6,500 rpm's in 5th gear = 217 mph ???


Fast Freddy

Fast Freddy

GPS'D 225 MPH
Mark II Lifetime
Aug 5, 2005
2,744
Avondale, Arizona
according to my calcualtions based on the GT's 28.9" tire height the GT will do 217 mph in 5th gear at 6,500 rpm's assuming you have enough mods to make enough power to wind it out that far. 5th gear has a .77 ratio and the rear gear is 3.36. is my math correct???
 
at 212 mph how many rpm's is the GT's engine turning in 5th gear???
 
One of 19 says he gets 215mph out of 5th, without any mods.

Allan
 
centerpunch said:
I think 212 is the number they use for top speed in 5th with the speed limited removed from the computer.

Chart here on post 7
http://www.fordgtforum.com/forums/showthread.php?t=296&page=1&pp=10&highlight=roush
Click to expand...

I still don't believe that there is a speed limiter anywhere in that car...
 
Pipelion said:
One of 19 says he gets 215mph out of 5th, without any mods.

Allan
Click to expand...


I am curious what a stock car will do with the rev limiter raised.
 
!

one of 101 said:
I still don't believe that there is a speed limiter anywhere in that car...
Click to expand...

Jason,
trust me, I´ve seen it with my own eyes on the stock ecu settings... Maybe the non - US 101 don´t have the limiter setting in (Haven´t had a chance to check), and that´s then why 1 of 19 gets to where he gets.

I know that stock, without the limiter activated at 207 mph (standard, not 205 as commonly believed, see also the SAE documentation), the car would reach 212 mph in normal conditions. (Maybe 1 of 19 had a slight declining road, or backwindeffect when he hit 215, or it was extremly cold air..)

HOWEVER,
1. If you power up the car with some wise& caring mods, and
2. increase the revv limiter by mere 500 revvs, and
3. to not have an issue with the speed limiter setting it to like 255mph,

you can get 225mph out of it, at maxx revvs in fifth. !

PS: I guess not really useful in US roads, but on German autobahn sort of needed to overtake 1 of 19 !


Tony G from HP performance can help you all on this, if so desired... will also help you save gas, by the way. That´s what a real good tune will do for you.

stefan
 
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as was posted somewhere else here, the standard MAF will pegg at 6400. Needs also some minor modd, if you want to get to 217mph..


The faster the GTr gets, the more impressed I am with how it rides, vs e.g. a flat out Ferrari 360 CS or so... They first glue nicely, but then feel real light and scary, particularily when a slight bend/curve is to be dealt with, while the GT is relaxing even at 190+.

Once I was flat out with 307km/h going to Imola in my 360CS, and decided ´light heartedly´ to take a (known) curve flat out, and almost considered myself dead halfway through... Man, that is scary s*** ! Following the curve, the tarmac was slightly uneven and twisted, something I never noticed at the frequent 250km/h´s there, but at that speed, it almost knocked me out when I thought I barely survived the previous bend...made me pray for survival. If I would have lifted off out of fear halfway through the curve, or even worst, hit the breaks, I surely would have had a very quick death right there.

Trust me, I´ll never try that again !

stefan
 
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Stephan,

Are you saying One of 19s' car may still have a limiter setting? And he might even go faster without mods, if the limiter setting was removed?

Great couple of posts. My 930 was light at 160mph, not scary light but not what I would call a feeling I wanted in the front end. I never went around corners above 120-140( very slight bends). The fact that the Gt is able to handle the speeds we are talking is without question an automobile milestone. Especially with the Ford GT having a streetable suspention. Rock hard race suspention,,,,OK. But a car with plus 200MPH stable speeds and drivable, simply awesome.

That's why the GT is so cool. It's not the top speed itself. It's the combo of a race car heritage and a smooth ride inside, and still able to hit Mulsane Straights speeds of muti-million dollar pure race cars. What a cool machine!!!

Please answer the included question.

Thanks,

Allan :biggrin

PS Two real cool posts. I'm trying to absorb it all.
 
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Some thoughts on euro car settings

Allan,
in short: yes he has. But might not be able to reach it !

in detail: if we take '1 of 19'th statements for what they are (he ran a GPS aswell), he has for sure not a limit setting in the ecu that limits at 207mph like US standard. You can adjust that in a reflash, (easy), so it is hard to say if there is an effective limit set that will be reached or not, given the standard power he (supposedly) erogates.
What you do is, you simply change the settings, e.g to 255mph, that you would not want to reach ever I guess, hence to not be limited by it.
If his is standard power, he would on a straight top out around true 212mph. If in favorable conditions, with backwind to reduce drag, or simply descending downhill, he could still however top that, if he does not get into the range where his speed reaches whatever his program set identifies as a limit for reduction.

To come to a final answer, we would need to have access to the program file they run on the euro cars. That would reveal their effective speed limiter setting plugged. Hey it's just a software parameter setting ! Or maybe one from Roush euro can tell us where they set it for the europ cars..

Trust me, there are US GT's that can do 225mph on a straight after careful mods and cals...I leave it to Tony G from HP performance to take over the discussion from here !

