Chaparral 2J what a car!

[VyPeR]

The 2J ... this is the one that loks like a wedge or the spaceship then?

I think it looks like a laundry machine on wheels. It probably uses bleach for fuel lol

 

[Jetboy.]

Ok, so we are talking about the doorstop here... Not too good on the Test Course. Short wheel base + Mid engine = Massive spinnies.

 

[~Sp33~]

Not sure what you mean. It cannot have a flat underside because the suction area needs to have the tarmac as its lower surface, otherwise the low pressure caused by the fans will have no effect.

As for sealing the perimeter, the better you can do that the more efficient the downforce is... you want to prevent air from infront, behind and to the side of the car rushing in to replace the air you are working so hard to pump out, but this seal is limited by the fact that the car is moving, so contact with the tarmac would cause friction, and the need for the suspension to be able to work. If you have solid suspension, traction becomes more difficult, the car is tricky to ride and it will buck all over the place on bumps. As it is, a problem with ground effect is that if the car bounces over a kerb or something, all the pressure returns, and you have a sudden, substantial loss of downforce, most likely in the middle of a corner where you need it most. You can't have suspension movement if the car's body is in contact with the track at rest. F1 ground effect cars used sliding rubber skirts to allow for the car's movement, and when the sliding skirts were banned, the drivers had to endure rock hard suspension.

Yeah, i heard about the rubber skirts being banned. I was just talking about why didnt they fully surround the perimeter of the underside of the car. As for the rapid decompression that you were talking about, isnt that what happened to that mercedes that did a billion flips over the guardrail?.. theres many pictures on that website mulsannes corner or whatever it is.. ( its earlier in the thread). Surely that was a massive problem with this car.

 

[Alfaholic]

Yeah, i heard about the rubber skirts being banned. I was just talking about why didnt they fully surround the perimeter of the underside of the car. As for the rapid decompression that you were talking about, isnt that what happened to that mercedes that did a billion flips over the guardrail?.. theres many pictures on that website mulsannes corner or whatever it is.. ( its earlier in the thread). Surely that was a massive problem with this car.

Yeah there is a horrible payback to aerodynamic, or static downforce, all the time. With wings, like an F1 car, you lose downforce as the car yaws. So, if you start to oversteer, the more sideways the car gets the less downforce and therefore grip it has, and the more likely it is to spin. Wings also carry a big drag penalty.

Ground effects cars that rely on venturis, like the F1 cars from 1979 to the early '80s have a smaller drag problem, but they create horrifying lift if the airflow direction was reversed. I saw a few '80s Group C cars spin, then get lifted up into the air while travelling backwards towards a barrier. That can't have been pleasant.

Fan cars rely on the fan for downforce, where as wings and venturis require motion, so fan cars get better downforce, particularly in slow corners, but there is a power penalty to drive the fan.

Cars with a flat bottom, like modern LMPs, will generate CLK style lift only if you manage to change the angle of incidence of the car (lift the nose up) and get air underneath. The effect that spun the Merc into the woods at Le Mans, I think, was similar to the force you feel if you flatten your hand, hold it in the airflow out of a window in a moving car, and then rotate your wrist so the leading edge of your hand is higher than the trailing edge. The airflow will try push your hand up.

I would expect that the Chap would not have a flat bottom, since that might hinder the effectiveness of the fans, it would probably rely more on a partially sealed engine bay, and you may find there's a lateral skirt underneath but within the wheelbase perhaps. I would think it's less likely to actually take off than a flat bottomed car. Even so, break the pressure difference, and all of a sudden you've got no grip, so bouncing over a kerp probably preceded a scary lateral slide.

This is all conjecture for me - I'm no aerodynamacist

 

[Gentry Coach]

I've been singing praises for the 2J for quite a bit now ever since jdw pointed out its ability to gain 200 in the All-Stars and GTWC. Yeah it looks like a washing machine but it can move and the tire wear is the best I've found. I still haven't been able to keep it on the Nurb yet though.

 

[jdw]

Thanks for the interesting read Alfaholic! 👍

Even so, break the pressure difference, and all of a sudden you've got no grip, so bouncing over a kerp probably preceded a scary lateral slide.

Depends on whether you regain contact with the pavement long enough to *have* a "scary lateral slide" before slamming into the guardrail.

