Suspension Options for Stock
05-31-2018, 09:47 AM
#1
Thread Starter
Suspension Options for Stock
Newbie auto-x question. Couldn't find a definitive answer even though the rules seem to address the issue.
For BS, will SCCA allow a complete MY09 suspension configuration (base or CR) on a MY05?
I have a MY05 that came with Tein H.Tech lowering springs. I want to change the suspension and run in stock for a season before investing in an STR configuration. I don't really want to restore the MY05 configuration. The path I was researching started with the CR configuration on Koni Sports. After working though Rob Robinette's spreadsheet with John McCanless' data (thanks guys for both) with some OEM part options, I was liking a Frankenstein configuration using MY09 CR rear springs on the front and MY02 rears on the rear with an adjustable sway bar hoping to hit a more balanced sweet spot between the MY09 CR and base configurations. Weekend street car with some auto-x potential, maybe a track day or two. The rules clearly don't allow that but would they allow a complete single model year configuration different from the original year?
Thanks, T
For BS, will SCCA allow a complete MY09 suspension configuration (base or CR) on a MY05?
I have a MY05 that came with Tein H.Tech lowering springs. I want to change the suspension and run in stock for a season before investing in an STR configuration. I don't really want to restore the MY05 configuration. The path I was researching started with the CR configuration on Koni Sports. After working though Rob Robinette's spreadsheet with John McCanless' data (thanks guys for both) with some OEM part options, I was liking a Frankenstein configuration using MY09 CR rear springs on the front and MY02 rears on the rear with an adjustable sway bar hoping to hit a more balanced sweet spot between the MY09 CR and base configurations. Weekend street car with some auto-x potential, maybe a track day or two. The rules clearly don't allow that but would they allow a complete single model year configuration different from the original year?
Thanks, T
Last edited by talboti; 05-31-2018 at 09:49 AM. Reason: typo
05-31-2018, 11:48 AM
#2
Community Organizer
BS will require stock, year-correct springs at stock perch heights. One of the stabilizer bars will have to stay stock for the year model; I would recommend a stiffer front and leaving the rear '05 OEM.
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talboti (05-31-2018)
05-31-2018, 12:47 PM
#3
04/05 has a balance F55.8% & R 44.2%
06-02-2018, 05:23 AM
#5
Thread Starter
noodels: How do you like Ohlins DFV 571LB front, 600LB rear, and CR FSB, 225/255? Do you find those spring rates harsh on the street? RobRob's model indicates similar F/R freq bias as the MY09 and slightly more neutral than the CR. Not too far from my design point and same stagger as well. How does it drive?
WRT the MY05 factory configuration: The model gives a front roll couple of 52%, which is not significantly different than any AP2 before CR. My street experience with lowered 270f/330r, factory bars and 225/255 Direzzas makes me think the front rates are a little soft. The f/r freq bias is closer to an AP1, which is fine but I think the sticky Direzzas are covering for an oversteer tendency. Not sure how the ~0.6in drop effects the bias. I understand how it can increase roll - other things equal.
WRT design point: others seem to have come to similar conclusions, but I am coming to believe that Honda designers came to the MY09 base and CR configurations aiming at the most street-able balance based on their experience with the performance of the model run for the base and anticipating that the CR could end up with non-staggered tires and would need more understeer bias from the chassis. Interesting to note that the F/R freq bias changes over the model years are decreasing in magnitude consistent with gradual design refinement until the CR. That conclusion, the consistent front spring rate increases by Honda and my likely usage led me to aim at a front stiffness in the 325-450 range and I sought a balance between the MY09 base and the CR using OEM springs/bars.
Thoughts?
-T
WRT the MY05 factory configuration: The model gives a front roll couple of 52%, which is not significantly different than any AP2 before CR. My street experience with lowered 270f/330r, factory bars and 225/255 Direzzas makes me think the front rates are a little soft. The f/r freq bias is closer to an AP1, which is fine but I think the sticky Direzzas are covering for an oversteer tendency. Not sure how the ~0.6in drop effects the bias. I understand how it can increase roll - other things equal.
