SimRacing.org.uk

The UKGPL F2 Club Challenge Fun Races round 2


To celebrate the end of this great Season 22 and to do a first step to F2s for some of you.
We will do 6 x 2 fun races with all the new F2 cars.  
Which is the best F2 car for you?

There will be 2 intermediate short races of 25-30 mins on the same track.
You have to use a different car in each race - but up to you which one you start with.
 
This will be the schedule:

Date	Day	Time	Car	Track	Laps
15/05/2012	Tuesday	20:45 UK	McLaren  vs  Lola FVA	Oulton Park 1967	16 Laps
18/05/2012	Friday	20:45 UK	Protos    vs   Lola BMW	Snetterton	18 Laps
22/05/2012	Tuesday	20:45 UK	Cooper   vs   Lotus 41	Goodwood	x Laps
25/05/2012	Friday	20:45 UK	BT24      vs   Matra MS5	Brands Hatch	x Laps
29/05/2012	Tuesday	20:45 UK	Ferrari    vs   BT14	Mallory	x Laps
01/06/2012	Friday	20:45 UK	Matra 7  vs   Lotus 48	Silverstone	x Laps

The second race will be the Protos    vs   Lola BMW at Snetterton 18 Laps

Race List	=	IGOR
Server	=	UKGPL_8
IP Address	=	tba
Race date	=	Friday 18/05/2012
Race Time	=	first Qualification (25mins) starts at 20:45 UK time (= 21:45 CET)
Track	=	Snetterton snett67 (ftp://ukgpl3.dyndns.org/Tracks/Snetterton/)
Variant	=	The new F2 Mod
Damage Model	=	INT - Unlimited Shift+R is permitted but each must be followed by a Stop & Go of a minimum 0,001sec. ;)
Race length	=	~30 min -> 18 laps
Password	=	see above (#post_event_password)
Replay	=	you will get here (ftp://ukgpl3.dyndns.org/replays/Fun_Races/)

GLA and FUN

Who wants a drive should sign up here – everyone is welcome!

I will be present.

I should be there, bleary eyed, coffee in hand...... :D

I will be there and I promise to behave myself  ;D

Yes Jason you need to set a good example now ;)

Yes please.  Another new track,  another 2 new cars.

Cheers,
Dave.

I would like to try a few races- (cant make the 18th though) I have never tried the F2's and don't even know what they are  :D

Thanks
John

Should be OK for this  event. Hopefully a bit more "on track" than at Outlon.

So spinny you can't even spell it, let alone race on it ;)

I hope to be there too.

In

some questions on driving F2

1. how good or bad do you think the default set ups are ?

2. do you use default set ups out of the box or modified insome way ?

3 do you think it best to max out the revs in all gears or short shift ?

I'm asking because as an F2 newbie my times are particularly bad on the tracks I have tried so far and have tried both the "out of box default" and "my own modified default" but not satisfied with the results .

My own feelings on the default are that the gearing isn't too bad but the suspension , tyre pressures , and differential seems all wrong but I cant seem to make much progress in the way of improvements .

what do you  think  :-\

Please send answers on a postcard to ..

F2ustrated Wigan England  :'(

i think they are brilliant... but then i did them (well most of them)


i have a different geatbox , diff and tyre pressure , but this is dependent on your driving style .


the FVA engine is pretty bulletproof so you can max the gears , however i would have a long top gear for getting a tow .


the defaults were made to be safe for "less skillful" drivers , that means they are towards the under steering end of setups . and people that like more over steer should start adding to the rear rollbar first , i'd start by adding steps of 10lbs till you get close to the amount of over steer you like . all the setups were made the same way so if you add say 15lbs to get the feeling you like in one car then add that amount to the rear rollbar of the other cars .

as for diff use your normal 65 diff or if you don't do 65 your 67 one .

tyre pressure is more to do with driving style , if they are getting to hot take some air out , if not heating put some in .

john

I should be there.

