stock dyno results: civic, gti, ms3

O

oaklandopen

Member
http://www.automobilemag.com/features/0610_gti_civic_mazdaspeed3_dyno/index.html

good article with numbing results from the ms3. (i apoligize if it's a repost)
the article is 4 pages with mazda on the last

the reason why it staggers me is the hp and tq loss from advertized bhp to actual whp. 50 something hp and 50 something tq loss. WTF?!

before i go off ranting, im gonna stop myself and and try to justify through brainstorming as to why there is so much loss (and im still having a problem not ranting cuz i keep remembering when the rx-8 made it's debut and the owners found out the true engine numbers).

im hoping only half of the loss (20 - 25 hp and tq) is coming from physical components, i.e. gearing, half shafts, wheels. what im hoping the other loss comes from is preventable (meaning the power is really there but was destroyed in the whole dyno process) like extra heat soak in the intercooler that is induced from a stationairy measurement (prevented in the real world by higher flowing air from actual driving).

i don't plan on modifying because for one, im not that rich and i have more priorities, and two (hopefully w/out starting another warranty hijack) if i did upgrade components i would wait until after 36,000 miles anyway.

can anyone explain these numbers? or has mazda pulled another rx-8 fiasco

sorry if i ranted anyway
 
I think the MS3 needs to be moving to exploit its full power. Not only this but I think Automobile Mag intentionally let the MS3's intercooler heat soak so that they could have an interesting story to tell in relation to the other cars. They really praise the motor on the civic si don't they? I traded in a 07 si for the MS3; the motor in the si was weak sauce in comparison. I've test drove a GTI 6-speed & with DSG before my purchase as well and felt the GTI was lacking seriously in comparison to the MS3. I would say just test drive all 3 on the same day if you can. Those Dyno results mean s*** as far as Im concerned. Just my .02 cents.
 
This article is as old as the internet and is the official GTI and civic si fanboi reference material when comparing their cars. If you look the various dynos posted since by members, you'll see they're all over the place and heatsoak as well as a host of other variables matter a lot.

The truth is in the actual numbers at the track. It's highly unlikely, given the weight of the ms3, that 216 to the wheels will alow it to trap 100+ and still get low 14s,high 13in the quarter. Take those numbers with a grain of salt.

Also as a point of reference check out the dynos of the caliber srt-4. That car is pretty much even speed wise(trapped 1 mph faster) and look at its dynos. It's also similar in weight (maybe a slight bit heavier).
 
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These dyno results are unsurprising. They reflect right around 15% drive train loss (about 18% for HP, about 12% for torque) which is normal on a front wheel drive vehicle.

This article discusses efficiency and usability, not peak performance numbers, and it is spot on. Our motor runs out of breath after about 5500, and it is a bit sluggish below 2500. We all know this. This is why we launch near 3,000 and shift before 6,000 in a drag. Why do some people sound a little butt-hurt after reading an article that tells us something we already know?
 
Betelgeuse said:
The truth is in the actual numbers at the track. It's highly unlikely, given the weight of the ms3, that 216 to the wheels will alow it to trap 100+ and still get low 14s,high 13in the quarter. Take those numbers with a grain of salt.
Click to expand...
Don't pay attention to the HP number, and keep in mind the 250 lb-ft of torque at the wheels and the short gearing. ~220 HP to the wheels with as much extra torque as we have and high 13's are not unreasonable.
 
Again, numbers and comparisons :)

Did you buy this or any other daily driven car solely on track numbers? Do you intend to run it at the strip repeatedly over the life of the car?

I think not on both counts. Also, both other cars in the comparison listed, even WITH the speed 3 loosing hp/torque to the wheels, and restricted power band, was it, or was is not still faster than both?

This is coming from a former Honda owner (1995 del sol vtec w/ jackson racing supercharger), I have also owned Porche, Lotus, even a maserati at one point All turbo cars. Forced induction is nothing new for me. Not one of them was a good drag racing car. Heatsoak absolutely KILLS turbo and supercharger performance. All of this matters NONE to me, since they were just soo much fun on the open highway and curvy backroads. Spend more time enjoying what you own, and less on defensive internet schlock. The speed 3 is hands down the most fun for the $ I have ever spent. In the right hands on a road circuit it would hang just fine with any of my previous cars.
 
happy and angry said:
Don't pay attention to the HP number, and keep in mind the 250 lb-ft of torque at the wheels and the short gearing. ~220 HP to the wheels with as much extra torque as we have and high 13's are not unreasonable.
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Hp is a function of torque (HP = Torque * RPM / 5252), so you can't pay attention to one and not the other. It's not about how much torque as much as WHERE it's being made in the power band. HP will always follow torque as rpm increases - it's a fixed relationship. With that said, peak hp to weight ratio is extremely valid when comparing performance.