WRT design point: others seem to have come to similar conclusions, but I am coming to believe that Honda designers came to the MY09 base and CR configurations aiming at the most street-able balance based on their experience with the performance of the model run for the base and anticipating that the CR could end up with non-staggered tires and would need more understeer bias from the chassis. Interesting to note that the F/R freq bias changes over the model years are decreasing in magnitude consistent with gradual design refinement until the CR. That conclusion, the consistent front spring rate increases by Honda and my likely usage led me to aim at a front stiffness in the 325-450 range and I sought a balance between the MY09 base and the CR using OEM springs/bars.
Thoughts?
-T
06-02-2018, 08:05 AM
#6
noodels: How do you like Ohlins DFV 571LB front, 600LB rear, and CR FSB, 225/255? Do you find those spring rates harsh on the street? RobRob's model indicates similar F/R freq bias as the MY09 and slightly more neutral than the CR. Not too far from my design point and same stagger as well. How does it drive?
WRT the MY05 factory configuration: The model gives a front roll couple of 52%, which is not significantly different than any AP2 before CR. My street experience with lowered 270f/330r, factory bars and 225/255 Direzzas makes me think the front rates are a little soft. The f/r freq bias is closer to an AP1, which is fine but I think the sticky Direzzas are covering for an oversteer tendency. Not sure how the ~0.6in drop effects the bias. I understand how it can increase roll - other things equal.
WRT design point: others seem to have come to similar conclusions, but I am coming to believe that Honda designers came to the MY09 base and CR configurations aiming at the most street-able balance based on their experience with the performance of the model run for the base and anticipating that the CR could end up with non-staggered tires and would need more understeer bias from the chassis. Interesting to note that the F/R freq bias changes over the model years are decreasing in magnitude consistent with gradual design refinement until the CR. That conclusion, the consistent front spring rate increases by Honda and my likely usage led me to aim at a front stiffness in the 325-450 range and I sought a balance between the MY09 base and the CR using OEM springs/bars.
Thoughts?
-T
WRT the MY05 factory configuration: The model gives a front roll couple of 52%, which is not significantly different than any AP2 before CR. My street experience with lowered 270f/330r, factory bars and 225/255 Direzzas makes me think the front rates are a little soft. The f/r freq bias is closer to an AP1, which is fine but I think the sticky Direzzas are covering for an oversteer tendency. Not sure how the ~0.6in drop effects the bias. I understand how it can increase roll - other things equal.
WRT design point: others seem to have come to similar conclusions, but I am coming to believe that Honda designers came to the MY09 base and CR configurations aiming at the most street-able balance based on their experience with the performance of the model run for the base and anticipating that the CR could end up with non-staggered tires and would need more understeer bias from the chassis. Interesting to note that the F/R freq bias changes over the model years are decreasing in magnitude consistent with gradual design refinement until the CR. That conclusion, the consistent front spring rate increases by Honda and my likely usage led me to aim at a front stiffness in the 325-450 range and I sought a balance between the MY09 base and the CR using OEM springs/bars.
Thoughts?
-T
I am just amazed at the car at present the best its been with adding the CR front sway with the 571/600 springs.
have 11 from full stiff on Ohlins on bumpy roads and is less harsh than 10/8kgs on the same 11clickes,the high speed stability is more than amazing
& not even set the geo yet on a Hunter laser tester, just a diy job geo wise and will improve more when done correctly
Edit
Spirited driving today=Poetry in motion
https://www.s2ki.com/forums/s2000-br...1183541/page3/
Last edited by noodels; 06-03-2018 at 01:38 PM. Reason: .
