UKGPL Season 22 F2 Club Challenge - Snetterton - May 18

[1967driver]

This was my setup in Oulton for both cars:

Protos have same chassis with differential ratio one tick shorter, Lola BMW two tick shorter with 5th gear one tick taller.

[1967driver]

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 ?

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

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.

[john roberts]

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 .

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

[john roberts]

at both graphs found here

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

I have doubt that numbers given by this table are correct

trust me they are correct for gpl .

john

[bernie]

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

what locks the diff ?

 

[john roberts]

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

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

[Cookie]

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

[blito]

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

[roguk]

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.

[NickyIckx]

  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.

[bernie]

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

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

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 ?

[john roberts]

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

[bernie]

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.

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 .

[bernie]

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

I'm talking straight line acceleration

[roguk]

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.