Parity Review Has Been Called

[GTRMagic]

Mr Walkinshaw, in his latest podcast with V8Sleuth, seems to think the aero on the Mustang is ok, but the engine needs work..

WP (as opposed to WAU) has a perfectly serviceable engine shop, with a long history of supplying multiple teams and cars, and providing powerplants to a very high level of tune.. if only they had access to tender for that piece of work..

[bluesport]

Originally Posted by GTRMagic

Mr Walkinshaw, in his latest podcast with V8Sleuth, seems to think the aero on the Mustang is ok, but the engine needs work..

WP (as opposed to WAU) has a perfectly serviceable engine shop, with a long history of supplying multiple teams and cars, and providing powerplants to a very high level of tune.. if only they had access to tender for that piece of work..

The Ford engine itself has been excellent, the problem is most likely torque related due to being of a smaller displacement.

[Tourer]

Originally Posted by bluesport

The Ford engine itself has been excellent, the problem is most likely torque related due to being of a smaller displacement.

Also of 4-valve design, that leads to lower torque down in the rev range, as the 4-valve design needs the airflow of rpm to come into its "sweet spot". Road cars overcome this with variable timing, which the race engines don't have.

Plus of course a much higher centre of gravity with 4 camshafts up high rather than one down low in the block.

Seems like CoG has all been sorted out and I tend to agree with you that it may be torque that is lacking in the small difference between the powerplants, however that is to be expected with a 4 valve design, which possibly has more impact than displacement on any difference.

[bluesport]

Originally Posted by Tourer

Also of 4-valve design, that leads to lower torque down in the rev range, as the 4-valve design needs the airflow of rpm to come into its "sweet spot". Road cars overcome this with variable timing, which the race engines don't have.

Plus of course a much higher centre of gravity with 4 camshafts up high rather than one down low in the block.

Seems like CoG has all been sorted out and I tend to agree with you that it may be torque that is lacking in the small difference between the powerplants, however that is to be expected with a 4 valve design, which possibly has more impact than displacement on any difference.

Agree, it will be interesting to see what transpires over the off-season as the mustangs are travelling quite nicely in Adelaide practice and it would be hard to put a case forward to make them even faster atm.

[V8 Fireworks]

Funny, how Mustang runners seem so much more competent as soon as parity is equal or better.

A lesson for those who were quick to attribute Chevrolet runners with competence and Ford runners with incompetence?

On the other hand, it is not good to have one brand 26 seconds up the road from the other brand, so the US testing will make sure everything is in order.

[bluesport]

Originally Posted by V8 Fireworks

Funny, how Mustang runners seem so much more competent as soon as parity is equal or better.

A lesson for those who were quick to attribute Chevrolet runners with competence and Ford runners with incompetence?

On the other hand, it is not good to have one brand 26 seconds up the road from the other brand, so the US testing will make sure everything is in order.

Haha love your work, It was a shame to to see Giz and Brown go out so early as it would have given a better indication of where the cars are at.

[V8 Fireworks]

Wind tunnel testing of all the Camaro bits and all the Mustang bits:
https://www.supercars.com/videos/634...nd-tunnel-test

Hopefully that will settle this mess for good!

Alarmingly the reference VCAT numbers on the laptop (comparing front and rear coefficients) do show the Camaro rear downforce bias disparity to Mustang that has been complained about -- how that was deemed an acceptable perfectly matched VCAT defies belief.

[bluesport]

Edwards: Gen3 Supercars “very close” in wind tunnel

https://www.speedcafe.com/2023/12/09...n-wind-tunnel/

[Casper]

Originally Posted by bluesport

Edwards: Gen3 Supercars “very close” in wind tunnel

https://www.speedcafe.com/2023/12/09...n-wind-tunnel/

That is a bit awkward so what do they do next to sort it out? The whole thing has become a bit of a circus and they are rapidly running out of easy answers such as this little exercise was.