Yes we all know our turboed engines (as well as many others) have a small powerband and the article was trying to make that an issue to make the other cars look better, however the op was discussing peak hp and loss to the wheels, not efficiency. All I'm saying is, you can't take one dyno posted as gospel.
 
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Betelgeuse said:
Hp is a function of torque (HP = Torque * RPM / 5252), so you can't pay attention to one and not the other. It's not about how much torque as much as WHERE it's being made in the power band. HP will always follow torque as rpm increases - it's a fixed relationship. With that said, peak hp to weight ratio is extremely valid when comparing performance.
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Not all torque curves are created equal, and the torque curve is what really tells the story of what a motor is doing. HP is a derived number that indicates less how much power you are putting down and more the rate at which work is being done. Twisting force, power put to the ground, is torque. The reason we don't make bigger horsepower numbers is because of the torque drop off - take a look at the equation again and consider what our HP would be if we were still making most of our torque past 5500 RPM all the way to red line. We are making comparable (or better) torque to other vehicles through the meat of our RPM range, and torque is what turns the wheels.

Because of this, our car is able to put up numbers in a 1/4 that do not accurately reflect WHP numbers. Peak HP to weight is a good way to approximate performance, but it's just an approximation. I don't think the dyno numbers in this article are that far off. Assume a 15% drive train loss and you get 263 * 0.85 = ~223.

Take a look at this: http://www.tunercalcs.com/hp-from-quarter-mile-trap-speed.html

Using trap speed (3100 pound car, 100mph trap) it approximates our WHP at ~240. That is an extremely unlikely number given the mechanics of drive train loss.

However: http://www.tunercalcs.com/hp-from-quarter-mile-et.html

Using ET (3100 pound car, 14 second ET) it approximates our WHP at ~ 223... much more realistic. So what's the explanation for the difference? Torque. Lots and lots of torque, and making the most use of it by picking efficient shift points.

Yes we all know our turboed engines (as well as many others) have a small powerband and the article was trying to make that an issue to make the other cars look better, however the op was discussing peak hp and loss to the wheels, not efficiency. All I'm saying is, you can't take one dyno posted as gospel.
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The article, however, was discussing engine efficiency and responsiveness. It doesn't talk much about straight out acceleration. It's obviously more concerned with linear power distribution than numbers on a strip or a track, and the point it makes is valid. If you read the entire article, it starts off saying "Here we have three fast FWD vehicles. They all make big power, but they all do it a little bit differently from the other. Let's look at what that means." And for what it's worth, what it says about our engine is spot on. Big numbers, peaky midrange torque, anemic after 5500 RPM. I don't think the HP number it shows us is "gospel", but it's similar to other dyno results I've seen from stock Mazdaspeed3s. I don't see any particular reason to be offended by the article or the numbers it shows. "There's no way their numbers are accurate, they must have let it HEAT SOAK to skew the numbers!" is just sort of silly to say (not that you've said it) given all this.
 
I can just say that the way the car feels compared to other cars I've driven with similar power/weight ratio and the FACT that this car consisently traps 98-101 mph STOCK that I'm not concerned about the dyno numbers. We've seen a pretty big variance from MS3 owners stock dyno charts on different dynos and different conditions so I take them all with a grain of salt.
 
happy and angry said:
Because of this, our car is able to put up numbers in a 1/4 that do not accurately reflect WHP numbers. Peak HP to weight is a good way to approximate performance, but it's just an approximation. I don't think the dyno numbers in this article are that far off. Assume a 15% drive train loss and you get 263 * 0.85 = ~223.

Take a look at this: http://www.tunercalcs.com/hp-from-quarter-mile-trap-speed.html

Using trap speed (3100 pound car, 100mph trap) it approximates our WHP at ~240. That is an extremely unlikely number given the mechanics of drive train loss.

However: http://www.tunercalcs.com/hp-from-quarter-mile-et.html

Using ET (3100 pound car, 14 second ET) it approximates our WHP at ~ 223... much more realistic. So what's the explanation for the difference? Torque. Lots and lots of torque, and making the most use of it by picking efficient shift points.
Click to expand...

How is the second one more realistic without knowing what each car trapped?

The fact that we DO trap at around 100 mph is very telling. Two cars of similar weight can do 14 flat but if their trap speeds are different, it means at some point along the way one is putting down more power than the other. There's really no other explanation for that.
 
I found it interesting that HP and Torque didn't intersect at 5250 rpm on the MS3 like it did on the other two dyno charts.
 
