# Stock 335i Dyno



## gjcm3 (Aug 4, 2007)

How did it lay down 284 stock if BMW claims 300 crank? Haha that's like 5% loss, which makes no sense. I'd imagine that thing is making more like 340 at the crank, or that dynojet reads high. I've been for a ride in one before and that thing pulled hard from so low in the powerband!


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## Terry @ BMS (Apr 27, 2007)

gjcm3 said:


> How did it lay down 284 stock if BMW claims 300 crank? Haha that's like 5% loss, which makes no sense. I'd imagine that thing is making more like 340 at the crank, or that dynojet reads high. I've been for a ride in one before and that thing pulled hard from so low in the powerband!


They are very underrated.  Most guys pull 265-275rwhp stock. I don't get caught up in crank hp since there is no way to verify it, but with a JBS1 guys see over 300rwhp!


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## franka (Jan 23, 2006)

So what is the correct percentage difference between flywhl and rearwhl hp?

Is it 20% less at the wheels than the fly?


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## Terry @ BMS (Apr 27, 2007)

franka said:


> So what is the correct percentage difference between flywhl and rearwhl hp?
> 
> Is it 20% less at the wheels than the fly?


Who knows, flywheel hp is like the tooth fairy. I think it's best to quote rwhp figures since one can measure those.


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## franka (Jan 23, 2006)

Terry @ BMS said:


> Who knows, flywheel hp is like the tooth fairy. I think it's best to quote rwhp figures since one can measure those.


Yes I would agree. But still, what is the factor to convert back and forth?


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## Terry @ BMS (Apr 27, 2007)

franka said:


> Yes I would agree. But still, what is the factor to convert back and forth?


There really is no factor, but I guess for conversations sake you could say 15%.


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## franka (Jan 23, 2006)

Terry @ BMS said:


> There really is no factor, but I guess for conversations sake you could say 15%.


You forced me to go to the internet for an answer. There is a lot of info on drive train loss and there are a lot of answers because there are many factors that are involved.

The bottom line is that the loss is around 30 to 60 hp for manuals and about 45 to 75 hp for automatics in general.

Putting it into percentage terms losses are in the very apprx range of 12 to 15% for manuals and higher for automatics.

If anyone disagrees I suggest they google "drive train loss" and read up on it for themself.


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## Terry @ BMS (Apr 27, 2007)

Sounds reasonable. As you said there are a lot of variables so it's difficult to model as a straight percentage.


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