From R&D
Registered User
Joined: Jun 2003
Posts: 50
Likes: 0
From: Redmond, WA
Originally posted by rpm_pwr
Elak, d your formula doesnt work. You can't substitute in RWHP and FW RPM and get FW torque!
Elak, d your formula doesnt work. You can't substitute in RWHP and FW RPM and get FW torque!
hp = tq * rpm / 5252
Multiply both sides by 5252 and you get:
hp * 5252 = tq * rpm
Divide both sides by rpm and you get:
hp * 5252 / rpm = tq
thus:
tq = hp * 5252 / rpm
I REALLY LOVE THIS CAR!
Joined: May 2003
Posts: 268
Likes: 0
From: SE Coast
Naysayers be damned
Originally posted by Speed Racer
Chill out a little bit with the nay saying. I've just given you guys proof that the car is capable of meeting the claimed performance specs and the only thing that you are interested in is discrediting my info. What's wrong with this picture?
So I don't think you should be so quick to discredit the times. Would it really be the end of the world if it turned out that there was no major Mazda conspiracy surrounding the RX-8's performance? More likely it would just be an end to this run away thread.
I just feel that all of the speculation is getting a little out of hand and its time for all of us to have a reality check.
Chill out a little bit with the nay saying. I've just given you guys proof that the car is capable of meeting the claimed performance specs and the only thing that you are interested in is discrediting my info. What's wrong with this picture?
So I don't think you should be so quick to discredit the times. Would it really be the end of the world if it turned out that there was no major Mazda conspiracy surrounding the RX-8's performance? More likely it would just be an end to this run away thread.
I just feel that all of the speculation is getting a little out of hand and its time for all of us to have a reality check.
So, I for one support your findings and think they do great justice to this thread.:D
RX-8: Hmmmmmmmmmmmmm.....
Joined: Feb 2003
Posts: 799
Likes: 0
From: Toronto, Canada
Re: Re: Re: Enough BS already
Originally posted by canzoomer
For about 25HP??
That's over 10%!
I am dubious..
For about 25HP??
That's over 10%!
I am dubious..
Again, just Read up on it in the European section.
Registered User
Joined: Aug 2002
Posts: 32
Likes: 0
From: Atlanta
Originally posted by 73JPS
I am sure this is a stupid question, but is there any chance that in the heat of the moment these cars were dyno'ed with the DSC still partially engaged?
I am sure this is a stupid question, but is there any chance that in the heat of the moment these cars were dyno'ed with the DSC still partially engaged?
The sounds feasible to me. There may be no way to turn the system completly off as in the M3. It works by senesing wheel speed, and if the front wheels are not turning, it's going to think something is seriously wrong.
Registered User
Joined: Jan 2003
Posts: 315
Likes: 0
There’s something wrong with Speed Racer’s G-Tech data.
A RWD car that is capable of a 14.0s quarter mile pass should get a faster 0-to-60 time (well below 6s). Here’s an example:
Car&Driver test data
___________________ 0-60mph ___ 0 – ¼ mile
Ford Mustang Mach 1 ___ 5.2 s ______ 14.0 s
The G-Tech data implies that the RX-8 is 0.8s behind the Mustang at 60mph and somehow catches up with the Mustang at the end of the ¼ mile.
A RWD car that is capable of a 14.0s quarter mile pass should get a faster 0-to-60 time (well below 6s). Here’s an example:
Car&Driver test data
___________________ 0-60mph ___ 0 – ¼ mile
Ford Mustang Mach 1 ___ 5.2 s ______ 14.0 s
The G-Tech data implies that the RX-8 is 0.8s behind the Mustang at 60mph and somehow catches up with the Mustang at the end of the ¼ mile.
Registered User
Joined: Jul 2003
Posts: 47
Likes: 0
From: Torrance, CA
If the DSC was on, the car would make about 10 hp on the dyno. Its very obvious when cars with traction control, etc. are dyno'd without switching the system off. Lots of bucking, shaking, groaning, etc. and very little hp.
