F250 does 160mph..
Lead Foot User
Joined: Nov 2008
Posts: 773
Likes: 0
From: Saskatchewan, Canada
Yup, got one right here.
Not to sound arrogant, but that is NOT possible with stock gearing and anything anywhere close to stock tires. You could do it with nothing short of 41" tires IF the power was there at 3,500 RPMs.
With 3.73 gearing and assuming 3500 RPMs as the max, with stock tires your truck will NOT go over 122 MPH. Speedometers can be off at that speed, which would explain why you thought you were going faster.
With a different cam and some very expensive engine parts you may be able to spin the engine past 4,000 RPMs, but I highly doubt you could develop any power at that RPM in stock form, tuned or not.
Play with this site and plug in some numbers. It's simple math, and numbers don't lie!
Not to sound arrogant, but that is NOT possible with stock gearing and anything anywhere close to stock tires. You could do it with nothing short of 41" tires IF the power was there at 3,500 RPMs.
With 3.73 gearing and assuming 3500 RPMs as the max, with stock tires your truck will NOT go over 122 MPH. Speedometers can be off at that speed, which would explain why you thought you were going faster.
With a different cam and some very expensive engine parts you may be able to spin the engine past 4,000 RPMs, but I highly doubt you could develop any power at that RPM in stock form, tuned or not.
Play with this site and plug in some numbers. It's simple math, and numbers don't lie!
Super Moderator
Joined: Aug 2003
Posts: 25,479
Likes: 742
From: Isanti, MN
Sorry but I know that I have had my truck up around 137mph (220km hr) on stock 20" rubber because I was tracking it with a GPS unit that has never steered me wrong, hate to disappoint you. That is the only way to accurately track these trucks at those speeds because the stock speedos only go to 160km hr up here in Canada. It might not hit 160 mph like I thought it would but I know you are flat out wrong when you claim that no one would get over 122mph on stock rubber. Aside from that I am done with the issue until someone actually tries to hit 160mph and posts their results.
I made the ASSumption that your tires were the same size as mine, which they aren't. Yours are 2" higher than mine!
So my question is how many RPMs were you turning and how high your engine will spin with your spartan setup?
Peefrog, good point. I have a lousy habit of posting very strongly worded statements on here without considering every possible variable. I got in a hurry and made an assumption and made an *** of myself. Certainly wasn't the first time I've done it and probably won't be the last.
But after all of that, I stand by the fact that 160 with stock gearing without monster tires isn't possible without extensive engine mods.
Lead Foot User
Joined: Nov 2008
Posts: 773
Likes: 0
From: Saskatchewan, Canada
GPS is certainly the best way to track speeds that high, do you remember what you RPMs were at the time? Looks like your factory 20s are 34" tires. Plugging that into the calc yields 134 MPH @ 3,500 RPMs.
I made the ASSumption that your tires were the same size as mine, which they aren't. Yours are 2" higher than mine!
So my question is how many RPMs were you turning and how high your engine will spin with your spartan setup?
Peefrog, good point. I have a lousy habit of posting very strongly worded statements on here without considering every possible variable. I got in a hurry and made an assumption and made an *** of myself. Certainly wasn't the first time I've done it and probably won't be the last.
But after all of that, I stand by the fact that 160 with stock gearing without monster tires isn't possible without extensive engine mods.
I made the ASSumption that your tires were the same size as mine, which they aren't. Yours are 2" higher than mine!
So my question is how many RPMs were you turning and how high your engine will spin with your spartan setup?
Peefrog, good point. I have a lousy habit of posting very strongly worded statements on here without considering every possible variable. I got in a hurry and made an assumption and made an *** of myself. Certainly wasn't the first time I've done it and probably won't be the last.
But after all of that, I stand by the fact that 160 with stock gearing without monster tires isn't possible without extensive engine mods.
Senior User
Joined: May 2007
Posts: 128
Likes: 0
I concur. It's not just the diameter of the tires, it's the fact that they are not designed to withstand the inertial forces at those speeds and would most likely come apart.
Factor in wind resistance, etc, 160 mph does not seem reasonable.
