No it isn't. That dyno reads 166.0 kW (225.7 whp). They apply a ridiculous correction factor to come up with the 210.5 kW (286.2 bhp). Surely, you know enough about chassis dynos to know that using "coast-down" measurements to extrapolate crank horsepower is nonsense. Coast-down driveline loss calculations are a great unspoken lie among European dyno shops (and with Dastek, apparently). None of them has the ***** to admit they are bogus. Find me ANY engineering book anywhere that shows how to get crank power from wheel power using coast-down measurements. There are none, because such a calculation is not possible. The amount of power being absorbed by the driveline and dyno rollers during a coastdown is NOT the same as the amount of power absorbed by the driveline during acceleration.

Wheel horsepower is the amount of power being transmitted from the tires to the rollers, or to the road. This power is significantly lower than crank horsepower (at the output shaft of the engine) due to several factors including:

clutch slippage
gears intermeshing at the input shaft to the transmission
gears intermeshing between gears in the transmission
drag induced by transmission fluid
gears intermeshing at the output shaft to the transmission
gears intermeshing inside the differential
gears intermeshing between the differential and half-shaft
gears intermeshing at the CV joints
Wheel bearing drag
tire deformation
tire slippage

Many of these factors behave very differently during a coast-down and some aren't applicable at all. There is no way to accurately measure crank horsepower with a chassis dyno. Period.

 

who is fighting? All I have ever done is asked to see the numbers. I have been attacked by your "customers" over and over for asking to see the numbers.... I applaud you for bringing new products to market and all I ask in return is to see quantifiable data. I have never said this kit sucks nor will I. It is a better system than the stock one. The question that remains to be seen is..... how much better for the $$$$.


The twincharge has been bashed by many on this board who have NEVER DRIVEN THE CAR!!!!!! WHY?

PS.. one quick question.... the 230hp number was crank correct?

 

I will post as many numbers as I can get off of a dyno (for you guys), and then I'll back it up with track times, same gear acceleration runs (much more accurate than 1/4 mile times), and density data.

The dyno reads what it will - this kit should have no problem making the 280BHP from an efficiency standpoint, or from a capacity standpoint.

Give me a few weeks for God's sake.


El,

I didn't see anyone bashing your system. I think people just get tired of hearing how great you are.

Randy

 

wow... selective reading
might want to go back and read Peters posts
I don't think I am great at all... but some of you apparently do.
I think Hubie's kit is great

 

If anyone is willing to pay for it, I'll volunteer my car for the following:


Install twincharge set-up, dyno test and get 1/4 mile and 0-60 times, plus 60-ft and trap speed.

Remove twincharge and install Webb/RMS kit, do the same under similar conditions.

Since I can't afford it, but would like to see it done, I'll offer my car as the guinea pig. I'd like to be the bread 'n butter, but I need a much bigger salary and one less fiancee...

Marty

 

Oh my god...

This is the reason so few tuners and or manufacturers posts here..
You get slamed, bashed, and harrased before you can even post data
or proof. Please give the man (Randy) a break, all he did was sharing
as he was excited about this new product.

As for the Turbo, all I said was that it's not as good as the SC at the track
no more no less (yes the underhood temps are horendous). With that said
the Turbo will ultimately give you more horsepower for sure....

peter
Team M7
562-608-8123

www.m7tuning.com

 

Maybe you forgot what you posted... let me refresh your memory....

"As a road racer my self, I would never even consider using the twincharge
on the track, or even a hard charging canyon run. The heat load in the engine compartment is tremendous, with deleterious long term effects.

The linear power delivery of the Autorotor is fantastic, without the Turbo's hair trigger power delivery.Just imagine that Turbo kicking in just as you
balancing the car on a knife's edge at 100mph.....not good"

Peter... I know you are a great driver and a smart guy... so tell me...
how does a 281whp car spin the tires @ 100mph? How is that knife edge? Furthermore the twincharge has the ability to have the best of both worlds.... low end torque and upper hp with the turbo.