Betelgeuse said:
How is the second one more realistic without knowing what each car trapped?
Click to expand...
Because 240HP (rounded down) at the wheels is much less than expected from drive train loss, it's about 8%. 8% mechanical power loss is pretty much impossible. Actually, I low balled the weight of the car by about 50 pounds, and ran a 100 mph trap speed when we've been seeing times upwards of 101. If I calculate for 3150 and 101 (or even 100.5) we get WHP numbers of around 245 - 250. 5% or 6% drive train loss? I think not.

Road and Track tested some of these cars here:
http://www.roadandtrack.com/assets/download/0607_pockets_dp.pdf

If you take their test weight numbers and run them through your normal "estimating horsepower with trap speed" calculations, you get the following results:

249 WHP for the Mazdaspeed3, which is an unrealistically small level of drive train loss.

220 WHP for the GTI, which is higher than the crank HP rated from the factory.

201 WHP for the Civic, which is also higher than the crank HP rated from the factory.

Like I've said: trap speed and trap time gives you a good estimate, but doesn't take into account torque distribution, RPM range, etc.

The fact that we DO trap at around 100 mph is very telling. Two cars of similar weight can do 14 flat but if their trap speeds are different, it means at some point along the way one is putting down more power than the other. There's really no other explanation for that.
Click to expand...
Just don't forget that torque is really measuring us "putting down more power." We hit peak torque early and hold most of our torque for about 3000 rpm, and that's when we're "putting down more power".
 
happy and angry said:
Because 240HP (rounded down) at the wheels is much less than expected from drive train loss, it's about 8%. 8% mechanical power loss is pretty much impossible. Actually, I low balled the weight of the car by about 50 pounds, and ran a 100 mph trap speed when we've been seeing times upwards of 101. If I calculate for 3150 and 101 (or even 100.5) we get WHP numbers of around 245 - 250. 5% or 6% drive train loss? I think not.

Road and Track tested some of these cars here:
http://www.roadandtrack.com/assets/download/0607_pockets_dp.pdf

If you take their test weight numbers and run them through your normal "estimating horsepower with trap speed" calculations, you get the following results:

249 WHP for the Mazdaspeed3, which is an unrealistically small level of drive train loss.

220 WHP for the GTI, which is higher than the crank HP rated from the factory.

201 WHP for the Civic, which is also higher than the crank HP rated from the factory.

Like I've said: trap speed and trap time gives you a good estimate, but doesn't take into account torque distribution, RPM range, etc.
Click to expand...


Very good points here and yes it's fairly obvious either calculator aren't the be all and end all. But also remember, we're assuming the crank horsepower is exactly as advertised which isn't always the case but your point is taken.


Just don't forget that torque is really measuring us "putting down more power." We hit peak torque early and hold most of our torque for about 3000 rpm, and that's when we're "putting down more power".
Click to expand...


Yes but you still seem to be trying to separate the two (hp and tq). A diesel engine has gobs of torque but they're generally not good for straight line performance. It's simply because their rpm range is limited. When turboed they makes a lot more torque with translates into more hp for a given rpm range. But the end result (and desired result) is more hp.

We put more torque down early and that definately helps gets us going quickly but it's only when the rpms rise to around 5500 rpms are we actually the quickest. The narrow band between 4000-5500rpms is the sweetspot which is were max hp is.
 
w/out quoting a bunch of individual responses i'll just say this...

i don't really care about how fast it is compared to anything else cuz i know it's a good amt of power for the money in the first place. i don't drag or track any car. all i was really trying to find out was if mazda was pulling another rx-8 fiasco. and if any of you remember this, back in the early 2000's when the rx-8 had come out the power was advertised much higher than anyone was really getting on dynos.

i saw the thread filled with everyone's dyno but i would trust a nationally syndicated magazine a little more than an individual (no offense to anyone)

so when i hear all these "that's normal" responses, i can just assume that it is normal, and i'll probably continue on my search over the net for more results.

ps...haven't actually received the car yet, but it is on it's way over from japan. and im obviously not changing my purchasing decision anyway, just trying to make convo
 
Regardless of the dyno #'s achieved by automobile mag the engine must be pretty decent to make it on Ward's 10 best engines for the 3rd consecutive time
 
I just re-read that article. Man they don't think too highly of the speed3's motor at all. They basically say it's "merely powerful" while the motors in the GTI and SI are truly magnificent. Is it just me or does it sound a little strange how a motor can be chosen for Wards 10 best engines just for being merely powerful as automobile mag puts it? I dont remember seeing the K20 on Wards 10 best
 
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