[SoCalC55]

Originally Posted by Vettezuki

I'd like to see these with boost and A/F on the same dyno on the same day (same car even better). Starting from stock you DON'T go from 300~ to 340~ on chip alone. At least not without seriously shortening the lifespan of the engine.

I know he had an intake aswell lol

[SeanPlunk]

Originally Posted by Vettezuki

I'd like to see these with boost and A/F on the same dyno on the same day (same car even better). Starting from stock you DON'T go from 300~ to 340~ on chip alone. At least not without seriously shortening the lifespan of the engine.

Actually you can. Here is a dyno chart on a complete stock 335i with the Juice Box from Burger Motorsports:



If you'll notice on 91 octane he went from 273rwhp to 313rwhp - exactly 40rwhp.

[Vettezuki]

Originally Posted by SeanPlunk

Actually you can. Here is a dyno chart on a complete stock 335i with the Juice Box from Burger Motorsports:[/IMG]

If you'll notice on 91 octane he went from 273rwhp to 313rwhp - exactly 40rwhp.

Yeah, except for the part where there's no boost or A/F or comparison to a Vishnu unit on the same car and day. I can see the top numbers are on 93 which makes a little more sense. A chunk of it is coming from the timing.

My point is this, it's hard for me to imagine BMW being that conservative with the stock tune. So much so that with still safe (close to ideal) A/F and timing you could pick up that much power at the wheels. That's more than the old days of the LS1s that came from the factory with VERY conservative tunes. Unless they just running very low boost fro the factory that can just get turned up and the fuel system can support it.

Is the JB a whole piggy back computer with lots parametric articulation than the stock unit?

[SeanPlunk]

Originally Posted by Vettezuki

Yeah, except for the part where there's no boost or A/F or comparison to a Vishnu unit on the same car and day. I can see the top numbers are on 93 which makes a little more sense. A chunk of it is coming from the timing.

My point is this, it's hard for me to imagine BMW being that conservative with the stock tune. So much so that with still safe (close to ideal) A/F and timing you could pick up that much power at the wheels. That's more than the old days of the LS1s that came from the factory with VERY conservative tunes. Unless they just running very low boost fro the factory that can just get turned up and the fuel system can support it.

Is the JB a whole piggy back computer with lots parametric articulation than the stock unit?

The JB is a piggy back unit AFAIK. The 335i runs relatively low boost stock and the fuel system is stout enough to handle the extra.

I don't know why you're so surprised by this. Remember, with a Cobra like mine you could easily make 60rwhp over stock with a pulley and tune only.

Factory forced induction FTW

[Vettezuki]

Originally Posted by SeanPlunk

The JB is a piggy back unit AFAIK. The 335i runs relatively low boost stock and the fuel system is stout enough to handle the extra.

I don't know why you're so surprised by this. Remember, with a Cobra like mine you could easily make 60rwhp over stock with a pulley and tune only.

Factory forced induction FTW

A pulley is a mechanical alteration. I understand completely. The idea BMW would come out with something that only DATA could increase implies to me they must have had a model lineup problem. As you describe, a 335i working at it's potential starts to cut into M3 performance at nearly half the cost. So model branding issue that can be exploited by those in the know.

[gsteichen]

Originally Posted by Vettezuki

A pulley is a mechanical alteration. I understand completely. The idea BMW would come out with something that only DATA could increase implies to me they must have had a model lineup problem. As you describe, a 335i working at it's potential starts to cut into M3 performance at nearly half the cost. So model branding issue that can be exploited by those in the know.

It's a popular belief that BMW deliberately understates the 335"s HP to max the spread between it and the M3. Given the price spread it's in their interest (financially). If it's true that there is that much power left on the table with the stock tune, esp. with the weight difference, why pay double???

[Chate]

I think a lot of it might have to do with the lifespan too, even though BMW could have tuned it up to more boost/power, it probably wouldnt last the 5 years or whatever that it is covered under warranty!
I've been looking at BMW forums, most of the guys are super anal about removing piggybacks whenever they take their leased cars/bought cars into service...because the techs are told to inspect for ECU mods...which violate warranty/lease terms!!!

but going back to the m3, i see one on my walk to school sometimes...yum!!

[WagonSleeps]

i wouldnt be able to afford to mod a bmw...and like my co-worker, get the lemon law treatment. He had major Fuel pump issues..

[SeanPlunk]

Originally Posted by WagonSleeps

i wouldnt be able to afford to mod a bmw...and like my co-worker, get the lemon law treatment. He had major Fuel pump issues..

Yeah, the high pressure fuel pumps on the first 335i's were a HUGE problem. My grandfather's had his fail on him at 9k miles.... It was a widespread problem.

[Vettezuki]

Originally Posted by SeanPlunk

Yeah, the high pressure fuel pumps on the first 335i's were a HUGE problem. My grandfather's had his fail on him at 9k miles.... It was a widespread problem.

Are those motors direct injection?