Noise Testing a Hybrid Automatic - BMW i8

Noise Testing a Hybrid Automatic - BMW i8

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Wicker Man

Original Poster:

824 posts

250 months

Sunday 3rd November
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My completely standard BMW i8 is whisper quiet at low speed and not too loud at full chat.

Prior to my first track outing in this car, I called MSV to ask about the noise test process for a hybrid automatic. There is no visible exhaust at the rear and it’s not possible to hold the engine at 3/4 max revs whist stationary. They insisted that a noise test was required and the noise tester would know what to do.

He had no specific advice, scratched his head looking for the exhaust and just said: “Right then, make some noise!”
Selecting sports mode makes the engine run continuously, and with my foot on the brake & parking brake set, pressing the throttle had the car straining at the leash but not much in the way of revs or noise.

This does seem like a pointless process and unnecessary abuse of the transmission. I can’t be the first to take an auto to a track, What are other experiences and views?

brillomaster

1,396 posts

177 months

Sunday 3rd November
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Good question... older autos, I'd say put it in N and rev it, but newer stuff... don't they limit revs when in neutral? And hybrid autos... do they even have neutral as a mode?!?

I guess in practice, a modern auto would never fail a static test, so would be monitored by drive by testing.

Wicker Man

Original Poster:

824 posts

250 months

Sunday 3rd November
quotequote all
There’s no neutral mode: just a Start/Stop button, Stop/Go pedals and three modes Econ/Comfort/ & Sport.

I was concerned that: Sport mode, hold it on the brake and floor the throttle might be the same as Launch Control, but apparently not! 😳

isleofthorns

547 posts

177 months

Sunday 3rd November
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more importantly...

how was the i8 on track??

Wicker Man

Original Poster:

824 posts

250 months

Monday 4th November
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It was a warm dry August evening session, so I wasn’t expecting the 4WD to add much. However, I was impressed at how early I could get back on the throttle, post apex, and how well the standard tyres and brakes coped. That’s despite late braking from 120 mph on both straights.

The only fly in the ointment was that Snetterton has a lot of WOT, so no chance for the battery to recharge itself on track. I could have taken my portable charger but the i8 only has a small EV battery. I’d have been lucky to get 5kWh between track sessions and at £25 to book a garage + £25 to plug in, it was too steep! Effectively £10/kWh when I pay 5p at home!

Once the battery was exhausted, I was left to mince around with just 230bhp RWD. That wasn’t so much fun, so called it quits after three outings.

There are no EV charging points at Snetterton circuit. Maybe MSV are waiting to see if EVs are a passing fad?

Edited by Wicker Man on Monday 4th November 09:01