flatair

Ok ran a few numbers through the car simulator, cars simulated:

2001 E46 M3 - power curve based on real dynojet plot

1995 993 intake/exhaust/chip - based on real dynojet plot

1995 993 intake/exhasut/chip/close gears - based on real dynojet plot and re-geared according to 993RS's current short gearing experiment he's doing with Steve W.

Results:
3rd gear rolling start at 30mph (lugging the engine, demostrates torque)
time.....M3 mph.......993 gap (ft).....993 geared gap (ft)
---------------------------------------------------------------
5............63.................-18.......................-3
10..........93.................-87.......................-4
15.........111...............-133......................+1
20.........128...............-162.....................-11

In the above test, with a low rpm rolling start, the stock M3 pretty much obliterates the 993 with regular gearing, though the 993 stops losing ground so quickly when it gets into higher speeds. Varioram would make a difference here, but prob not nearly enough. Interestingly enough, the very short gearing that 993RS is getting installed in his car puts him about even with the M3, slightly pulling on it at higher speeds (the -11 is due to a shift right at the 20 second mark). This tells us right away that the shorter and closer spaced gears will make BIG differences in performance.

Next test:
3rd gear rolling start at 60mph (more in the 993's power band)
time......M3 mph.......993 gap (ft).......993 geared gap (ft)
---------------------------------------------------------------
5..............91................-21.........................+9
10...........110...............-30........................+16
15...........126...............-29........................+31
20...........139...............-28........................+39

This is where it gets interesting, the regular 993 falls behind the M3 in the beginning, prob because starting at 60 in 3rd is just a tad shy of where the car really starts to make power. Notice afterwards, it holds its own, and starts to close the gap ever so slightly - basically if you're ready, in the right gear, you can *maybe* hold even with a stock E46 M3. The short geared 993 pulls ahead of the M3 at a fairly slow and steady pace.

So there ya have it, according to the simulator (which I find is quite accurate if set up properly) the E46 M3 is a fast car - faster than a stock 993, and probably an even match with a modified 993 if you're in the right gear. Do a close ratio & shorter gearbox, and that's when you'll start to see noticable advantages in acceleration.

993RS, we must hear a full report when you get your car back

flat

993RS

Say flatair, could you run the 997 Carrera S through your cartest program?

It would be neat to see how it compares to the others.

997 gear ratios:

1st: 3.91
2nd: 2.32
3rd: 1.61
4th: 1.28
5th: 1.08
6th: 0.88

nman413

Pin, dont sell your car!!!

abar

Thanks flat! BTW: Had no problems keeping up with an E46 M3 Cab yesterday, acceleration seemed similar, then started to gain until the next roundabout.

Cheers, Al

Toga

Flatair, do you mean that the varioram and the 3.8L of my car give me a chance? (up to now I never had the oppportunity to race a 993)

Phil,
I see that you're becoming a gearbox ratio specialist! I'm a bit confused about the different types on the 4S. Is the G64/21(that's the one I have) "longer" than the G60/21?

Cheers

993RS

Toga,
The g50/20 on the C2 is the g64/20 on the C4S. (gear ratios identical)
The g50/21 on the C2 is the g64/21 on the C4S. (gear ratios identical)

chris walrod

Not sure if this car simulator factors in aero cd, but this does play a huge role in longit. accel. with ground speeds above 60 mph.. This is why its somewhat unfair to compare old cars with new, not that the 993 is that old and it is somewhat slippery at a cd of .31 IIRC..

flatair

993RS,
Absolutely I could run a 997 S through, but I don't think anyone has a dynojet plot for that car yet. Cartest is a great program, but you have to set it up 'right' or it won't be that accurate. As soon as I find one we'll do a comparo, but I figure by that time you'll have your car back and probably will have had a 'run in' with a 997S on the road I'd expect your car to be alot faster, and *feel* tremendously responsive with the new gearing...but those 997S's are supposed to be pretty fierce

Abar,
I'll see if i can do a simulation of a varioram car next, as the torque curves I've seen might help out a bit (at least in the beginning). Also the M3 Convertible weighs in at 350lbs over the Coupe, so I can definitely see that combined with the extra flexibility of your VRAM setup leveling the 'playing field'.

Toga,
I've read people saying the 3.8 isn't that big of an upgrade as far as power, but taking into account the added displacement, matched heads, and matched cams, I find that hard to believe. I'd bet you'd see a significant lead over a stock 993 in acceleration (assuming you had the same gearing).

Chris,
Absolutely drag makes a big difference at the upper speeds, and yup, Cartest has many parameters including drag coefficient, shift times, coefficient of friction from tires, drivetrain losses, and much more (just about everything that is significant). In my case, I keep things like shift times and tire-friction the same between two cars for comparison sake, but set the drivetrain losses to 0 and program in the dynojet hp curve at every 500 rpm increments, since the dynojet measures hp after drivetrain losses. I do rolling start comparisons as I believe the one thing the program has trouble with is standing starts (wheels spin vs clutch slippage etc is just too complicated and environment related to be accurate). Look up cartest on google and download it. Then if you like I'll send you my 'data file' with the dyno curve cars.

Cheers!

Flat

abar

Flat,
Yep agree about clutch slip / traction. Would also be interesting compared to a vram with G21, lucky enough to have one of the eariler '96 models.

Al.

JM993

CP - as much as I love my E30 M3, I'd be happy to trade it for you're RUF

CP

Joe,

We can at least trade rides.

CP

JM993

Uh-oh, I've been dumping money right and left in my M3. One ride in your RUF and I'll be dumping money in the 993.

Oh.....but you are on though. Hopefully we'll get a chance to hook up in the near future.

993RS

flatair,
Cartest is a cool program. Just bought and installed it. Thanks for the tip.

ColoradoMark

Resurrecting an old thread with some first hand experience from last weekend.

I was instructing at at the BMW club driving event at PPIR the last three days. There were several E-46 M3's in the instructor's group:, one with the new competition package, one SMG and a couple of "normal" ones. I assume that since they are all instructors that skill is SOMEWHAT comparable. Me: I'm still learning to drive this new to me 993, car is bone stock with Pagid Sport pads and Kumho MX tires on 18" wheels.

The only car that passed me all weekend was a stock e-46 on Conti Extreme's street tires. He looked to be a better driver than I am and was probably about a second a lap faster. I passed, or didn't see, all the other cars in the run group. If you've been on the track I was running around 1:10's on a somewhat moist track with temps in the 30-40's.

BTW, one of my students had a slightly modified ZO6 corvette - nice ride on the track! He was about 5-10mph faster at the end of the straight than I was.

993polarsilver

Quote:
Originally Posted by riviera 93
then the engine on the M3 goes POP! common occurance from what i hear.

Quote:
Yeah, BMW has claimed to have "fixed" that problem for the fourth time now


Let's not be too smug. My 993 is dealing with the dreaded SAI problem (a $5,000 repair for poor emissions system design) and many fellow rennlisters have suffered from 986/996/997(!) main seal failures, many of those resullting in total engine replacement. Both BMW and Porsche have reason to feel shame, though I doubt if either do. That said, I still love my 993!