RK

iTrader: (1)

Mazda was sued and had to revise their HP numbers to be accurate. So I'm going to go with the HP numbers to be more accurate than most manufacture estimates.

And Team has one of hte highest NA whp on this forum but Japanese tuners have gotten more and some Koni challenge cars are probably getting over 223. Meyer had his at 223 (https://www.rx8club.com/showthread.p...i+challenge+hp) even with the restrictions put on those in the challenge.

tmak26b

THEY ARE MODDED, I am talking about stock out of the box. Transmission fluid and other fluids are not going to rob you of 10hp. A bad set of coils and plugs maybe, but not fluids.

chameleonGTS

I don't think that it’s making 232 hp. This car really doesn’t feel fast at all to me and I've been debating if it’s due to the super smooth power delivery of the rotary or if it is actually not making as much power as Mazda is claiming. I think I'm settling on it not making as much HP as Mazda is claiming.

I live out in a rural area so I drive a lot of country roads. You need to be able to do higher speed passes in these conditions because when the speed limit is 55, that means that majority of the slower cars I run into that I need to pass are still going around 50 mph. I expected this car to be able to zip right around this slower traffic with no problems, but I find myself hanging back so I can get a running start when the opportunity presents itself. Just based on this passing power and the feeling I get from the car during fast acceleration, I would expect this to be around a 190 hp car.

RIWWP

iTrader: (2)

Actually...YES, they can. Diff fluid alone was proven by KONI to reduce power by 5hp. Keep in mind that HP is a function of torque and RPM. Robbing 5hp at 8,500rpm for us is roughly equivalent to robbing 2hp at 3,000rpm for a similar torque car. Not exactly of course, due to actual torque values, but it is similar. We will always see higher HP loss due to fluids, because a slight change in torque means alot more for us multiplied at 9,000rpm than it does for piston engines mutiplied at 2,000, 3,000, or 5,500.


(Bold is mine)
That's your car. Each car varies heavily. NA, I have the strongest car between myself and 3 friends, followed by a 06 Touring, followed by an 05 Auto GT, with Blackenedwing's 05 Shinka (pre turbo obviously) His AP improvements brought his NA up to the point where mine is without. There really can be a significant difference between the different cars.


I am not saying your feelings are wrong, but you are attributing it to the wrong metric. That feeling is the torque, the instant push. You are feeling the ~160lbs of torque. With that amount though, you are certainly hitting 220+HP at the top of the RPM range. Again, because HP is a function of torque and RPM. I get about the same "punch" from my wife's Mazda5 (2.3 I4) that I do from the 8, which are only rated 3lbs of torque difference. But I put out ~50% more HP, because I can hold a given gear ratio a hell of alot longer.




Terminology matters people...

tmak26b

I don't know what fluid Koni was testing, but the same viscosity oil should provide relatively the same resistance. 1-3HP maybe

RIWWP

iTrader: (2)

It was primarily a temperature test, ambient vs warmed up, but exhibited the same dynamics of fluid in poor condition.

And again, it would be torque...where in the RPM range are you multiplying it for HP? You can't use traditional HP numbers from piston engines on power losses for fluid.

chameleonGTS

My previous car is a 2000 Toyota Celica GTS 6 speed of which I am the original owner. The Celica has a 1.8 liter engine that revs to 8k and is rated at 180 hp and only 130 lb-ft of torque, so I’m actually very used to the experience of a low torque but hard working motor. My new RX8 feels quite a bit slower despite having more torque. I know that there is a fairly significant weight difference between the two, however, the RX8 is no pig and 52 hp is a fairly large chunk to make up for it. When I find that the RX8 with more torque and more hp feels noticeably slower and takes longer to pass cars, it makes me raise an eyebrow at the 232hp 159ft claim from Mazda…

adamwzl

iTrader: (3)

Also what gear are you attempting to pass cars in. Most of the time when passing say at 50mph I have to get a running start on 4th gear or just down shift and rev match in 3rd and I feel the power kick in a lot and I have no problem passing people. Also is your 8 used? If so how many miles and when were the coils/plugs last changed. They make a insane amount of difference in power when they are going bad.

kartweb

Horsepower to the average male is like a diamond to the average female, and whatever they have isn't enough.