Hotshot
Joined: Dec 2003
Posts: 15,369
Likes: 121
From: Stuttgart, Ar
4K rpm's isn't squat in a 6.0. Mine has turned much more than that on the dyno several times. I've been 4400 RPM's down the interstate in overdrive (5R110) with 3.73 gears on 265/75/R16's with Matt's tunes on an SCT. YOU do the math and see if 160 is possible with a lot more HP than I had at THAT time (which was basically a stock truck).
and FWIW--I totally believe you Brandon. I know what kind of tunes Spartan Matt can write for top end first hand. I have one faster than this that Matt "hand wrote" just for my truck.
and FWIW--I totally believe you Brandon. I know what kind of tunes Spartan Matt can write for top end first hand. I have one faster than this that Matt "hand wrote" just for my truck.
Super Moderator
Joined: Aug 2003
Posts: 25,479
Likes: 742
From: Isanti, MN
My diesel supplement states that the maximum governed engine speed is 3,700 RPMs and to not exceed 4,000 RPMs for any reason.
Not sure about the absolute limits of the components, but I wouldn't push it that hard!
Not sure about the absolute limits of the components, but I wouldn't push it that hard!
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Posting Guru
Joined: Mar 2006
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From: Long Island, NY
We clearly aren't talking about what parameters these trucks were designed to run safely within... We are talking about reaching the 160 marker. I believe you reaches the 137 marker Brandon... And that must have been insane. Even if my truck did 160 I'm not sure I would attempt it. I know what 168 feels like in a car designed for that speed, and although stable from downforce, it's extremely scary. Until proven otherwise I stick to my guns in saying I don't think a tuned truck can break 160mph. My M3 was in 5th gear at 8000 rpms when it reached that speed. With stock ride height and aerodynamics... It's like trying to get a brick wall to 160mph.
Lead Foot User
Joined: Nov 2008
Posts: 773
Likes: 0
From: Saskatchewan, Canada
We clearly aren't talking about what parameters these trucks were designed to run safely within... We are talking about reaching the 160 marker. I believe you reaches the 137 marker Brandon... And that must have been insane. Even if my truck did 160 I'm not sure I would attempt it. I know what 168 feels like in a car designed for that speed, and although stable from downforce, it's extremely scary. Until proven otherwise I stick to my guns in saying I don't think a tuned truck can break 160mph. My M3 was in 5th gear at 8000 rpms when it reached that speed. With stock ride height and aerodynamics... It's like trying to get a brick wall to 160mph.
Lead Driver
Joined: Jul 2007
Posts: 7,868
Likes: 9
From: Rhode Island
A Super Duty is not going to do 160 without serious mods. There are equations calculating the power needed to drive a vehicle at a certain speed. Using front area numbers and drag coefficients I found for a Super Duty (which actually seem kind of low) that I put into a calculator that I found online, that also factors in drive train efficiency, rolling resistance, weight, etc..Ford a Super Duty do to 160MPH, it is going to need well in excess of 650HP, probably more if I had the actual frontal area and drag coefficient. It would also need the gearing to match.
Senior User
Joined: Oct 2005
Posts: 432
Likes: 0
I am gonna say... that is very close to impossible. Unless... 1) Dramatic weight reduction.
2) Dramatic change in aerodynamics, that means slamming this thing to the floor. 3) Dramatic increase in HP and adding more RPM through gearing or over revving.
I would say you need well over 800hp... the drag on this truck is insane. The front end is like a brick wall!
I would love to be proven wrong though.
2) Dramatic change in aerodynamics, that means slamming this thing to the floor. 3) Dramatic increase in HP and adding more RPM through gearing or over revving.
I would say you need well over 800hp... the drag on this truck is insane. The front end is like a brick wall!
I would love to be proven wrong though.
Super Moderator
Joined: Aug 2003
Posts: 25,479
Likes: 742
From: Isanti, MN
So has anyone here seen a PSD, however modded, make that much power above 4,100 RPMs?
The power can be made easy enough, but at a lower RPM which would require a much lower ratio rear end gear to get up to 160 MPH. A Spartan-ized 6.4L truck running the 310 tune with a 2.73:1 ratio rear end would hit 160 at 3,100 RPMs.