Braking at high speed - back end loose

  • Thread starter Thread starter ALB123
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Usually in this situations, if you keep some acceleration under braking, the power helps to keep the car stable. When you approach turn in point release the gas fully and you must be able to take the corner without much tail happy effect.

It's just a suggestion, not a fail proof solution. You must see how much gas you can carry and how much brake pressure you apply so you are comfortable.

Hope it was helpful. Take care
 
ALB123
I applied High Octane's terrific mod for the LFA Nurburgring Edition https://www.gtplanet.net/forum/thre...-break-will-be-back-soon.292731/#post-9171735 and I notice now, while tearing butt down high speed straightaways and then having to break hard for a hairpin turn the car gets very squirrely in the rear. I've already lowered the rear brake bias and that helped a bit, but what would you recommend to fix this problem?

Thanks!
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Try increasing the LSD braking sensitivity. A lot.
 
I've noticed the same problem with some cars. The ones I can remember at the moment are the Audi Pikes Peak and Nuvolari. And Ferrari GTO if I remember correctly. I'm not a professional tuner by far, but what puzzles me how some cars handle so badly while breaking hard (especially if breaking while slightly steering, and/or on a slightly uneven/bumpy/angled road), while some cars handle exceptionally well under the same conditions. And I'm not talking race cars vs road cars, I'm talking similar spec cars with all the best parts bought, with no aero, and not tuned at all. (I presume the aftermarket brakes and other parts are all the same for every car?)
Any explanations why is this happening and suggestions on solving the instability? (I have not yet tried the LSD)
 
Its usually the LSD deceleration setting that is to blame, increase this and the car should be more stable on the brakes and stop snapping when you come off them. Other solutions can be putting some ballast in the front to bring the weight distribution further forward or raising the rear ride height. The suspension also needs to be stiffened up to lessen the front to back weight shift and accommodate grippier tyres.
You may find all the answers in here https://www.gtplanet.net/forum/threads/general-tuning-guide.297354/
 
I guess it must be LSD then since I've tried stiffening up the suspension, and the weight distribution in some cases was already 55:45 or even more so I doubt putting more weight in the front would help much overall.

Thanks for the link, I'll give it a read when I manage enough time. :cheers:
 
Thanks for the suggestions guys! I've already lowered the break bias quite a bit, so I'm going to experiment with the LSD now. I had a sneaking suspicion that you were going to mention the LSD. Unfortunatey, the LSD is probably the single most confusing part of tuning to me. I must ask my brother to explain the three settings to me every 3-4 days...and he doesnt even play GT. LOL!

Thanks guys!!
 
ALB123
Thanks for the suggestions guys! I've already lowered the break bias quite a bit, so I'm going to experiment with the LSD now. I had a sneaking suspicion that you were going to mention the LSD. Unfortunatey, the LSD is probably the single most confusing part of tuning to me. I must ask my brother to explain the three settings to me every 3-4 days...and he doesnt even play GT. LOL!

Thanks guys!!
Click to expand...
Motor City Hami wrote the best explanation I've seen in his tuning guide. It's actually much simpler than it sounds, and his advice works perfectly for me.

Your LSD brake sensitivity is currently 10 if you followed the tune you mentioned. Try changing that to 30. If you have difficulty rotating while trail braking, lower it gradually until you're comfortable. But 30 should give you plenty of stability during deceleration, as long as your rear brake bias is not too high.
 
Another alternative is to try another tune that might fit your driving style better. Praiano also has a 550 pp tune that is excellent. When his first version was published, I also had some braking instability, so I changed the brake bias and LSD. But I think he has revised it since then due to changes in brake modeling in v.1.04. At least, I know the version on his app is revised.
 
On most of these cars the inherent issue that causes this is the weight over the rear tires shifting towards the front; the rear tires get unloaded, and so move around much easier.

Changing the LSD essentially treats the symptom. If you want to fix the cause (which does not have to be a better solution at all, depending on how you like your car), try lowering the ride height and stiffening the suspension all around.
 
you could also try letting your revs drop a bit more before downshifting (if you are running manual). I also found that having more of a front brake-vs-rear bias helps
 

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