Mark IV
- Thread starter BBRGT
- Start date
PL510*Jeff
Well-known member
It was great meeting you at Laguna , the car is at another level to any thing I have driven before , looking forward to getting it on track in the new year .
PeteK
GT Owner
Yes, it was a fantastic weekend at the track. I'll post up some pictures from my phone shortly.
I found Tom Hutchinson there, who is the chief designer for Mulitmatic for the MK IV and got him yakking about the technical details for a half hour. It's a very different car from the Mk II. About the only things that are the same are the center tub, windshield, and a few other bits. Mulitmatic and Ford agreed that changing the center tub would be too expensive, so they had to keep that common, but the front subframe, rear subframe, suspension parts, all the body panels, etc. are different. Even the diffuser, which starts at about the middle of the car, whereas the diffuser on the MK II starts about 2/3 of the way back. That moves the center of pressure forward a bit and helps balance the down force front to rear. Consequently, the keel is different in shape and length. As you can see in the pics, the front aero is quite different too.
Speaking of down force, the car generates about 2400 lbs of downforce at about 150MPH. That can be varied by changing the angle of the rear wing, but not by much, because then it upsets that front to rear balance. Although Tom said that they worked to balance the car to work well at a variety of tracks, I'm pretty sure that it gives up top speed at fast tracks due to the induced drag. But it gets time back in corners because it can pull 2G's. That's getting into F1 territory. We discussed lots of other details, such as why the MK IV does not have front fender top vents, and the MK II does, but too much to go into here.
Engine: It's 3.8 liters, essentially a bored and stroked 3.5 block. Heads are worked to use the additional displacement, but it's not a higher RPM engine. Redline is still around 6500, IIRC. Race gas of course. Boost is not particularly high, running in the 1.5 bar range must of the time, maybe a bit more. Race gas of course. I didn't ask him what CR it runs, but I suspect it bumps up the CR a little to generate 800HP on that moderate amount of boost. I didn't ask what the rod ratio was, although I wanted to know that number too.
Brake are carbon-carbon, not carbon ceramic like on the MK II. The rotors have a lot of 3mm holes drilled radially to ventilate them and remove heat. Pads are different too, to match the carbon-carbon rotors. The pads are really thick, about 3/4" by my visual estimate. Those are intended to run a full endurance race. I didn't ask if the rotors are different sizes, but they probably are, since they use different materials.
Wheels and track. The track is about 40mm wider--20mm per side-- than the MK II, thus the bodywork is wider too. The wheels are forged aluminum instead of carbon fiber. I asked Tom why, and he said it's for durability and impact resistance, and the carbon fiber wheels don't weigh much less than good aluminum wheels. We discussed some of the finer points of using unidirectional carbon fiber vs. aluminum in wheels and other structural and suspension parts.
Suspension: It's different from the MK II also. Looking under the cars side by side, I could see the parts are different, but I didn't dwell on that too much.
Bottom line: If you are not already a race-winning driver in an advanced class, you will need a lot of seat time and coaching to begin to approach the limits of this machine.
I found Tom Hutchinson there, who is the chief designer for Mulitmatic for the MK IV and got him yakking about the technical details for a half hour. It's a very different car from the Mk II. About the only things that are the same are the center tub, windshield, and a few other bits. Mulitmatic and Ford agreed that changing the center tub would be too expensive, so they had to keep that common, but the front subframe, rear subframe, suspension parts, all the body panels, etc. are different. Even the diffuser, which starts at about the middle of the car, whereas the diffuser on the MK II starts about 2/3 of the way back. That moves the center of pressure forward a bit and helps balance the down force front to rear. Consequently, the keel is different in shape and length. As you can see in the pics, the front aero is quite different too.
Speaking of down force, the car generates about 2400 lbs of downforce at about 150MPH. That can be varied by changing the angle of the rear wing, but not by much, because then it upsets that front to rear balance. Although Tom said that they worked to balance the car to work well at a variety of tracks, I'm pretty sure that it gives up top speed at fast tracks due to the induced drag. But it gets time back in corners because it can pull 2G's. That's getting into F1 territory. We discussed lots of other details, such as why the MK IV does not have front fender top vents, and the MK II does, but too much to go into here.
