Question about rev limiter

[NoVaGT]

Yeah man, the 17’s rev limit is 6,500 so going that far into the red zone worries me, after reading what everyone has to say I’m just going to reset the rev limiter back to 6,500 and be more careful, I really want this car to last a lifetime.

Are you sure? I thought 17s went to 7K or so.

Sponsored

 

[luc]

If so, 8200 rpm is still about 11% higher than that. Meaning that the accelerations and resulting inertial forces involved would be about 21% higher. That's way too much to just hand-wave away on the basis of 7400 being "safe".

And that doesn't really address the matter of fatigue.


Norm

Are you sure? I thought 17s went to 7K or so.

i believe that on my 17, before adding the Ford pack 2, the limit was 6800

 

[Bikeman315]

Are you sure? I thought 17s went to 7K or so.

This is from Steeda's site.

Mustang Gen II Coyote 5.0L Specs
Measurement Technical Specification
Configuration Aluminum block and head
Intake Manifold Composite shell-welded with runner pack and charge motion control valves
Exhaust Manifold Stainless Steel Tubular Headers
Valvetrain DOHC (Dual Overhead Cam), 4V Ti-VCT (Twin Independent Variable Camshaft Timing)
Valve Diameter/Lift Intake 37.3 mm/13 mm, Exhaust 31.8 mm/13 mm
Pistons Cast aluminum
Connecting Rods Forged steel
Ignition Distributor-less coil on plug design
Bore X Stroke 3.63X 3.65 in./92.2 X 92.7mm
Displacement 302 Cubic Inches/5.0L
Compression Ratio 11.0:1
Engine Control Sytem PCM
Horsepower 435 @ 6,500 RPM
Torque 400 LB/FT of Torque
Recommended Fuel 87 Octane
Fuel Delivery Sequential Multiport Fuel Injection
Oil Capacity Six Quarts 5W-30 w/Oil Filter 10K Mile Intervals
Redline 7,250 RPM

Mustang Gen III Coyote Engine Specs
Measurement Technical Specification
Configuration Cast aluminum block and head with plasma transferred wire arc cylinder liners
Intake Manifold Composite shell with scroll design and charge motion control valves
Exhaust Manifold Tubular stainless steel headers
Valvetrain DOHC, four valves per cylinder, twin independent variable camshaft timing
Valve Diameter/Lift Intake 31mm/8.31mm, Exhaust 30mm/7.42mm
Pistons Cast aluminum
Connecting Rods Forged aluminum
Ignition Distributor-less with coil on plug design
Bore X Stroke 3.63 in. x 3.65 in. (93.0 mm x 92.7 mm)
Displacement 302 Cubic Inches/5.0L
Compression Ratio 12.0:1
Engine Control Sytem PCM
Horsepower 460 @ 7,500 rpm
Torque 420 LB/FT of Torque
Recommended Fuel 93 Octane
Fuel Delivery Dual-fuel, high-pressure direct injection and low-pressure port fuel injection
Oil Capacity 10 quarts 5W-20 with filter (10,000-mile service interval)
Redline 8,000 RPM

 

[Torinate]

Well. Oil capacity for the Gen 2 on Steeda’s stats is incorrect.

 

[NoVaGT]

This is from Steeda's site.

Mustang Gen II Coyote 5.0L Specs
Measurement Technical Specification
Configuration Aluminum block and head
Intake Manifold Composite shell-welded with runner pack and charge motion control valves
Exhaust Manifold Stainless Steel Tubular Headers
Valvetrain DOHC (Dual Overhead Cam), 4V Ti-VCT (Twin Independent Variable Camshaft Timing)
Valve Diameter/Lift Intake 37.3 mm/13 mm, Exhaust 31.8 mm/13 mm
Pistons Cast aluminum
Connecting Rods Forged steel
Ignition Distributor-less coil on plug design
Bore X Stroke 3.63X 3.65 in./92.2 X 92.7mm
Displacement 302 Cubic Inches/5.0L
Compression Ratio 11.0:1
Engine Control Sytem PCM
Horsepower 435 @ 6,500 RPM
Torque 400 LB/FT of Torque
Recommended Fuel 87 Octane
Fuel Delivery Sequential Multiport Fuel Injection
Oil Capacity Six Quarts 5W-30 w/Oil Filter 10K Mile Intervals
Redline 7,250 RPM

Mustang Gen III Coyote Engine Specs
Measurement Technical Specification
Configuration Cast aluminum block and head with plasma transferred wire arc cylinder liners
Intake Manifold Composite shell with scroll design and charge motion control valves
Exhaust Manifold Tubular stainless steel headers
Valvetrain DOHC, four valves per cylinder, twin independent variable camshaft timing
Valve Diameter/Lift Intake 31mm/8.31mm, Exhaust 30mm/7.42mm
Pistons Cast aluminum
Connecting Rods Forged aluminum
Ignition Distributor-less with coil on plug design
Bore X Stroke 3.63 in. x 3.65 in. (93.0 mm x 92.7 mm)
Displacement 302 Cubic Inches/5.0L
Compression Ratio 12.0:1
Engine Control Sytem PCM
Horsepower 460 @ 7,500 rpm
Torque 420 LB/FT of Torque
Recommended Fuel 93 Octane
Fuel Delivery Dual-fuel, high-pressure direct injection and low-pressure port fuel injection
Oil Capacity 10 quarts 5W-20 with filter (10,000-mile service interval)
Redline 8,000 RPM

Well, that's wrong.

My 2019 redlines at 7,500RPM, not 8,000RPM.

 

[DonnieO]

Steeda is wrong. Stock 17 motor is 6800. My power pack 2 raised it to 7200.

