NEARLY 2 YEARS WAITING: New Mustang GT PP is finally mine!

[Gibbo]

Splitters also generate downforce my lowering air pressure. Not really sure that's the best location for a duct. Can you move it ?

Sorry to quote again m8, but just to explain my worries and idea.


This is the duct in the splitter, a littler easier to see in this image:

So it is angled correctly to try and scoop the air up and the front is filed down and flush with the botton of splitter. But of course my worry is that it could be actually doing the opposite of sending fresh air upto the intake (pushing air in) and actually sucking air out from the intake having completely the opposite of the wished effect.

Can anyone who knows better about air flow comment or answer that?


So my plan is to build something around that duct in the front splitter to assure the air is being scooped up and pushed towards intake, such as these examples:

Of course a much lower profile on that second picture due to how low my car is. Something I could easily knock up at of a sheet of aluminium and then self tap or rivet around the duct on the underside of the splitter.

Though someone might come along and say there is no chance it is sucking air out from the intake who knows airflow better and as such I can just leave it alone. When I blasted air under the car it was coming into the intake for sure and did not show any signs of sucking, but blasting some air is far from reality of driving on the road.

 

[ianh]

The one on the Mustang will be acting as a ram-air intake, forcing air into the car which, for intakes, is good.

The one on the bottom of the M3 will be acting as a Venturi and, due to the lower pressure across the face of the vent, it will be "attempting" to suck air out of the engine bay but the engine will still be trying to pull air in through the same hole which leads to a turbulent airflow (not great).

The bottom two (the NACA duct and the ali bodge) will be acting as ram-air again, forcing air into the car.

With anything that tries to force air into the car you'll be creating a higher pressure zone, so you'll also need a lower pressure area at the rear of the engine bay to allow that higher pressure to move to, otherwise you create a pressure dam where the pressure becomes static which is poor for temps/performance etc. For any engine intakes the engine itself acts as the low pressure area by sucking the pressure away.

If you look at most modern undertrays (google images) they use the NACA style duct with a lip to act as ram-air feeders to help cool radiators & various coolers etc as it's the most efficient form of duct around at the moment.

 

[Gibbo]

The one on the Mustang will be acting as a ram-air intake, forcing air into the car which, for intakes, is good.

The one on the bottom of the M3 will be acting as a Venturi and, due to the lower pressure across the face of the vent, it will be "attempting" to suck air out of the engine bay but the engine will still be trying to pull air in through the same hole which leads to a turbulent airflow (not great).

The bottom two (the NACA duct and the ali bodge) will be acting as ram-air again, forcing air into the car.

With anything that tries to force air into the car you'll be creating a higher pressure zone, so you'll also need a lower pressure area at the rear of the engine bay to allow that higher pressure to move to, otherwise you create a pressure dam where the pressure becomes static which is poor for temps/performance etc. For any engine intakes the engine itself acts as the low pressure area by sucking the pressure away.

If you look at most modern undertrays (google images) they use the NACA style duct with a lip to act as ram-air feeders to help cool radiators & various coolers etc as it's the most efficient form of duct around at the moment.

Yeah I did spot naca ducts, now found one ideal after I've actually gone and done this, as always perfect.

So how about a solution such as build the ali duct as picture obviously lower profile, and then have a couple of holes for some of the airflow to pass through, would that give a more desired result Ian?

 

[ianh]

The Ali duct wouldn't be pretty or as effective as a NACA duct but it would work as the airflow would no longer be passing across the existing brake duct and, instead, the ali duct would now act as a ram-air duct but adding a lot of untested drag and disrupted airflow underneath at higher speeds, plus with the added potential of detaching.

Ideally I'd swap the current plastic splitter duct for a NACA one which would connect to your existing pipework as they are designed as a ram-air rather than trying to convert what is currently a "sucker" into a "blower" with Ali

However if you stick with Ali then I'd put a few holes on the side wall of the Ali near the opening on the right of the pic, near the "entrance" but none on the left where it meets the plastic duct. You want the air forced into the intake but, when at low throttle but high speed, the air pressure will start to build at the wide open entrance as the engine isn't sucking enough away so the holes will allow any static pressure to bleed off and have less risk of ripping the Ali duct off.

***EDIT*** - As daft as it sounds, it's best to think of Airflow as being the same as water. In you existing setup the water will go past the duct because there's nothing to divert it upwards into the pipework and you're engine intake is trying to suck at the water as it goes past. The Ali duct would do the job of diverting the water but it would mess up the flow behind it, where you want it to be smooth (smooth = fast, fast = low pressure, low pressure underneath = higher pressure on the top pushing down = more down force). A NACA duct does exactly the same thing but is better at it.

