FC and TF chassis (1 Viewer)

[mick]

just for the heck of it. profiles of FC and PM. quick, crude trace program, overlayed to notice profile differences.
i believe nhra limits PM to 115" wheelbase?, and FC ranges from 110" - 120"? ... assuming equal wheelbase. not trying to suggest anything,
only showing a couple of profiles superimposed.

 

[none]

TF cars accelerate harder early, they run more speed at the 660' and since the rev limiter is RPM/time activated, they hit the rev-limiter (Timing Retarder) sooner.

Talking extremes, a TF car has gone 300 at the 660' approximately 8 mph faster then the fastest FC (I seem to remember 292) Without the limiter I believe that a TF car would continue to accelerate at roughly the same rate as a FC. Aero might let the FC make up a couple of MPH, but I don't think they would gain 8.

For a couple of years the FC limiter would come in a little more than .1 later than TF and in that .1 the FC would pass the TF in speed, hence FC running 3-5 MPH faster every week for a couple of years. Now the parameters are the limiter are the same for both, the FC running less speed (RPM) at the 660' allows it to catch up, but not to make as big a move as they did before the change to the limiter.

Alan

 

[ironpony]

So, my take on this based on some of my background and what I have read.
The TF has less initial aerodynamic drag because it has to get to a certain speed for the rear wing to create the big downforce, approx. 10,00 pounds worth.
The FC body creates more initial drag then at the 660 the TF wing and the FC body are creating similar downforce.
At the top end the TF car is continually creating more down force creating drag and the FC is coming into its aerodynamic efficiency.
On paper the FC should go faster because of better aero, the TF car is quicker because it gets to speed faster.

 

[Slowpoke96z28]

So, my take on this based on some of my background and what I have read.
The TF has less initial aerodynamic drag because it has to get to a certain speed for the rear wing to create the big downforce, approx. 10,00 pounds worth.
The FC body creates more initial drag then at the 660 the TF wing and the FC body are creating similar downforce.
At the top end the TF car is continually creating more down force creating drag and the FC is coming into its aerodynamic efficiency.
On paper the FC should go faster because of better aero, the TF car is quicker because it gets to speed faster.

This here I think. I'd guess the funny car has less drag on the big in since the whole body acts as a wing. Psi is lower, but acting on a way bigger surface area than the wing and front canard of a 300" dragster. They can get the negative lift they need to not spin on the big end without as much of a drag penalty. That's my guess.

 

[Slowpoke96z28]

Now imagine if we added all the aero knowledge man has to a funny car. Flat bottom, rear diffuser, dsr the spoiler, etc. It'd be insane.

 

[Cliff]

The front wings on T/F cars are about the same size as the rear wings years ago, say 1970's. Also, I understand that T/F rear wings must stay the same thru the run, per NHRA rules. Was told that if the wing could be adjusted during the run, would result in less drag and more MPH. Interesting to me how 2 totally different designs work to produce basically the same results, ie: F/C & T/F.

 

[Slowpoke96z28]

The front wings on T/F cars are about the same size as the rear wings years ago, say 1970's. Also, I understand that T/F rear wings must stay the same thru the run, per NHRA rules. Was told that if the wing could be adjusted during the run, would result in less drag and more MPH. Interesting to me how 2 totally different designs work to produce basically the same results, ie: F/C & T/F.

Yea, no drs (my fingers keep wanting to type dsr lol) allowed by NHRA. Doesnt stop it from being researched though outside of nhra competition though or on some non-sanctioned track/event . If I had that metric money lol.

 

[mick]

would a single element rear wing be allowed? i think the rules mandate a 3-element design with flat, parrellel spill plates?
don't think the rules would allow, but what about an upside down curved winglet on ends of rear wing? or curved up winglets on end of front wing? (think F1 / a350)

 

[mick]

this design was popular for a while; now it seems the 'cutout' is gone and back to a more streamlined plate narrow towards front and a little wider to rear of plate.
sidenote: these early salinas cars, and his pit tool boxes, were adorned with possibly the best paint i've ever seen a race car. ok, include head's bonzai group too.

 

[NITRO JUNKIE]

this design was popular for a while; now it seems the 'cutout' is gone and back to a more streamlined plate narrow towards front and a little wider to rear of plate.
sidenote: these early salinas cars, and his pit tool boxes, were adorned with possibly the best paint i've ever seen a race car. ok, include head's bonzai group too.

What was the thinking for the cutout, just trying something different?

 

[mick]

What was the thinking for the cutout, just trying something different?

best guess would be some sort of vortex generator? i'm really not sure.

 

[mick]

the canard wing (with outer spill plate) in front of rear tire on heritage series dragsters is so much different than the deflector plate used on TF chassis.
anyone know reasons why? is each suited perfectly to it's respective class? or would heritage style canard work equally as well, or better, on a TF chassis?

 

[J. S.]

the canard wing (with outer spill plate) in front of rear tire on heritage series dragsters is so much different than the deflector plate used on TF chassis.
anyone know reasons why? is each suited perfectly to it's respective class? or would heritage style canard work equally as well, or better, on a TF chassis?

I doubt any of the Heritage T/F guys even know the answer. "Everyone has a Canard wing", so everyone else puts one on, too.

I wouldn't be surprised if the same rational is in effect for NHRA T/F cars. Though it is far more likely that an NHRA T/F dragster has been in a wind tunnel to at least verify if those things actually do anything.

 

[Slowpoke96z28]

the canard wing (with outer spill plate) in front of rear tire on heritage series dragsters is so much different than the deflector plate used on TF chassis.
anyone know reasons why? is each suited perfectly to it's respective class? or would heritage style canard work equally as well, or better, on a TF chassis?

The deflector plate makes way more (-)lift. I can't remember who tested it properly to say, bu may have seen what happens when one comes off.