Yet another sh!tty JB3 1.22 dyno...

[ssabripo]

Originally Posted by jeremyc74

Not to take away from the numbers he put down, but you're reading too much into it. The 15% driveline loss is a guess, and it's hard to actually prove without doing an engine dyno and then a chassis dyno. On top of that you never know how exact the calibration on the dyno is. The factory numbers are standardized and are adjusted for a specific set of circumstances (temperature, oil level, fuel, altitude, ect.). If you run the car at a lower temperature you're going to see better numbers. In other words, too many variables to say BMW is actually under-rating the cars.

Numbers from a chassis dyno should be used as a tuning tool to demonstrate gain. Trying to derive exact flywheel numbers from them isn't really useful.

you are correct to a certain point. Conversely, if we assume that the 302hp rated power from BMW is the "correct" baseline, then according to these numbers the drive train loss factor is:

273/302 = 0.9
thus
362/0.9 = 402 hp, baselined from a 302hp initial value.

[Canexican]

Originally Posted by ssabripo

this wouldn't be just a function of the JB3.... the Procede, and even flashes like ESS or AA are taxing the HPFP in similar fashion, so while the theory of whether these tunes are taxing the filter beyond its limits is still unknown, this isn't a JB3 only issue.

That isn't exactly a bad idea though. If it was known that fuel pumps were problematic, i'd probably replace mine with the JB3 just as a precaution.

Are other JB3 users getting these extreme dyno numbers from just a tune or is this a freak occurrence as the result of a custom dyno tune via the JB3? If it is that reliable and easy to gain 90whp, I don't understand why everyone else hasn't done it (besides the whole "unreliability" and "voided warranty" issue is in the back of everyone's minds).

[jeremyc74]

Originally Posted by ssabripo

you are correct to a certain point. Conversely, if we assume that the 302hp rated power from BMW is the "correct" baseline, then according to these numbers the drive train loss factor is:

273/302 = 0.9
thus
362/0.9 = 402 hp, baselined from a 302hp initial value.

You still can't assume that. You're not correcting for temperature, altitude, or fuel, and you're assuming the dyno is perfectly calibrated. What was the temp when you did the dyno runs? SAE (I'm not sure if BMW is using that standard, I'm just throwing it out there) corrects to 70 degrees F IIRC. If you dyno an SAE rated vehicle when it's 40F you're going to see more power than it was rated at because of the cooler air, especially on a turbo car.

Don't get me wrong, the JB3 is clearly adding about 100Hp at the crank, I'm just saying that it's wrong to make the assumption that the factory is under-rating the engine to begin with. :w00t:

[jeremyc74]

Originally Posted by Canexican

That isn't exactly a bad idea though. If it was known that fuel pumps were problematic, i'd probably replace mine with the JB3 just as a precaution.

Are other JB3 users getting these extreme dyno numbers from just a tune or is this a freak occurrence as the result of a custom dyno tune via the JB3? If it is that reliable and easy to gain 90whp, I don't understand why everyone else hasn't done it (besides the whole "unreliability" and "voided warranty" issue is in the back of everyone's minds).

These are pretty typical numbers.

Guys, the problem with the high pressure fuel pumps isn't that they're being overloaded. It's a manufacturing defect that involves the seals. I'd be very surprised if the amount of fuel going through the pump (related to more HP) has any effect at all on the failure rate.

[My135]

I would not worry about the HPFP but the turbo. All tunes will increse the psi and thus dirve the turbo harder which may cause some problem down the road.

Any way, even I got the JB3, I will only occasionally drive my car hard and minimize the reliability issue.

[Canexican]

Originally Posted by jeremyc74

These are pretty typical numbers.

Is it pretty routine to get over 400whp with just bolt-ons and a tune :iono: ?

[jeremyc74]

Originally Posted by Canexican

Is it pretty routine to get over 400whp with just bolt-ons and a tune :iono: ?

No, it seems like most of the bolt-on cars are just under that mark, at least on pump gas.

[ridin135]

Originally Posted by Canexican

Is it pretty routine to get over 400whp with just bolt-ons and a tune :iono: ?

Horsepower close but torque is over 400 lb ft at the wheels with bolt on and tune. These cars are pretty sick and jb3 for 600 hell i got mine for 300 new. :headbang:

[ssabripo]

Originally Posted by jeremyc74

You still can't assume that. You're not correcting for temperature, altitude, or fuel, and you're assuming the dyno is perfectly calibrated. What was the temp when you did the dyno runs? SAE (I'm not sure if BMW is using that standard, I'm just throwing it out there) corrects to 70 degrees F IIRC. If you dyno an SAE rated vehicle when it's 40F you're going to see more power than it was rated at because of the cooler air, especially on a turbo car.

Don't get me wrong, the JB3 is clearly adding about 100Hp at the crank, I'm just saying that it's wrong to make the assumption that the factory is under-rating the engine to begin with. :w00t:

correct....SAE corrects the temps to 70deg. Temps during the runs were 64-65deg, so within tolerance. I also posted the "uncorrected" numbers which showed 367 I believe.

I'm pretty sure that given the temperatures, dyno conditions, and correction values, that the average drivetrain losses used are within the ballpark :wink:

[SpeedballTrix]

Temp and humidity and dyno cal don't matter at all to drivetrain loss.
The fact is he put down X before the tune and Y after the tune on the same dyno on the same day with all those factors (roughly but close enough) the same. Thats a solid mathematical delta.

You are right that it's hard (actually impossible) to tell what the drivetrain loss is for the 135i transmission until someone puts the N54 on multiple engine dynos, averages those numbers, and then puts the car on multiple chassis dynos and averages those numbers.

Until someone does that you have to assume.
Assumption is all we have without hard test data.
And the general assumption for well built street manual gearboxes (which havent changed much in design since the Model-A except for better materials, machining processes, helical cut gears and synchronization) is 15% loss. Maybe the 135i tranny has 14% loss. Maybe even 13%, but thats giving it a hell of a lot.

[ssabripo]

Originally Posted by squeak

do dinan

[stevenc]

I was hoping i would receive my JB3 1.22 before a dyno day this last weekend, but i didn't.

So my JB3 v1.1 made 342 whp and 368 wtq.

Not bad.

[ssabripo]

Originally Posted by stevenc

I was hoping i would receive my JB3 1.22 before a dyno day this last weekend, but i didn't.

So my JB3 v1.1 made 342 whp and 368 wtq.

Not bad.

Good numbers! anything at or above 340rwhp is good IMO

[stevenc]

Yeah, im not unhappy.

[5soko]

Originally Posted by stevenc

I was hoping i would receive my JB3 1.22 before a dyno day this last weekend, but i didn't.

So my JB3 v1.1 made 342 whp and 368 wtq.

Not bad.

Nice numbers with 1.1!!

With Map 5 and 6 with 1.22 your WHP should increase a good bit
Map 4 and 6 should also give you even more TQ. Of course map 4 being tq biased, map 5 being hp biased, 6 being the best of both worlds.