 

[Gibbo]

The Ali duct wouldn't be pretty or as effective as a NACA duct but it would work as the airflow would no longer be passing across the existing brake duct and, instead, the ali duct would now act as a ram-air duct but adding a lot of untested drag and disrupted airflow underneath at higher speeds, plus with the added potential of detaching.

Ideally I'd swap the current plastic splitter duct for a NACA one which would connect to your existing pipework as they are designed as a ram-air rather than trying to convert what is currently a "sucker" into a "blower" with Ali

However if you stick with Ali then I'd put a few holes on the side wall of the Ali near the opening on the right of the pic, near the "entrance" but none on the left where it meets the plastic duct. You want the air forced into the intake but, when at low throttle but high speed, the air pressure will start to build at the wide open entrance as the engine isn't sucking enough away so the holes will allow any static pressure to bleed off and have less risk of ripping the Ali duct off.

The few holes should I be putting this on both sides or just the side closest to vehicles edge?

Also thanks for your help. Removing the front splitter is quite a big job just to how its bolted on so a low profile aluminium scoop I think will suffice and I shall do as you advice.

 

[ianh]

Both sides, you want to get rid of as much static pressure as possible when the engine is at low revs/power demand.

As daft as it sounds, it's best to think of Airflow as being the same as water. In your existing setup the water will go past the duct because there's nothing to divert it upwards into the pipework and you're engine intake is trying to suck at the water as it goes past. The Ali duct would do the job of diverting the water but a big one would mess up the flow behind it, where you want it to be smooth (smooth = fast, fast = low pressure, low pressure underneath = higher pressure on the top pushing down = more down force). A NACA duct does exactly the same thing but is much better at it but obviously costs more too.

 

[Gibbo]

Both sides, you want to get rid of as much static pressure as possible when the engine is at low revs/power demand.

As daft as it sounds, it's best to think of Airflow as being the same as water. In your existing setup the water will go past the duct because there's nothing to divert it upwards into the pipework and you're engine intake is trying to suck at the water as it goes past. The Ali duct would do the job of diverting the water but a big one would mess up the flow behind it, where you want it to be smooth (smooth = fast, fast = low pressure, low pressure underneath = higher pressure on the top pushing down = more down force). A NACA duct does exactly the same thing but is much better at it but obviously costs more too.

Yeah I did think of it as water, though only difference is air is weightless in comparison to water, though maybe not scientifically, but like I admit I am no airflow expert or engineer, as the request for advice.

The scoop shall be very low profile, it has to be otherwise it is simply going to catch on the ground and be ripped or crushed.

The opening at the front will be no more than 10-15mm, will get a sheet of aluminium to play with from somewhere like Wickes as they cost less than £10, so I can have a few attempts to get the shape and size I need right.

 

[Gibbo]

HI there


Well today was more about removing a part to fix well a design floor with that part and replacing the part with a far better engineered unit.


As such I present you the Steeda G-Trac brace that has a floor in the design:

The brace itself does the job as advertised and well, but the design floor is the fact it reduces ground clearance by 1" on the car, which on lowered cars particular ones on Steeda Ultralite or Eibach Sportline can be an issue. For me I was scraping on taller speed bumps and even worse the car was stopped dead entering a business park that had metal runner sticking out the ground, thankfully I was going under 5mph so more a scare than any real damage.

In the below image you can see the reduced ground clearance and where the part has being catching:

You can even see how its bent/enlarged the opening in the subframe.
The reason I went with Steeda G-Trac brace is because at the time it was the only brace on the market.












Now I present you BMR's CB006:

The quality of this kit is in a completely different league to the Steeda, the thought and engineering that has gone into this part is above and beyond. Kelly at BMR should be over the moon with what they have achieved. Even the bolts, washers and spacers are a lot more beefier and chunky, the only downside is it is a little heavier. But the quality and finish are vastly superior.

Some pictures of BMR CB006 on the car:

In the above photo you can see the BMR has no clearance issues at all because it does not bolt into the subframe, it in fact connects to the front lower control arm bolts, so not only do you get more clearance and a better quality unit it is also more functional.

When we originally fitted the Steeda it was relatively easy but a little fiddly as things did not line up perfectly, whereas the BMR unit was like a factory piece, everything lined up. Infact it was so easy we had removed the Steeda and fitted the BMR in less than one hour.


