S2000 Racing and Competition The S2000 on the track and Solo circuit. Some of the fastest S2000 drivers in the world call this forum home.

S2000 STR prep resource

Thread Tools
 
Old Jun 16, 2011 | 08:50 PM
  #4011  
IntegraR0064's Avatar
15 Year Member
 
Joined: Jun 2010
Posts: 1,881
Likes: 6
From: Near Philadelphia
Default

I agree, my bias is around a 69% front and I like it a lot. I was actually just in the other thread and people were telling me I needed a lot more front stiffness. Maybe there's a calculation difference here?
Old Jun 16, 2011 | 09:07 PM
  #4012  
User 121020's Avatar
Registered User
 
Joined: Jul 2007
Posts: 1,376
Likes: 2
Default

Originally Posted by IntegraR0064
Maybe there's a calculation difference here?
That's kinda what I'm thinking, too...
Old Jun 17, 2011 | 06:58 AM
  #4013  
762's Avatar
762
Registered User
15 Year Member
 
Joined: Apr 2009
Posts: 369
Likes: 0
Default

Math is hard
Old Jun 17, 2011 | 07:06 AM
  #4014  
imstimpy's Avatar
 
Joined: Apr 2010
Posts: 570
Likes: 16
Default

Originally Posted by josh7owens
My bar on full stiff transtions perfect but half to watch it and not ask for to much from the front tires. For example you couldn't turn the steering wheel 90 degrees and exspect it not to push, It didn't like any steering inputs over 65-70 degrees. On the other hand a car with a softer bar you can turn the steering wheel 90 degrees and it won't push at all but the inputs feel delayed. Thats why on day one I couldn't slalom for shit. I was making my normal 60 degrees steering input and exspecting the car to "turn" but it wasn't. So I pinched every cone in the slaloms and my timing on getting in and out on boxes was way off. Des was able to drive it because he's used to a softer bar and from watching his video he was making 80-90 degree inputs where I was trying to get the car to do the same thing with my 60 degree inputs.

Now I know why I thought your car was pushy to me. Running that big of a bar really limits the useable steering degrees. I was asking to much of the front tires. It's all about what you get used to I guess. I myself need a pretty stiff bar although I don't want to add any more to my front roll stiffness.
Theoretical performance aside, that sounds like you just need to learn to adapt faster.


Originally Posted by josh7owens
matt,

your front roll bias is alittle higher then mine but not by much. I'm at 69.5 and your at 70.77. your natural frequency rate is 2.563 front and 2.375 rear. Thats a 8% difference. I'm at 2.719 front and 2.295 rear, A 18% difference. I wanted to be at a 15% difference because according to the chassis set up book it said to be at a 15% natural fequency rate difference with the end of the drive wheels on the lower end. I'll prolly end up going 800f/650r or 850f/700r if I can find a 850 spring. 900f/750r I think is just too stiff. Plus I'd like to have my NF rate in the 2.563-2.642 range, not in the 2.719 range like I am now. Although I'm worried about eatting fenders with softer springs.
While I agree you should continue testing, your reason is a little weird. You take all those calculations to get you a starting point then you go out and test- let the clock tell you what is better, not a book or a spreadsheet. Comparing numbers is wonderful, but he might be smoother or more abrupt, is lower or higher, has more compression or less, more rebound or less, different alignment, tests on a different surface or course style, et al. All the pieces work into a system that can balance itself out through the sum of its parts (then the driver can throw all the theory out the window).

Originally Posted by josh7owens
We are both in ap1s but alot of ap2s are like that too. It's to transition fast and keep the rear wheels on the ground
There are more components to a course than just transitions, just like there are more suspension parts than the front bar. For argument's sake, you might find a super stiff front bar feels good but may not be faster than a softer bar that requires you to lead the inputs. The stiffer bar felt worse to me but was verified to be faster for both drivers. It wasn't in the slalom, either, it was the higher average speed through the sweeper.

