Buger

I would come and watch you guys if you do some autox thing close to here. How much have you put into your car 5.0THIS?

Brian

Buger

InfinitePat wanted more info that first gear. The below graph is from about 0 - 100 mph and takes tire slippage into account too.

NashuaCLS

How about Velocity Vs. Time Graphs?

Rx4FUN

Based on the dyno numbers that 5.0This is listing, I'm guessin' he's got an LS1 under the hood. So that means a Vette, Camaro, or Firebird. If he had a Vette, I would think his dyno would have been a bit higher, so I'm guessing he's got an F-Body.

I too have an F-Body. A '98 Z-28 Convertible. It's not stock and is putting down about 320HP at the rear wheels. But I'm still looking at the RX-8. And why you may ask?

'Cause horsepower isn't everything! I've upgraded the suspension and it corners fairly well, for a car that weights over 3600 lbs. But the car just isn't any fun to drive if you are on anything but a straight and smooth stretch of pavement. (Or your just cruisin' with the top down.) Throw in a curve or a bump and you really have to work to keep the car composed. I can powerslide with the best of them (on a track of coarse), but I wouldn't dare push the car to its limits on anything but a well prepared track because one bump, or divot, or patch of sand in the road and it's all over. The solid rear axle just isn't forgiving.

Now the RX-8 is a bit more like it. If I can shed 700+ lbs. get independent rear suspension(not to mention other handling goodies), seating for four (for those rare occasions), better styling(IMO)... I'd be willing to give up some of those ponies. Actually, quite a few ponies. The car would be so much more fun to drive. It would have enough composure at the limit that I'd push the car harder than my Z even though it had less power to do it with.

I haven't decided yet if I will sell the Z-28 when and if I get an RX-8... I may keep it around for those occasions when I just want to cruise with the top down. But I'd bet that if I keep both, the RX-8 would see a lot more miles!

~Robert

pmacwill

A Trans-Am is probably what he thinks he has, but considering he called it a Grand-Am, he obviously has no idea what he is talking about. Bring your Grand-Am to the track, leave your Trans-Am at home and the Rx-8 will run laps around the Grand-Am.

Are you even old enough to drive? Do you have a car? Get your story straight.:p

Buger

I tried to be a little optimistic when making the s2000 curve in cartest. The s2000 has an incredible engine but there is an engine that is smaller, lighter, and produces more power and torque throughout the rev range...

RX-8
torque peak: ... 159 ft-lbs
redline: ....... 9000
engine band: ... 8300 (9000 - 700)
95% or > tq: ... 43.4% (8400-4800 = 3700, 3600/8300)
90% or > tq: ... 59.0% (8900-4000 = 4900, 4900/8300)
80% or > tq: ... 83.1% (9000-2100 = 6900, 6900/8300)

s2000
torque peak: ... 153 ft-lbs
redline: ....... 8900?
engine band: ... 8200 (8900 - 700)
95% or > tq: ... 30.5% (8600-6100 = 2500, 2500/8200)
90% or > tq: ... 41.1% (8900-5500 = 3400, 3400/8200)
80% or > tq: ... 80.5% (8900-2300 = 6600, 6600/8200)

I have a feeling that somebody may try putting a renesis in a s2000 sometime in the future...

Brian

ZoomZoomH

iTrader: (1)

buger you da man!

good cartest software usage!

Buger

Thanks ZoomZoomH,

I'll try to do a comparison of some other cars tomorrow. I think I remember reading that people wanted to see how Altimas, 330is, 350zs and 6-spd G35 would do in a "bench race" for whatever it's worth.

It's too bad that out of handling, braking and performance, people want to always compare the weakest performance metric of the RX-8 to other cars.

