View Full Version : Auto vs Manual Perf numbers


Calibus
05-24-2003, 02:02 PM
Hi i am new to this board though i have been trollin it for a while.
I am new so plz put up with the stupid questions.
1. I am in the market for a sports coupe i have it down to a Z350 or a RX-8 the prob is i have not sat in the RX -8 yet.
when will cars hit showrooms so i can actually sit in one.
2. Does Mazda have official perf numbers posted for the Auto and Manual Trans cars.
As i see it the Auto trans car has less HP but more Torque and torque is more important down lown then HP.
3. I have not owned a Mazda Product in 10 years
Previous ownership of 2 626 cars one was a 91 that went over 100k miles with no probs and was still goin strong when i got rid of it " my friend drove it for another 45k miles" and the other was a lemon blown trans at 17k miles after which i dumped the car. My Question is how are the Renisis engines on reliability and the RX LINE in general. Am i tied into the dealer network for Oil changes and such because of the Rotary Eng and does the Rotary have any inherent eng probs in the long term.

SA22C
05-24-2003, 09:29 PM
Firstly, torque down low is not more important than top end. Do a search on the subject and ye shall see the light.

Secondly, the magazine numbers for the manual transmission pegs 0-60 in 5.9 seconds. No official numbers for the auto, but it's expected in the 7 second range.

Thirdly, the rotary engine is very reliable, and there is no reason to believe that the Renesis will be any different. There have been some problems with turbocharged rotaries, but the NA motors are strong runners and do so for a good long time.

Haris
05-24-2003, 10:43 PM
SA22C, he meant on rx7. You know those engines sucked big time in reliability. But then again, it was fast like bullet. RX8 shouldn't have any of those blowing engine problems at all. So it's not a problem. I'll hate mazda if they make auto RX8 in 7 second range or more. I want to see it hit 0-60 in under 7 sec. to still be competitive. If it's in 7 second range, then even honda odyssey auto can be on your level. :( This would suck. Please mazda, make auto rx8 a little faster than we predict! :)

Elara
05-25-2003, 12:27 AM
Originally posted by Haris
SA22C, he meant on rx7. You know those engines sucked big time in reliability. But then again, it was fast like bullet. RX8 shouldn't have any of those blowing engine problems at all. So it's not a problem. I'll hate mazda if they make auto RX8 in 7 second range or more. I want to see it hit 0-60 in under 7 sec. to still be competitive. If it's in 7 second range, then even honda odyssey auto can be on your level. :( This would suck. Please mazda, make auto rx8 a little faster than we predict! :)


Actually, the only one that was unreliable was the twin-turbo, and that was really only a problem in the 93s (from what I understand, as I've never had one). There are several people on here, even, with first and second generation 7s with well over a hundred thousand miles. I believe (help me out here guys!!) that the second generations were consistently ranked as most reliable in their class at the time. We shouldn't have anything to worry about with the Renesis, especially since there isn't a turbo in it.

SA22C
05-25-2003, 12:49 AM
Actually, the only one that was unreliable was the twin-turbo, and that was really only a problem in the 93s (from what I understand, as I've never had one). There are several people on here, even, with first and second generation 7s with well over a hundred thousand miles. I believe (help me out here guys!!) that the second generations were consistently ranked as most reliable in their class at the time. We shouldn't have anything to worry about with the Renesis, especially since there isn't a turbo in it.

I've owned two RX-7's, a 1982 GS and a 1979 GS. Both have over 100,000 miles on them, and still pulled hard and burned the proper amount of oil. The 13BTT was a notoriously short-lived motor because of cooling issues. Basically there was too much underhood heat, and it cooked critical vaccum lines, causing the motor to lean out, detonate, etc etc. The twin turbo setup was very complex, with 76 vaccum lines needed to actuate both turbos. The later models had far better cooling and better longevity as a result. As with any high performance turbo application, engine life decreases on the rotary when boost is added.

Superfan
05-25-2003, 01:07 AM
I had my 2nd Gen RX-7 go over 210k. I sold my 3rd Gen RX-7 recently at 72k /w no problems. Yes the third gen RX-7 has some problems with reliability. The main problem stems from the cooling system. Any car with an inefficient cooling system is going to be unreliable. The turbos and engine are reliable; as long as you tune the car properly it will easily go 150k. With all the R&D that has gone into the RENESIS engine, I cat see why it wouldn't be the best rotary yet.

Haris
05-25-2003, 01:37 PM
Yes, I meant 3rd generation rx7. Not the first 2.

Haris
05-26-2003, 06:17 PM
Anybody found out 0-60 and 1/4 mile for auto rx8? I'm dying to know what it is.

Calibus
05-27-2003, 07:10 AM
i have gone and read up on some torque vs hp questions and from what i gather it is better to have higher torque which actually gives u better off the line aceleration and HP matters only at higher speed what actually matters is how high u can rev the motor or somethin like that i am confused :-) but from all the boards i read the consensus is that torque is important for off the line but hp is important for high speed

pelucidor
05-27-2003, 12:32 PM
There are others here (Buger, Wakeech etc) who can explain this WAY better than I can but until they respond...

Ideally it would be good to have high torque throughout the whole rev range AND have a big rev range where that torque is fairly high. The area under the torque curve is what matters. Sadly high torque NA engines tend to be large and do not rev very high unless you are spending a lot of money (e.g. M3, Ferrari 360, Acura NSX etc).

In your comparison of the auto vs 6MT RX-8 there is a trivial 3% (5lb ft) difference in peak torque (which probably does not apply throughout the whole rev range) but the actual rev range is much less in the auto as the engine is limited to a much lower rpm, so the area under the torque curve is much smaller. The other thing is that available torque at high rpm allows you to make use of gearing that can give the effect of low-down power from a small engine which is why the S2000 and RX-8 are so fast accelerating for the size of engine they have (but you have to like revving them). Of course weight plays a part too - small engines tend to be lighter and allow for a lighter/faster overall vehicle.

In other words the 6MT RX-8 will be much faster than the auto...

Calibus
05-27-2003, 12:43 PM
I understand that the 6mT will be faster i am just thinkin cause the AT has a bit more torque i hope it at least wont be in the 7's 0-60 i hope for a 6.7