Slow s2k
09-09-2011, 01:43 AM
#21
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Hi guys Thanks for all your replies. I appreciate it.
1. On handling - the car "handles" great, abit of oversteer on the initial if you turn in but is planted on the way out. I think we've got the balance right here but mechanical grip just seems low, i am concerned that we may be currently sacrificing grip for handling.
2. The staggered setup is a legacy issue - we already have too many wheels in that configuration to move to a non staggered setup. Is the disadvantage apparent?
3. Im from Asia so i doubt you would be familiar with the tracks here. But it is a long one - 3.4 miles long.
4. On toe, thanks for the input - i'd be trying zero toe for the front and perhaps 3.5mm in the rear? (halfway between the recommended 2-5mm toe in)
Thanks again for the input
1. On handling - the car "handles" great, abit of oversteer on the initial if you turn in but is planted on the way out. I think we've got the balance right here but mechanical grip just seems low, i am concerned that we may be currently sacrificing grip for handling.
2. The staggered setup is a legacy issue - we already have too many wheels in that configuration to move to a non staggered setup. Is the disadvantage apparent?
3. Im from Asia so i doubt you would be familiar with the tracks here. But it is a long one - 3.4 miles long.
4. On toe, thanks for the input - i'd be trying zero toe for the front and perhaps 3.5mm in the rear? (halfway between the recommended 2-5mm toe in)
Thanks again for the input
Yes, do try the front toe to neutral. I was running front toe out previously too. The turn-in was sharp and precise, track out was good but lacks mid corner grip in the rear. If you track on SIC, you'll know that lots of time can be lost from better mid-corner grip in T5-6 and T12-13. I changed the front toe to neutral and the grip was much better, but have to help the turn-in with a bit of brake.
For the rear toe-in of 3.5mm, is it on 17"? And do you mean total toe? I'm on 255/40R17 and my total toe-in is about 4mm.
I have just switched to non-staggered setup. The whole balance of the car is off, even with a bigger ARB in front, the car still feels a bit loose. I haven't tried it on the track, but I think overall the performance should be better with a non-staggered setup, once the balance issue is sorted out.
I'm using the Yoko A050 medium compound. They are way better than R888. Stiffer sidewalls than the R888 and FZ201. Compared to the FZ201, the A050's grip is about the same, but the A050 lasts longer, and I find the steering feedback is better. They cost much more than the FZ201 though. My car's weight is almost stock, and I run tire pressure of 30 PSI hot (for SIC). One caveat though, I'm relatively inexperienced, so the feedback above might not be dead accurate.
09-09-2011, 02:50 AM
#22
Member
2 things I note...
More front than rear camber?
I use just over -3 deg rear, and just over -2 front.
-2.75 isn't a lot for the rear imo, especially with high tyre loads. Although your contact patch may be good with such massive spring rates. I'd still swap the front and rear cambers though.
Also, I use Nitron custom coilovers, with 12 front 14 rear (as tested with one of the top JDM tuning houses
) and it's about right for even the smoothest tracks. 18 seems a very high rate to me.
More front than rear camber?
I use just over -3 deg rear, and just over -2 front.
-2.75 isn't a lot for the rear imo, especially with high tyre loads. Although your contact patch may be good with such massive spring rates. I'd still swap the front and rear cambers though.
Also, I use Nitron custom coilovers, with 12 front 14 rear (as tested with one of the top JDM tuning houses
) and it's about right for even the smoothest tracks. 18 seems a very high rate to me.
09-10-2011, 06:54 AM
#23
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Thanks again. Yes the track in question is SIC. I do sense that consensus seems to suggest that a non staggered setup seems to be most optimal. That said, i will note that Js racing still runs a staggered set up and achieves impressive time.
On toe, the current toe settings are also a legacy issue. Previously, The car was run on 14kg/mm / 9k/mm F/R springs, which resulted in very poor turn in and chronic understeer. The current equal spring rates has appeared to solve this, and hence we should be dialling out the toe settings which were an attempt to mitigate the understeer.
On camber, i remain uncertain. I cannot see the logic of running less camber in the front compared to the rear...can you kindly explain the rationale? I do not find power out oversteer to be a problem. It remains fairly planted and our problems with poor grip appeared to be mid corner. I will note however that on the current 18/18 set up, the corner blocks of the tires are cold, suggesting the springs are too hard, or that there is too much camber.
Some kind members here provided a theoretical calculator which suggests an optimal spring rate. With ACRs of 20deg and a presumed spring frequency of 2.5hz, the suggested spring rate is 16/kg per mm. However i am unsure if the lower ride height will significantly affect ACR.
The end game here is to run the car in michelin slicks, which we will be trying next with the new toe settings. Any further comments/observations will be appreciated.
Thanks!
On toe, the current toe settings are also a legacy issue. Previously, The car was run on 14kg/mm / 9k/mm F/R springs, which resulted in very poor turn in and chronic understeer. The current equal spring rates has appeared to solve this, and hence we should be dialling out the toe settings which were an attempt to mitigate the understeer.
On camber, i remain uncertain. I cannot see the logic of running less camber in the front compared to the rear...can you kindly explain the rationale? I do not find power out oversteer to be a problem. It remains fairly planted and our problems with poor grip appeared to be mid corner. I will note however that on the current 18/18 set up, the corner blocks of the tires are cold, suggesting the springs are too hard, or that there is too much camber.
