Reliable Top Speed Info: Whipple S550 GT

[HKusp]

EXTREMELY dumb, kinda like trying to apply some cynical sarcasm in a post relating to the top speed of a car that we all like and is the common interest we have, assuming that’s enough for us to have a conversation without insulting people.

That really was dumb of me.

PS: hope you have better luck with your 2018 GT. Totalling two cars will start looking like a habit, or worse. Happy to help with some tips if you want, as a friend.

Easy there, Tiger. I wasn't calling YOU DUMB, I was calling the media dumb. MY bad for not being more clear. That being said, I won't be needing any of your help, I'm sure. I learn from my mistakes. Have a nice day playing internet tough guy from 17 hours away from me.

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[MisterScobbles]

Easy there, Tiger. I wasn't calling YOU DUMB, I was calling the media dumb. MY bad for not being more clear. That being said, I won't be needing any of your help, I'm sure. I learn from my mistakes. Have a nice day playing internet tough guy from 17 hours away from me.

Yo. I’m no tough guy, no matter how far away I am from you.

Let me apologise for the snide remarks. It wasn’t called for.

And I wish you and your fine machine no harm.

We’re all here to have a bit of fun. It’s in my nature to generally say stupid things without meaning them, and I crossed a line due to my jumping to a conclusion.

Won’t happen again, and I’ll be sure to have my passport with a valid visa and all the USD to prove that I have the means to buy a ticket outta there also.

 

[ShadesOfBloo]

AI says 239.5 MPH. You would obviously need a very long stretch of road to achieve this.

Who decided on that coefficient of drag? For our Mustangs it's probably more like 0.37.
Unless you have a GT350, and then I remember reading 0.34 or something.

Ford doesn't like to talk about the Mustang's coefficient of drag because they haven't improved on the 0.34 from 1987. They made it worse with the 2005 Mustang (about 0.38 if I remember correctly) and the styling department has won out over aerodynamics ever since.

EDIT: Found this post from an S197 forum saying the 2007 GT500 had a drag coefficient of 0.38.
The 2010 GT
https://www.s197forum.com/threads/drag-coefficient.30803/
Most guys on that thread have some idea what they're talking about, but the guy using bullets as a reference... Some did a really bad job explaining aerodynamics to him and no one on the thread set him straight.

This MustangSource thread agrees, and the user who posts numbers cites sources
https://themustangsource.com/forums/f726/coefficient-drag-481371/

This old thread from Mustang6g, someone quotes Ford as saying the 2015 Mustang had a drag coefficient 3% lower than the 2014 model. (Unfortunately, the Ford Media link is broken.)
https://www.mustang6g.com/forums/threads/drag-coefficient.11294/
...So, it looks to me like Ford was being vague, on purpose, for quite a while.

 

[Mach VII]

Auto, 6 speed, PP, so 3.73 diff, stock 19” wheels with 275 tyres.

Auto's never came with 3.73 diff, even PP is 3.55...

 

[MisterScobbles]

Auto's never came with 3.73 diff, even PP is 3.55...

My second stupid post.

Sorry, you’re right. I know it’s a 3.55, and then started talking to myself about the 3.73, so I wrote 3.73.

I’ll close the door on the way out.

 

[WD Pro]

I apologise in advance for what is most likely one of the most irritating discussion points for anyone who‘s spent time on this planet.

I’ve searched the forum, the rest of the internet, youtube, and even tried to imagine an answer, but there is a surprisingly no amount of information on this.

I have a son who is a bit of a car fanatic. And I own a 2016 GT with a 2.9l Whipple on it. I live at around 1,700m altitude and the last dyno recorded 420kW (~565hp) at the wheels. At zero altitude, I’d expect about 610-620whp.

My kid has asked me a few times what I’d expect the car to top out at, and I could only offer a guess, which I would expect to be around 320km/h.

Has anyone actually managed to do an instrumented top speed run on a similar car?

Thanks in advance. A lot.

Have a look here :

https://www.mustang6g.com/forums/threads/my-supercharged-200-mph-build.131531/

WD

 

[SheepDog]

Who decided on that coefficient of drag?

I did, because I couldn't find any data, nor the cross-sectional front area, so I made assumptions. Another thing it isn't accounting for is rolling resistance of the tires. I also generalized the HP as 700 at the crank

Safe to say it would do near 200 MPH, probably not more than that, provided the car didn't shake itself to pieces, the hood was bolted down, the tires didn't explode, Engine didn't overheat etc. These cars were never designed to go this fast.

 

[ShadesOfBloo]

I did, because I couldn't find any data, nor the cross-sectional front area, so I made assumptions. Another thing it isn't accounting for is rolling resistance of the tires. I also generalized the HP as 700 at the crank

I was totally ready to blame the AI.
Whenever I do a Google search related to cars, their damn AI butts in with some answer so bad, I know it's wrong before I even scroll away.
Like when the AI mixed up deck height and bore spacing.

Safe to say it would do near 200 MPH...
...These cars were never designed to go this fast.

Yeah, Ford put in that 150mph limiter for a reason. And the other limiter at 180mph.
I guess all the tuners know how to defeat them, now.

 

[MisterScobbles]

Have a look here :

https://www.mustang6g.com/forums/threads/my-supercharged-200-mph-build.131531/

WD

Hey thanks. This was a really interesting read. Hats off to the guy. He’s not only dedicated and meticulous, but he’s got some real talent also.

I call a handyman over to change lightbulbs, so I have real admiration for peeps who are able to make their vision a reality. On their own.

Seems like 200 Mph is not just about bolting on a pump when it comes to Mustangs.

 

[Bob Lob Law]

I was totally ready to blame the AI.
Whenever I do a Google search related to cars, their damn AI butts in with some answer so bad, I know it's wrong before I even scroll away.
Like when the AI mixed up deck height and bore spacing.



Yeah, Ford put in that 150mph limiter for a reason. And the other limiter at 180mph.
I guess all the tuners know how to defeat them, now.

OEM speed limiters are based on the tire speed rating that comes on the car stock.

 

[WD Pro]

OEM speed limiters are based on the tire speed rating that comes on the car stock.

Unless you dive certain variants of the S197, then it's the driveshaft ...

WD

 

[tdstuart]

Been 180 n/a. Gearing and rpm limit will affect you the most. With 3.55 gear ratio you will be shifting into 5th before 180. I think you have the power to accelerate in 5th (n/a with 3.15 I don’t). So I think it’s possible to get 190-200, just depends how that 5th gear acceleration is.

 

[MisterScobbles]

Been 180 n/a. Gearing and rpm limit will affect you the most. With 3.55 gear ratio you will be shifting into 5th before 180. I think you have the power to accelerate in 5th (n/a with 3.15 I don’t). So I think it’s possible to get 190-200, just depends how that 5th gear acceleration is.

Seat dyno says it’s still building power to the limiter (7,500 rpm). Actual dyno proves the seat dyno right.

Torque peaks around 4,500 rpm, but it’s pretty much a flat curve between around 3,000rpm and the limiter.

I’ll never know what the car will max out at, though, as there’s no road I know of where it’s legal and safe to try it. And I don’t think I’ll invest enough in the car to even make it safe enough to attempt.

I definitely learned a lot though.

 

[gsxr1300]

 

[paulm1]

I’d say you have the power to go about 200 mph but the hood would rip off and the car would be really unstable overall. The regular mustang GTs don’t have any aero or downforce so it would be floaty and extremely unstable due to the lift. I’ve seen hoods bowing out at half that speed

I can confirm at 130mph, the stock gt hood looks like it's having a seizure on steroids, pretty scary.

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