MarkRx

Well I finally got to take a demo Rx-8 overnite. It's a red GT with a rotary accent pkg, and no nav. I have an old G-tech and decided to play. Car had over 500 miles during the testing. I only tested some 0-60 times and quarter mile times. i tried 9 different launches using 4000, 6000 and 8000 rpm clutch release points. I did each with DSC ON, OFF, and completely OFF (press and hold for 5 sec) the car did 7.5-7.7 sec with the DSC fully activated. The G-tech flashed the 0-60 speed exactally when the digital speedometer read 60 which was quite nice. (first time comparing g-tech with a digital speedometer) So here are my final figures, on a smooth level paved surface at 2:30am, 74-degrees outside with lots of humidity. 40 psi in each tire. I'm 5'9 160, girlfriend maybe weighs 100 soaken wet. Equipped with a 1/4 tank of chevron techron 93 octane, here we go...

DSC OFF 0-60

4000 rpm 6.8 sec
6000 rpm 6.8 sec
8000 rpm 6.9 sec

DSC completely off (press and hold)

4000 rpm 6.6 sec
6000 rpm 6.6 sec
8000 rpm 6.7 sec


I shifted from 1st to 2nd at 9000 rpm with a moderate shift, no power shift. With better outside conditions, i.e. weather, road grip, and a more pronounced shift, a 6.3 sec 0-60 isn't out of question.

After dialing in my launch, I played with my quarter mile times. All were consistant in the mid to high 15's with the best run of 15.55 @ 94.1 mph.

MarkW

Interesting info, sounds like you had some fun

Makes me wonder how the 228bhp Euro spec claims 0-62 in 6.4 then......

Quick_lude

Interesting.. I hope the Gtech is a little off or the engine needs to break in because while the 0-60 time is pretty good, the quarter mile time is very bad for 247hp. I hit 15.1 with my car with 168 Whp.

Hercules

DSC OFF and DSC Completely OFF would yield the same results... the only time the latter DSC would activate is under braking and to get a straightline time... you aren't braking.

I am happy with the power nonetheless

Quick_lude

I'm not talking about how the car "feels", it's just simple math. A 3050lb car with 247 hp should be in mid 14's in the 1/4 mile, NOT mid 15's. That's why I think/hope somehow the ECU is "detuning" the engine at high rpms during the break in process. If people are still hitting 15's in the 1/4 after say 5,000miles on the car then something is wrong imo.

Lensman

If the ECU is dynamically mapped then shouldn't Mazda mention it in the owner's manual??? It's a rather important feature to hide away don't you think?

Quick_lude

I think they should have if they did this. Honestly I don't know what to think. I hope more people put the 8 on the dyno soon and on the 1/4 strip so we can get some real world numbers. Especially the dyno. Because right now with the low dyno number posted the other day and this mid 15 sec 1/4 mile time I'm a little worried.

delhi

whoa... 250hp is getting the same performance as an RSX-S?! I'm a bit disappointed. Perhaps it's the driver. Or there really is a power deficit (from that dyno thread). Is Mazda pulling a Ford with their Mustang Cobra years ago?! Hmmm.... Mazda is now partly owned by Ford.

Sputnik

Actually, those times would match up with what we did see on the dyno. And we've talked about the "power deficit" a little more recently, and most of us are fine with what we see at this point.

---jps

Quick_lude

So are you saying that the engine will "open up" over time? Because I wouldn't be "fine" with these numbers UNLESS I knew that after the break in period is over, whenever that is, my car would hit the mid 14 mark as it should because of the advertised hp/weight ratio.

Good Duck

15.55 sec @ 94.1 mph

This give me a little pause. A 94 mph at the end 1/4 miles should result in 15.1 or 15.2 sec not 15.55 sec. Maybe there's too much wheels spin at start or some other factor. To optimize launch the tires psi should be alot lower than 40psi, more like 28psi or lower.

donaldc

Wheels Magazine (Aug 2003) in Australia just did a comparision of the RX-8 vs the 350Z.

Here's their results on standing start acceleration times:

RX-8
0-60km/h: 3.1sec
0-80km/h: 4.8sec
0-100km/h: 6.4sec
0-120km/h: 9.1sec
0-140km/h: 12.0sec
0-160km/h: 15.7sec
0-400m: 14.8sec at 155km/h

350Z
0-60km/h: 3.0sec
0-80km/h: 4.4sec
0-100km/h: 6.4sec
0-120km/h: 8.3sec
0-140km/h: 10.8sec
0-160km/h: 14.1sec
0-400m: 14.3sec at 164km/h

The track they tested on was dry, temperature 11C.

Donald

Quick_lude

That's a little better and more realistic for the hp/weight.