Also, if the DSC system were on, why would performance be so normal/good below 6000 rpm?
The torque curve on this car simply falls off too fast to make the advertised hp. Mazda has not provided a suitable explanation yet, and no one else has either.
SC
Also, if the DSC system were on, why would performance be so normal/good below 6000 rpm?
The torque curve on this car simply falls off too fast to make the advertised hp. Mazda has not provided a suitable explanation yet, and no one else has either.
SC
Pure Gold
Joined: Sep 2002
Posts: 763
Likes: 0
From: Bucks County, PA
I told you so....
Originally posted by pelucidor
I know this is a long thread but I wish people would read it (especially the first few pages) before making comments. This is about the 50th time these same two items have been posted. Some of the dyno tests were done in 3rd, 4th and 5th gears - about 1% difference between them. An older RX-7 had 'something' happen to the ECU at 20k miles to provide a little more hp - this was documented in the technicians manual for that car. Unfortunately nothing similar is documented in the Tech CD that various people have for the RX-8, and no dealership techs have been made aware of such a 'mileage related switch' even after asking Mazda specifically about such a thing - if it was so simple you would think Mazda would tell someone by now.
The other very common question is 'was the DSC/Traction turned off during the dynos'. The answer is YES, in at least all the dyno tests I know about. No doubt this will be revisited in a page or two...
At this point EVERY SINGLE OBVIOUS QUESTION has already been asked, and some VERY KNOWLEDGEABLE dyno experts, rotary experts and tuners have said what they know/think. I wish this thread would only be added to with people providing new real information or new data (especially a Mazda rep), not the same old questions. Forgive me if I am being terse, but every time I see a new post I think we might have an answer or more data, and I get disappointed every time.
I know this is a long thread but I wish people would read it (especially the first few pages) before making comments. This is about the 50th time these same two items have been posted. Some of the dyno tests were done in 3rd, 4th and 5th gears - about 1% difference between them. An older RX-7 had 'something' happen to the ECU at 20k miles to provide a little more hp - this was documented in the technicians manual for that car. Unfortunately nothing similar is documented in the Tech CD that various people have for the RX-8, and no dealership techs have been made aware of such a 'mileage related switch' even after asking Mazda specifically about such a thing - if it was so simple you would think Mazda would tell someone by now.
The other very common question is 'was the DSC/Traction turned off during the dynos'. The answer is YES, in at least all the dyno tests I know about. No doubt this will be revisited in a page or two...
At this point EVERY SINGLE OBVIOUS QUESTION has already been asked, and some VERY KNOWLEDGEABLE dyno experts, rotary experts and tuners have said what they know/think. I wish this thread would only be added to with people providing new real information or new data (especially a Mazda rep), not the same old questions. Forgive me if I am being terse, but every time I see a new post I think we might have an answer or more data, and I get disappointed every time.
You can turn the DSC off totally by holding down the DSC button for 5-7 seconds. The DSC will not come back on again under any conditions until you restart the engine. Most people who ran dyno tests knew this.
Forum Vendor
Joined: Jul 2003
Posts: 1,223
Likes: 1
From: Edmonton, Alberta
Re: Re: Re: Re: Enough BS already
Originally posted by Smoker
This is already a proven fact since June. Info were directly from Mazda UK. Different car setup for different region, is that so hard to believe ???
Again, just Read up on it in the European section.
This is already a proven fact since June. Info were directly from Mazda UK. Different car setup for different region, is that so hard to believe ???
Again, just Read up on it in the European section.
I see that in the USA the cars going to California are being sold with the same performnce claimed. As we know California has some pretty stringent emissions specs. These are not dissimilar to those in Europe.
UK emission specs are vistually identical to Canada.
Let's face it, the USA market tends to attract some pretty vast performance claims, often above reality!
And we tend to get lumped in with the USA..