Apart from the steering ratio, I used the default setup for the Oulton race and it was great (I had to change the steering ratio to make it compatible with my G25 settings, I always use a 5:1 ratio).

that is pretty cool JR.

first thing is to congratulate John on his set ups and thank him for a job well done

Straight off I noticed  the understeer ( you could hardly fail ) I thought this was a product of the diff (all them clutches ) so tried a 45/60/2 which helped ,  then started playing with ARB's and tyre pressures so it felt better yet (to my style) but the lap times where about the same as before , though a slight improvement  ::)

My cocnclusion was that I was now losing time gained in corner exit speed in straight line acceleration,  which is what 5 clutches gives you (spool axle) hence the question about short shifting to reduce wheelspin with a loose diff ?

maybe I should try shorter gears as well , I didnt have much time in qually and had no time spare to practise off line so hopefully will improve as the series progresses (along with everyone else)  ;D

 

i think you have a misunderstanding how the clutches work , it's not the number but how they work with the ramp angles .

a 85/85/6 will have more friction than a 70/70/1

for more info on friction you could take a look at the graphs that somebody made here ..

http://srmz.net/index.php?s=6df2a4cde3b7c759e88404b614704db5&showtopic=6141&st=0&p=52295&#entry52295

john

hmmmmm. ::)

Well I found default setups did not suit me at all...sorry John  ;)

So yes, I changed springs..shocks...rollbars....gearbox...diff...clutches.....brake balance and steering ratio.

Of the cars I have tried so far .. Lola FVA, Mclaren, Lola BMW and Protos... they all seem pretty similar with only minor differences in setup. The exception so far, being the Protos which I find does not settle into the corners like the others, but I am still playing with the setup on that one so that migt improve.

My aim in building a setup, is to get the car to do what I expect it to do and not give me any nasty surprises like snap oversteer mid corner or locked brakes and no turn in at the end of the straight. I still have not fully mastered or understood how all the parameters in GPL interact, but I am gradually able to find the adjustment I need to correct a given problem.

One useful thing I have found is that sometimes when you have a car that insists on swinging the rear end around in a corner, it is not always a case of trying increase the grip on the rear axle. Instead I often work on reducing the grip/bite at the front, thereby removing the "pivot point" for the car to work around. The ass cannot sweep around if the front wheel does not give it a lever to work against...simples..maybe

well the protos is made of wood , so i guess your setup tricks woodn't (gettit ! wouldn't) work .

john

Bernie,
I struggled with the default - so I ended up building a set up by trial & error which seems to work for all the F2 cars I have driven. It's very different from the default & also quite different from my base set-up for a 65 or a 67.
If you PM me with an e-mail address I can send you my set up for Snetterton.

I'm not sure if your offer was aimed at me Billy, thanks for the offer but I have found no probs in getting the cars to behave. All have responded to my setup mods well, except for the Protos thus far.

 It does seem that the same setup will work for many of the F2 cars with just minor tweaks. I am grateful that this fun series allows us to try all the cars and compare ourselves against real competition.  Until now I have not really found the time to really experiment with these cars....so thanks Axel. ;) ;D

John,
So I do understand that the torsion of the Protos chasis is more than all other cars?

 

Why dont post your setup ?
It's interesting for all, imho.

Clive,
My post was adressed to Bernie, per his request. Based on your performance at Outlon maybe we need to give you a different set up to slow you down a bit.
Alex - not sure how to go about posting a set up?

BTW - the Protos was an absolutle pig to set up. The handling is very different from the other cars.

well most of the cars are very similar with weight distribution , weight and power ( most have the same engine ) , from the heaviest to the lightest the difference is only 16kg ( 67 is 125kg and 65mod 30kg ).

john

I'm not at home now, but you can try this old site to easy obtain a publishable setup:
http://www.gplsc.net/gplsc/compare.jsp

Try this Johnny Ackermann setups (http://srmz.net/index.php?showtopic=7715) for Goodwood!
They are very driveable for me...

But on SRMZ! Bernie, do you still have problems with it?

Well im no expert by a long means but from what I understand you are saying that a diff with 6 clutches has more friction (i.e. more effort required to turn one rear axle before the other axle turns  ) than a diff with 1 clutch which will allow one axle to almost spin freely regardless of the other ) Or we could say 6 clutches is closer to a solid rear axle 1 clutch almost likend to a free axle ?

If we accelerate in a straight line a locked diff is always better for getting the power to both wheels because it will not allow one wheel to spin freely which is what it would do if say one wheel hit a bump and became disconnected from the road surface .

