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Discussion Starter · #1 ·
Sup guys,

I recently went to Dyno my car because I was racing a couple of other M5s and M6s, and every one thought I had a software or a pulley since I was way faster than them. I tried to explain to them that it was because of the RPi Exhaust and RPi Ram Air Kit. So I went to Dyno for proof last week. The first file is when I had the RPi Exhaust on. 4th gear power was 452whp and 345wtq. 5th gear power was 462whp and 355wtq. In 6th gear, I hit the limiter, as you can see. So I don't have a software. I made the most power at 464whp and 362wtq. Today, I put my stock exhaust on. My numbers were: 4th gear power was 430whp and 324wtq, 5th gear power was 432whp and 329wtq, and 6th gear power was 422whp and 325wtq. I think 6th gear was the lowest because the stock exhaust is more restrictive. Both time Dynoed, my RPi Ram Air Kit was always installed.
 

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Company Representative of RPI Power
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Thanks for sharing. It explains why you were killing the other cars.........and why all our other customers get the same results on the street as you :)






Best line in this video cause he didnt believe the guy only put our exhaust: "Whatd you really do f**ker" lol

 

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awesome numbers! glad you are enjoying your RPi exhaust!
 

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Discussion Starter · #6 · (Edited)
RPI M6 vs C63

From 2nd gear 40mph- 150mph. afer the honk he pulled away which i expected i have a passenger he doesnt. then about 120mph i started to pull and past him at like 135.



RPI M6 vs another C63 (yes both were blk) no passengers

From 2nd gear 40mph- 150mph.




RPI M6 vs M5 ( M5 Stock only Charcoal delete)

from 40mph to maybe 100mph m5 gave up



RPI M6 vs M5 (M5 has RPi Scoops And E-race ) Bad Start

From 2nd gear 40mph he definitely got the jump as u can here his exhaust and he hits 3rd gear first . i have no problem playing catch up. at 135mph i was going to zoom past him. at about 8-9 secs into the vid if u look at my right mirror passing his bumper then his light you can also hear i got to 5th gear first. then i guess he got nervous and brake and gave up because he seen me coming and we did NOT run out of road . u can also tell by the shifts.that he had jump at first and that i got to 5th first.

 

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Company Representative of RPI Power
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Yeah there are a LOT of guys with all kinds of different mods here in so cal. We get to race them a lot. You do have to work on your reaction time though :)
 

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Another happy RPI customer. :)
 
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Sup guys,

I recently went to Dyno my car because I was racing a couple of other M5s and M6s, and every one thought I had a software or a pulley since I was way faster than them. I tried to explain to them that it was because of the RPi Exhaust and RPi Ram Air Kit. So I went to Dyno for proof last week. The first file is when I had the RPi Exhaust on. 4th gear power was 452whp and 345wtq. 5th gear power was 462whp and 355wtq. In 6th gear, I hit the limiter, as you can see. So I don't have a software. I made the most power at 464whp and 362wtq. Today, I put my stock exhaust on. My numbers were: 4th gear power was 430whp and 324wtq, 5th gear power was 432whp and 329wtq, and 6th gear power was 422whp and 325wtq. I think 6th gear was the lowest because the stock exhaust is more restrictive. Both time Dynoed, my RPi Ram Air Kit was always installed.
These numbers are worthless from a comparison perspective because you are comparing uncorrected dyno numbers on different days with different weather conditions. You need to use dyno graphs using corrected numbers for more of an apples to apples comparison.
 

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Company Representative of RPI Power
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I noticed that as well but we usually see numbers in the 20s and that is with out harsh testing methods as well. 25-30whp on a Dynojet is possible. It would be nice to see if the graphs can be printed corrected though.
 

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Discussion Starter · #13 ·
These numbers are worthless from a comparison perspective because you are comparing uncorrected dyno numbers on different days with different weather conditions. You need to use dyno graphs using corrected numbers for more of an apples to apples comparison.
The dyno tech claims the weather conditions were on my side, Humidity etc.. . So he did not need to correct w/e that means?
 

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The dyno tech claims the weather conditions were on my side, Humidity etc.. . So he did not need to correct w/e that means?
Well that depends....

It means by not using the correction numbers in this case, your numbers were inflated over what they would have been had you used the SAE method of correction which is the automotive standard for measuring rear wheel horsepower. This method gives you your power readings as if the temperature were 77°F, the barometric pressure 29.23" Hg, and 0% humidity. This method is more conservative, and is supposed to more closely reflect real world driving conditions.

A lot of tuners however opt to use the STD method of correction which corrects to a 59° F, 29.92" Hg barometric pressure, and 0% humidity level. STD tends to be about 3%-4% higher than SAE. I see a lot of tuners using this method not because it's a better method, but because it inflates horsepower numbers making their products look better. One of my pet peeves. Your numbers would have been fairly close to the STD method.

The weather conditions were definitely different on both days you dynoed, so the weather is likely causing some of the difference in the dynos between the two days. How much? Dunno.
 

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Discussion Starter · #15 · (Edited)
Well that depends....

It means by not using the correction numbers in this case, your numbers were inflated over what they would have been had you used the SAE method of correction which is the automotive standard for measuring rear wheel horsepower. This method gives you your power readings as if the temperature were 77°F, the barometric pressure 29.23" Hg, and 0% humidity. This method is more conservative, and is supposed to more closely reflect real world driving conditions.

A lot of tuners however opt to use the STD method of correction which corrects to a 59° F, 29.92" Hg barometric pressure, and 0% humidity level. STD tends to be about 3%-4% higher than SAE. I see a lot of tuners using this method not because it's a better method, but because it inflates horsepower numbers making their products look better. One of my pet peeves. Your numbers would have been fairly close to the STD method.

The weather conditions were definitely different on both days you dynoed, so the weather is likely causing some of the difference in the dynos between the two days. How much? Dunno.
Ok I see now .LoL I was never a big dyno fan. I was the type to set to race and see how the car performs . I really just dyno the car because I was tired of hearing I got a pulley or a tune when I dont . In my 6th gear pulls u clearly see I hit the limiter.
 

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These numbers are worthless from a comparison perspective because you are comparing uncorrected dyno numbers on different days with different weather conditions. You need to use dyno graphs using corrected numbers for more of an apples to apples comparison.
Do u have mods on your car just curious?
 

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I would say "worthless" is going a bit far, it's just a set of correction factors. The air temps and humidity favor the stock exhaust dyno, but the barometer favors the RPI dyno. Even if the correction knocked down the RPI dyno by 5hp it's still a significant gain.
 

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You needs to ask the dyno operator for SAE corrected numbers. You will **** when you sees how much lower they are this time of year. An uncorrected dyno means nothing.

You could have made other changes b4 you hit the dyno also
 
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