Originally Posted by josh7owens
I need that magical 850 spring hyperco doesn't make.
You mean the springs I have on the front of my car? You can always try a different diameter or length. I made sure to run the same lengths, front and rear, so I could swap springs freely. I'm pretty sure I'm running 7B0850.
Old Jun 17, 2011 | 07:14 AM
  #4015  
imstimpy's Avatar
 
Joined: Apr 2010
Posts: 570
Likes: 16
Default

Originally Posted by nmrado
Originally Posted by josh7owens' timestamp='1308264758' post='20690750
your front roll bias is alittle higher then mine but not by much. I'm at 69.5 and your at 70.77.
71:29 roll bias?? Holy crap! That sounds like an AP1 BS bias.

I'm liking my 56:44 distribution. It's a handful at lapping days...
I'm at 62.7% roll rate bias with an assumed 50/50 weight distribution. All the ST* cars I've built shift weight bias forward by 2-3% and the roll rate bias doesn't account for differences in weight distribution nor dynamic weight transfer.
Old Jun 17, 2011 | 07:26 AM
  #4016  
daverx7's Avatar
 
Joined: Jul 2004
Posts: 1,578
Likes: 1
From: Kentucky
Default

Originally Posted by imstimpy
While I agree you should continue testing, your reason is a little weird. You take all those calculations to get you a starting point then you go out and test- let the clock tell you what is better, not a book or a spreadsheet. Comparing numbers is wonderful, but he might be smoother or more abrupt, is lower or higher, has more compression or less, more rebound or less, different alignment, tests on a different surface or course style, et al. All the pieces work into a system that can balance itself out through the sum of its parts (then the driver can throw all the theory out the window).
Very well stated! Get a decent starting point and start tweaking until you are the fastest.... or whatever is more fun... just depends on what you are wanting from the sport.

Of course, I am saying this as a mid-packer, so what do I know?

-Dave
Old Jun 17, 2011 | 07:46 AM
  #4017  
ViperASR's Avatar
 
Joined: Jul 2009
Posts: 2,048
Likes: 1
Default

Originally Posted by daverx7
Very well stated! Get a decent starting point and start tweaking until you are the fastest.... or whatever is more fun... just depends on what you are wanting from the sport.

Of course, I am saying this as a mid-packer, so what do I know?

-Dave
I agree with you, and I'm a backmarker using stock suspension
Biggest improvement that can be made to the car is the driver. Focus on driver as your #1 goal. Leave the maths at home.
Old Jun 17, 2011 | 09:11 AM
  #4018  
daverx7's Avatar
 
Joined: Jul 2004
Posts: 1,578
Likes: 1
From: Kentucky
Default

Originally Posted by ViperASR
Leave the maths at home.
I left math at school about a billion years ago. Okay, over 20 years ago. Maybe that's the reason I have my attitude. 2+2=? Where's my calculator?
Old Jun 17, 2011 | 09:34 AM
  #4019  
ViperASR's Avatar
 
Joined: Jul 2009
Posts: 2,048
Likes: 1
Default

Originally Posted by daverx7
Originally Posted by ViperASR' timestamp='1308325599' post='20693073
Leave the maths at home.
I left math at school about a billion years ago. Okay, over 20 years ago. Maybe that's the reason I have my attitude. 2+2=? Where's my calculator?
I'm an accountant with an MBA (well 6 months out on that, but close enough). I can make 2+2 equal whatever you and your business associates would like it to.

And I would die without a calculator...
Old Jun 17, 2011 | 12:15 PM
  #4020  
josh7owens's Avatar
Registered User
 
Joined: Jun 2009
Posts: 4,340
Likes: 0
From: Frankfort, KY
Default

imstimpy- your right you can't compare set up over the internet. I drove matts car and matt drove my car, we bothe agreed our cars felt simular in balance regardless of the rest of the set up. Therefore I did the math and sure enough our cars are within 1%age on front roll bias. thats all.

spread sheets are nice to get a base line and then tune to your driving style. Thats all. I tried what it said was ideal and it didn't work as well as my previous set-up. Which means one more click of bar is prolly going to happen soon.



All times are GMT -8. The time now is 10:23 AM.