RX-8

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Anyone know what Mazda is suggesting as far as oil for there new RX-8 and the "new" Rotary motor? I like how they are bringing the rotary up in commercials as new. I guess it's been out of production so long there is a whole new demographic that has yet to experiance it?
 
quote:

Originally posted by Starbreaker666:
Anyone know what Mazda is suggesting as far as oil for there new RX-8 and the "new" Rotary motor? I like how they are bringing the rotary up in commercials as new. I guess it's been out of production so long there is a whole new demographic that has yet to experiance it?

With the prior 13B-REW twin turbo engine, Mazda recommended 10w30 dino. I'd be surprised to see that change...
 
quote:

Originally posted by cvl:
5w20 dino is recommended. Synthetic is still specifically discouraged since it doesn't burn well.

Has everyone heard about Mazda overestimating the HP on these cars? They did the same thing with the new Miatas. They are now offering free maintenance for the life of the warranty and $500 debit card, or will buy the car back for free, no questions.


My next door neighbor was telling me he has a friend who bought a new RX8 and he's decided to give the car back, that's how pissed off he was.

I personally think the last generation RX7 was MUCH better looking.
 
quote:

Originally posted by Patman:
My next door neighbor was telling me he has a friend who bought a new RX8 and he's decided to give the car back, that's how pissed off he was.

Why did he give it back? I've read a few road tests of that car and they've all been extremely positive. I think they look nice too.


As for Mazda overstating the HP... it depends on the model of car. I had a '95 RX-7 and it was underrated on HP. It was rated at 255 so one would expect around 215-220 at the rear wheels SAE corrected. But mine but put down 240 at the rear wheels which is closer to 275 BHP.


edited, but I changed it back, I hit edit instead of quote and almost wiped out your post, but I managed to get it back

[ September 16, 2003, 02:27 PM: Message edited by: Patman ]
 
'79 to '85 body style was "it." I like the older ones too. I personally don't think a sports car should have 4 doors. I like the commercial though.
 
quote:

Originally posted by MRC01:

Why did he give it back? I've read a few road tests of that car and they've all been extremely positive. I think they look nice too.



The guy apparently had his dynoed and it was considerably weaker than he had expected, so the car basically just left a sour taste in his mouth and he couldn't refuse the offer to get rid of it. I'm not sure what he replaced it with, but supposedly the guy has a lot of money so he's probably picked up a different toy.

I'd prefer a new Corvette myself, as you all know, but second choice if that weren't available would be the new 350Z. I also love it's cousin, the Infiniti G35 coupe.
 
quote:

Originally posted by Patman:
The guy apparently had his dynoed and it was considerably weaker than he had expected, so the car basically just left a sour taste in his mouth and he couldn't refuse the offer to get rid of it. I'm not sure what he replaced it with, but supposedly the guy has a lot of money so he's probably picked up a different toy.

I've seen two different BHP ratings for the RX-8 stick shift: 250 and 238. I know the auto has less power but these two ratings were both for the stick shift version. Is Mazda restating their HP numbers more conservatively?

The auto has less HP because the engine has to be rev limited for the torque converter. I wonder why Mazda did not put in a primary reduction gear like Honda did with the S2000... That way, the engine crankshaft revs would be reduced before it even goes to the tranny. The S2000 has a 1.16:1 primary reduction. This also has the benefit not not requiring a big differential ratio. And that's good because big differential ratios make the driveshaft spin faster at any given speed, increasing the liklihood of balance problems.

As an owner of the prior twin turbo version of the car, I always was skeptical whether Mazda could get the same HP out of the engine without the turbos. However, I still love the Wankel engine and hope Mazda does will with the RX-8 so they can release a true 2-door turbocharged sports car version in the near future...
 
There is supposed to be a new RX7 coming out soon too. It looks awesome. IIRC a turbo may be offered too. I am looking forward to it
 
This thread has taken a big OT turn, but I'll join in anyway.

The RX-8 is NOT a replacement for the RX-7. It's a completely different car aimed at a slightly different market, not to mention it is only a fraction of what a '95 RX-7 cost (not even considering inflation). I'd love one, especially since I have a small family now.

The Corvette is a 2 seater (as is the 350Z) and $15k more than it, so I don't even see why it is mentioned as an alternate vehicle. Trust me, I'd much rather a Corvette, but again only 2 seats. The G35 will come down to buyer preference is is very comparable IMHO.

I'd never buy an auto in such a low torque vehicle, but running through the gears at 9k RPM would definately be a blast with my 3 year old in the back seat.

I'd probably be pretty upset if it is over-rated, but if the performance numbers are correct (0-60, 1/4 mi), I'd get over it.
 
The auto is not rev limited to save the auto from high revs, it is due to the higher power which the auto can't handle. Not uncommon amongst high power cars, the auto version is detuned one way or another, in the RX-8 it is by rev limiting.
 
quote:

Originally posted by theguru:
The auto is not rev limited to save the auto from high revs, it is due to the higher power which the auto can't handle. Not uncommon amongst high power cars, the auto version is detuned one way or another, in the RX-8 it is by rev limiting.

