deonStang

Is there any chance anyone out there happens to have a link to the drag coefficient [cd] of the 2k7 mustangs, their frontal area, and track tested top speeds in GT (with 3.55 rear gears) and Cobra 500 GT trim? And perhaps any speculation on top spoeed for the GT 500 KR with it's closer ratio tranny and 540 hp?

I have a reason for asking, but it's late tonight and I don't want to make THAT post till I have it completed.

dB

mot250

Well, not exactly the answer to your question but I think the 05/06 GTs were aerodynamically limited to 140 or 145 mph in stock trim. Add more power and they could go a little faster. I do not know what the gearing limited top speed would be.

281GT

I have the stock 3.55 gears. I normally shift at 6500 rpm and I ran it to 6500 once in 4th gear which was VERY close to 140 mph. I grabbed 5th and it continued acclerating past 140 mph but that was fast enough for me. The car did appear as though it was going to continue acclerating although I am unsure as to how much faster it would go. I have removed the speed limiter in my tune. I only had a CIA and tune so I doubt if there would have been much more at that point.

theedge67

It is NOT AERODYNAMICALLY LIMITED AT 145, It is ELECTRONICALLY limited to 145-149 depending on who you talk to. Either way, I have found the electronic limiter on my car, and it was still accelerating at the time. Bone stock, not even a CAI or tune.

TRQ QTRHRSE

Have had the STEEDA TRQ well past 150. Hit the Rev limiter in 5th gear GPS Tracked Top Speed as 167.3 I live in Kansas so you know our roads are flat and straight in some parts. Took a little over two miles to build speed up for the run. My car was one of the press car for STEEDA in 2005 so it has numerous upgrades to assist the aerodynamics's and drive train. By the way it has 4.10 gears. It also has 1.2 G's of lateral grip on the pad. Check it out at www.steedamidwest.com I do not recommend trying to run speeds this fast in a stock car with a tune and none of the aerodynamics's and drive train upgrades.

shaun_beauchamp

I burried the speedo at Road America easily and that's a closed circuit track. I imaging what we feel in fourth gear (pull) will taper off in 5th, but I would go with about 170 mph as posted by the crazy guy in Kansas.

deonStang

Thank you. I've been looking for documented top speeds, aerodynamically limited prefferably. If doing simple math calc using factory 1900rpm in 5th with 3.55 rears = 60mph, and factory rev limiter at 6200, 195 would be the gear limmited top speed.

I am in the process of cramming for a mid term and my brain is fried - I will make another more comprehensive post later. My questions are pointed and spefic because I'm considering building my 2k7 GT up to punch a sanctioned, documented real live 200 mph hole in the atmosphere sometime down the road. (IE long term goal spread over next 4 to 6 years) Built by me. Driven by me. Documented by someone proffesional.

I don't know if it'd be easier to do Nevada Silver State closed road, a Texas closed road, an airport, or beg track time at a big track somehow - BUT I'll figure those things out if I decide to get on with it.

I'm gathering information, and will likely develop an underbody tray, and look into various aftermarket aero aids, as well as possibly develop my own.

Basically I need to see if it's feasible with our platform - I haven't even been able to find a drag coe efficient [cd], lift numbers at speed, or real measured top speeds of GT's or Cobra's. I'll be doing some coast down measurements and calculations shortly.

If our CD is at or below .36, I'm going to give it a shot. In the end in addition to the obviously built motor, suspension, wheel, TIRE, and Brake systems - it will likely need to have a 10 point harness, brakes to arrest it, 5 point racing harness and racing seat, fuel cell, extinguisher, fire retardation system, external fuel and engine kills, and of course I'll have to go through several race classes to get into unlimmited and will need the full gammut of persoanl safety gear, etc.

Its easy to make 600 plus with our cars these days. Almost every large gathering of Mustang owners has at least one or two guys running 10's in a DD or pushing over 600 wheel hp on a dyno.

I haven't been to ONE where a privateer punched a legally documented sanctioned 200mph hole in the atmosphere. At least not in an S197.

I'm thinking it might be a fun project, and wouldn't mind being that cuke. Yes expensive. Yes not optimal platform. Yes dangerous. Yes time consuming. Yes it'll turn a perfectly good street car into something else. And the list goes on and on. So what!

What would be cooler than a genuine normal American muscle car being built, tuned, and driven by a normal american gear head to the illusive double century mark?! Not some uber exotic 100k piece of hardware, or a car built by some guy dripping money, or a race car on a race track. But a street driven, Mustang - most decidedly an american Icon if ever there was one. Just a normal guy in his back yard err garrage, or wherever..