Some kind members here provided a theoretical calculator which suggests an optimal spring rate. With ACRs of 20deg and a presumed spring frequency of 2.5hz, the suggested spring rate is 16/kg per mm. However i am unsure if the lower ride height will significantly affect ACR.
The end game here is to run the car in michelin slicks, which we will be trying next with the new toe settings. Any further comments/observations will be appreciated.
Thanks!
09-10-2011, 07:14 AM
#24
Member
I'd turn that back and ask where you got those settings from??
It's not an F1 car... Camber is all about maximising tyre contact with the tarmac on hard cornering.
I bet if you draw some chalk marks across your front tyres, and go out on track, your outer edges will still have chalk on them. You have massively stiff springs, and assuming your tyre pressures are right, you will have little "give" in your car anywhere, meaning the outside wall won't be contacting.
The chalk trick is a good way of finding your optimum camber.
Re your spring rates, do you have any rear aero mods? If you speak to Nitron UK, they will give you some good advice.
(all imo!)
It's not an F1 car... Camber is all about maximising tyre contact with the tarmac on hard cornering.
I bet if you draw some chalk marks across your front tyres, and go out on track, your outer edges will still have chalk on them. You have massively stiff springs, and assuming your tyre pressures are right, you will have little "give" in your car anywhere, meaning the outside wall won't be contacting.
The chalk trick is a good way of finding your optimum camber.
Re your spring rates, do you have any rear aero mods? If you speak to Nitron UK, they will give you some good advice.
(all imo!)
09-10-2011, 07:29 PM
#25
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Thanks again.
The current camber settings were also an attempt to reduce the understeer we were experiencing on a 14/9 kg/mm set up. Conventional train of thought suggests that you want to run as much camber in the front to maximise the contact patch when the car rolls without sacrificing grip under braking. Usually u do not run as much camber in the rear as there is the issue of rear grip when powering is being put down on the exits.
The s2k is one unique car that, in stock form, still runs less camber in the front. I do not understand why, but i believe it was to tame the tail happy nature of the car. One could observe Honda's attempt to tone down the car for novice drivers as the car aged thru the generations. That said, i reckon we could be too firm on the spring settings and perhaps camber as well. I think i might trying running 2.75deg camber all round, and also chalk the tires to see how the wear rates are.
Now that i believe i have the *correct* relative front/rear spring rates, i think i can move on to more conventional camber/toe settings.
Interestingly Guy from Nitron advised never to run harder springs in the rear of the car, as such a setup is only reserved for cars with significant downforce in the rear. He also suggested running as much camber as possible in the front and dial it back from there.
I must also highlight that the track we run on is of f1 standard and thus extremely smooth.
The current camber settings were also an attempt to reduce the understeer we were experiencing on a 14/9 kg/mm set up. Conventional train of thought suggests that you want to run as much camber in the front to maximise the contact patch when the car rolls without sacrificing grip under braking. Usually u do not run as much camber in the rear as there is the issue of rear grip when powering is being put down on the exits.
The s2k is one unique car that, in stock form, still runs less camber in the front. I do not understand why, but i believe it was to tame the tail happy nature of the car. One could observe Honda's attempt to tone down the car for novice drivers as the car aged thru the generations. That said, i reckon we could be too firm on the spring settings and perhaps camber as well. I think i might trying running 2.75deg camber all round, and also chalk the tires to see how the wear rates are.
Now that i believe i have the *correct* relative front/rear spring rates, i think i can move on to more conventional camber/toe settings.
Interestingly Guy from Nitron advised never to run harder springs in the rear of the car, as such a setup is only reserved for cars with significant downforce in the rear. He also suggested running as much camber as possible in the front and dial it back from there.
I must also highlight that the track we run on is of f1 standard and thus extremely smooth.
09-11-2011, 12:06 AM
#26
Member
Yep I have a full underbody diffuser and big rear wing, so guy told me to go with 2kg more at the rear.
In the uk almost everyone uses more rear camber. From what I can see even the Js car has a bit more at the rear. I am told more camber up front gives better turn in, but I feel tyre contact is more important. So maybe optimise that first and go from there.
Id love to try Sepang!
In the uk almost everyone uses more rear camber. From what I can see even the Js car has a bit more at the rear. I am told more camber up front gives better turn in, but I feel tyre contact is more important. So maybe optimise that first and go from there.
Id love to try Sepang!
09-11-2011, 06:55 AM
#27
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Yep I have a full underbody diffuser and big rear wing, so guy told me to go with 2kg more at the rear.
In the uk almost everyone uses more rear camber. From what I can see even the Js car has a bit more at the rear. I am told more camber up front gives better turn in, but I feel tyre contact is more important. So maybe optimise that first and go from there.
Id love to try Sepang!
In the uk almost everyone uses more rear camber. From what I can see even the Js car has a bit more at the rear. I am told more camber up front gives better turn in, but I feel tyre contact is more important. So maybe optimise that first and go from there.
Id love to try Sepang!
09-11-2011, 07:33 AM
#29
Member
I use Yokohama A048...
Toe as follows:
Front left -0.02
Front right -0.03
Rear left -0.11
Rear right -0.10
That's in degrees and then minutes after decimal place.
Toe as follows:
Front left -0.02
Front right -0.03
Rear left -0.11
Rear right -0.10
That's in degrees and then minutes after decimal place.