1969mod for GPL released today !!

[Arturo_Pereira]

http://1969gpl.speedgeezers.com



Review of the mod

http://www.simhq.com/_motorsports2/moto ... _070a.html

[PTRACER]

Brilliant! Welcome to the forum, by the way, Arturo

I have to get back to college now, but once it's finished, I'll download straight away!

Are skins available for most/all drivers of the 1969 season, or were only 20 made?

[flyinsii]

Wahey, happy bloody christmas or what

[Arturo_Pereira]

Brilliant! Welcome to the forum, by the way, Arturo

I have to get back to college now, but once it's finished, I'll download straight away!

Are skins available for most/all drivers of the 1969 season, or were only 20 made?

Hi
I visit this forum frequently but there is little I can add to its brilliant content You and all the forum members are doing a great job imho

About the 69mod, it includes the respective AI files so we can race with the majority of the 69mod RL drivers. Some had to be excluded because there was no way to include them all, though maybe there will be some addons in the future.
This release only includes the High Wing carset. The low wing and the med wing carsets will be released next year, so to have a complete 1969 season at hand

[PTRACER]

That'll be great, I can't wait!

I've driven it a little bit, and I'm impressed! I noticed some clipping problems with the Lotus 63, though. When I turn it over, the engine disappears Guess I'll have to keep all four wheels on the ground

The cars have got a lot of grip and turning ability. I think I'm going to be faithful and stick to my Lotus 49 (well, the 49b anyway) while playing the mod...I've only tried the Lotus 63 at Monza so far, and well...I got lapped. Pretty slow in a straight line!

[Arturo_Pereira]

Hi
I think this information may help to a better understanding of the complexities of wings, and to use them in a useful manner with the 69mod cars

I guess that you will find of interest some articles and comments about the wings effects and the 1969 F1 cars

Here they are:

http://rapidshare.de/files/7352682/Inte ... n.zip.html

http://rapidshare.de/files/7352760/Cosworth.zip.html

http://rapidshare.de/files/7353114/Airfoil.zip.html


"This is the way I INTENDED the wing mod to work:

With no wings attached, the body and tires create a lifting force on the
car. This causes a reduction in grip that is proportional to the square of
the speed. The car should feel light and "floaty" at high speeds.

Attaching wings that are adjusted to 0 degrees adds a small amount of
downforce and drag but the lift is still there and still causes a reduction
in grip as the speed increases. This or no wings should be best on circuits
with long straights.

At about -4 degrees the downforce from the wings should be about equal to
the lift from the body and tires. The grip will be more or less constant
throughout the speed range. This is the equivalent to the assumption Papyrus
made that there is no lift on the 67 cars. This should feel like the 67's
with more grip, more power, more weight and more drag.

From -4 to -15 the downforce from the wings is supposed to exceed the lift
and grip should increase with the square of the velocity. My intention was
that -8 to -10 would give the best lap times for most circuits.

As you approach -15 degrees the wings begin to stall and drag increases
rapidly as the downforce continues to increase. This should give the best
times on small, tight circuits.

Above -15 the wings begin to loose downforce and the drag continues to
increase."

Car Characteristics
A car's handling characteristics are of course influenced by set-up as well
its it's basic design. This is also true in GPL. It is hard to differentiate
between the setup and the physics. "Extreem" setups can mask deficiencies in
the basic balance of the physics. I think this is where historically based
setups will be helpful.

Having read several driver's accounts of this period, they rarely comment on
the car's inherent understeer or oversteer, except when there is a problem
in setup or the car is 4WD. So no car (except the 4WD and perhaps the BRM
which I haven't found driver comments for) were so bad that they couldn't be
set up to handle satisfactorily.

Racing Car Design and Development, written by Len Terry and Alan Baker, in
the early 70s states "Most racing drivers today seem to prefer the car to be
set up with marginal understeer in the steady-speed state. They can then
convert to oversteer if they wish by applying more power.

This fits well with Fittipaldi's description of his first drive in the Lotus
49 (at Silverstone). He came in after 5 or 6 laps and Chapman asked him
"Hows the car doing?" He replied "Well the car's understeering just about
everywhere." Rindt smiled and said "I know how to change the car: just use
the throttle, then you will have oversteer!" "And of course he was right!"
says Emerson.

Some drivers certainly did use power oversteer.

Amon "I don't think the early Lotus 49s were particularly good (in terms of
handling). I always felt through 1967 that my Ferrari appeared to be a
better handling car than the 49, which always looked a bit difficult to
drive. Then in 1968 when they put those big wings on it became a very good
car. Chapman was the first one to do the suspension-mounted wings and they
had a huge amount of downforce. That seemed to transform the car. By then a
lot of people had DFVs but it really was the car to beat."

