s2k2fast4me

After seeing Ron's comments about the SFR divisional where he said he was down on torque to the Boxster, I thought it would be interesting to run some numbers.

Assumptions include estimated competition weights for each car, no transmission losses (I took the dyno results from an S2K and multiplied it back up assuming peak at 153 ft-lbs), tire diameters are the same at 24.5 inches (245/45 16 and 245/40 17 Hoosiers).


The following numbers are all done assuming the car is in 2nd gear, torque is in ft-lbs at the wheel, and accel is in G's (theoretical). Overlay the plots and you get some interesting results (I would have attached the chart but didn't know how). Basically, it looks like the S2K suffers very little to the Boxter at lower speeds, while showing a clear advantage after the VTEC switchover.

Anyway, I thought it was an interesting comparison and how "seat of the pants" impressions can often be misleading. Comments welcome.

Weight 2650

MPH 2nd torque Accel
24.2962749 1274.186347 0.471012281
26.16521913 1265.027775 0.467626748
28.03416335 1257.014025 0.464664406
29.90310757 1244.420988 0.460009299
31.7720518 1231.827951 0.455354191
33.64099602 1223.814201 0.452391849
35.50994024 1243.276166 0.459586107
37.37888447 1257.014025 0.464664406
39.24782869 1270.751883 0.469742706
41.11677292 1293.648313 0.478206539
42.98571714 1307.386171 0.483284838
44.85466136 1377.220284 0.509099527
46.72360559 1464.226719 0.541262091
48.59254981 1491.702435 0.55141869
50.46149403 1488.267971 0.550149115
52.33043826 1480.25422 0.547186774
54.19938248 1476.819756 0.545917199
56.0683267 1469.950827 0.543378049
57.93727093 1461.937076 0.540415708
59.80621515 1439.040646 0.531951875
61.67515937 1416.144215 0.523488043
63.5441036 1355.468675 0.501058886
65.41304782 1287.924206 0.47609058


Weight 2800
2nd Gear
MPH 2nd Torque Accel
9.657532536 1057.64048 0.370019993
14.4862988 1196.803701 0.418706834
19.31506507 1252.468989 0.438181571
24.14383134 1308.134278 0.457656307
28.97259761 1363.799566 0.477131044
33.80136388 1391.63221 0.486868412
38.63013015 1419.464854 0.49660578
43.45889641 1441.73097 0.504395675
48.28766268 1441.73097 0.504395675
53.11642895 1430.597912 0.500500727
57.94519522 1402.765268 0.490763359
62.77396149 1324.833864 0.463498728
67.60272775 1196.803701 0.418706834

s2k2fast4me

And here's adding a Boxster S to the mix. If you overlay all three cars, it looks like the S2K lives like a Boxster 2.7 below VTEC and like a Boxster S when on VTEC.

Also interesting was that the Boxster S doesn't get any better ratio than the 2.7 in 2nd gear, even though it's a 6-speed. Though final drive and 2nd gear are different, together they are almost exactly the same.

I'm guessing on the S's weight, as I have a good idea on a 2.7 in competition weight and the factory manual lists the S at 100lbs heavier.

Boxster S
Weight 2900
2nd Gear
MPH 2nd Torque Accel
9.630989635 1255.92078 0.424237843
14.44648445 1339.648832 0.452520365
19.26197927 1412.213144 0.477031885
24.07747409 1495.941196 0.505314408
28.89296891 1562.923637 0.527940426
33.70846372 1618.742339 0.546795442
38.52395854 1663.3973 0.561879454
43.33945336 1696.88852 0.573192463
48.15494818 1696.88852 0.573192463
52.97044299 1674.56104 0.565650457
57.78593781 1624.324209 0.548680943
62.60143263 1507.104936 0.509085411
67.41692745 1283.830131 0.43366535

leonard

pretty interesting stuff..i think i know who this is but that's beside the point..
your rims looked pretty cool from a distance..as you got closer to them, they reminded me of waffles or something you could almost eat..like a cake..
in the end, it's the driver..great driving at mather..

Jason Saini

Very interesting comparison... I do not, however, agree to the statement that "S2K suffers very little to the Boxter at lower speeds, while showing a clear advantage after the VTEC switchover."

Let's look at some specific MPH's... (all Stook/Boxster 2.7/Boxster S)

28mph: 1257lb-ft / 1363lb-ft / 1562lb-ft
So at this speed, the Boxster has 106 more lb-ft, and the S has 305 more.

33mph: 1223lb-ft / 1391lb-ft / 1618lb-ft
At this speed, the Boxster has 168 more, and the S 395 more.

38mph: 1257lb-ft / 1419lb-ft / 1663lb-ft
At this speed, the Boxster has 134 more, and the S 406 more.