Brian

5.0THIS

Hey man, I was just kiddin with ya earlier. RX4fun was close, I do have a camaro, but it's just an LT1. I've only got some bolt ons, maybe 1500$ or so in stuff that gives it more power, no internal motor work, no blower, no bottle. I myself have not autocrossed before, but have many friends that do in the denver metro area. We'll have to meet up sometime if you want to get feel for the motorsports scene in Denver

RX4fun: interesting you should say a vette should have higher dyno numbers.... not necessarily. The engines are essentially the same, despite GM attempting to rate them differently. but the vette has to go through the Getrag transaxle, which soaks up more power than the live axle in the f-bodies, so in many cases the f-bodies put down more power, although they still arent faster because they weigh more.

pmacwill: I have a camaro, not a grand am. I was messing with you guys, apparently some of you are way too easy to get to! I apparently have no idea what I'm talking about. I admit freely that an RX-8 will handle better than an f-body, but 99% of people cant take any car to it's limits. I know how to drive my car, I've been racing for years, 3 years road course racing, and currently race in NASCAR's Weekly Racing Series (let me know if you want me to post a pic of me and my racecar). Exactly how much racing experience do you have? I'll bet if a grand am had equal power to an RX-8 I could run rings around you even with you in an RX8 In fact you pick the track... dragstrip, road course, autocross, whatever, and I'll bet you money my camaro could beat you in your RX8 at any venue! And yeah, I'm apparently old enough to drive, and I dont own A car, I own a few cars. Have a good day sir

Take it easy guys.

Andy

Rx4FUN

5.0This-

I know this isn't an F-body forum so I'll make this quick. The reason I said I didn't think you had a Corvette is because even a stock '97 or '98 Corvette will dyno at over 300rwhp. The stock intake and exhaust on an LS1 Vette are much more freeflowing and the vette motor doesn't have EGR. I agree that the LS1 F-body is underated by GM, but the stock vette does dyno about 10 rwhp higher. If you had a vette that was a 2001, 2, or 3, you should definitely be higher than the dyno numbers you posted.
As it is, you're numbers look pretty good for an LT1 with no internal mods or forced induction mods.

Everyone Else-
Speaking of drive train losses...I wonder what the drive train loss will be in the RX-8. The 6-speed RX-8 is using a composite one-piece drive shaft that is pretty short and 11 lbs lighter than the steel version in the automatic. Mazda also did a lot of work to make sure the tranny, drive shaft, and differential line up to reduce vibration. I would think these would add up to reductions in drive train loss as well. This could result in getting more power to the pavement.

I've heard rumors that the drive train loss on the 350Z is higher than people expected. (That is if the Nissan published HP numbers are accurate.)
It will be interesting to see how the actual RWHP numbers compare between these two cars. (Whoops, I forgot...HP isn't everthing...HP isn't everything...HP isn't everything. Sorry, I've just been a member of the F-Body world too long. There, HP is everything.)

~Robert

revhappy

I wonder just how much weight the freestyle doors and the related bracing added to this car? If this added a significant amount of weight, I think they made a huge mistake here. To sacrifice handling and performance for doors that still require the driver and passenger to get out first seems to be a questionable decision, at least for a sports/sporty car.

I eagerly await the true unveiling of the production model on the 17th at Laguna Seca.

5.0THIS

Actually, many corvettes dyno below 300rwhp, even 6 speeds, it is actually quite common for 97-99s. The intake manifold on the vette is the same as f-body motors, and the manifolds are almost identical as well, however, after the manifolds the vette exhaust is indeed much better flowing than the f-body design.

pmacwill

5.0this - you know I was messin with you. I'm not a racer. I am going to use my car to get from point a to point b, and maybe to try to pick up some girls. thats about it. throw up a picture of the race car for kicks though, I'd like to see it.

cheers.

Toadman

Yeah, lets see this bad boy. :D

5.0THIS

No problem man, I too was just messin with you I hope you have fun with your car whatever you want it for

Well, I think it would be too big to just show it here, so here's the link to a pic of me and my racecar
http://www.bigwestracing.com/gallery...ndylewis24.JPG

And here's a pic of my weekend toy, my "grand am", and this pic might not be work safe for some of you :D

http://www.off-road.com/~sspickler/andy/girlsfront3.jpg
http://www.off-road.com/~sspickler/andy/side.jpg

scotty_passat

great discussion/analysis buger ( and others)

we in the vw community are watching this car (and the Sti and evo-8 ) with interest

Buger

Thanks Scotty_Passat,

Hopefully we'll get more info this week after Dan gets to drive some of the pre-production RX-8s at Laguna Seca.