Registered User
Joined: Sep 2002
Posts: 95
Likes: 0
What if the last part of the quarter mile with the G-tech was a bit downhill? You can't compare two 1/4 mile runs which are done at different time & different locations
Originally posted by Supercharger
There’s something wrong with Speed Racer’s G-Tech data.
A RWD car that is capable of a 14.0s quarter mile pass should get a faster 0-to-60 time (well below 6s). Here’s an example:
Car&Driver test data
___________________ 0-60mph ___ 0 – ¼ mile
Ford Mustang Mach 1 ___ 5.2 s ______ 14.0 s
The G-Tech data implies that the RX-8 is 0.8s behind the Mustang at 60mph and somehow catches up with the Mustang at the end of the ¼ mile.
There’s something wrong with Speed Racer’s G-Tech data.
A RWD car that is capable of a 14.0s quarter mile pass should get a faster 0-to-60 time (well below 6s). Here’s an example:
Car&Driver test data
___________________ 0-60mph ___ 0 – ¼ mile
Ford Mustang Mach 1 ___ 5.2 s ______ 14.0 s
The G-Tech data implies that the RX-8 is 0.8s behind the Mustang at 60mph and somehow catches up with the Mustang at the end of the ¼ mile.
Registered User
Joined: Sep 2002
Posts: 95
Likes: 0
I know folks who weighted the car on precise race scales, right after that run with the g-tech comp on a flat road and the gtech dyno results were almost identical to what rwhp/rwtq the real dyno machine said at that time.
Results at 2-5 hp difference ...
Results at 2-5 hp difference ...
Originally posted by Speed Racer
Chill out a little bit with the nay saying. I've just given you guys proof that the car is capable of meeting the claimed performance specs and the only thing that you are interested in is discrediting my info. What's wrong with this picture?
There is an 18 HP discrepancy between the two runs because the second run was dramatically slower. If you read the Gtech page that you linked to then you should understand that the HP figures are calculated from the measured G forces (acceleration) / time = speed, speed * acceleration * vehicle weight = HP. Looking at this general formula you can see that time is inversely proportional to HP (i.e. if the time increases the HP decreases). For that reason alone, the Gtech is not an accurate tool for measuring HP or torque for that matter which is determined from the HP and current RPM as measured by the voltage through the cigarete lighter. The HP and torque numbers will not match those of either a chassis or engine dyno but the general shape of the curves should match them when done properly (i.e. smooth shift at low RPMs into preferred gear and hold until redline).
As for the recorded times to 0-60 and 1/4 mile, they should be accurate to 0.01 seconds (manufacturer's spec). Real world accuracy should be about 0.1 seconds. So I don't think you should be so quick to discredit the times. Would it really be the end of the world if it turned out that there was no major Mazda conspiracy surrounding the RX-8's performance? More likely it would just be an end to this run away thread.
P.S. I apologize for taking this out on you , it is nothing personal. I just feel that all of the speculation is getting a little out of hand and its time for all of us to have a reality check.
Chill out a little bit with the nay saying. I've just given you guys proof that the car is capable of meeting the claimed performance specs and the only thing that you are interested in is discrediting my info. What's wrong with this picture?
There is an 18 HP discrepancy between the two runs because the second run was dramatically slower. If you read the Gtech page that you linked to then you should understand that the HP figures are calculated from the measured G forces (acceleration) / time = speed, speed * acceleration * vehicle weight = HP. Looking at this general formula you can see that time is inversely proportional to HP (i.e. if the time increases the HP decreases). For that reason alone, the Gtech is not an accurate tool for measuring HP or torque for that matter which is determined from the HP and current RPM as measured by the voltage through the cigarete lighter. The HP and torque numbers will not match those of either a chassis or engine dyno but the general shape of the curves should match them when done properly (i.e. smooth shift at low RPMs into preferred gear and hold until redline).