When at the track are you under 4k RPM's? The turbo is in the sweetspot and power can be applied smoothly with the pedal. (you know, the thing under your right foot) So this whole garbage about the turbo balancing you on the edge at track RPMs is just nonsense. How many top racing cars use turbo's vs. s/chargers?

PS... there is nothing wrong with being excited... we all are..
again for the 100th time, all we want are the numbers when you get them

 

I want a cheapest way to get to 300hp...that's all I need.


...sell a MINI and buy a WRX....that's not an option.

 

El....

Think about what I said....on a knives edge ie. in a turn and for you who
has attended any drivers events at Willow springs large track Turn 9

peter
Team M7
562-608-8123

www.m7tuning.com

 

El,

Forced induction cars, especailly those employing turbos, have a reputation for non-linear power delivery when compared to naturally aspirated cars. Yes, we are comparing two types of forced induction. Superchargers, although parasitic, are a bit more linear in nature. I may not know much about the actual inner workings of engines, but I can tell you that a linear
power supply is extremely important, as I'm sure you know. Running a TT is quite different from running a race with a group of folks with differing abilities; in a TT you get to pick your favorite line, you get to use descrete applications of throttle in an effort to make a clean fast run. In a race the environment is quite different; it is rare that the best line is offered up unless you are well in the lead - not protecting yourself from the second place guy. In all other positions, you are asking the car to potentially work outside of its ideal envelope. This defensive and offensive environment places extra strain on concentration and the last thing I would personally want to worry about is a power spike while trying to set up a guy or gal for take-over. In this environment you are forced to take strategies that are less than perfect. I would personally give up a bit of power in lieu of a linear 'package'. Drive any recent Ferrari on a track and the meaning of a linear package will be permanently emblazened in your mind.

I'm personally very interested in results. This forum is to my way of thinking a way to share thru experience and excitment. But at times, some of us take an elitist approach - that's how it comes across. Some of the experiences are shared as secret tuning rendesvous while others are boastful. Neither of these is desirable from this novice's perspective. I cannot learn anything here. Good attitude is everything and it is sorely lacking in this forum. Attitude, however, it has aplenty!

 

"Many of these factors behave very differently during a coast-down and some aren't applicable at all. There is no way to accurately measure crank horsepower with a chassis dyno." Period.[/QUOTE]

Andy,

Wheels and tires are removed while testing with a Dynapack. How are driveline losses accounted for using this type of dyno? Any inaccuracy with regard to tire slippage, psi, and or wheel weight, is removed, yes? I would think then that some of the operator margin is also removed, creating the potential to define purely mechanical losses.

 

The two items related to the tires are, in the case of a Dynapack, eliminated. That only leaves the other dozen or so factors that do not behave the same way under acceleration as they do under decelleration. Anyone claiming to be able to MEASURE engine horsepower from a chassis dyno is blowing smoke up yer kiester.




Andy,

Wheels and tires are removed while testing with a Dynapack. How are driveline losses accounted for using this type of dyno? Any inaccuracy with regard to tire slippage, psi, and or wheel weight, is removed, yes? I would think then that some of the operator margin is also removed, creating the potential to define purely mechanical losses.[/QUOTE]

 

it is amazing my character is being called into question when all you have done is show your childish behavior. now onto something important and worth responding too

 

So let me ask because maybe I missed something somewhere.
Water is used to cool the intercooler but this is less efficient because the water retains heat. So we add more water. Doesn’t this retain the same heat and add weight too? Now this does keep the intercooler at a more constant, more predictable temperature and this is good.
Next we add a more efficient supercharger to compensate for the higher air temperature. Now as stated this new supercharger will provide up to 20 lbs of boost under racing conditions and under street conditions, one would assume less.
As I understand it we need to remove the air conditioning to use this new system. Of course for racing we don’t need air conditioning. But then I only track my car two times a year.
The dyno information is very difficult to understand at best and my car gets 17 lbs of boost now. So what do I gain by this $5,500.00ish system?


Dave

 

Anyone claiming to be able to MEASURE engine horsepower from a chassis dyno is blowing smoke up yer kiester.