In the meanwhile, a couple of people wanted some speed vs time graphs. I did a more in-depth comparison of the 2003 s2000 and the RX-8. See some of the specs used below:

RX-8 (Hi-Performance)
Price : Approx 27,000 US
HP: ... 247 hp
Torque: 159 ft/lbs
weight: estimated 3,011?
Gearing: Diff - 4.444
........ 1st - 3.76
........ 2nd - 2.269
........ 3rd - 1.645 <-- note that US has diff 3rd gear ratio than Japan
........ 4th - 1.187
........ 5th - 1.00
........ 6th - 0.843
Wheels/Tires: 225/45R18
Diameter ......... 25.97"
Circumference .... 81.59"
Revolutions/mile . 776.52

2003 s2000 (from http://www.edmunds.com/new/2003/hond...tml?id=lin0018)
Price : Approx 33,000 US
HP: ... 240 hp
Torque: 153 ft/lbs
weight: estimated 2,809
Gearing: Diff - 4.1
........ 1st - 3.133
........ 2nd - 2.045
........ 3rd - 1.481
........ 4th - 1.161
........ 5th - 0.971
........ 6th - 0.811
Wheels/Tires: 225/50R16
Diameter ......... 24.86"
Circumference .... 78.09"
Revolutions/mile . 811.32

Although it appears the RX-8 is geared much shorter in every gear (multiply diff by gear ratio), it's wheels/tires have a bigger circumference. Because of this, the s2000 actually reaches it's redline at a lower speed in every gear except first.

RX-8 approx speeds at redline:
1st gear ... 42
2nd gear ... 69
3rd gear ... 96
4th gear ... 132
5th gear ... 157 but drag limited at approx 155
6th gear ... 186 but drag limited at approx 150

S2000 approx speeds at redline:
1st gear ... 42
2nd gear ... 65
3rd gear ... 91
4th gear ... 116
5th gear ... 139
6th gear ... 198 but drag limited at approx 147

The RX-8 could have had much faster acceleration if it were geared shorter. Many sports cars today are geared so that redline for second gear is reached right around 60 - 65 mph. This is done so that 0-60 figure which many people find so important will be higher. Mazda took a different approach for the RX-8 spreading the gears out so that top speed is reached in 5th gear and 6th gear is specifically for better fuel economy.

Below are graphs of the comparison. The Edmunds page has the 2003 s2000 0-60 time at 6.1 seconds. Cartest estimated the 2809 lb s2000 a little higher at 6.18:

rotisserie

Buger, can you make one for the quarter mile please?:D

NashuaCLS

How about a 3D graph

X= Time
Y= Distance
Z= Velocity (Speed)


Kick *** Graphs!

Niebla

If is possible to change the gearing ratios, how much do you think that it will cost and what the gain could be.

Thanks

nk_Rx8

The graphs show that both cars will be very similar, despite the fact that some have claimed that the RX8 will be able to easily outperform the S2000. And I looked at a few S2000 dynos this weekend and they show at least 85% of max torque from ~3000rpm and up, compared to the claimed 90% on the RX8. It doesn't seem that much different to me, so I'm still looking for the graphs that maybe some people have seen that show the RX8 curve to be way better. Any links?

Rich

Dang it! Mazda threw away one of the biggest benefits to a high revving/high RPM torque engine. You would see the benefit every time you drive with shorter gear ratios, but the longer gear ratios only give you the benefit of a tiny fuel economy increase, from what I can see. Couldn't they shorten 1st and second and end up at the same point for 6th as a fuel economy gear?

This is now my #1 question for Mazda, if I could have a conversation with one of them. If there's anyone here who might have the opportunity to interview someone from Mazda, please ask why the gearing is as tall as it is!

Buger

Hi nk_RX8,

Who are the people that claimed that the RX-8 will be able to "easily outperform the S2000"? I don't remember reading any posts here that mentioned anything like that?

