Dyno Results
09-08-2010, 11:15 AM
#46
Rennlist Member
Thread Starter
So here's the basic calculation I was talking about..
Let's calculate the crank hp from 448 rwhp by using 12% driveline losses = 448/0.88 = 509 crank hp.
Think of boost as a multiplier of the engine breathing capacity in N/A form. So next step is to compensate for boost. That is done by dividing crank hp with (atm pressure + boost level) = 509 / (1+1.45 bar) = 208 bhp.
This engine would produce 208 bhp in N/A form? Not likeley.
Remember that only modifications that improve the engine breathing capacity (VE) will let the engine produce more power without changing boost (simplified). That means that regular bolt-ons don't net you more power without upping the boost. However, if done right they will let you run higher boost without loosing efficiency.
And in this case about the only mod improving VE is the exhaust. Even with headers, head work, cam etc it would be hard to reach 200+ bhp in N/A form.
Let's calculate the crank hp from 448 rwhp by using 12% driveline losses = 448/0.88 = 509 crank hp.
Think of boost as a multiplier of the engine breathing capacity in N/A form. So next step is to compensate for boost. That is done by dividing crank hp with (atm pressure + boost level) = 509 / (1+1.45 bar) = 208 bhp.
This engine would produce 208 bhp in N/A form? Not likeley.
Remember that only modifications that improve the engine breathing capacity (VE) will let the engine produce more power without changing boost (simplified). That means that regular bolt-ons don't net you more power without upping the boost. However, if done right they will let you run higher boost without loosing efficiency.
And in this case about the only mod improving VE is the exhaust. Even with headers, head work, cam etc it would be hard to reach 200+ bhp in N/A form.
I ran the dynos within 2 days of each other as well with the only thing changing being the octane of the fuel. Didn't realize there would be this much scrutiny even with charts! That being said, I'm going to politely step out of my own thread. If anyone does have questions, feel free to PM me and I'll be more than happy to help. I just hope that people that are contemplating or have a similar build/tune don't get detracted from some of the naysayers here
09-08-2010, 11:49 AM
#47
Nordschleife Master
So doing a basic calculation exercise and a basic explanation of how getting more power out of an engine is done makes you step out of your own thread? That seems a bit harsh 
I considered my own post very polite and after all this is a technical forum, I would think technical posts were accepted.
I considered my own post very polite and after all this is a technical forum, I would think technical posts were accepted.
09-08-2010, 12:01 PM
#49
Rennlist Member
Thread Starter
So doing a basic calculation exercise and a basic explanation of how getting more power out of an engine is done makes you step out of your own thread? That seems a bit harsh
I considered my own post very polite and after all this is a technical forum, I would think technical posts were accepted.
I considered my own post very polite and after all this is a technical forum, I would think technical posts were accepted.
Even if your calculations were correct, it still wouldn't be more than 20-30hp off they dyno charts.
09-08-2010, 12:01 PM
#50
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Thread Starter
09-08-2010, 12:07 PM
#52
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Thread Starter
09-08-2010, 12:10 PM
#53
Drive-by provocation guy
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09-08-2010, 12:11 PM
#54
Rainman
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For fun, let's say that it's equivalent to the NA's output of 150bhp. Cold Air Intake (mine is deep in the wheel well) with 3" inlet and MAF conversion... let's say 10hp. 3" catback. Let's say 10hp. Catless? Another 10hp. Tuning with timing? Another 10-15 hp? Not unreasonable to say 200ish.
09-08-2010, 12:13 PM
#55
Rennlist Member
Thread Starter
no unfortunately. It was at the track and sadly no one was filming at the time.
09-08-2010, 10:08 PM
#57
Rennlist Member
So here's the basic calculation I was talking about..
Let's calculate the crank hp from 448 rwhp by using 12% driveline losses = 448/0.88 = 509 crank hp.
Think of boost as a multiplier of the engine breathing capacity in N/A form. So next step is to compensate for boost. That is done by dividing crank hp with (atm pressure + boost level) = 509 / (1+1.45 bar) = 208 bhp.
This engine would produce 208 bhp in N/A form? Not likeley.
Let's calculate the crank hp from 448 rwhp by using 12% driveline losses = 448/0.88 = 509 crank hp.
Think of boost as a multiplier of the engine breathing capacity in N/A form. So next step is to compensate for boost. That is done by dividing crank hp with (atm pressure + boost level) = 509 / (1+1.45 bar) = 208 bhp.
This engine would produce 208 bhp in N/A form? Not likeley.
Yeah, on top of that the NA version is probably 10+ compression ratio, so you're behind there.
Then, I'd say the injectors are probably too small to support the supposed horsepower and are at 100%.The combination of the "on/off" meth injection not varying with the increased in RPM (this is normal) and the injectors reaching 100% duty cycle before max power reflect an increasing air/fuel number on the chart with raising RPM.
Also, to be on par with a NA in terms of VE and pumping losses, you probably have to be around 1.2 to 1 in turbine inlet pressure/boost pressure ratio. Highly doubtful that 500 crank horsepower is getting through the #8 housing.
I know some of yous are pretty defensive about your dyno charts and throwing around words of "proof" instead of "just belief".
But, I'd rather use some aquired knowledge and I'd be questioning the dyno charts, not posting them.
That's all I'm saying.
asiancaucasion;
You did say that you have "p-trim"
How big is the exhaust wheel and how big is your exhaust from the turbo back?
This means alot and you never know
09-08-2010, 10:30 PM
#58
Rennlist Member
Thread Starter
Well, not going to argue with you there. If you don't think my car makes 400+, well so be it, there's really no rhyme nor reason to try to dispute with you if I have two separate dynamometers saying I do... You post up a dynojet number and people want to see a "Mustang" chart. Post up a Mustang chart and people say that they can be fudged and want to see a Dynojet reading. Can't please everyone
But seriously, I have nothing to prove here. My car is fast, it makes me happy and at least it's running correctly now! In fact, I was a bit surprised as well that it made 448, but I was aiming for at least 400 with the build.Just keep in mind one variable that you guys may not have considered... Tuning for meth allows for a gigantic ton of timing up top which my tuner did do. If you take a look at the HPF E46 M3 meth kits, many guys were making huge gains as the tuning allowed for quite ridiculous timing up top. On the dyno dynamics run, we disconnected the meth and tuned for that and I made 358whp safely (I have the chart for that run somewhere as well.) so it's not really inconceivable to me that the numbers are possible. I'll have to get my duty cycle logged next time, but yes I am worried that it's nearing 100% although it really doesn't feel like I'm running out of fuel.