06-02-2018, 05:14 PM
#7
It is possible to put the stock spring perch on a coilover body with OEM springs in B/Street. PSI sells Ohlins TTX and Penske 8300s this way, both of which could be used in B/Street and STR. In B/Street you could use the Penske 7500 DA, an excellent base valve shock, but it won't work if the car is lowered for STR. Rear shock travel on the S2k is an issue which is why the OEM Showa shocks and the Bilstein PSS shocks both have external reservoirs in the rear.
If you are using regular S2000 springs I doubt anyone will inspect or care what year they are from unless you are the nationals or pro-solo and are cleaning up. Since the S2000 is no longer the dominant car in B/Street or STR it is unlikely anyone will care.
The car will need a larger front bar for either B/Street or STR and I strongly recommend the Karcepts.
You will need an alignment getting max negative camber in front (-1.7-to--1.9 in B/Street, over -3 in STR with an offset balljoint) and Tires, either Bridgestone RE71r or BFG Rival S 1.5. In STR they will be 255/40-17 square on 17x9+60 rims. In B/Street OEM rims are fine, but tire size is more a problem I've got 225/255, other run 245/255 squeezing a 245 on a below recommendation 7" rim. 245 square has been proposed and I doubt even running OEM 215/245 sizes would hurt times more than a few tenths on a 50sec run. In 2014 a CR placed 4th in A/Street on a 225/255 setup.
In STR your 2005 engine is the bigger PITA. The 2006 added drive by wire eliminating the air pump. It also has a flashable ECU, large throttle body opening, larger throttle body, and EBD. For STR you will need to run a piggyback ECU, also available with STR tunning from Karcepts. Right now, it appears the ND Miata is faster in STR and a variety of Corvettes are faster in B/Street.
Your best solution for 2018 might just be a set of working OEM shocks and springs, Karcepts bar, and RE71r tires.
If you are using regular S2000 springs I doubt anyone will inspect or care what year they are from unless you are the nationals or pro-solo and are cleaning up. Since the S2000 is no longer the dominant car in B/Street or STR it is unlikely anyone will care.
The car will need a larger front bar for either B/Street or STR and I strongly recommend the Karcepts.
You will need an alignment getting max negative camber in front (-1.7-to--1.9 in B/Street, over -3 in STR with an offset balljoint) and Tires, either Bridgestone RE71r or BFG Rival S 1.5. In STR they will be 255/40-17 square on 17x9+60 rims. In B/Street OEM rims are fine, but tire size is more a problem I've got 225/255, other run 245/255 squeezing a 245 on a below recommendation 7" rim. 245 square has been proposed and I doubt even running OEM 215/245 sizes would hurt times more than a few tenths on a 50sec run. In 2014 a CR placed 4th in A/Street on a 225/255 setup.
In STR your 2005 engine is the bigger PITA. The 2006 added drive by wire eliminating the air pump. It also has a flashable ECU, large throttle body opening, larger throttle body, and EBD. For STR you will need to run a piggyback ECU, also available with STR tunning from Karcepts. Right now, it appears the ND Miata is faster in STR and a variety of Corvettes are faster in B/Street.
Your best solution for 2018 might just be a set of working OEM shocks and springs, Karcepts bar, and RE71r tires.
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talboti (06-03-2018)
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06-03-2018, 08:55 AM
#8
Thread Starter
DavidNJ: thanks for the thoughtful and insightful reply!
I would love to have a set of Penske 8300s, but I can't put that much in my toy at the moment. I am leaning towards an OEM Frankenstein configuration 343f/309r or 309f/294r on either a set of Koni Sports or the MY05 dampers I currently have, unless I can source a complete MY08-9 set of shock assemblies. Would I be stretching the Showa damper design too far by putting a 343 spring on a damper designed for 262? Only the CR front Showa damper was designed for a spring rate close to that. That might drive me in the direction of Koni. Thoughts?
I appreciate your front bar recommendation. That looks like a good bar. I could imagine street at one end and auto-x at the other with a track day in between.