I posted some similar torque curve stuff on the Car&Driver forum a couple of months ago and found out that S2000 people are very sensitive about the "torque" issue (almost as much as RX-8 people might be! ) There were claims that the s2000 had a flatter torque curve than a LS1 Corvette and that the s2000 had 5400 rpms of 90% or greater torque!?!?!

Perhaps you haven't seen the RX-8 - S2000 torque curves overlayed in http://rx8forum.com/showthread.php?s...0339#post20339 ? You will notice that I was very conservative in my #s on the RX-8 torque curve. If you can't tell the difference in the engine torque curves by looking at that graph, then I may not be able to help you.

Nevertheless, the below post that I made on the Car&Driver forum that has some links and is pretty much on this topic and may help explain things further...

----------------------------------------------------------------------------

So the question is: Does the emperor have any clothes on or not? As I mentioned earlier, I have looked at many s2000 torque curves before. The one that Waldorf posted appears to be the same one at: http://www.autospeed.com/A_0911/page1.html. It even has the same name but unfortunately it is rather small. The curve that Zorro19s posted appears to be graphed from excel but unfortunately has no grid between 100 and 150 so it is a little difficult to determine where the 90% mark is.

Fortunately the s2000 has been out for awhile and there are many sites that have the stock s2000 torque curve.
These are from dynos and have tick marks that make it easy to determine the values:

http://www.dynospotracing.com/s2000.htm
peak wheel torque: ... 137.5 ft-lbs
90% of peak: ......... 123.75 ft-lbs
range above 90%: ..... 5800 to 8600 = 2800 rpms or 31%

http://www.flyinmiata.com/tech/dyno_...99TvsS2000.pdf
peak wheel torque: ... 139.0 ft-lbs
90% of peak: ......... 125.1 ft-lbs
range above 90%: ..... 6200 to 8600 = 2400 rpms or 27%

This one is a rather small graph of the engine torque but it does have tick marks that make it easier to determine the values:

http://www.cartoday.com/content/tech...er_torque3.asp
peak engine torque: ... 208.0 Nm
90% of peak: ......... 187.2 Nm
range above 90%: ..... 5800 to 8600 = 2800 rpms or 31%

Was I a little generous to the s2000 with my earlier estimates? Perhaps only a small one, unencumbered by bias or a fear of the Emperor, can see that 5400 rpms of 90% or greater torque might be a little exaggerated. Seriously, you love getting pushed back in your seat around 5500 rpms right? That is where your s2000 is starting to enter it's powerband.

Quite a ridiculous example but what s2000 owner would care about a flat torque curve? Just joking of course but if it could be geared about 10% more... I would imagine that first gear would go by too quickly. After that the driveability would be incredible. There wouldn't be the same top end "peak" that would be made peakier by the tighter gearing. Seriously though, you shouldn't think about lowering the torque of the s2000.

If you've read my earlier posts, you would know that I am aware of revs and gearing and I even stated that "The problem that many people have with the s2000 *shouldn't* be the peak torque of 153 ft-lbs. It is more than enough to move the 2800 lb s2000 very well". My problem with high gearing ratios on an engine that has a raised area in the upper 3rd of it's range is that it will make it seem even peakier than it is.

Perhaps some s2000 owners can't appreciate a powerband at low rpms because they have no use for it? Perhaps some people that have a powerband at low rpms can't appreciate a powerband at high rpms because they have no use for it? I don't agree with the trollish attitude the original poster of this thread had but there is something to be said for the driveability of cars with very wide powerbands. Not everyone is going to have the same views as you. If someone is closed minded and is only interested in ridiculing your view, just ignore them because your energy will be wasted on them. After saying that, I'm sure many people are tired of my rambling so I will exit this thread.

Brian
----------------------------------------------------------------------------

Buger

Hi Rotisserie,

I'll give the Cartest 0-60 and 1/4 mile RX-8 results for a variety of weights from 2950 - 3015 tomorrow morning.

Time to go to work now.

Brian

Buger

Hi Niebla,

I'm not sure how much it would cost to change some of the gearing ratios or to change to a higher ratio rear diff. I'm sure that there are some crazy people here who have done that sort of thing to their cars before though.

Seriously, are 0-60 times that important to spend the money to do that?

Brian