[bluesport]

Originally Posted by Casper

That is a bit awkward so what do they do next to sort it out? The whole thing has become a bit of a circus and they are rapidly running out of easy answers such as this little exercise was.

I guess the aero is no longer much of a problem after the more recent changes to the mustang, so now it's over to the transient dyno testing results to come through.

[Casper]

Originally Posted by bluesport

I guess the aero is no longer much of a problem after the more recent changes to the mustang, so now it's over to the transient dyno testing results to come through.

When they accept that different motor configurations such as they have can't be matched to give exactly the same result the answer is obvious. How can a smaller capacity motor with OHC 4 valve give the same result as a larger pushrod 2 valve motor? Didn't they learn the last time they tried this same thing and it was an utter failure in every respect?? Are they really that thick??

[V8 Fireworks]

Originally Posted by Casper

That is a bit awkward so what do they do next to sort it out?

How is it awkward?

These were the VCAT numbers from the Supercars video above:

Front height 110mm Rear height 140mm
Camaro Front Cf 0.214 Rear Cf 0.707
Mustang Front 0.224 (+5%) Rear 0.699 (-1%)

Front height 95mm Rear height 140mm
Camaro Front Cf 0.211 Rear Cf 0.676
Mustang Front 0.230 (+9) Rear 0.655 (-3%)

The suggestion was never that they weren't close, the suggestion is that they weren't identical enough for aerodynamic differences to have no influence which was the case. In no world is 1-9% difference the same as 0% difference!

Presumably those are the numbers before a little more front downforce was added to Camaro at Newcastle, which would have still left the Mustang with a 1-3% deficit on the rear (and apparently still more downforce & drag than Camaro on the front given the Mustang was further reduced on the front end later)!

As soon as the updated Mustang package to bring it more into line was introduced at Gold Coast, Mustangs were miraculously more competitive.

While it's good a lesser difference was eventually achieved via CFD and/or trial and error, that doesn't negate that the VCAT process -- and especially permitting the cars to have different aerodynamic performance after the VCAT process -- was unacceptable. It failed to acheive identical aerodynamic performance between the vehicles.

While it is easy to blame DJR for putting too much drag and front-end downforce, I don't believe they were aware of the Camaro numbers before the fact and Perry Kapper is adamant on his interview with Fogarty that DJR did not have free choice of aero parts (Burgess or others in Supercars changed their minds from identical downforce front and rear, as discussed before VCAT, to instead deciding to make the Mustang a qualifying car and the Camaro a race car?)
.
Clearly the VCAT process was not reliable or repeatable enough to get it to 0% difference (or <0.1% difference), whereas the more controlled wind tunnel should allow that to be dialled in precisely.

[bluesport]

Originally Posted by Casper

When they accept that different motor configurations such as they have can't be matched to give exactly the same result the answer is obvious. How can a smaller capacity motor with OHC 4 valve give the same result as a larger pushrod 2 valve motor? Didn't they learn the last time they tried this same thing and it was an utter failure in every respect?? Are they really that thick??

Agree, that would seem to be the case.

[bluesport]

Day 2 aero testing.

https://www.supercars.com/news/next-...tunnel-program

[bluesport]

Supercars completes wind tunnel test

https://www.speedcafe.com/2023/12/11...d-tunnel-test/

[V8 Fireworks]

Originally Posted by bluesport

Supercars completes wind tunnel test

https://www.supercars.com/videos/634...sting-ramps-up
https://www.supercars.com/videos/634...north-carolina

This is what I gathered they have settled on:

Camaro

• Change to radius of front splitter leading edge near the centreline (smoother radius) to improve pitch characteristics [a temporary plasticine part which will then be 3D scanned and made]
• Slight bootlid extension / bootlid lip spoiler (much smaller than the Mustang one)

Mustang

• Gold Coast-spec front bumper fills (they trialled a third version and also a temporary plasticine version at the bottom corners, but seemed to abandoned these)
• Narrower bootlid lip spoiler (seems to be close to camber of the Townsville version, or slightly less cambered, while being narrower width like the original version)
• Reinstatement of maximum rear wing angle to 10 degrees, up from 7 degrees
• Rear wing span seems to remain wider than on Camaro. Unclear if this is still +100mm or reduced to +50mm. Presumably the rear wing height is the same as Newcastle & Gold Coast (so 50mm lower than Camaro, but not 75mm lower like Townsville spec), but this is also unclear.
• Fitment of Gurney flaps on the inside of the rear wing endplates to depower the rear wing and add drag.
• Fitment of Gurney flaps on the rear wing mounts to add drag and downforce.

