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Old 05-18-2003, 11:56 AM   #1
snoopewite
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A Question Of Speed

Supposing that 240mph can be fitted into the gearbox of a 98 Camaro SS, would 310bhp be enough to get a car with the weight and aerodynamics of the 98 Camaro SS up to that speed regardless of how long it would take to get there? If that sounds doubtful then what if it had 360bhp? If it was geared for 240mph through a six-speed transmission even though 360bhp wouldn't be enough, what does anyone think would happen i.e. 205mph at 3500rpm in sixth gear before a plateau against the wind resitance.
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Old 05-18-2003, 02:33 PM   #2
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Re: A Question Of Speed

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Originally Posted by snoopewite
Supposing that 240mph can be fitted into the gearbox of a 98 Camaro SS, would 310bhp be enough to get a car with the weight and aerodynamics of the 98 Camaro SS up to that speed regardless of how long it would take to get there? If that sounds doubtful then what if it had 360bhp? If it was geared for 240mph through a six-speed transmission even though 360bhp wouldn't be enough, what does anyone think would happen i.e. 205mph at 3500rpm in sixth gear before a plateau against the wind resitance.

The answer to your first two questions is almost certainly no. Remember engine power must increase expotentially to increase the speed of the vehicle. My admittedly rough calculation is that it would take at least 600bhp for that particular car to do 240mph.

Also realize that there is a difference between attaining a speed and maintaining a speed. A perfect example is a top fuel dragster. It has no trouble attaining 300+mph but it certainly couldn't maintain it for long. So with that in mind it would take less power for the Camaro in this exercise to reach it than to keep going at 240mph.

Lastly, if you look at the gearing of the stock car you'll get a pretty good idea of where power stops pushing air. I don't have specs in front of me but it's my recollection that they had a higher top speed in fifth than sixth gear. Lower gearing but more power through increased rpm.
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Old 05-19-2003, 03:18 AM   #3
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Re: A Question Of Speed

Quote:
Originally Posted by snoopewite
Supposing that 240mph can be fitted into the gearbox of a 98 Camaro SS, would 310bhp be enough to get a car with the weight and aerodynamics of the 98 Camaro SS up to that speed regardless of how long it would take to get there? If that sounds doubtful then what if it had 360bhp? If it was geared for 240mph through a six-speed transmission even though 360bhp wouldn't be enough, what does anyone think would happen i.e. 205mph at 3500rpm in sixth gear before a plateau against the wind resitance.

Not a chance dude. You will need a lot more power to push that weight.
They had speed trials in NZ not so long ago. 1000hp @ wheels skyline gtr did around 340km/h. There not that heavy. And that car is designed for high speed runs. The could get more with that hp. But even that car, forget about 240mph. U need a very sleak car.
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Old 05-19-2003, 10:11 PM   #4
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Thanks for the replies lads. I just used the 98 Camaro SS as an example because I’ve had a 6-second, road legal car theory for a while) although there are a few grey areas. It involves relying on nitrous to get a trap time of about 220mph.
Fords have been proven to work well with nitrous but turbos also compliment the use of nitrous so a Mustang 5.0 might be a better base for a 6-second car. It should then be possible to fit a couple of Cosworth turbos at some time.
Here are the steps to making my theoretical dragster -
*Have the engine rebuilt with stronger components to be able to withstand a 750bhp shot of nitrous.
*While that’s being done, have higher compression pistons (and change the fuel to suit), get the cam timing retarded, get the car converted to 4WD, and of course get the transmission modified i.e. dog box, long gear ratio, cerametallic clutch plate etc.
*Also get high performance spark plugs (ideally iridium with 0.4mm tips as they work well large capacity engines with forced induction and nitrous + cold, hard spark plugs would be needed anyway), Megatronic ignition and get the nitrous system installed.
*Bigger exhausts and wheels and high performance tyres would be needed.
If a stock Ford can turn a 25bhp jet of nitrous into 75bhp at the wheels, then couldn’t a Mustang 5.0 Twin Turbo convert an input of 750bhp into over 2200bhp at the wheels?
That’s on top of the power that it would have to start with!
The nitrous could be set so that the power gradually builds up to avoid any wheel spin e.g. after one second – nothing, after 2 seconds - an input of 200bhp etc.
With 4WD, 20” wide wheels all round and the best road legal tyres available, the car should be able to put the power down well on a good road surface after a quick burnout to warm the tyres up.
The grey areas are -
*Mustangs aren’t very aerodynamic.
*How much would it cost to strengthen all the right components to be able to take all that power? (I heard that the cylinder head on a top fuel drag bike costs about $20,000)
*The Cosworth turbos would be compatible with the Mustang engine after a bit of tinkering wouldn’t they?
*Wouldn’t one off exhausts need to be tailor made?
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Old 05-19-2003, 11:01 PM   #5
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Quote:
Originally Posted by snoopewite
Thanks for the replies lads. I just used the 98 Camaro SS as an example because I’ve had a 6-second, road legal car theory for a while although there are a few grey areas. It involves relying on nitrous to get a trap time of about 220mph.
Fords have been proven to work well with nitrous but turbos also compliment the use of nitrous so a Mustang 5.0 might be a better base for a 6-second car. It should then be possible to fit a couple of Cosworth turbos at some time.
Here are the steps to making my theoretical dragster: -
*Have the engine rebuilt with stronger components to be able to withstand a 750bhp shot of nitrous.
*While that’s being done, have higher compression pistons (and change the fuel to suit), get the cam timing retarded, get the car converted to 4WD, and of course get the transmission modified i.e. dog box, long gear ratio, cerametallic clutch plate etc.
*Also get high performance spark plugs (ideally iridium with 0.4mm tips as they work well large capacity engines with forced induction and nitrous + cold, hard spark plugs would be needed anyway), Megatronic ignition and get the nitrous system installed.
*Bigger exhausts and wheels and high performance tyres would be needed.
If a stock Ford can turn a 25bhp jet of nitrous into 75bhp at the wheels, then couldn’t a Mustang 5.0 Twin Turbo convert an input of 750bhp into over 2200bhp at the wheels?
That’s on top of the power that it would have to start with!
The nitrous could be set so that the power gradually builds up to avoid any wheel spin e.g. after one second – nothing, after 2 seconds - an input of 200bhp etc.
With 4WD, 20” wide wheels all round and the best road legal tyres available, the car should be able to put the power down well on a good road surface after a quick burnout to warm the tyres up.
The grey areas are: -
*Mustangs aren’t very aerodynamic.
*How much would it cost to strengthen all the right components to be able to take all that power? (I heard that the cylinder head on a top fuel drag bike costs about $20,000)
*The Cosworth turbos would be compatible with the Mustang engine after a bit of tinkering wouldn’t they?
*Wouldn’t one off exhausts need to be tailor made?

