2016 Viper ACR Smashes 13 Track records

[ViperDave]

chuntington101 said:

That really makes this even more impressive. The aero doesn't look anything out of the ordinary for a track style car. Splitter and canards at the front and a decent sized rear wing. Does anyone know what the actual downforce figures are? The US guys are saying it's very high. Also has anyone got any links to what the splitter looks like from the bottom? I wounded just how race car it really is.

The Gen4 ACR had 1000lbs of downforce at 150mph I think the Gen 5 has pushed that up to 1200 - 1500lbs. As for what it looks like underneath again i can speak for a gen4 and the gen5 will be a further evolution on that. But the Gen4 splitter is flat in the center section and extends back about 3 feet where there is about a 10" gap before the flat bottom of the sump and then the belly pan all the way to the diffuser at the rear, all those element coupled with the floor pan of the cabin the underside is flat and filled in with just the cut outs for wheels and suspension and a NACA style vent to draw cooling air over the rear transmission

on the outer thirds of the splitter the rear starts to curve up (presumably creating low pressure) drawing air up past the exhaust headers and out of the bonnet vents and side gills. On the Gen 4 the adjustable support wires are hidden behind the bumper but you can see them out front on the Gen5. The spliter itself is bolted directly to the lower frame rails with additional support and sealing to the lower facia and outer edges, so catching it on a curb stone when parking is rather dramatic and you certainly know you have stopped followed by a twinging in the wallet department. So if you see an ACR parked with its tail hanging out of the space and a big gap to the curb, please dont post a pic on the bad parking thread.

It is very much what you would find on a race car and is certainly not a 4" plastic molding body kit stuck on the bottom of the bumper. I'm not certain of the exact changes between the Gen4 and 5 but they appear to the on the basis of more and tweaked, the splitter looks a bit bigger, the wing is slightly bigger and is duel plane, i think they have put a lot of extra work in the rear diffuser area as now it has removable rub strips whereas the gen 4 diffuser was the same as on the standard car (not insignificant)

[ViperDave]

this is the GEN4 splitter

[chuntington101]

Dave, are they recesses either side of the middle section? Are they a sharp transition or a gradual one? I have seen these used before on aftermarket corvette spliters and it's these sections that cause the low pressure underneath the car and help generate front downforce.

1500lbs at 150mlh is a hell of a lot! No wonder the Gen 5 was touching 1.9 lateral Gs! Lol

[ViperDave]

yeah looking at that picture i have myself questioning my own memory, and i have to shamefully admit that when i took the splitter off a couple of months back i did not spend the time i should have to admire its beauty as by the time i had done the job that needed its removal i was well and truly at the time and point of "get the dam thing back together and done"

But if you are referring to the area which looks recessed and has 2 of the 4 frame mounting holes in it, then I'm 99% sure that surface is flat from underneath, I think what is happening though is the front of the splitter is 10-20mm thick but that goes down to 2-3mm where the frame bolts go through, so i think that area looks recessed as its that transition of thickness on the upper (non airflow) side.

The sections either side of the center though do have some shape, so going left to right on the above pic from the center there is a step up transition beside the frame center section and then two smaller steps back towards flat further out with a small flat (front to rear) section again before a further step back up for the shape of the outside end of the spitter and edge lip. If you csn follow any of that.

Front to back the transitions are gradual and in an upwards direction which whilst I'm no aero engineer would cause a vacuum and acceleration of the airflow and therefore down-force.

Did i say it was flat underneath earlier!!! opps

Here is another diagram showing the gen 4 aero and the down-force chart for the Gen4, which had the 1000lbs at 150mph. Dodge have been a little more cagey about the figures for the Gen5 and i'm not sure why that is, the 1200-1500lbs figure could be at top speed rather than 150mph in order to make them sound like a bigger step from the gen4, i guess we will never really know unless someone tests it or they release the same info for the gen5. But i think its safe to say there are a few fat blokes sitting on the front and quite a few more sitting on the wing when doing a decent bit of speed.

[ViperDave]

I found a pic of what could be (is claimed) the Gen 5 splitter, Its pretty similar to the Gen4 in shape but additionally has an upwards curve in the center section, Would be interesting to see the airflow handling around the sump and bottom of the engine though.

[chuntington101]

If the above is the case, that's pretty much a race splitter used on the road!!!!!

But it looks a lot like the corvette c07 with the profile of the leading edge!

Edited by chuntington101 on Friday 6th November 20:05

[ViperDave]

It is. The front profile is the road configuration, I assume the Gen5 is the same but the Gen4 comes with two versions of the leading edge, you can see them both in the pics above, the street version is cut back to help with catching on curbs and presumably pedestrian safety, although i think it still wouldn't do ankles any good. The full track extension replaces that cut back strip with one that fills in the front to a more normal round profile as you would find on a race car and makes a noticeable difference to the handling even at road speeds.

[gt500nick]

Will post more pics tomorrow after doing a photo shoot on both vipers.

Also started discussing a new acr with dealers over on usa, will however mean the gen 2 will have to be sold

[gt500nick]

Will post more pics tomorrow after doing a photo shoot on both vipers.

Also started discussing a new acr with dealers over on usa, will however mean the gen 2 will have to be sold