I cannot tell you if car feels different, it has not being driven far, what I can tell you is I have piece of mind now regarding speed bumps and clearance issues and can rest that my subframe won't take any further damage.

The Steeda unit is good, but I would not recommend it on cars lowered more than 1" due to clearance issues, this part is now for sale to a good home.


So thanks to Kelly at [MENTION=9986]BMR Suspension[/MENTION]


P.S. The only issue potentially now could be with headers, when I go LT's if this conflicts with them I shall have to remove it and get CB007.

 

[Gibbo]

Hi there


Car and Driver did a recent lap battle on one of the most demanding circuits Virginia International Raceway in US (a lot of turns ) in the same day, same driver:

Results:
Tesla S P85D: 3:17.4
Audi TTS: 3:07.7
Mazda MX5 Cup car: 3:06.4
Lexus GS-F: 3:05.9
Camaro V6 1LE: 3:04.0
Focus RS: 3:03.9
Charger Hellcat (707HP): 3:03.5
F-Type SVR: 3:02.2
BMW M2: 3:01.9
R8 V10 Plus: 2:56.1
Camaro V8 SS 1LE: 2:54.8
Porsche Cayman GT4: 2:54.0
BMW M4 GTS: 2:52.9
Mustang GT 350R: 2:51.8
Honda NSX: 2:50.2
Mclaren 570S: 2:47.4
Corvette Grand Sport: 2:47.1
Porsche GT3 RS: 2:47.0
Ferrari 488 GTB: 2:45.1
Viper ACR: 2:44.2
Lexus RC-F GT Concept: 2:43.2


Obviously an incredible result for Ford's Mustang GT 350R considering it cost half to one third of the cars around it and is still a perfectly easy car to live with on a daily basis.

But the most impressive fast stuff has to be the GT3 RS and 488 GTB, because again they can be driven daily and have mod cons. I cannot count the Viper ACR as you could never live with one on a daily basis with it being essentially a race car with a road license and the Lexus is concept.

Also the Honda NSX, very impressive performance.

 

[ianh]

Gibbo - its "flaw" not "floor"

That new cross-brace does look like it's had much more engineering thought gone in at the design stage over the first one.

 

[P.B]

lovely car gibbo quite growing a soft spot for the new mustang.

 

[timmeh]

I'd say the Corvette is the most impressive on that list. It's starting price is only $3k more than the Mustang and it's 0.1s off a GT3 RS

 

[Diddums]

I can't believe that the GT350 is faster than the M4 GTS


I thought that was meant to be BMW's pinnacle in the twisties, yet it's been pwnt by a yank tank. I'm impressed!

 

[Dis86]

More great updates Gibbo - nice one.

 

[Gibbo]

I can't believe that the GT350 is faster than the M4 GTS


I thought that was meant to be BMW's pinnacle in the twisties, yet it's been pwnt by a yank tank. I'm impressed!

Would be ace if the 350's, Camaro's and Vettes came to the UK, they absolutely wipe the floor when it comes to performance and handling compared to their European rivals at similar price points.

How heavy is an M4 GTS? I'd suspect an M4 and a Mustang are pretty similar in weight, a GT 350R is like 1650kg, guessing M4 is around 1600kg.

What makes it more impressive for the Mustang and Corvette times, they are manuals, no fancy PDK/DCT to help them lap faster.

 

[Clarkey]

Come on now, GT350r runs on 305/315 section tyres versus the 265/285 on the GTS. No wonder the car laps faster.

 

[Gibbo]

.

 

[Jonnycoupe]

I can't believe that the GT350 is faster than the M4 GTS


I thought that was meant to be BMW's pinnacle in the twisties, yet it's been pwnt by a yank tank. I'm impressed!

It might have corners but it's still a race track! Flat smooth, nothing like a B road here for example. Can't cherry pick all the attribute for all road types.

 

[ianh]

Taking your advice onboard which other people who I know also said this is spot on and I've made the following changes/additions:

{PICS}

No clearance issues so far and it will certainly prevent air from being sucked out the air box now and in theory will ram more air into the air box. Thank you for your help buddy.

No problem. Looks bodge-tastic but one thing I'd consider changing in the future is replacing the current self tappers with bolt/nut instead with a large washer on each side, just to help spread any load at high speeds (100+ )

 

[Dis86]

Might be worth adding a quick bit of some sort of sealant around the back - looks to have warped slightly where you've fastened it.