Wow, I just don't know where to begin. Let's start with a question.

How is it possible for a Ford, or any car for that matter, to turn to turn a 25hp shot of nitrous into 75hp at the wheels? No matter what the engine power is measured at the crankshaft you will always see less at the wheels due to mechanical losses. That is a simple fact.

Now for the idea of a six second "road legal" car. It just isn't going to happen. Not anytime soon anyway. What are the fastest production cars, including exotics running right now, high tens? Even cars that are nowhere near legal but still licensed for the street aren't close to that kind of number.

Let's take a look at NHRA Pro-Stocks. Just this weekend Greg Anderson set the new E.T. and top speed mark for that class, 6.723 @ 205.91. Obviously these cars are not even close to street legal. And if you did put a license plate and lights on one you still couldn't drive down to the local store for a quart of milk. Granted they are restricted to a certain extent by class rules but they're still way more radical then anything you could put on the street.

As a side note, reading through your list of modifications many of them just wouldn't work together. Well maybe if you had an astronomical budget and a large group of engineers. This would be on the scale of developing an F-1 car from scratch. Sorry, just ain't gonna happen.

Second side note. 57ock, at that speed weight (within reason) is not the enemy, aerodynamics is. Weight is the enemy of acceleration.
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Old 05-20-2003, 06:19 PM   #6
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oops I read the part wrong from www.nitrous-solutions.com when I said that a Ford can turn an input of 25bhp into 75bhp at the wheels but you can read what it says first hand -

"The power rating is calculated from the flow rate of nitrous oxide liquid through the nitrous jet, and is therefore only theoretical. The actual power increase achieved by a particular engine depends on i) the richness of the fuel to Nitrous ratio, eg. Too rich, reduces the power output, ii) the engines particular characteristics, so different engines will produce different power increases from a specific amount of nitrous oxide (eg. i), a V6 Ford had 25 bhp injected but measured 70 bhp extra at the crank, (eg. ii), a Shogun V6 had 25 bhp injected, but only measured a 16 bhp increase at the wheels)".

I didn't think that the modifications that I listed in my theory were much different from the following modifications featured in www.carcraft.com -

"We've had this particular system for quite some time. In fact, we've been intending to install it on our '86 Mustang project car for over a year now (hey, we've been busy compiling the results of our reader survey), but we finally couldn't wait any longer and bolted it onto a small-block Chevy we had at our dyno shop to see how it worked. The test engine, which we chronicled in "530 hp From Spare Parts" (Dec. '02) is equipped with Edelbrock E-Tec 200 aluminum cylinder heads, a rumpity Lunati solid flat-tappet camshaft (254/259 degrees duration at 0.050 and 0.562/0.561-inch lift), and a stout bottom-end consisting of Probe forged pistons, Probe 6-inch forged I-beam rods, and a GM forged crankshaft. We knew it could take a stout hit of laughing gas, and the smallest set of jets in the Wilson system, which is adjustable from 175 to 350 hp, looked like a good place to start.
All it took was one pull to find the answer we were looking for. We poured in some good gas (Wilson recommends race gas for any engine running more than 9.01 compression; our 350 has 11.251 so we ran Union 76 114-octane leaded racing fuel), dialed back the timing 10 degrees from 36 to 26 total degrees (Wilson recommends retarding timing about 3 degrees for every 50 hp of nitrous), cracked open the bottle valve, and whacked the throttle to wide-open. At about 4,000 rpm, we manually hit the nitrous button and cackled as the engine practically leaped off the dyno stand. The results were impressive 706 hp at 6,300 rpm and 637 lb-ft of torque at 5,500.
We still had a handful of jets that could have taken us to even greater heights--750, 800, maybe more. But why get greedy?"

The Megatronic ignition and boost controller are products from www.nitrous-solutions.com
Well If that 86 Mustang only produced an extra 1hp over the estimated jet, I doubt that any other Twin Turbo conversion would make all that much more power anyway… Never mind.
Thanks again for the reply vwhobo wink Appreciated as always.
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