The 49B introduced quite extensive suspension changes (including softer
springing, longer wheel travel, reduced camber change and rear bump steer,
longer wheelbase, different weight distribution, and removal of anti-dive
and anti-squat geometry.) I suspect these improved the handling as much as
the wings. The 49B was very prone to large changes in pitch with the removal
of the removal of anti-dive and anti-squat geometry.

Jack Brabham "The big thing the Lotus 49 had over competitors, such as
ourselves, was that it had much better traction out of corners."

Jackie Stewart "Jacky Ickx's performances in the past had given us all
reason to think that in a Brabham (with which the driver has a lot of
freedom), he would be very fast against some of the more precise machines
like the Lotus."

Jackie Stewart "I don't think there was much question that it (the Lotus
49B) was the best car. My Tyrrell Matra may have been the best-built, nicest
engineered machine, but the Lotus had the ultimate edge."

Graham Hill (who drove a BT26A in practice at Silverstone) "The Brabham is
an extremely good-handling car - it might not have the ultimate in traction,
perhaps not as much as the Lotus, but it can be thrown about with impunity
and this gives the driver a lot of confidence at a place like Nurburgring."

Chris Amon "Our Ferrari was probably the best handling car that season
(1968). That '68 Ferrari was a gorgeous thing to drive, in that it was a car
you could over-drive; you steered it with the throttle, really. What it
lacked, though, was horsepower."

So in summary, the Lotus 49B handled better than its 67 counterpart, but
still required more precision than the Brabham. It had good traction, but
had noticeable squat and nose-dive. As set up, it probably had mild
understeer, easily convertible to oversteer with the throttle and even if it
wasn't as foolproof as the Brabham it could certainly be driven in a
tail-out manner.

The Brabham BT26A is a very good handling car which is easy to control on
the limit. It can't match the traction of the Lotus.

The 69 Ferrari almost certainly handled in a similar manner to the 68 car
i.e. very well and almost as forgiving as the Brabham.

It is interesting that the 69 Brabham and Lotus still share many of the
characterisitcs of the 1965 counterparts. I will see what I can find on the
Matra, McLaren and BRM.



Historically based setups
The following is a guide. We have snippets of information from 1965-1972 but
no actual setups from 1969. The closest is Rindt's race setup for Monaco in
1970, but this doesn't have all details like spring rates.

The setups used in 69 were basically full race setups. Changing ride-heights
was done if the cars were bottoming but was not done routinely as getting
corner weights correct in the very basic pit areas of the day was not easy.
So ride height was optimised around a race setup with full tanks. When
running with less fuel in practice sessions they didn't lower the car to
compensate for the lower fuel weight, the car just ran higher.

The main difference between 1969 and 1967 was downforce. Unless they
stiffened the suspension or ran higher ride heights the cars would bottom
more because of the downforce. This was one reason why most teams opted for
wings mounted directly on the suspension uprights before this was banned. It
meant that the wings didn't interfere with the suspension, and the preferred
soft settings could be used.

In Len Terry's Racing Car Design and Development, he says wheel rates for
winged cars increased by 60-70% over non winged cars by 1972. On the basis
that in 69 the wings were generating less downforce than in 72, I have
suggested a smaller increase in stiffness. When running without wings,
similar stiffness to 67 can be used and I suggest a range of stiffnesses.

The other change was a shift in weight distribution rearwards, by 2-3%, to
improve traction.

All settings should be symmetrical*

Tyre pressures free choice (symmetrical)
Wheel rate between 70 and 85 lbs/in front, and 100-150 lbs/in rear
Dampers free choice (symmetrical)
Camber free choice (symmetrical)
Bump Rubber 1.75-2.25" front and rear (symmetrical)
Toe-in Front 0 to 0.075" Rear 0.075 to 0.175" (Note no front toe
out) suggested initial toe 0.050" front 0.125" rear
Roll Bar - suggest 140 lbs/in F 80 lbs/in R as a starting point.
Stiffen or soften as necessary. Avoid rear bars more than 70% of
front. Maybe try stiffer rear springs if the car understeers too much. I am
not aware of the teams using especially stiff roll bars. The attached photo
clearly shows that these cars rolled. If possible I'd suggest not exceeding
GPLs original 200 lbs/in limit.
Static Ride Height
with 48 gallons fuel (full race) Front 2.75-3.0" Rear 3.25-3.5"
with 24 gallons fuel (mid race) Front 3.0-3.25" Rear 3.5-3.75"
with 12 gallons fuel (practice) Front 3.25-3.5" Rear 3.5-3.75"
Front Brake Bias - free choice
Differential locking 60/85 or 45/85 with 1-3 clutches. I cannot rule out the
use of lower ramp angles but keep the power side lower than the coast side.