I still haven't been able to keep it on the Nurb yet though.

No kidding! Talk about jittery... Think after a few tries I managed to be in 3rd about 2/3 of the way around. But, while it's wonderful on relatively flat tracks, on the Nurb it's just too stressful!

I will to anyone who can keep that thing on the Nurb long enough to win All Stars!!!

 

[Alfaholic]

Depends on whether you regain contact with the pavement long enough to *have* a "scary lateral slide" before slamming into the guardrail.

For the record, I didn't state that I had not managed to keep it on The Nurb.... I haven't been brave enough to even try yet

 

[INTALECT]

right now my 2J is kickin the **** out of everyone ont he nurb 24hr race by at least 2 laps at all times

 

[~Sp33~]

is that with b-spec bobby?.. Its strange, shakyness has no effect on that guy.. he has some balls

 

[SirBerra]

Before you start singing it's praises, just try to drive it down the Sarthe Circuit straight in A-spec. If you can keep it going in a straight line three-quarters of the way down the back straight at over 200 mph, I'll applaud you. Guaranteed it feels like the middle of the chassis has a flex joint in it. Then you may say that the 2J is an easy car to drive if you can manage to do that. Great on perfectly flat tracks, otherwise, hell on wheels. Believe me, I've tested it for hours on every long track with almost every suspension setup you could imagine. It cannot handle bumps and undulations very well. Good luck.

 

[~Sp33~]

Does putting that rollcage thing in it change its instability on the sarthe straight?

 

[Ezz777]

Believe me, I've tested it for hours on every long track with almost every suspension setup you could imagine. It cannot handle bumps and undulations very well. Good luck.

Have you tried raising its rear ride height by say 15 - 20 mm over the front. I find that helps a lot with the jitteryness.

 

[INTALECT]

is that with b-spec bobby?.. Its strange, shakyness has no effect on that guy.. he has some balls

yup....

right now i have over 5100 b spec points...... what pisses me off tho... good ol bobby boy cant handle the 150 mile super speedway race, eveytime he hits the corner on either side the dumbass spins out and i get lapped by like 3 laps in a matter of mins, even with the black nissan race car... whats wierd about it is when im driving the car handles just fine so why is it that the dumbass AI cant handle it?

 

[GranTuri55]

I think its a good car anyways 👍

 

[route_66]

Before you start singing it's praises, just try to drive it down the Sarthe Circuit straight in A-spec. If you can keep it going in a straight line three-quarters of the way down the back straight at over 200 mph, I'll applaud you. Guaranteed it feels like the middle of the chassis has a flex joint in it. Then you may say that the 2J is an easy car to drive if you can manage to do that. Great on perfectly flat tracks, otherwise, hell on wheels. Believe me, I've tested it for hours on every long track with almost every suspension setup you could imagine. It cannot handle bumps and undulations very well. Good luck.

What? It's fine... a little bumpy perhaps, but nothing that can't be kept under control, and it'll do 225mph stock at Sarthe. After much testing, I have concluded that on R1's, with no turbo, the 2J can beat anything the AI brings, including winning both Sarthe I and Sarthe II 24hr races (I know, I know, I've yet to put my money where my mouth is and do the race and write it up, but i'll get round to it.)

Great car (to drive. To look at? ).

66.

 

[356C]

Thanks for the interesting read Alfaholic! 👍




Depends on whether you regain contact with the pavement long enough to *have* a "scary lateral slide" before slamming into the guardrail.





No kidding! Talk about jittery... Think after a few tries I managed to be in 3rd about 2/3 of the way around. But, while it's wonderful on relatively flat tracks, on the Nurb it's just too stressful!

I will to anyone who can keep that thing on the Nurb long enough to win All Stars!!!

So, has anybody posted times around the nurburgring in a 2J?

It would be interesting to see just how fast is possible. I'm sure it wouldn't beat any of the modern LM cars, but I bet it could do under 6 minutes.

 

[Gentry Coach]

So, has anybody posted times around the nurburgring in a 2J?

It would be interesting to see just how fast is possible. I'm sure it wouldn't beat any of the modern LM cars, but I bet it could do under 6 minutes.

I did it in 6.25. I only tried it a couple of times though and with only Racing Mediums. A few more practice runs and Super-Softs and it could probably finish in under 6.00.

