Random1

=============== STR Threads ===============

STR Prep - Suspension and Alignment
STR Prep - Shock / Damper and Springs Discussion
STR Prep - Differential Discussion
STR Prep - ECU and Tuning Discusson
STR Prep - Wheels and Tires
STR Prep - Exhuast (tip to tail)
STR Prep - Weight Reduction
STR Prep - Sway Bars
SCCA Solo - STR Rules Discussion ---> (Debate rules and proposals here...)
STR Prep - AP1 vs AP2v1 vs AP2v2 vs CR
STR Prep - Intake • from DIY to Mugen
STR Engine Mounts

=============== STR Threads ===============

What are the pros and cons of the different S2000 versions for the purpose of running in STR class autocross?

This topic has been discussed/debated within other threads. The attempt here is to capture it in one place and re-open the topic for more discussion under the newer set of separate STR threads.

Work IN PROGRESS, some of the obvious difference relevant to autocross are listed below, help by posting additional information.

AP1

Pros

1. Top of second gear 65 MPH with 255/40R17 tires
2. Faster steering rack than AP2, same as CR
3. Lighter fly wheel (14 lbs)

Cons

1. Gearing - challenging on the power on tight courses
2. Less torque than AP2

AP2v1

Pros

1. More torque

Cons

1. ECU cannot be re-flashed for tuning
2. Heavier fly wheel (22 lbs)
3. Slower steering rack

AP2v2

Pros

1. ECU can be tuned by re-flash
2. Can achieve more HP and Torque via tuning

Cons

1. Heavier fly wheel (22 lbs)
2. Slower steering rack
   

CR

Pros

1. Can achieve lighter weight via top removal, no radio and no A/C options
2. Faster steering rack like AP1
3. ECU can be tuned by re-flash
4. Can achieve more HP and Torque via tuning
5. Wing may provide minimal rear down force

Cons

1. Heavier fly wheel (22 lbs)

Random1

From another thread I posted...

AP1 vs AP2 will always be course dependent. You are more likely to be frustrated with an AP1 at local events where there can be courses with low average speeds. In these cases it's clear that an AP2 has the advantage, just put it in second and leave it there. An AP1 can still get the job done in most cases, but you will need to raise your willingness to become a frequent 1st gear down shifter. Then once in first you will need to learn to carefully modulate power so you don't upset the car (grip). It's truly a labor of love once into this mode. I see drivers that don't have the dedication to make it work and they get frustrated (especially AP2 owners trying out AP1s).

IMO at a Tour with higher average speeds the differences become less between the AP1 and AP2. It's more likely that an AP2 will need to shift to third gear rather than an AP1 down shifting to first gear. Obviously this is all course dependent.

steguis

I started the season in my AP1 but am now codriving an AP2v1 (as I've converted my AP1 into a track car). The choice is pretty much course dependent and I like the added torque of the AP2 coming out of a corner or even getting out of the start (especially important at ProSolos). However, I do feel the more sluggish steering with the slower steering rack but at the same time, I feel that AP2s in STR trim are easier to drive and less twitchy at the limit. AP1s gearing is so nice if you're on a fast course. The extra mph going to redline can make a big difference as I personally find it much easier to get a 2nd to 1st downshift right than a 3rd to 2nd. I've also noticed that I've sometimes accidentally shifted to 5th while trying to go to 3rd in the AP2 which obviously sucks.

I think that once AP1s and AP2v1 can get a proper tune, the differences will flatten out as you can pretty easily get the AP1 into VTEC at 4-4.5K and increase the rev limiter to 9200. That could eliminate the need to downshift to 1st and still have the tall gearing advantage. At the end of the day though, I think the AP2 is the more competitive car across more types of courses. Tuned, it delivers more power and more usable torque enough to offset the heavier fly. I'm only choosing AP2v2 because of flashpro but if AP2v1 has similar tuning capabilities, I'd choose AP2v1. I don't really like DBW, the more mechanical the better, but this is just a personal preference, performance wise it makes no difference.

All things equal the CR has the edge as it has the best of both worlds but frankly, if I had a CR, I'd just run BS as autocrossing is so much more fun on Hoosiers, BS is faster and in the end cheaper.

//steve\\

With a Flashpro on ap2v2+ you can also safely raise the rev limit a tad although that's probably only getting you 1-2mph more out of 2nd. Might be enough though on a few courses. I know the Toda reflash has the rev limit bumped to 8500.

CKit

I think this thread may wind up being a "what color car would you autocross in STR if you had a choice" kind of thread.

Lots of variables aren't discussed in the oversimplified vote:
1. Are people talking real world or ideal (money no object) world?
2. Are they talking about pure STR prep vs. a car that would have to serve dual purpose as a street car?
3. What other non-autocross factors play into the "ideal" car decision?

I cannot imagine that anyone prepping for STR with unlimited budget and no need for the car to serve dual duty would pick anything besides a CR.

For people that voted AP2v2, are there any who would pick that over a CR if money and dual duty were not an issue?
For example, if you had a purely street AP2v2 at home and had unlimited money to pick up a second S2000 for STR prep only... would you still pick another AP2v2 or would you pick a CR?

I can see why you wouldn't pick an AP2v1, the limited gearing and not able to compensate with higher redline makes it the least competitive, IMHO.

But I still don't see any "racing" reason for an AP2v2 over a CR. Leading to my assumption that the "other" reasons are non-racing and not a great focus of discussion.

TTMartin

The poll looks like all AP2V2 said they would keep their AP2V2s. For STR there isn't enough difference from a CR to warrent a change. The only meaningful difference is the faster steering rack. Everything else is pretty much duplicatable under STR rules.

If I had a CR I would run B Stock and not STR.

ViperASR

This. I see no reason for me to upgrade from my AP2v2 to a CR. I still daily mine, to the tune of 15k per year.

I think any s2000 is going to end up being very competative in STR, with the AP1 benefitting on certain courses due to the higher redline.

sirbunz

Having raced all different S2000 models, I still like my CR. I enjoyed racing it in B-Stock, but the tire expense and pain of scrubbing OPR off 8 tires after each event was taking the fun out of it. After adding a few more parts with the initial expense for STR and the much needed power mods, the cars is much more enjoyable to auto-x on a local level. Where we were downshifting 4-8 times per run, now we just leave it in 2nd. For the National events, I think the courses are much more balanced. I drive an AP1 as my daily driver and love it. I still prefer the CR for racing due to the fact that this is the car I have driven since '08. I do believe any S2000 can get it done, even in B-Stock for reasons I have posted before and also proven.

-Marc

Zeus2k

I love my AP1 but I voted for AP2V2 simply because of the flashpro. I know that it looks like the tuning options are going to be opened up but I do love the simplicity of the flashpro and if I could run that I would. As for the cr debate... sure if money is no issue then cr is the way to go as you could have a second car but I would be using my car for a daily driver as well and I would miss the soft top too much to buy a cr.

If you could use a flashpro on an AP1 I think my vote would be different however.

Forcednduckshn

+1. If the question was revised to "What car is the fastest?" then Newton, Einstein and many other great scientist's contributions to a well known but still seemingly underrated, under-acknowledged and misunderstood set of laws called "Physics" would dictate that the CR is the way to go. On a budget but want a car that can win if you are a top notch driver? AP1. Already have an AP2? Sure, that'll do it. AP2V2? Even better. Unlimited budget? Go pay $27K for a CR, mod to your hearts content and have a machine that when fully prepped offers no excuses for not winning a jacket other than the driver not getting it done. At least the chassis are similar enough that in STR form, they can all battle for wins, and for that, I'm thankful.