Why doesn't NASCAR use direct fuel injection?

[bil588]

Any reasons?

[duke_toaster]

I don't know, probably because they have an irrational phobia of technology that isn't from the 30's, it does make it harder to have TC though.

[Adam43]

They simply don't want to, I guess. Ultimately there is no need either.

[Knowlesy]

Personally, I don't sit up at night worrying about this.

Everything works fine as is.

[gachjoel]

i was always under the impression that nascar ran engines with an original format and not make it in to a techno sport thing like most series.
They run well
they race well.
If it aint broke
Why fix it.
imo

[AU N EGL]

358ci motor and 750 bhp Enough said

[bil588]

Originally Posted by gachjoel

i was always under the impression that nascar ran engines with an original format and not make it in to a techno sport thing like most series.
They run well
they race well.
If it aint broke
Why fix it.
imo

but Mercedes-Benz used dfi in the mid 1950s...

[broadrun96]

I have seen reasons listed for the exclusion of any FI tech in the cars ranging from cost to with minimal electrical runnings under the hood the easier it is to limit other things not legal from being installed, mainly TC and other systems. But this is the series that was almost removed from 1/3 of their tracks due to the use of leaded fuel until last season. Personal opinion that running a nascar developed standardized FI system in the cars would be the safest thing to do on superspeedways, but that would minimize the "big one" chances and as we all know most of the tv coverage is all about those wrecks.

[mmciau]

Possibly because the Technicians can effectively restrict the engines with the restrictive plates under the carburettors and that has a immediate fix with the air/fuel ratio.

DFI/FI would possibly more difficult to restrict because a restrictor on the air intake wouldn't necessarily be so effective or easily regulated.

("or the straw chewing, hill billies of the south-east can't spell fuel injection!!!!!")

Mike

[kelvin88]

I'm sure if you asked someone from nascar they would simply say "why should they?" Why introduce a technology that they dont need? Carbs work fine.

[duke_toaster]

Originally Posted by kelvin88

I'm sure if you asked someone from nascar they would simply say "why should they?" Why introduce a technology that they dont need? Carbs work fine.

Eh ... how many road cars can you buy with carbs?

358ci motor and 750 bhp Enough said

Surely if they wanted to restrict power the best way to do it is to have engines smaller than 5.7 litres ...

[Adam43]

I see no reason to change. It is a bit backwards, but so what? It is different too, changing would just make it the same as other series out there. Dull.

You can't buy cars with carbs, but that doesn't mean it doesn't work. Mercedes and others used FI over fifty years ago? Again, that doesn't mean it is broke.

I think the suggestion that NASCAR have chosen a route because it is more dangerous and attract higher TV ratings is unfair.

[AU N EGL]

The NASCAR powers that be really dont want computers in the race cars. Changing computer code would be too easy and too easy to hide from the tech inspectors.

So by keeping the one carberator and not using fuel injection, no computers.

and as for going to a small displacement engine, that will not happen for a long long time. Hell NASCAR just discovered aerodynamics COT, when the remainder of the racing world starting useing aerodynamics back in the early 60s

[Knowlesy]

I don't think it was a case of discovering, just not wanting it. Or needing it for that matter.

And NASCAR restricting aspects of cars for the "Big One", for TV ratings? Purlease.... So they spend ages working on safety of the cars and suchlike but still want the most dangerous shunts imaginable. Yes, that is logical.

[kelvin88]

Originally Posted by duke_toaster

Eh ... how many road cars can you buy with carbs?



Surely if they wanted to restrict power the best way to do it is to have engines smaller than 5.7 litres ...

i dont understand your point. How many road cars can you buy with wings and slicks? Most of the road variants of cup cars don't come with V8s or are even rear wheel drive as far as i am aware. This isn't Production Saloons.

[AU N EGL]

NASCAR is a SHOW. It is entertainmnet. Big BIG DOLLAR entertainment.

Being in the pits during a Nascar qualifing sesson and seeing the grand stands filled with spectators, 100,000 or so is unbelievable.

[StuiE]

Having computers running the show engine wise won't make the racing any better, so why bother? Carbs are easy to police, aswell as less parts to break.