I do have the internal gear ratios used by Lotus for a number of tracks in
1970 if anyone wants to try the gear spacing used, but perhaps the above is
enough for now.

*I've often wondered when non-symmetrical setups were introduced in F1. Some
have suggested it was Jacques Villeneuve, but yesterday I was reading
Tipler's book on the Lotus 78/79 and according to that, Mario Andretti used
non-symmetrical settings on these cars using his oval experience. The
mechanics initially put them back to symmetric indicating that he was
probably the first to do this. Certainly Lotus setup sheets from 1970 are
symmetrical.


Relative Performances
Based on 1967 WR, taking times at all 11 standard tracks as a % of the
fastest (so no track has more weight than another)

Lotus fastest
Eagle 0.4% slower
Ferrari 0.7% slower
Brabham 1.2% slower
Honda 1.9% slower
Cooper 2.1% slower
BRM 2.4% slower

Now the 69s While the relative performance of the cars will be based on
their historical performance there are a few factors which make this an
imprecise art and allow flexibility. The two main factors are development
during the season and driver ability. The main development factor which
seems to have had the greatest effect was the tyre war, with Goodyear being
behind for the first part of the season but catching up in the second half
and being ahead at Mexico.

My analysis of practice times shows there was little to choose between the
Lotus 49B and the Matra MS80 all through the season. Over the whole season
the BT26A was around 0.6% slower than these two, but when Goodyear improved
their tyres in the second half of the season, this gap was eliminated. The
M7 was around 0.9% slower than the leading two over the whole season, but as
it also used Goodyear tyres in the second half of the season the gap was
about 0.3%. The Ferrari, over the whole season was about 2% slower than the
leaders, but a fairer comparison with Amon driving in the first half of the
season it was around 0.75% slower.

So we could opt for the Brabham, Matra and Lotus to have very similar
performance, the M7 about 0.3% slower and the Ferrari about 0.75% slower.
Or we could opt for a greater range of performance for the top five, with
the Matra and Lotus the quickest, the BT26 around 0.6% slower, the M7 around
0.9% slower and the Ferrari between the two.

The BRM P139 was about 3.3% slower than the Lotus 49 and Matra. There is no
obvious reason why it should be so slow. It wasn't over-weight, and not too
much down on power (425 bhp after being retuned for more mid range torque).
The aero package looks poor and the car reportedly handled badly but, just
as Hill wasn't really as competitive in 69 as he had been in previous years
you could argue Surtees wasn't at his best and was unhappy in the team. If
you compare Surtees times with Hill the gap to the Lotus closes to 1.85%
which might be more sensible and achievable without fudging the physics too
much.

I haven't looked closely at the Lotus 63 yet. At least we can compare the
same driver in this and the 49. I'm guessing the difference will be around
2%. This is understandable given the 63 was a bit overweight and had higher
transmission losses through its use of 4WD.
"

The comments were made by 69mod makers and should be used as a reference


In any case, the 69mod physics will demand a new approach to driving these F1 cars, with or without wings activated.
This not about settings the wings ON and going to the track out of the box. As it happens with GPL, things are a bit more complicated and so much more interesting for the hardcore car sim racer

[PTRACER]

Thanks I don't suppose 4WD is simulated in the 1969 mod, is it?

[Arturo_Pereira]

Thanks I don't suppose 4WD is simulated in the 1969 mod, is it?

No, it can not be simulated because GPL can only handle rear wheel drive cars. What we found is that Chapman corrected the Lotus 63 setup close to the one of a rear wheel drive car by the end of the season. In spite of this, the car proved to be overwheigted because of the 4WD stuff and so it´s inherent problems could not be corrected and the whole project was put on hold. Basically, we did the same of Chapman, with the same results The car handles so so and, as a consequence, it is much slower than the rest of the field.
An ideal car for aliens, if you ask me

[PTRACER]

All I can say is - it's amazing! The Lotus 63 I drove was just rubbish! It's a slow car, not got much power, but got a good amount of grip and the nose of the car points where you want it to go. Handy at Monaco, but not at Monza!

I just did a race in a Brabham at Monza online...qualified 3rd, got up to the first Lesmo, and 1st place got taken out by 2nd place. I inherited the lead and stayed there until the last lap, when coming under the bridge under the old banking, the car began misfiring...I got passed at the Parabolica and finished second...by 1.62 secs Great race though, anyway!

[Arturo_Pereira]

Glad you liked them Paul
Certainly, the Lotus 63 is not a good option, much as the 1967 BRM or the 1967 Cooper.

[PTfan54]

A Matra around Spa is the most fun in GPL that I've EVER had.

[PTRACER]

Part 2 was released the other day...be sure to download