 

[Caio]

A snowmobile engine that works like a vaccum cleaner?????????

OOOOOHHHHHH the 70´s.

Too much acid for everyone............

The 2J had 2 engines, a Chevvy V8 and a second Rockwell snowmobile engine, mounted at the rear. This produced an 55hp, which "sucked" the car down towards the road. The lexan side skirts created a vacumn under the car. Total downforce = around 1500lb.

http://www.mulsannescorner.com/chaparral2j.html

also: http://www.ashcom.homestead.com/Elford2J.html

Quote from a guy who drove the car:
"It was a semi-automatic transmission, it wasn't fully automatic. It had a three-speed transmission with a torque converter and a lock-up at 5,000 rpm. It was quite complicated to get it running. The steering column went down between your two feet so the left foot could only work the brake and the right foot could only work the gas pedal."


Alex

 

[ali3n]

hard to drive

 

[jdw]

I did it in 6.25. I only tried it a couple of times though and with only Racing Mediums. A few more practice runs and Super-Softs and it could probably finish in under 6.00.

You are my hero.

I tried to use it in All Stars and failed. Could NOT keep that damn thing on the track.

 

[Thrust-Master]

i havent had the pleasure of driving it, but competing against it, i was pleasently surprised of its incredible features!

 

[meister_dan]

You are my hero.

I tried to use it in All Stars and failed. Could NOT keep that damn thing on the track.

Also tried it but it can't keep up with the Audi R8..

 

[thebindley]

i disagree i have blown away all these LMP and grop C cars in the 2J and am a big fan of its big block chev, i have to concede that it is a bit trying down the straights at sarthe, but it's immense speed makes up for it, i even have the fastest time on amalfi in it. not bad for 1970!

 

[s12ken]

I believe this flying brick has more to it than it seems hell it got disqualified before it started racing (thank you Gordon Murray). I've driven it and loved it, takes a bit of getting used to having only 3 gears oh well! hahaha

 

[Master_Yoda]

looks like **** handles like **** there for its ****

 

[Alfaholic]

I believe this flying brick has more to it than it seems hell it got disqualified before it started racing (thank you Gordon Murray). I've driven it and loved it, takes a bit of getting used to having only 3 gears oh well! hahaha

Hmmmm I think Murray's only connection with the 2J is that it inspired his 1978 Brabham F1 fan car, which is the only car I know of that has a 100% win rate outside of a 1 make series. I've read reports when the Brabham was seen stationary in the pitlane, someone noticed that it settled towards the road surface when revved. It raced once, and won, in the hands of Niki Lauda. This was in the year of arguably the most beautiful formula 1 car ever raced - the original Black Beauty, the Lotus 79. The '79 was revolutionary in formula 1 as the first ground effects car, and until this race nothing could keep up with it. Mario Andretti in the Lotus later commented on how Lauda had overtaken him on "an impossible line". He overtook him around the outside on a bend . I believe the Brabham was withdrawn voluntarily after that, but never actually banned, although it was the subject of huge controversy from the moment the opposition first clocked the huge ducted fan bolted to the ear end.

Chaparral, as far as I can gather, were real aerodynamic pioneers in motor racing. I believe they were the first to use inverted wing sections, and they came up with the vacuum cleaner car concept. I am sure a small bit of research will dig up other examples of their obvious ingenuity.

 

[Gentry Coach]

So, has anybody posted times around the nurburgring in a 2J?

It would be interesting to see just how fast is possible. I'm sure it wouldn't beat any of the modern LM cars, but I bet it could do under 6 minutes.

Finally did it today with Super Softs: 5.57.773 (after about 10 tries). It wasn't pretty, or completely clean, but it was fun.

 

[slotcarrod]

looks like **** handles like **** there for its ****

Oh Yoda! What shame you bring!

Learn to drive, you must! A true master, this would know.

 

[Cole]

You know, the car for me is the Nissan GTR LM racecar. It's not a Skyline. Just GTR. It has exellent no perfect shifting. Not to mention 7 gears. It starts out with 626 horsepower. but when you equip the best turbo, it goes all the way to 1000.

 

[Cole]

You know, I orginally thought the 2J was jet propelled because it had 2 ducts in the rear that kind of looked like jet boosters.