Above VTEC, the highest value for the Stook is 1493 lb-ft, and the Boxster S's peak is 1696, a difference of 203, so I can hardly agree that the Stook behaves like a Boxster 2.7 below VTEC and a Boxster S above VTEC. When looking at the Boxster 2.7 vs. Stook comparison, that's about as close as you can get between two cars, with the course dependancy becoming painfully obvious in the fact that the Boxster rules below 46 mph, and the S2000 rules above 46 mph.

With the risk of being accused of cherrypicking the data, I feel that your charts prove that the S2000 and Boxster are a better match than the S2000 vs Boxster S. Let's not forget that the Boxster S and Boxster both have bigger tires, wheel widths and brakes. Power delivery isn't everything.

I maintain that a well-driven Boxster 2.7 is a good match for a well driven S2000.

s2k2fast4me

I think that maybe you're getting your Boxster's confused. Pre 2000 Boxsters have a 2.5 motor (201hp, 181ft-lbs). 2000 base models upgraded to 2.7 (217hp, 192 ft-lbs) and the S came with a 3.2l (250hp, 225 ft-lbs). The line between the 2.7 and 2.5 is smaller than expected, as the earlier cars had shorter gearing which makes up somewhat for the torque deficiency.

Of course the peak torque numbers for the S2K look worse, even including the gearing. No argument there. But you have to take into account the weight of each car to get acceleration. A Ford pickup puts out way more torque than the Boxster S at any RPM, that doesn't mean it accelerates faster. The fact that the S2K is so light (one of it's greatest virtues) let's it "make up" for the less torque.

If you divide through the torque numbers by the weight of each car, you'll see what I'm talking about. The S2K trails the 2.7 Boxster by only a little up until ~45mph, then pulls ahead when on VTEC. The implication being that it's not really an underdog at low speeds, but is a clear overdog at higher average speed courses. Please plot the numbers before disagreeing.

In comparison to the S, the S2K is behind by ALOT below VTEC, and only pulls up to be close to the S above 45mph. An S2K could probably do fine against Boxster S's, but ONLY on very high average speed courses (and those don't come around that often unless you live in San Diego).

Regarding the tire argument, the S2K does run a smaller front tire, but gives up almost nothing in width to either of the Boxster's in the rear (assuming they are running 245/40 17's or 245/35 18's). If a Boxster owner wants to run 275's, they can go right ahead and suffer the gearing loss.

From a long term classing standpoint, I'm not really choosing sides here. After seeing all of these cars perform and running the numbers, I think an S2K will hold it's own or better the the 2.7 Boxster on slow-medium speed courses, and be a clear dominator on faster ones. Net win for the S2K. I think it would be just the opposite against the Boxster S. The S2K would have to hope for only fast courses with the expectation to at best stay even with the Boxster S.

I don't really envy the SEB on this one. You either ...

A) Keep S2K's in current AS - they dominate
B) Bump the S2K's up to the "new" AS - they lose to the Boxster S
C) Bump the S2K's up to the "new" AS, bump the Boxster S to the "new" SS - Boxster S gets creamed (do we care?), Boxster 2.7 dominates "old" AS, S2K vs. C4 outcome?
D) Bump S2K's and 2.7's to "new" AS, bump Boxster S to "new" SS - S2K's vs C4?, "old" AS low on participation without S2K or Boxster?
E) You win an award for following the above logic.

Personally, I'd prefer A or C if we want healthy classes with competition. However, the only way you don't have a blurry distinction between the new AS and BS is if both the Boxster and S2K go to the new AS.

Of course, with Porsche and BMW (and maybe Honda?) adding bits and pieces of hp to their cars year by year it gets even harder to spread them apart.

Glad I'm not on the committee.

Jason Saini

Show's ya how much I know about Porches! I thought the S was 2.7... thanks for clarifying. I agree with your preference of either choice A or C, and it took me a while to reach E!

I'm working on posting a graph of your data...

Jason Saini

Please ignore my ignorance... Boxster 2.5 on my chart = Boxster 2.7, and Boxster 2.7 = Boxster S. Sorry, I didn't feel like redoing the chart! Also, keep in mind that there was no data for the S2000 below 20mph, that's why it's line is shorter.

s2k2fast4me

Hey! You went and corrected your message about the 2.5, 2.7, etc. That's cheating. Now don't I look like the A-hole.

leonard

i have a better suggestion, lettered:

F) buy gary thomason a Boxster, all dialed in with Hoosiers, let him dominate AS at nationals, then move the Boxster to Class 2 and keep the S-2000 in class 3..

that sounds even better..hmm, waffles.

GMan

IMO, torque at the wheel doesn't tell the whole story. Looking at the acceleration numbers, the S2000 is better than the Boxter 2.7 over 45 MPH, and better than the S over 60 MPH (although that's stretching it for AutoX). However, the stook doesn't play between 25 and 45.
I have the G's chart ready, but I am not set up for posting GIFs, can somebody do that for me?