Slashdot Mirror
Gentlemen, Hack Your Engines!
Les Gasser writes "Ahh, drag racing! If you've never experienced the scent of nitro or
the flashing flames of a top fueler running 320MPH+ in 4+ seconds in a
standing-start quarter mile run at dusk, you're missing world-class
performance art. (See 'High Performance' for the classic on drag racing history and
culture). Now the NYTimes (registration needed) has 'Gentlemen, Start Hacking Your Engines,' an article on
're-engineering' engine control computers for maximum performance,
combining the drag racing and tech-geek traditions." Having learned everything I know about racing from Gran Turismo, I'm amazed to learn there's more than just buying a "racing chip".
Here you go, tiger.
get your reg-free link right here.
ECU hacking has been around for a while. For popular cars, you can get aftermarket ECUs which are tuned for more performance. On a non-turbo, street legal car, the best you can expect is a 10% power increase. On turbocharged cars you could get more (just turn up the boost), but you quickly run into reliability problems because the engine can't handle the increased loads.
To get significant power increases, you still need to apply 'old style' tuning tricks like adding forced induction, changing camshafts and uprating engine internals.
Have to agree with this. On non-forced induction cars, all you're doing is removing any safety margin built into the current map by playing with timing. Advancing ignition may give some benefits but runs the risk of det, or pre-ignition, or pinking, or pinging, or knocking or whatever your locality calls it ;-)
;-) ) but runs the risk of det again which'll knacker your engine pretty damn quickly.
With a turbo on the car, things start getting more interesting as you can get more air into the engine, which means it'll need richer fuelling to achieve anywhere near stoich (or even safety
With the Impreza, which is my weapon of choice, the map is incredibly rich before doing anything... The general concensus is that this is done to keep engines from going bang, as out of the box they'll come with between 218 and 275BHP from a 2 litre engine, along with a 3 year warranty.
Tune them simply and carefully and for a little money you'll see high 200s from them. Beyond that, my opinion is that your internals will need some consideration - particularly con rods and those little gudgeon pins which hold your piston heads on.
The fact that people have done what manufacturers think is impossible is a cause for some small celebration in my eyes, and allows the little guys to stick a finger in the air to those who would have them only use franchised dealers with the necessary hardware to talk to the ECUs...
Mind you, it's far more effective to use an aftermarket ECU.
Check out http://farnorthracing.com to see the team website, and http://www.gems.co.uk to download the software I use.
DG
Want to learn about race cars? Read my Book
F1 gearboxes have been fully automatic for most teams for a couple of seasons now. They retain the ability to do manual gearchanges if the driver wants to, but that almost never happens.
They are not torque-converter slushboxes like passenger cars. These are sequential-gearchange boxes like motorcycles, with hydraulic-actuated, computer-controlled shift mechanisms. There are zero drivetrain losses compared to a full-manual version, and they outperform a driver shifting in every respect.
DG
Want to learn about race cars? Read my Book
Yes! There's loads of information out there...
:-)
The interface in some cars is called OBDII (On board diagnostics) - see ODBII.com, which incidentally claims that all cars sold in the US after 1 Jan 96 have to be compliant...
Now the protocol that they use is something else. There's many flavours, but at least you can start hacking should you be feeling brave
There is, of course, open software to help and naturally it's on sourceforce here.
Plenty more information out there - just google.
Not only can the engine management engineer retune the engine on the fly during a race, most of the teams go even further.
Every team has what is called a "7-post shaker rig". This is an electro-hydro-mechanical device that places a hydraulic ram under each tire, plus 3 more attached to the aero centre for feeding in aero loads. By playing back the loads recorded by the car during operation by the position sensors, load cells, strain gauges, and accelerometers though these rams, the engineers can watch the car operate under real racing conditions in the lab.
Well, the bigger teams transmit the telemetry coming off the car during the race back to the shop in England, where the shaker righ data is played back on a duplicate car on the shaker rig in near real-time, so that they can keep an eye open for problems.
F1 has more money and technical ability than can be imagined.
DG
Want to learn about race cars? Read my Book
Kenny Bernstein was one of the leaders in pushing for pit lane analysis via computer...many, many years ago. I believe he's turned that into a side business since then.
It is really impressive what parameters are monitored and what kind of telemetry they employ. F-1 is the same way...tons of analysis done real time. The Japanese (Honda), again, years ago, would transmit telemetry from the car, on the race track, from one of the many tracks worldwide...all the way to their labs in Japan.
For those with a bit more esoteric interest, note that originally, physics types deemed it impossible to obtain trap speeds in the 300mph range...that was before the spinning tire effect was carefully considered.
Based on the following, it will be quite some time before the electrics are doing 320+mph and 4s in the 1320.
Some interesting Top Fuel dragster facts:
* One dragster's 500-inch Hemi makes more horsepower then the first 8
rows at Daytona
* Under full throttle, a dragster engine consumes 1 1/2 gallons of
nitro per second, the same rate of fuel consumption as a fully loaded
747
but with 4 times the energy volume.
* The supercharger takes more power to drive then a stock hemi makes.
* Even with nearly 3000 CFM of air being rammed in by the supercharger
on overdrive, the fuel mixture is compressed into nearly-solid form
before
ignition. Cylinders run on the verge of hydraulic lock.
* Dual magnetos apply 44 amps to each spark plug. This is the output
of an arc welder in each cylinder.
* At stoichiometric (exact) 1.7:1 air/fuel mixture (for nitro), the
flame front of nitromethane measures 7050 degrees F.
* Nitromethane burns yellow. The spectacular white flame seen above
the stacks at night is raw burning hydrogen, dissociated from
atmospheric
water vapor by the searing exhaust gases.
* Spark plug electrodes are totally consumed during a pass. After 1/2
way, the engine is dieseling from compression-plus the glow of exhaust
valves at 1400 degrees F. The engine can only be shut down by cutting
of
it's fuel flow.
* If spark momentarily fails early in the run, unburned nitro builds
up in those cylinders and then explodes with a force that can blow
cylinder
heads off the block in pieces or blow the block in half.
* Dragsters twist the crank (torsionally) so far (20 degrees in the
big end of the track) that sometimes cam lobes are ground offset from
front
to rear to re-phase the valve timing somewhere closer to
synchronization
with the pistons.
* To exceed 300mph in 4.5 seconds dragsters must accelerate at an
average of over 4G's. But in reaching 200 mph well before 1/2 track,
launch
acceleration is closer to 8G's.
* If all the equipment is paid off, the crew worked for free, and for
once NOTHING BLOWS UP, each run costs $1000.00 per second.
* Dragsters reach over 300 miles per hour before you have read this
sentence.
Do really dense people warp space more than others?
Why don't you read the F1 rules ?
Transmission
Transmission
Only two wheels may be driven and automatic gearboxes are banned
Each individual gearchange must be initiated by the driver
The minimum number of forward gear ratios is 4 and the maximum is 7
All cars must have a reverse gear operable any time during the race when the car's engine is running