Engine: It's 3.8 liters, essentially a bored and stroked 3.5 block. Heads are worked to use the additional displacement, but it's not a higher RPM engine. Redline is still around 6500, IIRC. Race gas of course. Boost is not particularly high, running in the 1.5 bar range must of the time, maybe a bit more. Race gas of course. I didn't ask him what CR it runs, but I suspect it bumps up the CR a little to generate 800HP on that moderate amount of boost. I didn't ask what the rod ratio was, although I wanted to know that number too.
Brake are carbon-carbon, not carbon ceramic like on the MK II. The rotors have a lot of 3mm holes drilled radially to ventilate them and remove heat. Pads are different too, to match the carbon-carbon rotors. The pads are really thick, about 3/4" by my visual estimate. Those are intended to run a full endurance race. I didn't ask if the rotors are different sizes, but they probably are, since they use different materials.
Wheels and track. The track is about 40mm wider--20mm per side-- than the MK II, thus the bodywork is wider too. The wheels are forged aluminum instead of carbon fiber. I asked Tom why, and he said it's for durability and impact resistance, and the carbon fiber wheels don't weigh much less than good aluminum wheels. We discussed some of the finer points of using unidirectional carbon fiber vs. aluminum in wheels and other structural and suspension parts.
Suspension: It's different from the MK II also. Looking under the cars side by side, I could see the parts are different, but I didn't dwell on that too much.
Bottom line: If you are not already a race-winning driver in an advanced class, you will need a lot of seat time and coaching to begin to approach the limits of this machine.
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The pads are 30mm thick and you can run the car on 93 octane if you choose but Multimatic recommends race fuel .
I found the car to be very easy to drive in map 2 , but map 3 is a big step up . The power delivery is totally different from the Mark II and overall the Mark IV does everything better.
Cobrar
GT Owner
Great write-up Pete. Just to add a couple of points of interest: Wheelbase of the Mk4 is 50mm longer, but the overall footprint is the same as Mk2.
Mk4 Suspension is constant variable design - adaptive/active & offers cockpit/driver adjustability vs. Mk2 passive adjustable DSSV vs. selectable DSSV on our ‘standard’ GT’s.
Also, speaking with the DD S. Maxwell, there are three (3) selections for power 500HP, 700HP and 800HP+. He said that he utilized 500HP to warm the tires and felt the 700 setting best suited the duty cycle & Sonoma circuit.
IMO the car is about as close to F1 performance and insanity. I believe it’s going to tease Ford to do what it really needs to do - HyperCar - or - another GT in say, 2027 (60 years from 1967
) - It’s that damn good! Congrats to MultiMatic, Ford and some lucky owners!
Cobrar
GT Owner
Ed - Rebecka let me have a long leash.
I wanted to see the cars at the far end of the circuit (turns 2-6) - how the cars handled elevation changes and the off/on camber sections.
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Close up of the wheel , most of the buttons are self explanatory, , the ASV + and - control the 5 modes of the active spool valve dampers , the centre rotary is used to select the 3 engine maps , auto shift mode , epas steering effort and reset fuel usage .
Once you select the mode you can alter the settings using buttons on the back of the wheel. The traction control and ABS rotary dials have 10 and 12 settings , the EC drive and EC man are used for the Megaline auto clutch , in drive mode you select first gear , engage the wheel mounted clutch level and drive away . In EC man mode you use the clutch lever manually . The system also has an anti stall feature .
You can see on the bottom of the dash the current engine map , ABS and TC mode selected.
The dash displays tire pressures , predictive lap time and current lap , if you select lap on the lower rotary dial you can reset the reference lap used for the predictive feature . The 2 smaller displays are the side mirrors and the right side display also has the shift lights .
PeteK
GT Owner
PeteK
GT Owner
PeteK
GT Owner
Fast Freddy
GPS'D 225 MPH
Stef
GT Owner
Yes , the dash photo of my car was at the Mutimatic factory , they tape over the fire button so it is not accidentally discharged