Looking at the heat dissapation factors from the tranny and dif, there is about 11-14% loss at worst case. Add another 1% for tires on a dyno.

Even at 15% loss that would equal 232/1.15 = 201 HP.

Mazda uses a brake dyno to measure the engine. Brake dynos measure the torque at all times and plot the HP output at the RPM. They also create a little different behavior pattern for the engine; its easy to hold the engine at a constant speed while loading it down and vary the engine speed by load. Sustained engine loading will alter the output due to the thermal conditions inside the engine and that can be optomized to get the best results.

Consumers typically use a Dynojet or some other inertia system driven off the rear wheels. While that gives a better idea of whats actually delivered to the rear tires it still has a few factors that affect accuracy and consistency. We've noticed with the smaller end Dynojets used for motorcycles, if you park two "trailer" units side by side and try to run the same vehicle under identical conditions there can be a 7-10% difference in outputs. Not to mention it that on the same unit running several pulls often yields differences of 4-5%. Yet on a brake dyno, identical pulls are generally within 1-2%.

That said I think the stock M6 RX8 with the an up-to-date flash is in the 220 HP range on a brake dyno although it may be capable of 232 HP just by tuning. I also think Mazda chose to detune the engine as a way to mitigate the seal issues they were suffering from on the early years of production. Just my hunch anyway.

As far as Dynojet numbers I look at them as +/-5% accurate, so if someone says they got 180 HP, that could have been 171 - 189 HP to the wheels & 217HP at the crank.

RIWWP

iTrader: (2)

I'd be interested to ride in your car then. Cause something doesn't sound right.

Even from 50, assuming a drop to 3rd instead of 2nd, you still should be hitting redline and 93 in about 4 seconds, 5 seconds tops (I'll time mine today in a spot I always nail it on). Even pulling out from right behind a slower car, can easily clear them by 4-5 car lengths in that time. So either you have bad power loss, or aren't dropping into low enough of a gear? :shrug:

I don't want to seem offending or confrontational, it just doesn't sound normal. (Although I acknowledge that my normal is certainly not everyone else's normal)

Edit:
In my '02 Corolla (120hp stock, I was faintly higher), I would have to do the dropping back to gather speed, but even that wasn't that rough.

adamwzl

iTrader: (3)

I hit between 91-93 in redline on 3rd gear also. Passing someone going 50mph really is not hard at all... I can even do it fairly well in 4th if im 2 car links behind and too lazy to down shift.

chameleonGTS

Nah, your not coming across in a negative way. Maybe something really is up with my car. I usually put it in 3rd to do a 50mph pass; if you do end up timing your car I would really appreciate it if you would let me know how long it takes you to pull through 3rd gear starting @ 50.

RIWWP

iTrader: (2)

I took a look for your other posts and see you have a 2009 R3. That does change a bit, but generally not worse since you have the different rear end gearing. I don't know if the 19s make a difference with rotating mass, rolling resistance, different total diameter, etc.. Obviously though, your 8 should certainly still be healthy this new, though problems right off the showroom have been known to happen.

I'll time it and let you know.

Marklar

I drop to third to pass on the highway all the time. The 8 may not be quick from a dig, but from a 50 MPH roll it's pretty quick. When I drop gears and pass I can really scream past traffic, and my car is bone stock.

My problem in passing isn't going fast enough, but avoiding going too fast and getting a ticket. I haven't timed it, but I can get from 50 to 90 in a damn big hurry. When I pass on the highway people sometimes chase me because it looks like I'm about to go warp snot (though I just slow down and get back in the middle lane, I don't like to cruise at more than 10 over the limit).

Your experience is vastly different than mine. The 8 should not feel slow at all when accelerating at highway speeds, that's where rotaries shine. Maybe you need to have the coils checked or something? Try going to the dealership and complaining about power loss, if nothing else you may get a free de-carb.

