the rear wheels, kind of like a FWD moved to the back.

dynosheet_wheels_awe_981_cayman_exhaust.jpg
 
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F8L SN8K

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A non brake dyno jet has a wheel of a given mass and size. The software takes a reading of the rate of acceleration of this drum and spits out the number based upon the physics of the ability to do work. Using mathematical formulas to calculate the HP. This is why torque and HP always cross at 5252rpm. The brake dynos(some dyno jets and all MDs) can have inputs added to change these calculations by trying to accommodate for rolling resistance, coefficient of drag, weight and a host of other things. It applies the break to "simulate" what a car would experience on the road. The more parameters the end user can input the more the data can be skewed. This is why most dyno jets are considered the industry standard when looking at chassis dynomoeters.

Now a lighter more efficient drivetrain will have less Powertrain loss. Even running different gear ratios and friction of the tires can affect dyno results. But don't forget the weight is only one factor as where the weight is located for the calculated polar moment of inertia can be VASTLY different on 2 objects that have the same mass.

In all 12% drivetrain loss is standard affair on today's modern drivetrains for manual transmissions. Car dyno'd exactly where it should have given the Flywheel rating. Get the car to the strip for a true HP reading/calculation and it should be in the 119mph range at 4030 race weight. Isn't math fun?!?
 

AustinSN

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The final straw for the 7.3 guys on a mustang dyno was when a drop in turbo dually made 490rwhp.

Definitely a 300hp truck.
 

DSG2003SVT

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I meant the GT350 wasn't dynoed the same day, just that it was the same dyno. The BMWs were dynoed the same day in the link I posted.
 

AustinSN

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Those numbers put it no where near the actual 1/4 or trap for those cars, including manuals.

Are those uncorrected numbers?
 

DSG2003SVT

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Those numbers put it no where near the actual 1/4 or trap for those cars, including manuals.

Are those uncorrected numbers?

In the link I posted, the F80 made 379hp. If you figure the GT350 shows about 12% drivetrain loss, then it should make about 89whp more. It made 88 more, so I'd say the numbers are pretty dead on.
 
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westwest888

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The tuning industry has a bias for starting with a larger number, because it shows a larger absolute gain that they can advertise (+20 HP, +100 HP, etc.) This is a red pill vs blue pill problem. Do you want to get to the bottom of the reasons why your car is not making ideal horsepower, or do you want to assume every fleet vehicle is performing at 100% spec even though there is tremendous variance in the real world. Dynojet makes it seem like every car is perfect, maybe even doing better than expected!

Meanwhile the MD guys go back to the drawing board, retrace their steps, double check that intake, etc.
 
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AustinSN

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In the link I posted, the F80 made 379hp. If you figure the GT350 shows about 12% drivetrain loss, then it should make about 89whp more. It made 88 more, so I'd say the numbers are pretty dead on.

I was talking about West's post.
 

jtfx6552

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I went 11.7x @ 123 repeatedly in my 03 with DJ 441 SAE, on F1s.

This car is what, 200-300 # heavier? With another 25-26 hp? Should run similar. Not bad for its "not intended" purpose.
 

ScreaminRedZ

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Mustang Dynos are great pieces of equipment in the right hands. The problem is that it's also the go to dyno for shady shops and people who have no idea what they are doing, so you get numbers all over the place. Way too easy to fudge or just screw up the numbers.
 
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AustinSN

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I went 11.7x @ 123 repeatedly in my 03 with DJ 441 SAE, on F1s.

This car is what, 200-300 # heavier? With another 25-26 hp? Should run similar. Not bad for its "not intended" purpose.

These cars have a drag setting for the suspension too. I'd imagine the R could throw down some pretty decent 60's with the right driver.
 

Snorman

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I went 11.7x @ 123 repeatedly in my 03 with DJ 441 SAE, on F1s.

This car is what, 200-300 # heavier? With another 25-26 hp? Should run similar. Not bad for its "not intended" purpose.
If your Cobra was close to stock weight, they are 3665#, so the same as an R, ~50# lighter than an R with the Electronics Pack and ~120# less than a GT350 with TP. Unless you took quite a bit of weight out of your '03.
S.
 

jtfx6552

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If your Cobra was close to stock weight, they are 3665#, so the same as an R, ~50# lighter than an R with the Electronics Pack and ~120# less than a GT350 with TP. Unless you took quite a bit of weight out of your '03.
S.

I was stock weight. I guess it will come down to the clutch, if it's stout, a good ET might be possible, because it's going to need the shit slipped out of it to get a good launch, lol.
 

DSG2003SVT

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Launch control and drag mode will probably help a lot with that. LC helped a lot on the Boss.
 

Snorman

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LC only allowed the ECU to be less aggressive with any clutch slip in LC on the '13/'14 GT500's. Hopefully Ford's calibration for the Electronic Powertrain Feature (i.e. clutch protection) won't be nearly as aggressive with the GT350 as it was with the GT500.
S.
 

jtfx6552

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LC only allowed the ECU to be less aggressive with any clutch slip in LC on the '13/'14 GT500's. Hopefully Ford's calibration for the Electronic Powertrain Feature (i.e. clutch protection) won't be nearly as aggressive with the GT350 as it was with the GT500.
S.

Just came here to type this!


In my ideal world, all the crap TC can be turned off, the car engine calibration stays constant, and the driver can control the throttle and the clutch.
 

black92

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LC only allowed the ECU to be less aggressive with any clutch slip in LC on the '13/'14 GT500's. Hopefully Ford's calibration for the Electronic Powertrain Feature (i.e. clutch protection) won't be nearly as aggressive with the GT350 as it was with the GT500.
S.

I posted these links in another thread and both appear to move out decent from a dig. R a little better because of the better tires obviously.

GT350: https://instagram.com/p/8L0ND9Ix67/
GT350R: https://instagram.com/p/8MRr8gox85/
 

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