newb question - problems at top speed

[grnshwrcrtn]

Hello all this is my first post/thread don't know if this has been covered elsewhere and i'm sorry if it has, but whilst trying my shiny new jaguar XJ220 LM on the test track I noticed that the car would top out at around 215 and then decelerate by a few mph and then accelerate, decelerate etc wondering if you folk at GTP could tell me whats happening and if there is any settings I could change to iron this out

thanx in advance 👍

 

[EGFerio]

Hello all this is my first post/thread don't know if this has been covered elsewhere and i'm sorry if it has, but whilst trying my shiny new jaguar XJ220 LM on the test track I noticed that the car would top out at around 215 and then decelerate by a few mph and then accelerate, decelerate etc wondering if you folk at GTP could tell me whats happening and if there is any settings I could change to iron this out

thanx in advance 👍

May be you a hitting the rev limiter.
Change your gear ratios.

 

[grnshwrcrtn]

thanx for your quick response but i really am new at this, i don't suppose you could be a bit more specific, how would i change them, bigger/ smaller, what gears would i change?

thanks again

 

[EGFerio]

thanx for your quick response but i really am new at this, i don't suppose you could be a bit more specific, how would i change them, bigger/ smaller, what gears would i change?

thanks again

There are 3 ways to change it by the final drive or easy set up (with the slider from close to wide)

you can increase top speed by decrease final drive ratios. eg: from 4.000 to 3.500

or you can move the slider for quick adjustment. eg: 12 to 14

the final way is a little more complex due to adjusting individual gears and quick adjusttment to achieve best ratios to power band to different courses. you can try this one when you comfortable with complex set up. I'm sure there might be a guide some where about gearbox set up.

eg: 6 speed

1st - 3.125 1st - 2.512
2nd - 2.103 2nd - 1.8
3rd - 1.495 3rd - 1.5
4th - 1.125 4th - 1.25
5th - 0.972 5th - 1.02
6th - 0.840 6th - 0.921

Final drive - 4.785 Final drive - 4.2

this is just and example

 

[grnshwrcrtn]

There are 3 ways to change it by the final drive or easy set up (with the slider from close to wide)

you can increase top speed by decrease final drive ratios. eg: from 4.000 to 3.500

or you can move the slider for quick adjustment. eg: 12 to 14

the final way is a little more complex due to adjusting individual gears and quick adjusttment to achieve best ratios to power band to different courses. you can try this one when you comfortable with complex set up. I'm sure there might be a guide some where about gearbox set up.

eg: 6 speed

1st - 3.125 1st - 2.512
2nd - 2.103 2nd - 1.8
3rd - 1.495 3rd - 1.5
4th - 1.125 4th - 1.25
5th - 0.972 5th - 1.02
6th - 0.840 6th - 0.921

Final drive - 4.785 Final drive - 4.2

this is just and example

thanks, i tried this out and managed to get the Xj220 to 228mph before i had to turn but seemed to come at the sacrifice of acceleration, slightly, but as I plan to use it for the endurance races it doesn't matter to much. It will take me a while to find a balance and become comfortable with fine tuning but you have been a great help.

cheers

 

[slipknot10wa123]

you either have high top speed or good acceleration. you can't have both... unless you add more gears.

 

[grnshwrcrtn]

you either have high top speed or good acceleration. you can't have both... unless you add more gears.

is there any disadvantages to adding more gears?

 

[Zardoz]

...trying my shiny new Jaguar XJ220 LM...

I'd forgotten I had one of these. I've never tried it. Thanks for reminding me...




.

 

[grnshwrcrtn]

I'd forgotten I had one of these. I've never tried it. Thanks for reminding me...

let me know what you what you think of it and if you don't mind post any changes for the settings you might come up with 👍

 

[MaxxTraxx]

is there any disadvantages to adding more gears?

Not much , but you will have to shift more . The average human can shift a car at .5 secs so you would have to do :


(number of gears)
x .5
_____________________



That would be the increase in time used shifting. You could also the gear ratios so that you have GREAT accl. in the first couple gears, then have your final gear (not final) longer .