MarkRx

You bet there was mega wheel spin! The tire said not to exceed 50psi, i checked the tires and there was 40 in them so i left it... but there was alot of wheel spin, the car is very stable off the line during the spin, it was fun i might add, the nose went to the left the same amount every time, just turn slightly to the right and straighten out.... i got the wheels to light up on dry pavement for almost a solid 4 seconds... took a 15 mph corner with dsc off at 40 mph and the drift was smooth and controlled, a little sloppy compared to a boxster S, but very fun. Just the excitement of being in a rotor powered machine again and the nice exhaust note ressonating in the cabin at 3300 rpm and then pouring on the revs from 6-9k brings a smile to my face. it's not all about 0-60, but since i had the car and a g-tech i figured what the heck.

Sputnik

When I said "fine", I don't mean that they are satisfied with the numbers as a final result, I mean they are satisfied that the engine is still breaking in, and the ECU is probably holding the engine back during the break-in period.

---jps

brillo

how were you engaging the clutch? Was it a clutch dump at those RPM levels, or were you slipping or feathering?

akrx8

recent road and track has rx8 at 0-60 at 5.9 sec with 7000 rpm launch and 1/4 at 14.5 at 96 mph.

MarkRx

pretty much dumping it... i eased off it slippig it also, didnt seem to do much, made the times worse, lots of wheel spin when you dump it of course. But like i said, there are some other minor factors that play a role in getting the times down a little bit more...

fishsauce

Would the weight of the passengers make a difference? If magazines test the car with only the driver and MarkRx had another passenger, wouldnt that be the reason he went slower than expected? Or does passenger weight not matter that much?

seikx8

After reading the thread and I was bored, so I went out for a spin and here is the result according to GTech Pro:

Run #1: Launch at 3k - wheel spin, DSC activated, AC off
60ft : 2.422s
330ft : 6.627s
1/8mi : 10.010s @ 74.91mph
1000ft: 12.901s
1/4mi : 15.363s @ 92.63mph
0-60 : 7.36s

Run #2: Launch at 3k - wheel spin & hop, AC ON (forgot to turned off, duh!)

60ft : 2.515s
330ft : 6.484s
1/8mi : 9.607s @ 81.58mph
1000ft: 12.838s
1/4mi : -- (brake applied before 1/4 mile due to incoming traffic!)
0-60 : 7.089s


According to G-Tech Pass software:
Run #1 registered 186 HP @ 7600 RPM, 132.6 ft-lbs TQ @ 7100 rpm
Run #2 registered 234 HP @ 7400 RPM, 169.9 ft-lbs TQ @ 6088 rpm

The follow is vehicle information entered:

Vehicle name: 04 RX8
Vehicle weight: 3800 lbs
Redline: 9000 rpm
Shiftpoint: 8500 rpm
Rollout: 12 in, 0.84sec

There is also a run that didn't come out right and registered: 5.862s 0-60! It was a perfect launch, no wheel spin, tire just grab and go. Probably these data weren't accurate anyway.

Since my car only have 900 miles, I don't feel like doing too many hard run, so I will wait until then. The attach are the data downloaded from the GTechPro via GTech Pass software. Btw, If I view the data at the GTechPro unit, the HP & TQ numbers are a little bit higher, so I have no clue what to believe; Therefore I would wait until a real dyno run to make any judgement after proper breakin period.

And of course, the weight was assumed to be 3800 lbs of the driver side doors sticker :D

BillK

I hope the :D was because you were kidding...

The 3800 lbs on the door frame is the maximum gross weight the vehicle is built for, or given the 3029 lb "with popular equipment" weight given in the RX-8 brochure, roughly the car plus a maximum of four 200 lb. people.

So given that, you really should have entered roughly 3030 lbs + (your weight.)

brillo

i'd really like to see your street start times, or you runs while slipping the clutch @3000-4000 as that is something you would do more often and wouldn't result in serious wear to your car

delhi

I'm not convinced. I mean the WRX STi out of the box with low mileage clicks of low 5s 0-60 and high 13s. I cannot buy that. Why should I have to wait for my car to reach 20k before seeing any real performance improvements?! 20k to me is about 1.5years of regular driving! Yikes!
I still like the 8 however. but am disheartened at it's performance so far vs. claimed performance.

ChrisW

I agree. The idea of waiting for 10000 or even 20000 miles to get the advertised performance does not seem right to me.

Of course many cars do get faster as the engines "loosen up" with age, but that's just a bonus. Surely, the vehicle must produce close to the specified power FROM NEW (allowing for reasonable break in i.e. 1000 miles) or the manufacturer is guilty of some sort of misrepresentation?

seikx8

That is correct :D. It was over estimated. The original weight that I thought would be was somewhere around 3200. Given the fact that I weight in the two digit figure, that would bring it down to 3100lbs max. I don't know how GTech caculate its HP & TQ, but I think you can find out the TQ & HP via weight, G value and RPM.