my 35is dynoed today

[s2000jan]

As the title already says, I went to dyno my 35iS

And boy, was I in for a surprise !

It took a while for the guys to get the test going as the computer was nagging about the rear wheels turning and the front wheels where not. DCT would not shift up and rpm did not go above 2000rpm

Finally they managed to get it going, but with so much wheel spin that someone had to sit in the trunk !

And for the numbers ....

371 Hp

539 Nm

On the graph included you can very well see when the 'overboost' takes place

[Mr. ///M3 RD]

Looks Good

[teagueAMX]

They must have calculated brake horsepower based on your rear wheel horsepower. Typically rear wheel horsepower is around 15-18 percent less than brake horsepower. Did they give you an actual rear wheel horsepower figure?

That's pretty amazing how close your figures are to BMWs. BMW shows 340 max which is consistent with your dyno results from about 5500 to 6500 RPM, but BMW hasn't released hp figure with the Overboost, only torque. And your torque of 539 is higher than BMW advertised figure of 450 w/ Overboost.

.

[richard in NC]

Impressive, but the high RPM drop off would bother me if that's how it acts on the road.

[teagueAMX]

Originally Posted by richard in NC

Impressive, but the high RPM drop off would bother me if that's how it acts on the road.

+1

I think that's were Dinan's Stage II would be better overall. I belive he did some other tweaks, such as the water pump flows, in order to sustain the output across the board. I believe Dinan has a bigger heat exchanger as well.

But the 35is is not a bad package, especially when you consider the suspension and steering tweaks.

[firewalker]

The high RPM drop-off is caused by the tappering of the boost at high RPM. If the boost did`nt taper the engine would destroy itself at high RPM.

[zEdP]

Originally Posted by teagueAMX

They must have calculated brake horsepower based on your rear wheel horsepower. Typically rear wheel horsepower is around 15-18 percent less than brake horsepower. Did they give you an actual rear wheel horsepower figure?

Strange that they don't show the actual correction factor in the print out.

Ed

[HerrK]

All the data is there. It looks like they only used about a 4-4.5% loss for drivetrain. Anyway 341hp at rear wheels looks pretty good. Are the BMW figures BHP?

Motorleistung (gemessen)= engine power (measured)
Radleistung (gemessen)= wheel power (measured)
Verlustleistung (gemessen) = (power loss measured)
Motorleistung (Korr) = engine power (Corrected)
Drehmoment (Korr) = Torque (corrected)

[teagueAMX]

Thanks for the translation. I didn't pickup on those other numbers.

BMW uses brake or flywheel horsepower rather than rear wheel. I just don't remember which measurement standard the Germans use.

Yes, 341 hp PS is outstanding rear wheel hp. And frankly, 4-4.5% is extremely conservative. Using the US HP conversion from PS, that's 333.53. Applying a 18% increase for powertrain loss put it up around 393 hp US. Everyone says that BMW figures are conservatively low and they aren't kidding!

[datbimmerdoe]

great numbers!

[Dr Stig 2]

Thanks heaps S2000Jan!

I may be biased but I think they are some of the most interesting numbers I have seen all week!

I am especially fascinated by the two peaks of the overboost - power and Torque.
The way it adds a hump to the power curve on the way up is awesome, and makes it look like it has a huge power loss at high RPM, when it is merely backing off the boost.

I'm tempted to get mine done as well - but if you wouldn't mind sending through a high quality scan by PM I would like to electronically digitise it into a workable graph....

[Alext]

Wow, I've seen many a N54 dyno and this one is exceptional, even for a Z4 35is. If they are accurate, then it looks like BMW seriously underrated (just like the standard N54 engines) the 35is output as some reviewers suspected. Or you just have a freak of an engine!

A recently dynoed (on a Dynojet) 335is by Automobile magazine came in at 293HP at the rears. The standard N54 at 277HP done in the same test/day.

Drivetrain loss should be around 10-15% so this shows that even the standard N54's are very underrated from factory. ie around 15-20HP+.

[Dr Stig 2]

Originally Posted by Alext

Wow, I've seen many a N54 dyno and this one is exceptional, even for a Z4 35is. If they are accurate, then it looks like BMW seriously underrated (just like the standard N54 engines) the 35is output as some reviewers suspected. Or you just have a freak of an engine!

A recently dynoed (on a Dynojet) 335is by Automobile magazine came in at 293HP at the rears. The standard N54 at 277HP done in the same test/day.

Drivetrain loss should be around 10-15% so this shows that even the standard N54's are very underrated from factory. ie around 15-20HP+.

And how close is your new baby Alex?
I saw another 35is in the western suburbs of Brisbane today - a space grey!
I was in the family truckster though going int he opposite direction, or I would have chased him down to say gudday!
Yes - I know this is .
Shoot me.

[Alext]

Still hasnt entered production yet Stig Gotta be patient though by the looks of these numbers it's gonna be worth the wait!!

BTW S2000jan what octane fuel did you use?

The 350whp range is what a JB3 V2.0 map5+DCI puts down which is pretty impressive! Different dynos etc I know but still.

[Dr Stig 2]

A challenge for anyone with access to a Dyno...
- Assessing the impact of pressing the overboost button on the curve at different times in the rev range...

If you floor it from the get/go, you only get 7(?) seconds of boost.
While that seems an eternity in a single low gear, what is this time limitation doing to the curve (I wonder aloud)...

If you go full throttle without the overboost being engaged until say 5000 rpm, then press harder to engage the boost - do you get the same curve?

[Dr Stig 2]

Originally Posted by Alext

Still hasnt entered production yet Stig Gotta be patient though by the looks of these numbers it's gonna be worth the wait!!

BTW S2000jan what octane fuel did you use?

The 350whp range is what a JB3 V2.0 map5+DCI puts down which is pretty impressive! Different dynos etc I know but still.

Alex, is it the 25 car quota limit each year in Oz that is causing yours to take so long?
Seems like 2 months since you ordered...
I thought yours would be on the boat for sure by now.

[Alext]

Im not sure, they didn't say why it takes so long, but I have come to expect it since I waited about 3-4 months for my 135i.

I think the Regensberg plant where the Z4 is made had a holiday recently which would compound any delays. I remember when I asked a long while ago when the Z4 factory had their break but no one seemed to know.

The Z4 35is has to be allocated a production run so I assume if Australian units are made on a specific run then the 25/year limit would cause these delays. (Im not sure if other countries have some sort of limit too).

[ttuner]

any mods?

[s2000jan]

ok, some answers:

- no mods whatsoever
- 98 octane here in Belgium
- I also think the measurement is a bit optimistic; I will do a second run on another one in a few months
- will send a high quality scan of the measurement but not today will be for the next week

[Dr Stig 2]

Muchas gracias!
No hurry...

[cdeslandes]

Originally Posted by s2000jan

- 98 octane here in Belgium

For us North Americans, that translates to 93 octane over here.

[Rubber Ducky]

A couple documents for reference (tune in the Dinan report is essentially equivalent to Stage II in the E89 35s - & note date).