As for the recorded times to 0-60 and 1/4 mile, they should be accurate to 0.01 seconds (manufacturer's spec). Real world accuracy should be about 0.1 seconds. So I don't think you should be so quick to discredit the times. Would it really be the end of the world if it turned out that there was no major Mazda conspiracy surrounding the RX-8's performance? More likely it would just be an end to this run away thread.
P.S. I apologize for taking this out on you , it is nothing personal. I just feel that all of the speculation is getting a little out of hand and its time for all of us to have a reality check.
Registered User
Joined: Feb 2003
Posts: 215
Likes: 0
I don't buy the underlying suspicion. You might expect something fishy like this if all engines were linear like a turbine or came off the line equally or shifted as fast as one another... or anything else for that matter.
Originally posted by Supercharger
There’s something wrong with Speed Racer’s G-Tech data.
A RWD car that is capable of a 14.0s quarter mile pass should get a faster 0-to-60 time (well below 6s). Here’s an example:
Car&Driver test data
___________________ 0-60mph ___ 0 – ¼ mile
Ford Mustang Mach 1 ___ 5.2 s ______ 14.0 s
The G-Tech data implies that the RX-8 is 0.8s behind the Mustang at 60mph and somehow catches up with the Mustang at the end of the ¼ mile.
There’s something wrong with Speed Racer’s G-Tech data.
A RWD car that is capable of a 14.0s quarter mile pass should get a faster 0-to-60 time (well below 6s). Here’s an example:
Car&Driver test data
___________________ 0-60mph ___ 0 – ¼ mile
Ford Mustang Mach 1 ___ 5.2 s ______ 14.0 s
The G-Tech data implies that the RX-8 is 0.8s behind the Mustang at 60mph and somehow catches up with the Mustang at the end of the ¼ mile.
Registered
Joined: Jan 2003
Posts: 510
Likes: 0
From: Qatar
Originally posted by Rotor_Newbie
Just a thought... if the car is capable of the claimed performance (0-60 times and top speeds), why do we care what the hp is?! We paid for the 0-60 times and the top speed, we knew what it will do, why do we care how much hp it really produces?!
-John
Just a thought... if the car is capable of the claimed performance (0-60 times and top speeds), why do we care what the hp is?! We paid for the 0-60 times and the top speed, we knew what it will do, why do we care how much hp it really produces?!
-John
Those are similiar to my thoughts. And that is why I'm not fretting over it, for now.
However, I must add that many here, including I, did buy the car expecting better than 25% HP loss to the rear wheels. If the car is indeed performing to these levels at 187 HP, then oh, how sweet it will be when they get the missing 15-20 HP problem solved. I do think there is either a planned reason (ECU mapping) or a mechanical problem (port not fully opening, not full throttle, ECU malfunction), and there will be a remedy by Mazda.
Pu-36 Space Modulator
Joined: Feb 2003
Posts: 463
Likes: 0
From: St Charles, MO
Originally posted by RX-8 Zoomster
I do think there is either a planned reason (ECU mapping) or a mechanical problem (port not fully opening, not full throttle, ECU malfunction), and there will be a remedy by Mazda.
I do think there is either a planned reason (ECU mapping) or a mechanical problem (port not fully opening, not full throttle, ECU malfunction), and there will be a remedy by Mazda.
read here for THE OFFICIAL explanation from Mazda
https://www.rx8club.com/rx-8-discussion-3/mazda-admits-power-deficiency-9347/
6 speed: 238HP
auto: 197HP
I can't believe Mazda blundered on HP ratings AGAIN
but at least now we know what's going on
https://www.rx8club.com/rx-8-discussion-3/mazda-admits-power-deficiency-9347/
6 speed: 238HP
auto: 197HP
I can't believe Mazda blundered on HP ratings AGAIN
but at least now we know what's going on
Thread Starter
Registered
Joined: Aug 2002
Posts: 274
Likes: 0
From: Viva Las Vegas!