I've never dyno'd my car, but this thread is tempting me to see what it's actually getting to the wheels. I see people complain on this board all the time about how slow their 8s are, and while mine is no muscle car it has never felt slow to me. It's not torquey and it's got nothing below 6k RPMs, but it really scoots at high revs. Maybe I have a strong 8, it's possible since I only have 10k miles on the car. Or maybe it's the weight, I have a stock sport and I only weigh 105 pounds, and weight really makes a difference in a low-torque car.

RIWWP

iTrader: (2)

We checked it yesterday, and there is something wrong with his 8. He timed an average 9.41 seconds 50mph to redline in 3rd gear. A bit less scientific timing on my part is ~6 seconds for the same 3rd gear pull. Granted, I have an '05 GT, and he has an '09 R3 (so different RPM at 50, different speed at redline, different gearing, different wheels, weight, etc...), but the changes should have been better or about the same, not 50% slower.

I ended up dealing with a salesman for 2.5 hours last night, so didn't get the video tape of my pull for him, will do it this morning and get it up.

shazy

holy crap. That's terrible! Heck I'd call this car slow if it took that long to go from 50mph to redline.

I know the coils are the same as the previous gen, but I think it places a bigger part in the new one, don't ask me how I know, because I dont how to prove it mechanically, but someone recently had an 09 with 6k miles or something and upgraded the coils. The person said that it was quite a difference and pretty noticeable.

tmak26b

Not sure about 50 to 93, but 65-83 in 3rd is 3.9 sec, 3.8 sec best on my car. That's from a GPS datalogger, not stop watch

RIWWP

iTrader: (2)

I just got video of two 50-93 pulls, and a 0 to 120 pull (redline in 4th) Uploading them now. Not making the 0-120 pull public If you want access to it on YouTube, PM me your YouTube user id. The 0-120 was approximately 25 seconds, including have the TCS cut in when I grabbed 2nd (always does there, crests a peak in the road just as it shifts left and I grab 2nd) and it was a bit of a downhill slope for the 70-110 range, so that drops a bit of time off.

Just so he has something to closely compare to, even with the 05 to 09 differences.

RIWWP

iTrader: (2)

Here are the two public clips:
From the dash:
[embed]<object width="560" height="340"><param name="movie" value="http://www.youtube.com/v/MVEudrksLR8&hl=en&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/MVEudrksLR8&hl=en&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="560" height="340"></embed></object>[/embed]
Redline tone at ~7 seconds.

Showing the gauges:
[embed]<object width="560" height="340"><param name="movie" value="http://www.youtube.com/v/HKCS7RpFKU4&hl=en&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/HKCS7RpFKU4&hl=en&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="560" height="340"></embed></object>[/embed]
Redline tone at ~6.5 seconds

tmak26b

Looks about right, i am looking at my datalog from VIR. 50-89 (I shifted at 90mph) was 7 sec exactly. The OEM tachs are off and so is the speedo. I think the speedo is off by about 2mph.

shazy

oh cool. BTW RIWWP give me the link!

JinDesu

iTrader: (2)

If that's the case, I hope chameleon gets his car checked out. I've never ever felt lacking in power while rolling... especially since you are in, or can shift down into, the proper RPM ranges.

freaklinkmusic

how many FAST cars do you know of that have 232 hp?? not very many. It aint like they said the car has 280 hp. 232 is right. the rx8 isnt that much slower than the 1st gen 350z (287 bhp).

tmak26b

Your car isn't as fast as you think, get over it. 230hp is still 230hp. I have doubts about it making that much power.

Just as a reference

50-89mph

4.77 sec 400HP C6 in 3rd
7.08 sec RX-8 in 3rd only
6 sec flat for 350z, include a 4th gear shift

Correct me if i am wrong, but doesn't 09 have a shorter rear end, wouldn't he hit the rev limiter before 90mph? With my race rubber, i can barely hit 90mph at fuel cut. Keep in mind this is actual speed, not indicated speed.

RIWWP

iTrader: (2)

FYI, you might want to read the posts above yours. We timed his acceleration, and his R3 is running 2-3 seconds slower than our Series 1, so something is wrong with his car, and he wasn't aware of it. Relax and turn off the flame thrower.