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Dyno Results: Stock with Charcoal Filters Removed

9K views 20 replies 13 participants last post by  Wolverine 
#1 · (Edited)
My only mod so far is removing the charcoal filters. I had one run at 417 - I'm told I have a pretty strong car for stock. For comparison those that have dyno numbers with same setup please post.

 
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#4 ·
Keith,

Maybe u can chimp in on my dyno thread I posted especially a/f ratio. I pulled 399hp (CF removed, section1&2+stock muffler, K&N filter). Then after Evo pulley+exhaust, the car pulled 402hp. Then it pulled <400hp after BMC filter installed. I used Dyno Dynamic all on 5th gear (temp 82-92F) I'm ouich:confused2right now...

Thanks.
 
#3 ·
Good call, the pull was done in 4th. You obviously know more about this than I do. Also the car seemed to run on the rich side, perhaps that is normal for stock?
 
#7 ·
keang24, the way KeithTa explained it is the way it goes with mods and he's seems to have traveled a long road. With all my mods I went from 408 to 460 rwHP. I had expected more and was initially disappointed but the mechanics of how mods work and their synergy or lack of synergy at times only God could know. With these cars you spend alot and get very little. Good luck m5Ranger
 
#8 ·
M Ranger you will get more power by putting the stock mid section back in (cats and resonators) you need back pressure. I had your set up SS headers sec 1&2 and race exhaust. Car has more power and runs better with stock mid section in. That was my experience
 
#9 ·
Avery & M5Ranger, both of you running SS header with stock 2nd cat and resonator? I consider just stock 2nd cat (still with x-pipe) when installing my Evo header(initially just for loudness reason, but if the car has more power and feel better, I would take it as a plus). I still anxiously waiting for response from neighbor about my new exhaust(Arqray), hopefully with header will not be any louder.
 
#10 · (Edited)
I agree with Keith. My car shows only 445rwhp on an archaic dyno, but the races I have done tell a different story.
 
#11 ·
I agree with Keith. My car shows only 445rwhp on an archaic dyno, but the races I have done tell a different story.
Come on Russ its not like you beat super charged Viper or any fast cars like that.
 
#14 ·
can you dyno in 6th gear if your car is not delimited? Wouldn't you hit the top speed limiter in 6th?
 
#15 ·
Two reasons:

1) my dyno shop's dyno cannot handle the speed the M5's can make in 6th gear. We did one dyno in 6th and the in-ground dyno went nuts due to excessive speed needed to hit redline

2) we hit the speed limiter before we could end the dyno

Cheers,

Darren
 
#16 ·
Two reasons:

1) my dyno shop's dyno cannot handle the speed the M5's can make in 6th gear. We did one dyno in 6th and the in-ground dyno went nuts due to excessive speed needed to hit redline

2) we hit the speed limiter before we could end the dyno

Cheers,

Darren
You should be able to hit the hp peak just before the speed limiter in 6th IF you have the 3.91 diff. Any gear less than 6th (1:1) will give you a reduced hp reading, so the dyno results we're seeing are a bit lower than the actual hp.
 
#17 · (Edited)
Is it valid to extrapolate the RWHP in 6th, e.g.,:

1. Do a dyno in 6th up to its rpm/speed limit.
2. Do another dyno run in 4th noting the power output at the same rpm in #1.
3. From the same #2 dyno run (in 4th) get all of the normal figures up to and including peak RWHP. Multiply these by #1/#2 to factor out the extra transmission loss when running in 4th. It would seem that these would represent (assuming fairly linear loss) the output in 6th were that possible.

Tom
 
#18 ·
well, I had them dyno my car in 6th and the only issue was that I did hit the limiter in 6th, but I think the dyno I was on can handle the speeds, it just cut out at 7400rpm because of speed limited.
 
#19 ·
well, I had them dyno my car in 6th and the only issue was that I did hit the limiter in 6th, but I think the dyno I was on can handle the speeds, it just cut out at 7400rpm because of speed limited

2008 Interlagos Blue M5
Every option except HD radio
Tubi-style exhaust
Charcoal filters removed
431whp at 7400rpm with 850 rpm to go!!
You would have easily hit the HP peak of 7750 with the 3.91 diff.
 
#20 ·
Dyno's are the conventional way for measuring whp. A better way IMO is to look at trap speeds at the drag strip. This way there is cool air flowing into the engine and is also better for cooling. If you add a mod and your trap speed goes up under similar conditions then you know you gained power. Theres also ways for correcting for different altitude, humidity, and temperature.
 
#21 ·
Agree that trapspeeds are probably the best way to gage a mod. The bottom line is I have yet to see/hear about a modded M5 break 120 mph trapspeed. You can apply the SAE correction factor that takes into account the three key parameters, temperature, humidity, and barometric pressure. Very accurate for revising HP, but doesn't always translate accurately to revised ET's and trapspeeds.
 
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