Interesting. Some sources say it's the torque converter can't spin that fast, others say it was that the auto couldn't handle the power.

Of course, the 2nd explanation might be a simplified version of the 1st.
 
That is kind of unusual. With most older musclecars, the autos can handle much more torque than their manual brethren.

[ September 16, 2003, 07:10 PM: Message edited by: sbc350gearhead ]
 
Torque converters don't last long at 9000rpm. It becomes expensive. RWD transmissions can be easily made to accept almost any power ratings.
Plus the rotary is torqueless. The auto should have no problem with its powerband. The TC, on the other hand, will balloon/rupture/self destruct. I was actually more surprised that Mazda didn't just cough up more money for a high RPM TC. Primary reduction adds complexity.

Another thing to consider is that a 4port engine is used for turbocharging. If the rotary gets turbo, it will be the auto engine with the manual transmission. Good to work out the bugs now with lower power ratings.

Can anyone here prove that synthetic doesn't burn well? Break out the bunsen burners and dishes/tubes!

Fords influence on Mazda is noted. 5w20 is now used. Ford Motorcraft is labelled--synthetic blend. How can Mazda say that synth is bad when, I'm assuming that, they are using a blended synth 5w20?
 
quote:

Originally posted by sbc350gearhead:
That is kind of unusual. With most older musclecars, the autos can handle much more torque than their manual brethren.

Thats because they have upgraded torque convertors with better auto trannys. Most auto trannys were terrible for racing until art carr came out with the turbo trannys. Lets also not forget that the more the tranny gets upgraded, it has to have a transmission cooler to cool that tranny down. However, I prefer a stick over an auto because I like shifting more than I do letting a computer do it for me, and its part of my youth hood to drive a stick. Not making a debate whether one is faster than the other, I just make my preference a stick.
 
Carr trannys are cool, but not necessary until you start playing with the big boys (blown big blocks, blown smallblocks with nitrous, etc). Most smaller racers still get by with relatively stock th350s and 400s (with hi stall convertors and tranny coolers of course).
 
5w20 dino is recommended. Synthetic is still specifically discouraged since it doesn't burn well.

Has everyone heard about Mazda overestimating the HP on these cars? They did the same thing with the new Miatas. They are now offering free maintenance for the life of the warranty and $500 debit card, or will buy the car back for free, no questions.
 
quote:

Originally posted by unDummy:
Plus the rotary is torqueless.

What matters is the SHAPE of the torque curve, not the amount of torque. If the engine has a flat torque curve it is going to respond well at all RPM.

The problem with rotaries is not that they lack torque, but that they develop their torque at high RPM and don't have much down low. Once the car is moving it's not a problem. In fact it's actually BETTER to get torque at high RPM. But due to the lack of low RPM torque they are hard to launch from a standing start.

On an autox or open track it's not a problem. On your favorite twisty canyon road it's not a problem. But for 1/4 mile drag racing or 0-60 times it is a problem.

BTW, if Mazda is overrating these cars, they're not the only company doing so. Honda rates the S2000 at 240 BHP but the 2 dynos I've seen of cars in our local autox group were both under 200 at the rear wheels. For 240 BHP one would expect to get around 205 at the rear wheels SAE corrected. The ones I saw were in the mid 190s, which is more like 225 BHP.

Some companies overrate the HP and others underrate. Sometimes the same company will overrate some models and underrate others. The factory HP and TQ numbers can only be used as a ballpark estimate.
 
quote:

Some companies overrate the HP and others underrate. Sometimes the same company will overrate some models and underrate others. The factory HP and TQ numbers can only be used as a ballpark estimate.

That's what is nice about the LS1 Camaros and Firebirds, they were rated at 305hp from 98-00 and 310hp from 01-02, but yet I know people who put down 320rwhp bone stock! (mine only put down 288rwhp bone stock, but with break in mileage and some minor mods it pulled 320rwhp a year later) At 320rwhp, we're talking 370 horsepower at the crank. GM did this so that the Corvette could still retain bragging rights to the higher horsepower.

[ September 17, 2003, 11:21 AM: Message edited by: Patman ]
 
Quick Note....

Though the preproduction and production Rx8's have different raw HP numbers...the performance is identical.

Same 0-60 times...
Same 1/4 mile times...
Same 60-0 times...
Same skidpad...

This is primarily due to the auxilary ports not opening on the preproduction models. (Or something like that)

So technically a production RX8 with the preproduction's rated horsepower, would be faster then a preproduction rx8.

Most of the people bitching and complaining aren't RX8 owners...just a bunch of people posting on forums.

All the rx8 owners (actual owners who actually HAVE the car www.mscw.com) love it to death and wouldn't trade it in for the world. Anyone who trades in a car after finding out some "number" is different, either didn't own the car in the first place, or was a freaking idiot for not test driving it enough before their purchase.

Its not about the numbers, its all about the driving experience.

[ September 17, 2003, 11:18 AM: Message edited by: crossbow ]
 
Lots of RX8 owners have given their cars back to Mazda. I agree about many of them not driving it enough though. They get infatuated with the looks and novelty of the car, but once that wears off, all they're left with is mediocre performance for the price they paid.
 
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