For a road car, EFI is preferred, for low emissions/noise/fuel comsumption etc etc but for a race car these are less important, a carb (IMO) is pretty damn close efficiency wise at WOT, it's on part throttle/decelleration where they aren't as good as EFI (in terms of driveablility/emissions, consumption blah blah). This makes it an additional challenge for teams, which is a good thing, rather than tuning an ECU where everything will be perfect.


Basically, imperfection makes it better.

[Tim Falce]

Originally Posted by duke_toaster

Eh ... how many road cars can you buy with carbs?

How many road cars run at a constant 180+mph for 2 to 3 hours at a time?
If you just need a constant flow of fuel/air at a more or less fixed rev range there is no need to go to all the extra engineering and electronics needed when a carb is just as efficient.

[gttouring]

i bet its the same reason most non stock classes in the SCCA run Carbs
it can be policed by anyone with a set of pictures and a measure.
weber DCOE 45 have a limit to power no matter what you do as does a holley 350CFM carb
yes you can run spec injectors, inspection might take longer to measure the injector nozzle spray pattern and size and the associated sensors to make sure they all read in the same range and none are tweaked to work different.

i think it come down to consistent and equal performance of the cabrurator, more variables cuase more money to be used to exploit the nuances.

beside RYR engine and hendrick motors were dyno'd at 835 horsepower last year... ZOINKS!
imagine what they do now... (from hendrickmotorsports website "Nextel Cup “open”, or non-restrictor plate engines, run over 800-horsepower and Busch Series open engines run at over 700-horse power"
toyota truck motors simliarly were pumping out 710hp befor it was in the car...
so no worries on power and reliability
fuel injection the ECU is the problem- even F1 objects to a spec ECU (its going to happen isn't it though)- that's where the magic would happen.

[bil588]

Originally Posted by kelvin88

i dont understand your point. How many road cars can you buy with wings and slicks? Most of the road variants of cup cars don't come with V8s or are even rear wheel drive as far as i am aware. This isn't Production Saloons.

Super cars come close.

[chemhead1]

Originally Posted by bil588

Super cars come close.

Last time I checked, my neighbor's Toyota Camry wasn't in the same league as a Pagani Zonda C12S.

[AU N EGL]

Originally Posted by gttouring

beside RYR engine and hendrick motors were dyno'd at 835 horsepower last year... ZOINKS!
imagine what they do now... (from hendrickmotorsports website "Nextel Cup “open”, or non-restrictor plate engines, run over 800-horsepower and Busch Series open engines run at over 700-horse power"
toyota truck motors simliarly were pumping out 710hp befor it was in the car...
so no worries on power and reliability
.

That is why IMHO that Pocono is one of the best tracks. Long, but not a restrictor plate race. Plenty of Giddy up

[R59]

The restrictor plate argument is probably the best one in this "bun fight".
You just change the plate to suit the track. No re-jetting should be necessary.

However, you tend to run a higher static compression ratio with a small restrictor as it's pretty asmatic. It's the only way to get the VE back up with the engine being strangled.

And yes, it's amazing the amount of pony's these flat tappet engines push.

With EFI, if you change the air restrictor, the map has to be changed. Re-mapping costs much more.

Ultimately, the engines will push the same power for the same CFM through the inlet, it's just that a EFI (with fully mapped ignition) will give far more mid-range power and driveability.

So now tell me why you need to use EFI on an engine that runs Talledega or Daytona - flat out for 500 miles?

I'd say that the reliability would suffer on the short or road courses where more grunt from the engine starts to take it's toll on the drive train.

EFI in this type of car was only ever tried in the ASA Pro Tour cars, though they all used the same GM Vortec ASA crate motors(a dry sump LS1), regardless of the body shape (Chevy Monte Carlo, Ford Taurus, Dodge Intrepid, or Pontiac Grand Prix). That series would have flourished had it not been for MTV.

[Jacko44]

If it ain't broke don't fix it

[gttouring]

ofcourse it would allow for some innovation and possibly some better drivability overall and better racing- but yes the expense of creating fuel maps for driving styles/ tracks and software to deal with cheating and multiple fuel maps and trims per engine like IRL does...
it would be a mess.
of course they could go with TPI (throttle port injection) a natural evolution of the carb...and start there to ease into it.
but it isn't broke aso why mess with it Fuel economy- in nascar again? or any racing...they'd be better switching to alcohol or ehtanol/methanol first.