That wasn't my question. That was a quote by someone else in another thread. My question was ... which one was right? 6.1 or 6.2. BTW, .88g these days is not very good but I'm sure someone will say RFs

 

Remove the rear seats -- problems solved. Huge trunk space and no problem with rear seat comfort.

They were comparing the MINI to 4-door sedans? Are they brain-dead? Sort of like comparing a Corvette to a Cadillac Escalade and dinging the 'Vette for limited number of passengers.

 

It's Car and Driver, what do you expect? Great writing but they always tweak the numbers so the car they want wins. Doesn't really bother me though, I *love* Car and Drivers writing.

 

I'm only going to be using mine for securing the child seats!

 

SAE Corrected?

See http://www.sdsefi.com/techdyno.htm

"Be aware that SAE correction factors do not apply to turbocharged engines! If your dyno sheet lists SAE corrected HP, ignore it as it is incorrect. You are better off getting an idea of where you stand by looking at observed hp with a turbo engine."

In fact it goes further ...

Other things to watch are correction factors applied for altitude, barometric pressure and temperature. These factors are NOT the same for atmo and turbo engines. Using atmo factors inflates the true, corrected HP figures on a turbo engine. ... This is a case where the dyno sheet DOES lie. Chassis dynos are essentially for tuning purposes, they are not well suited to giving an accurate hp figure.

 

chows,
I find that page quite interesting, but i couldnt find either there or in any of the links he provides a reason why the sae correction will not work on a turbo engine. I undertand the other concepts, tire pressure, altitude etc. I dont however understand the difference between NA SC and turbo charged cars when it comes to correction. This may just be me not fully wrapping my mind around it, but I wouldnt mind an explanation. for example Alta just realesed quite a few findings about their car stock and with their mods. I have no problem believing a company could alter statistics for their benefit, but why post that alteration right there on the information. If it is known that SAE corrected info is incorrect for turbos then why post that on the info. I hope someone else can make sense of this. because i cant.

 

http://www.sportcompactcarweb.com/ed..._technobabble/

Corrected numbers, on the other hand, can be suspect in certain cases as well. Turbocharged cars running at high altitude, for example, might be more accurately represented by uncorrected numbers. Say you are testing an FD3S RX-7 in Denver, where the elevation is approximately 5,000 feet. Shiv Pathak, master of our FD3S RX-7 project, reports that he always sees higher boost levels at high altitude. The reason is simple. The wastegate opens when boost is 12 psi higher than the normal sea-level reference air behind the wastegate actuator diaphragm (air that has been stuck in there ever since the diaphragm was sealed somewhere in Hiroshima). As the air density drops at high altitude, the actual pressure in the boosted intake manifold remains constant. The boost gauge, though, reads pounds of boost over ambient pressure. If the ambient air pressure in Hiroshima was 14.5 psi when that diaphragm was sealed, but it is only 13.5 psi when Shiv drives through the mountains, his boost gauge will read 1 psi higher than normal.
The SAE correction factor used by Dynojet assumes that lower air pressure at the sensor box means lower air pressure in the intake manifold, though, so at 5,000 feet the dyno is applying a 20-percent correction factor to compensate for a loss of air density that the engine never sees. This is fine if you are doing all your tests in Denver, but if you do one test in Denver and one test in New Orleans (the highest mountain in New Orleans is 12 feet above sea level) uncorrected numbers will be more accurate.

http://www.neuspeed.com/faq/faq_view...&ltype=ns_euro

The Society of Automotive Engineers (SAE) has established a test standard that helps standardized engine horsepower testing and results so that the variable effects of barometric pressure, altitude, and intake air temperatures do not bias the test results. The SAE J1349 test procedure includes an engine horsepower correction factor so that, for example, dyno readings taken at 3500 feet on a 40 degree day can be compared with dyno readings taken at sea level on a 77 degree day. This correction factor is used for Normally Aspirated Engines, not forced induction engines.

If I read that correctly, its saying that for example, the correction factor is making the number look 20% higher than they should be, at least for Denver.What is the new MINI?, 172 bhp x 1.2 = 206bhp

This would seem to explain why Randy's 209 number is so high but I have no idea, just read the article and it makes sense to me.

 

I think we are starting to see why SAE is giving 209 hp at the wheel. Thanks for the reference articles.

It will be fun to see the uncorrected numbers and how that compares. My R56 should go to the dyno this week. You know, it is well broken in because I have put 150 miles on it...

I still think there will be need for some correction factor for reasonable direct comparisons with sealevel cars, just much less than 20%. We'll find out.

Remember, if someone is using SAE at sealevel (as far as my knowledge goes) it doesn't do anything to the final number. Should be similar to uncorrected. Only at high altitude does SAE inflate the final number with turbos.

 

That definitley makes sense for Ramdy's numbers. But what about those running at sea level? didnt we see quite alot of SAE correction on the R53 despite force induction?

 

Superchargers use SAE correction, they are not effecient like turbochargers.

SAE is the norm even at sealevel because it will slowly compensate as the dyno is moved to a higher elevation. At sealevel it won't compensate at all. Dynos "know" what elevation they are at and SAE compensates accordingly (For normally aspirated and supercharged cars only).

 

Just started reading this forum today after picking up my MINI yseterday. GRM is pretty much THE respected automotive magazine. Check out his autocross results to date, they know what they are doing.