238 HP
_________________
Joined: Feb 2003
Posts: 1,384
Likes: 0
From: Cambridge - UK
Well it's surely an indication that this forum has come of age. Had not the issue been raised here then today's announcement probably wouldn't have happened. We have the (collective) power!
8 the HARD way.
Joined: Feb 2003
Posts: 1,001
Likes: 0
From: San Antonio
Inquiring minds want to know why..
Limited for a reason?
That's all the Renesis can actually muster?
The secretary mistyped every piece of doc coming outta Mazda?
Cruel Joke?
Mazda secretly wants all their cars back?
Hmmm..
Limited for a reason?
That's all the Renesis can actually muster?
The secretary mistyped every piece of doc coming outta Mazda?
Cruel Joke?
Mazda secretly wants all their cars back?
Hmmm..
Registered
Joined: Jan 2003
Posts: 510
Likes: 0
From: Qatar
Originally posted by RX-8 Zoomster
I do think there is either a planned reason (ECU mapping) or a mechanical problem (port not fully opening, not full throttle, ECU malfunction), and there will be a remedy by Mazda.
I do think there is either a planned reason (ECU mapping) or a mechanical problem (port not fully opening, not full throttle, ECU malfunction), and there will be a remedy by Mazda.
I still think the lower HP was an emission issue. I believe Mazda had to throttle the performance to meet US emissions spec. Maybe the rumor of an emissions mod at the port was true.
Moderator
Joined: Jul 2002
Posts: 813
Likes: 0
From: London (England)
The Renesis equipped with the Euro3 ECU is rated at 240PS (238HP)...
Coincidence, I think not!
This is an emissions issue, pure and simple... I bet they couldn't get the Jap (250PS) equiped cars through so reverted to the slightly lower powered map...
We get Euro4 equipped cars and only 231PS... but it's not gonna worry me... the car is great.
One good thing is that you can probably still get it re-mapped to regain the extra 9hp...
Coincidence, I think not!
This is an emissions issue, pure and simple... I bet they couldn't get the Jap (250PS) equiped cars through so reverted to the slightly lower powered map...
We get Euro4 equipped cars and only 231PS... but it's not gonna worry me... the car is great.
One good thing is that you can probably still get it re-mapped to regain the extra 9hp...
Registered User
Joined: Sep 2002
Posts: 95
Likes: 0
So they fixed the horsepower number with less than 10 hp ?! ( 247 -> 238 )
238 hp at the crank -> 180 hp at the wheels ?? 58 hp drivetrain loss? yeah, right ....
How can a Miata with the same power output have just 26 hp drivetrain loss .... ?
238 hp at the crank -> 180 hp at the wheels ?? 58 hp drivetrain loss? yeah, right ....
How can a Miata with the same power output have just 26 hp drivetrain loss .... ?
Forum Vendor
Joined: Jul 2003
Posts: 1,223
Likes: 1
From: Edmonton, Alberta
Originally posted by BlueAdept
The Renesis equipped with the Euro3 ECU is rated at 240PS (238HP)...
Coincidence, I think not!
The Renesis equipped with the Euro3 ECU is rated at 240PS (238HP)...
Coincidence, I think not!
About 228HP
See:
http://www.theallnewrx-8.com/
http://www.mazdarx8.co.uk/rotary/rot...ocumentid=1277
Germany lists the same figure:
http://www.mazda.de/rx-8/de/rotary/r...ocumentid=1647
Interestingly, Mazda Italy claims 177KW, which is equal to 237HP
http://www.mazda.it/rx-8/rotary/rota...ocumentid=1277
One good thing is that you can probably still get it re-mapped to regain the extra 9hp...
I have friends in Japan, so it might not be hard to get access to one over there..
Registered User
Joined: Feb 2003
Posts: 215
Likes: 0
except its been said that the 238 number is the result of an average of dyno tests on 11 different cars. This is indicative of more sheer variance in power output (disheartening in itself in addition to the power drop). In light of this the argument of ROW spec for US is unconvincing