Okay, now I'm lost. I thought the purpose of the 'dyno' was to measure horse power? Or, is it simply to verify hp relative to a particular dyno as a way of establishing some working hp value from which to make improvements?

 

The key word is ENGINE. Maybe I should have bolded that too. :smile: Whp is the amount of horsepower being transferred from the wheels to the road (or to the rotating drum of the dyno). The purpose for a dyno is to measure that power, in most cases to see the effect of various mods. I dyno'ed my MCS stock, got 144 whp, dyno'ed it again with pulley, intake, exhaust, and got 173 whp. We can give MINI the benefit of the doubt and ASSume the stock engine really does put out the 163 bhp as advertised (seems fairly reasonable, IMHO), but I don't really know what effect my mods had on power, other than that it gained about 30 whp. Whether that means it has 190 hp or 200 hp or some other figure at the crank is unknown. Unless you yank the engine and bolt it to an engine dyno, there is no way of knowing.

 

Oh Stop. I'm just bustin your hump.

 

I don't get it. Our Eatons work the same way. More RPMs, more boost, more throttle, more boost. That's what the bypass valve achieves.

 

Okay, thanks. One last question, does gearing affect dyno results? ie 04 S vs 05 S with the same hp. My intellect says no; the power curve may look different, but there nonetheless???

 

This becomes more comical with each post. It seems to me that there a few people here that don’t understand the concept of horsepower and I believe this is true because they have never had a real good opportunity to have it or use it. High horsepower is a good thing; you just need to learn how to control it when you drive. In high speed driving you are always on the edge or you are not driving fast. Some people say that a Mini cannot be controlled on a road course with over 250 HP. To this I say BS. Normally aspirated, forced induction, liner or non liner power curve, no mater what it is or what you call it, you learn to drive what you have. The statement of not being able to control power coming out of turn nine at Willow is the biggest crock I have ever heard. Once I get straightened out that’s where I want the most power possible, to power down that long front straight.
Now I don’t know a lot of other tracks but I do know Willow, so for all you others.
http://www.willowspringsraceway.com/.../nineturns.asp
Even if you don’t have 250 HP how do you handle turns 3, 4, and 5? My point being, that you need to let off the throttle and reduce power, thereby controlling the power you have to make it around the course.
Remember that a road race course is nothing more than a group of turns connected by straight-aways. The turns are only there to scrub off speed and to get you back to the beginning.


Dave

 

The difference in gear ratio / transmission may have an impact on the drivetrain loss.

 

Linear power delivery , not surprising hp spikes I'm a hp freak just like the rest of us. But I want it progressively, not in huge lumps. There is a difference. I'm not debating a hp limit. The Ferrari I spoke about above is way faster than me, but the power delivery was never ever a surprise.

A road course is a series of turns connected by straight lines. But that does not define the character of racing, which changes with each race and each lap. Boxer creed; if some power is good, then more must be better. Not always true.

 

meb,

Gearing is sort of transparent, as far as horsepower is concerned. I say "sort of" since the amount of time it takes to do a dyno run does have an effect in both heat soak and inertia. But neglecting that, a car that has 130 whp at 4000 rpm in 3rd gear should have 130 whp at 4000 rpm in 4th gear.

In any case, a dyno is a valuable tool for MEASURING wheel horsepower, specifically the change in wheel horsepower resulting from mods to the same car.

D1JL,

Two systems can each put out a peak boost of 17 psi, yet can behave very differently. Thermal efficiency of each supercharger determines how much heat is created while the air is being compressed (twin-screw designs are typically better than Roots-types). The amount of engine power that is absorbed by the supercharger varies with the different designs as well (again, twin-screw designs are typically better than Roots-types). Finally, it is possible to have wildly-different shapes to the boost curves between different designs of compressors. So, you could see 17 psi at 7,000 rpm, but only 14 psi at 4,000 rpm, while a different design could produce 17 psi from 4,000 rpm to 7,000 rpm. Despite the same peak boost reading on the same engine, you could see a great difference in the driveability, torque curves, and even the peak power output of the two engines.

 

Thanks Andy! Very helpfull.

Ciao,

Michael

 

Thanks Andy,
That makes sense.

Dave