Well. Oil capacity for the Gen 2 on Steeda’s stats is incorrect.

Yup. Its 8 quarts

 

[racingandfishing]

Steeda is wrong. Stock 17 motor is 6800. My power pack 2 raised it to 7200.




Yup. Its 8 quarts

Same. My would hit the rev limiter at 6800 under hard acceleration before power pack 2 and now 7200. Redline has been reported to be 7000 at times, but maybe the rev limiter kicks in at 6800 to keep it from going over 7000.

 

[Bikeman315]

Well. Oil capacity for the Gen 2 on Steeda’s stats is incorrect.

Well they either got it wrong or it is a typo. Yes, of course, it's 8 quarts.

My 2019 redlines at 7,500RPM, not 8,000RPM.

Steeda is wrong. Stock 17 motor is 6800. My power pack 2 raised it to 7200.

Well this is from Lethal.

GEN 1 5.0 COYOTE SPECS (2011-2014 MUSTANG GT)
The first generation of the 5.0 Coyote was in every 2011-2014 Mustang GT — and it was an absolute revelation to Mustang enthusiasts. The latter two model years also got a nice little bump in horsepower, along with some powertrain calibrations to boost overall power. These early engines utilized a port fuel injection system.
• Horsepower: 412 hp in 2011-2012 / 420 hp in 2013-2014
• Redline: 7000 RPM
• Torque: 390 lb-ft

GEN 2 5.0 COYOTE SPECS (2015-2017 MUSTANG GT)
For the 2015-2017 Mustang GT models, we saw some solid upgrades in power. While it wasn't a drastic change, it was clear that Ford knew they had a winner, giving it larger intake and exhaust valves, updated intake and exhaust camshaft and plenty of tweaks to allow for higher RPMs.
• Horsepower: 435 hp
• Redline: 7000 RPM
• Torque: 400 lb-ft

GEN 3 5.0 COYOTE SPECS (2018-2020 MUSTANG GT AND BEYOND)
The third generation 5.0 coyote engine has been a true revision, offering tons of power upgrades, bigger intake and exhaust valves, an added high-pressure direct injection system and more. It also has a larger total displacement than previous versions. We first saw this on the 2018-2019 Mustang GT models, but it's on the now-current 2020 Mustang GT, as well. As for the future, we'll just have to wait and see.
• Horsepower: 460 hp
• Redline: 7500 RPM
• Torque: 420 lb-ft

At the end of the day, let's just all agree they over-revving your engine on a regular basis will not be good for it.

 

[luc]

That just prove that you just can’t believe everything that you read on the internet...
Seriously, who are you going to believe?
You have 3 owners of 17 GT telling you that factory rev limiter is 6800....

 

[BkaayRandy]

Same. My would hit the rev limiter at 6800 under hard acceleration before power pack 2 and now 7200. Redline has been reported to be 7000 at times, but maybe the rev limiter kicks in at 6800 to keep it from going over 7000.

Yeah hard acceleration on stock factory tune does allow it to go a little over 6,500 but I know for sure mine never hit 7000, I guess I meant to say redline starts at 6,500 but rev limiter is a little higher, 6800 sounds about right.

 

[RoyalCrimsonGT]

valve float can happen when the valve springs cannot keep up with high rpm's and will cause the valve to make contact with the piston and if you're lucky you'll just have a bent valve stem and/or rod and lose compression. worst case scenario if your valve breaks off then a catastrophic chain reaction of damage occurs from broken head, piston, cylinder walls, crankshaft, ect basically grenading your engine.

 

[WildHorse]

Yeah hard acceleration on stock factory tune does allow it to go a little over 6,500 but I know for sure mine never hit 7000

My stock tune went to 7000. My performance tune goes to 7300. That's when the gen 2 cams fall off the curve powerwise. So why the need to rev it to 8k? Cause the GT350 intake? Neutral revs? Laughable. Gen2 cams and intake are a killer setup. If I go stage 3 comp cams, then yeah, I'll goto a GT350 intake. Otherwise I'll be faster with the stock intake & cams.

 

[ORRadtech]

valve float can happen when the valve springs cannot keep up with high rpm's and will cause the valve to make contact with the piston and if you're lucky you'll just have a bent valve stem and/or rod and lose compression. worst case scenario if your valve breaks off then a catastrophic chain reaction of damage occurs from broken head, piston, cylinder walls, crankshaft, ect basically grenading your engine.

That's no joke. I've dropped a valve before, turned that long block into scrap iron...

 

[Norm Peterson]

valve float can happen when the valve springs cannot keep up with high rpm's and will cause the valve to make contact with the piston and if you're lucky you'll just have a bent valve stem and/or rod and lose compression. worst case scenario if your valve breaks off then a catastrophic chain reaction of damage occurs from broken head, piston, cylinder walls, crankshaft, ect basically grenading your engine.

Yup.

The exhaust valve that used to live in that cylinder was reduced to a bent stick, and was probably the cause of the missing bits of cylinder head around the valve stem that is shown there. The red oval shows where what used to be metal, suddenly became an unwanted branch to a coolant passage.

The next time he-who-shall-remain-nameless got to borrow the same car again, with its new and further improved engine, he wasn't informed about any hard rev limit or that it had been temporarily reset to 4700 rpm . . .

Norm

 

[DivineStrike]

I’m setting mine to 8k for now so I don’t bounce off the limiter until I do OPGs. Would do 8200 but SCT doesn’t give that option. Suppose I could ask my tuner to do that but I won’t get anywhere near that really unless I decide to go to a drag strip

Sponsored