When I met Tony, I was really impressed. What more can i say !?
well, my car finally impresses me (and others like Florida Chris)



Hope that's clear enough.

Stefan
aka
SLF360
aka
'Stefan Likes Fast 360 (kmh=225mph)'

(now you all know the logic of my handle here) :biggrin


PS: Tony is also the driver/tuner of Piko's GT that did the 10.4 recently in Orlando. They had clutch issues (changed over to ceramic clutch to deal with all that torque), and as you could see in the video, he took it real easy on start.. Piko's car can do better.
 
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I'll contact Roush Europe and ask about the limiter..


My buddy has got a US car and has just ordered the pulley and flash unit from Dallas Mustang - could I use that unit to get acces to the limit-data on my car??
 
Stephan,

Thanks.

One last question. Are all 'mods settings', done through the GTs' one computer?

Also; I was impressed when you stated earlier "a good mod improves gas milage". Thats real cool.

Allan
 
Pipelion said:
Stephan,

Thanks.

One last question. Are all 'mods settings', done through the GTs' one computer?

Also; I was impressed when you stated earlier "a good mod improves gas milage". Thats real cool.

Allan
Click to expand...
Yes, all in the ECU. There is no mechanical limiter at all. I am also impressed with the gas milage effect. The more you are able to personalize the tune to the actual engine, the better and precise you can set the parameters. Speaks a bit against off the shelf 'tunes', custom is definitely better..

stefan
 
Top end, and ECU updates

I had asked 1 of 19 about his five minute autobahn blast. He tells me that during that run, his car was stock. At that time he never touched anything due to warranty issues. One theory I had discussed with him was that the export models had NO electronic speed limiting, due to different liability issues in the USA . I think that you guys are right in saying that there is no speed limiting on all models, just RPM limiting (which works quite well and has saved my ass and engine!).

I know from many years (during my crazy kid years) of driving my various cars 'flat out" for several minutes straight, there are always small variations in the top speed. One car I had owned about 20 years ago would go about 140 MPH (it would go the same speed in 4th or 5th gear) and with enough time (say several minutes) I could find another 5 MPH! This may be due to a slight change in tailwind, slope in the highway, tire pressure increase due to heating, etc. There were also days when this car was lucky to go 130, so all conditions must be considered, air density, quality of fuel, oil level in the engine, etc.. I want to say that my top speed runs were not always repeatable when attempted on different days.

The top speed percentage variations during 1 of 19's autobahn run were quite typical of my experiences.

I agree with you guys about a good mod can also improve gas mileage. I always thought that the GT was set way too rich for light throttle cruising. I would rather save the fuel and use it for my full throttle blasts! David Vizard wrote a good book on that topic many years ago.

Can a slight leaning out of the A/F ratio be done for light throttle positions only, while slightly richening the mixture at WOT increase the top end HP a bit? Would any leaning out (again, at light throttle) affect the throttle response of the engine? My question is to better understand how much control of the fuel map does a tuner have access to at the various throttle positions? I only have experience with carbs,:ack not EFI.

Good posts guys!!!

Jay
 
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I didnt read the whole thread, but the 212 top seems about right on, I could see a few more MPH out of a stronger car?

The SVT enthusiast mag did a top test run, the Ford driver at Nardo went 211 with no limiter.
 
I drove my car all day today, it feels SLOW...
 
Fast Freddy said:
according to my calcualtions based on the GT's 28.9" tire height the GT will do 217 mph in 5th gear at 6,500 rpm's assuming you have enough mods to make enough power to wind it out that far. 5th gear has a .77 ratio and the rear gear is 3.36. is my math correct???
Click to expand...
FWIW, your math sounds right to me. MPH = pi*Dtire*RPM/(1056*GRtot), where Dtire is the tire height in inches, and GRtot is the total gear ratio (= 0.77*3.36, in this case). I came up with 216 mph from the info you gave, which is close enough. That would have to be scarey going that fast! Wow!
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SLF360 - So do you know what the maximum mass-air flow rate (in lb/min, or what ever) of the stock MAF is then, or do you recall where you saw that about where it pegged? Does anyone have the transfer curve?

Thanks!
 
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Black2003Cobra said:
SLF360 - So do you know what the maximum mass-air flow rate (in lb/min, or what ever) of the stock MAF is then, or do you recall where you saw that about where it pegged? Does anyone have the transfer curve?

Thanks!
Click to expand...
Black Cobra (sounds like Fat Cobra from the funny movie to me),
it usually peggs at 6400. Don't recall the mass-air flow rate, but think Air/fuel was 11,5 or close..
 
SLF360 said:
Black Cobra (sounds like Fat Cobra from the funny movie to me),
it usually peggs at 6400. Don't recall the mass-air flow rate, but think Air/fuel was 11,5 or close..
Click to expand...
Thanks SLF. I suppose I can calculate/estimate it if you can tell me the pulley ratio. I assume this was on a pullied car, yes? (That would suck for it to peg on a stock vehicle below the engine redline!)
 
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