I.e., lots of fiddling with plasticine bits and aluminium sheet bits to get the differences dialled down to zero!

I didn't see them testing the cars in yaw at any point, which is a little concerning! Did they match the cars in yaw, or only in a straight line?

[billy bleach]

Originally Posted by V8 Fireworks

https://www.supercars.com/videos/634...sting-ramps-up
https://www.supercars.com/videos/634...north-carolina

This is what I gathered they have settled on:

Camaro

• Change to radius of front splitter leading edge near the centreline (smoother radius) to improve pitch characteristics [a temporary plasticine part which will then be 3D scanned and made]
• Slight bootlid extension / bootlid lip spoiler (much smaller than the Mustang one)

Mustang

• Gold Coast-spec front bumper fills (they trialled a third version and also a temporary plasticine version at the bottom corners, but seemed to abandoned these)
• Narrower bootlid lip spoiler (seems to be close to camber of the Townsville version, or slightly less cambered, while being narrower width like the original version)
• Reinstatement of maximum rear wing angle to 10 degrees, up from 7 degrees
• Rear wing span seems to remain wider than on Camaro. Unclear if this is still +100mm or reduced to +50mm. Presumably the rear wing height is the same as Newcastle & Gold Coast (so 50mm lower than Camaro, but not 75mm lower like Townsville spec), but this is also unclear.
• Fitment of Gurney flaps on the inside of the rear wing endplates to depower the rear wing and add drag.
• Fitment of Gurney flaps on the rear wing mounts to add drag and downforce.

I.e., lots of fiddling with plasticine bits and aluminium sheet bits to get the differences dialled down to zero!

I didn't see them testing the cars in yaw at any point, which is a little concerning! Did they match the cars in yaw, or only in a straight line?

Why has the Drag on the Mustang been upped? I thought straightline speed was an issue?

[bluesport]

Originally Posted by billy bleach

Why has the Drag on the Mustang been upped? I thought straightline speed was an issue?

To add downforce I guess.

[bluesport]

More wind-tunnel tests.

https://www.v8sleuth.com.au/supercar...r-wind-tunnel/

[Sandgroper]

Originally Posted by bluesport

More wind-tunnel tests.

https://www.v8sleuth.com.au/supercar...r-wind-tunnel/

But why?
Did they find the balance with the last one?

[bluesport]

Originally Posted by Sandgroper

But why?
Did they find the balance with the last one?

Just checking that windshear isn't a problem I guess.

[GTRMagic]

AA is suggesting this week in both the magazine and the podcast that the transient dyno testing for the Chev and Ford control powerplants has been cancelled for its original dates…

The mob with the blue side seem to be changing hardware again, possibly causing a delay…

Amateur
Hour
Continues

[bluesport]

Originally Posted by GTRMagic

AA is suggesting this week in both the magazine and the podcast that the transient dyno testing for the Chev and Ford control powerplants has been cancelled for its original dates…

The mob with the blue side seem to be changing hardware again, possibly causing a delay…

Amateur
Hour
Continues

What is hardware change that you speak of?

[GTRMagic]

Originally Posted by bluesport

What is hardware change that you speak of?

Definitely sounds ominous…
And not a word from the black & green mob.

[bluesport]

Originally Posted by GTRMagic

Definitely sounds ominous…
And not a word from the black & green mob.

Well isn't a good idea to do the testing after the engine changes?