One regret I have on my S is the lack of tune-ability of the MY05 engine. I wish I had picked up a MY06+ S for that reason.
- T
I would love to have a set of Penske 8300s, but I can't put that much in my toy at the moment. I am leaning towards an OEM Frankenstein configuration 343f/309r or 309f/294r on either a set of Koni Sports or the MY05 dampers I currently have, unless I can source a complete MY08-9 set of shock assemblies. Would I be stretching the Showa damper design too far by putting a 343 spring on a damper designed for 262? Only the CR front Showa damper was designed for a spring rate close to that. That might drive me in the direction of Koni. Thoughts?
I appreciate your front bar recommendation. That looks like a good bar. I could imagine street at one end and auto-x at the other with a track day in between.
One regret I have on my S is the lack of tune-ability of the MY05 engine. I wish I had picked up a MY06+ S for that reason.
- T
06-03-2018, 12:51 PM
#9
DavidNJ: thanks for the thoughtful and insightful reply!
I would love to have a set of Penske 8300s, but I can't put that much in my toy at the moment. I am leaning towards an OEM Frankenstein configuration 343f/309r or 309f/294r on either a set of Koni Sports or the MY05 dampers I currently have, unless I can source a complete MY08-9 set of shock assemblies. Would I be stretching the Showa damper design too far by putting a 343 spring on a damper designed for 262? Only the CR front Showa damper was designed for a spring rate close to that. That might drive me in the direction of Koni. Thoughts?
I appreciate your front bar recommendation. That looks like a good bar. I could imagine street at one end and auto-x at the other with a track day in between.
One regret I have on my S is the lack of tune-ability of the MY05 engine. I wish I had picked up a MY06+ S for that reason.
- T
I would love to have a set of Penske 8300s, but I can't put that much in my toy at the moment. I am leaning towards an OEM Frankenstein configuration 343f/309r or 309f/294r on either a set of Koni Sports or the MY05 dampers I currently have, unless I can source a complete MY08-9 set of shock assemblies. Would I be stretching the Showa damper design too far by putting a 343 spring on a damper designed for 262? Only the CR front Showa damper was designed for a spring rate close to that. That might drive me in the direction of Koni. Thoughts?
I appreciate your front bar recommendation. That looks like a good bar. I could imagine street at one end and auto-x at the other with a track day in between.
One regret I have on my S is the lack of tune-ability of the MY05 engine. I wish I had picked up a MY06+ S for that reason.
- T
You can even take the car to autocross exactly as you have it. You may not be in the right class, but you will some seat time, a different perspective, and input from the driver's there.
06-03-2018, 01:38 PM
#10
I ran re-valved Koni yellows on my AP1 STR car and liked having the adjustability, you'll also need to have the rear pistons shortened to run STR ride heights. Pro Parts did mine and I was happy with the results. Locally I had no issues running with the cars that had pimp shocks. That being said this was 8? years ago... there exist many cheaper coil-over options today that I'd probably go with over the Koni yellows if I were in the same boat today. A 'budget' STR build is still probably one of the most fun autocross vehicles.
You're not giving up a ton by not having an '06+. Tuning may not be quite as 'easy' as an '06 and up car but Karcepts has a fairly affordable GReddy Emanage package when you're ready to take the plunge.
I also have some Small Fortune Racing spring perches that allow you to run your stock Honda springs on most of the pimp shock brands that I'm no longer using. If you decide to stretch the budget for pimpy shocks but run B Street for a few years before making the jump to STR.
You're not giving up a ton by not having an '06+. Tuning may not be quite as 'easy' as an '06 and up car but Karcepts has a fairly affordable GReddy Emanage package when you're ready to take the plunge.
I also have some Small Fortune Racing spring perches that allow you to run your stock Honda springs on most of the pimp shock brands that I'm no longer using. If you decide to stretch the budget for pimpy shocks but run B Street for a few years before making the jump to STR.