In my eyes what could be cooler is if I were that guy

Really interested in finding out how far I have to go, and what I'm up against starting with the brick wall that is our cars....

DynamicmustangGT

My 05 gt stopped going faster right around where the 150 mark was. The previous (94-04) stangs were limited to 149 apparently so I can't see much faster than that although I have heard claims of the electro limiter being set to 169 on the 05+, but personally don't believe it, without the tuner. A posibility to get there with tune though, might take a while though.

Speeddmn

I hit 5500 rpms in 5th in my '05. No speed limiter stock 3.55 gears and 285/35/18 tires out back. doing the math it's like 175 or so. It still had some pull left but my nutz where crawling away. hitting 200 in these cars in a legal environment will be easier then you think. the main focial pont is safety, then building a motor to withstand 5k+ rpms for a few minuets. I would do the motor n/a first and see what happens, plan on needing enough length to drive and slow down. Shoot for 375 at the tires with a fully built motor and no power adder.

If that dont work, do some aero work on the car then try again. I know vortech tried with a car and got out of it I think at 190 ish. little things like the mirros, antena, wipers and so forth add drag. But you should know this. stick to your plan and have fun. I'd try to make it to were it wont take to long to re-convert to street use though.

deonStang

If I do this it'll be putting down over 600 to the wheels. 375 won't punch a 200mph hole in a car with this much frontal area and drag.

Error404

had mine (whipple, 4.10's, automatic) to 140-145 out at El Mirage flat lake bed :-) Look forward to going out there with some shallower gears! I didn't notice the hood wobbling or anything (I have heard this may be a problem). There was still some gear left in 5th, if I would have let it keep on going it would have gone a little faster, but for practical purposes, 140 is about my top speed right now, I'd need alot of space to go faster, but it gets to 130 pretty darn fast!

After 140 the acceleration slows down dramatically. I assume this is because #1 I'm in an overdrive gear, and #2 the car hasn't been altered in any way to improve aerodynamics.

metroplex

i'm looking at my stock calibration and the factory sets a speed limiter of 145 mph.

RobK

OR A CAGE!!! At those speeds it doesn't take much to unsettle a car and the results usually look like a crushed aluminum can.

RobK

Sounds like fun! I would imagine one of your biggest challenges will be lift and the "brick factor" you've mentioned. An undertray should help. Drop the car uber low as well. Lots of reinforcements - 10 point cage sounds good. If you're really doing big HP/torque you'd probably be fine with shorter gears (3.31, 2.73??) to get more top speed. Don't be surprised if you're into that $100k "exotic" territory once you're all done. This won't be cheap! Maybe you can get TMS to sponsor you! We could call it Project
Downforce Horse!

RadBOSS

deonStang

Maybe you need to start thinking about Speed Week at Bonneville. Its easier to sort the car under steady conditions. Its sanctioned. You will get recognized for your effort /accomplishment. Its a lot simpler than on a big oval track or a cross country road coarse. El Mirage in CA is good as well, but it must 1344 miles or more from San Antonio TX.

If you do some decent coast down tests on a controlled surface (old runway?), perfectly still moment, you should get a pretty good prediction of the aero dynamic coefficients. Get your hands if not already on a copy of the AIAA 2nd Symposium Aerodynamics and racing cars (1974) and read up on vehicle aerodynamics. There have probably been subsequent symposiums with more work.

classj

I did some looking on the Cd topic. The 2005+ GT has a Cd of 0.36, and the GT500 has a Cd of 0.38.

The gt should be good for at least 170 without much trouble whe comparing it to other cars with similar gearing, HP, and drag.

theedge67

Do you mean the stock GT should be good for 170 except with the speed limiter removed??

Error404

would be interesting to see what it maxes out at, if you had all the space you needed. Problem is, you are usually limited to a few miles for top speed runs (if you want to make it official) and if you do it legally (IE, not freeways) you are usually limited by space! at least here in the US where the freeways have speed limits. The lack of space (or mile limits) means you have to get up to speed quick, because one you get rolling at high speeds the miles click off pretty quick!

That said, I think it would be quite interesting to see what a stock GT with the limiter removed would do, if you had all the space you needed!

fordboy97f150

i remember in a magazine they installed a super-charger and she did 192 before rev limiter hit

deonStang

I'd guess you were approaching the speed limmmiter. Have you corrected your speedo for the 410's? My hood wobbles above 90, get's realy bad between 125 and 130, and looks like it's about to head for the sky about 140 (indicated). I'll be pinning it if regardless of whether it's factory or not.