Thus losing forward momentum .

Unfortunatley a locked diff is usless in a corner because the outside wheel has to turn faster than the inside wheel , or the inside wheel (being less loaded ) will spin , losing traction , also it wants to push the car straight on (understeer )

I have seen the graphs and read the books (too many) but quite how the differential gear ramp angles work with the clutches is a whole black art to me . I thought they were used to  determine the responce time of the "bite" between the clutches

Billy[/u]

thanks I will try your set ups and anyone elses for that matter , however i always end up using my own because I think we all drive very differently (look at Clive for god's sake )

Axel

thanks for the link I have recently settled my difference with SRMZ

Any one else , your feedback is very welcome , please keep it coming   

Hi Bernie,

For me those ramp angles are also some strange numbers...

The easiest way to understand a Differential is the percentage of locking!

In the Setup Manager that comes with GEM, there is allways shown the locking percentage besides the ramp angles checkbox.
By adding clutches you raise the percentage of locking

no thats not what i'm saying ... what i'm saying is that you cannot say by the number of clutches only ! you have to see what the ramp angles are (as cookie is also saying) .

if you use setup manger or look at both graphs found here

http://srmz.net/index.php?s=6df2a4cde3b7c759e88404b614704db5&showtopic=6141&st=0&p=52295&#entry52295

everything should become clear .

john

This was my setup in Oulton for both cars:
(http://www.gplsc.net:80/gplsc/setup.jpg?p=Brabham+BT7%7c1965%7cF1%7c24%7c24%7c24%7c24%7c300%7c300%7c300%7c300%7c2%7c2%7c2%7c2%7c3%7c3%7c3%7c3%7c0.00%7c0.00%7c0.00%7c0.00%7c0.5%7c0.5%7c0.5%7c0.5%7c0%7c0%7c300%7c300%7c2.5%7c2.5%7c70%7c20%3a1%7c6%7c60%7c30%7c1%7c0%7c0%7c8%2f22-12.179%3a1%7c20%2f36-7.971%3a1%7c18%2f26-6.397%3a1%7c19%2f23-5.361%3a1%7c26%2f26-4.429%3a1%7c26%2f26-4.429%3a1%7c7%2f31%7cENG)
Protos have same chassis with differential ratio one tick shorter, Lola BMW two tick shorter with 5th gear one tick taller.

I have doubt that numbers given by this table are correct: clutches introduces only a retard about differential action (when it lock or unlock), ramp angles are only parameter that determines at which amount of torque there is a lock/unlock.
Clutches are a time, ramp angles are a force.

sorry can't agree with this .. if you are accelerating in a straight line the diff will be locked .

the diff can be altered , so when you apply the gas exiting a turn the rear end of the car kicks out , this is because the diff has started to lock and the inside wheel is turning more than it need for the arc it is on .

john

trust me they are correct for gpl .

john

what locks the diff ?

 

the power from the engine . hope your not forgetting the diff has two angles power and coast , simply put under acceleration it the power side angle and when your not accelerating it's the coast angle at work .

john

And don't forget:
If you brake with some assisting throttle only the power angle works!

I shall have to miss this race - I'm off to the pub to watch a live band :)

Hi ... i would like to try f2s if poss, my times are slow so will be at back and try not to get in any ones way, will wait on iGOR if server not full will join if that is ok.

 ;) as to the setup talk :

never forget GPL is just a simulation . Even , for sure , still best up till today , there is no question that physics are plain bullshit in some particular parts . track physics sometimes serves stupid turn stuff and in general car physics suffer sometimes badly :
e.c .  just for demo ; set up 80% front brake and extreme stiff front antirollbar , as well stiff front springs .
under braking into a turn , no matter left or right in reallity it must lead to heaviy understeer and the car must missed the turn in and run wide . BUT in GPL its even possible that you will lost your rear , with that kinda setup .
another example : lotta people do complain that Protos wont turn in proper .
NOT on my side , even with default setup ; Protos is doing everythingg like expected to me . BUT Lola BMW all over tends to oversteer suddenly after appex , no matter if I am on throttle or not , or still gentle tail barking ; and it couldnt cured by diff settings .

Guess thats why setups are soooo extreme different for one car&track . Depends more on driving style and hardware (wheel &pedals ) then on realistic physics.

so why the need for the clutches ramp angles etc if as you say the diff is locked all the time with the power on , doesnt make sense to me and tbh I know for a fact with an open diff and lots of power my westfield will spin one rear wheel when accelerating away from a standstill , with an LSD diff I get traction from both wheels ?

i said in a straight line ... i then said about power/coast angles .

the clutches change the amount of friction as you can see by the graphs , the diff is not a on/off switch , it is analog .

john

Nail on head Nicky

GPL doesnt model a proper Differential as far as I can see and I dont know anyone who can explain properly how it works (in GPL that is ) I have read books on tranmissions , I currently have 3 differentials in my garage , Ive taken them apart and re assembled them , but I couldnt set one up for a particular car and none of the books ive read teach me anything about the GPL diff . Neither the books ive read or John's graph means anything to me regards the GPL model, I just cant
 relate that to GPL .

I'm talking straight line acceleration

Great mod enjoyed the first race, 2nd race lola spun out several times, then pc decided to lock up, just as well as i was becoming a hazard.

i am only taking about the gpl diff , the graph shows locking friction that gets applied on power or coasting and is directly proportional to the torque load though the diff .

hope this make sense .

john

SORRY for the mass freezes and disco in second race!

Server ran fine...

First race I had low fuel and ran out of it 2 laps to go...

This track has always had inconsistent freezing, particularly near the bridge  :-\ 

Oddly enough, I had a couple of GPL crashes offline whilst I was in the pits with the Lola  ???

Thanks for putting this little series on Axel  :clap:

OK.  Good information , but I don't see how to apply it to GPL ?

the diff splits the power to the wheels , a locked diff means both wheels rotate together .

if the diff is not locked and power is going though it (torque) , then put simply the power is divided differently to the two rear wheels .

john

I think we already decided that  ;D

Heck!

....just drive it like you stole it, and the diff will take care of itself !!!   :thumbup2:

Strangely enough for me ( apparently I have a reputation for excessive smearing of rubber across tarmac!! ::) ) I find these F2's remarkably easy to drive and extremely forgiving when you exceed the coefficient of friction mid corner. It was not until I did 3-4 laps of outrageously over driving the Protos that the tyres started to lose grip and one lap treating them gently restored some sanity.

In last nights race ( yes! it should have been 2 races, but Bernie was apparently getting bored with me and pulled my plug I think  :-\) I was throwing the Protos at corners trying to find the absolute limit and even when I thought to myself   "aha smartass!! now you have really overdone it this time and you are going to suffer" I was able to persuade the car to stay at least in partial contact with the grey stuff and continue.

The one time that I lost it completely was mid race when I had lost Ron somewhere. He had been hounding me for 9 laps and occasionally he was difficult to see in the mirrors but I knew he was not far away! Then  leaving the hairpin at the end of the straight I realised that I had not heard him and could not see him either?? On the run up to the bomb hole I appeared to be clear and free, so I slowed slightly to check pribluda through the final long right hander and managed to just clip the brake marker on the inside because I was not concentrating on my driving. That contact was enough to squirt my car up and onto the grass bank facing in the wrong direction and allow me to realise that I had just squandered a good 5 second lead!!
Fortunately I was able to rejoin the track and just hold 1st spot as we croseed the S/f line and with no apparent damage or woodworm in my car. Ron kept the pressure on right to the flag and we were very evenly matched for speed in the "Wooden Wonder".

Qually for race 2 was exciting and once again Ron showed that he had his Lola BMW going just as quicly as mine, so it was all set for another tight race. Until we approached the bridge on lap 1 and Bernie used his space time continium flux generator to freeze my existence on the apex of the bend and send me to planet IGOR.  :-\

Grats to the podium of the 2nd race, it looks like it might have been a great dice to be involved in.

Thanks to Axel for the chance to get to know these cars a little better. My initial impressions are that they are like 65's but smoother and more predictable ( and slightly faster?)

Sorry 'bout that , me Flux capacitor wasn't charging properly  :D

so you understand how a Flux capacitor works but not the gpl diff !      :)

The Flux capacitor is easier to understand and please dont get me started on ohms law  ;D