OV9

Mito Man wrote: Tue May 21, 2019 12:42 pm Well if you use the Toyota logic the most important part of the car is the engine. Doesn’t matter where it’s sourced from, what chassis or where it’s placed, as long as it maintains the same engine configuration as the previous model it is sufficient.

Which this one still doesn't quite as its an inferior single turbo set up whereas the prior lump was a twin turbo! 15hp more from 25 years of advancement

I can’t wait for the new Mitsubishi 3000GT which is basically a C53 coupe in a new frock.

GG. wrote: Tue May 21, 2019 4:30 pm

Mito Man wrote: Tue May 21, 2019 12:42 pm Well if you use the Toyota logic the most important part of the car is the engine. Doesn’t matter where it’s sourced from, what chassis or where it’s placed, as long as it maintains the same engine configuration as the previous model it is sufficient.

Which this one still doesn't quite as its an inferior single turbo set up whereas the prior lump was a twin turbo! 15hp more from 25 years of advancement

It isn't a single turbo. It's a twin impeller turbo with each impeller looking after 3 cylinders. Very quick spool up and lots of torque. Mine for example was running just over 400lb/ft as standard which is a fair amount.

McSwede wrote: Tue May 21, 2019 7:56 pm

GG. wrote: Tue May 21, 2019 4:30 pm

Mito Man wrote: Tue May 21, 2019 12:42 pm Well if you use the Toyota logic the most important part of the car is the engine. Doesn’t matter where it’s sourced from, what chassis or where it’s placed, as long as it maintains the same engine configuration as the previous model it is sufficient.

Which this one still doesn't quite as its an inferior single turbo set up whereas the prior lump was a twin turbo! 15hp more from 25 years of advancement

It isn't a single turbo. It's a twin impeller turbo with each impeller looking after 3 cylinders. Very quick spool up and lots of torque. Mine for example was running just over 400lb/ft as standard which is a fair amount.

That’s not how Twin-scroll turbos work. It’s a single impeller but with the exhaust gasses split in two and delivered separately to it at different angles, with the blades angled to make efficient use of the flow from each nozzle. One nozzle works best for response, the other for high boost. Overall you end up with a turbo with great response and great top end flow.

That's not my understanding after watching the Engineering Explained video. It's described as a twin scroll and each scroll is fed by a separate half of the engine. Cylinders 1-3 go via 1 manifold to one scroll and cylinders 4-6 go via a different manifold to the other scroll. I might be understanding it incorrectly but see link below from 6.45.

https://youtu.be/z_7aTQzpIOI

McSwede wrote: Tue May 21, 2019 9:21 pm That's not my understanding after watching the Engineering Explained video. It's described as a twin scroll and each scroll is fed by a separate half of the engine. Cylinders 1-3 go via 1 manifold to one scroll and cylinders 4-6 go via a different manifold to the other scroll. I might be understanding it incorrectly but see link below from 6.45.

https://youtu.be/z_7aTQzpIOI

Your explanation is correct, but a scroll is not an impeller. Each “scroll” is the path taken by the split exhaust gasses to the single impeller.

So it’s a single turbo with twin scrolls.

Mito Man wrote: Tue May 21, 2019 10:12 pm So it’s a single turbo with twin scrolls.

Yes, it’s a single, twin-scroll turbo.

It causes confusion in a lot of people who lift a BMW bonnet and see 'twin-power turbo' written and assume that means two turbos..

But RIC in his description.

One of the 'Murican mags put one on the dyno and it apparently had a lot more power and torque than quoted.

Simon wrote: Tue May 21, 2019 10:55 pm It causes confusion in a lot of people who lift a BMW bonnet and see 'twin-power turbo' written and assume that means two turbos..

But RIC in his description.

Didn’t the first 335i have two turbos, then it dropped to one, but kept a very similar name? Plus the triple turbo on my X5 and the new quadruple on the new 6-cylinder M50d. Not surprised people are confused.

DeskJockey wrote: Wed May 22, 2019 8:14 am One of the 'Murican mags put one on the dyno and it apparently had a lot more power and torque than quoted.

339 bhp at the wheels apparently which is a substantial jump on the quoted 335 at the crank.

JLv3.0 wrote: Wed May 22, 2019 8:33 am

DeskJockey wrote: Wed May 22, 2019 8:14 am One of the 'Murican mags put one on the dyno and it apparently had a lot more power and torque than quoted.

339 bhp at the wheels apparently which is a substantial jump on the quoted 335 at the crank.

And 420+ lb/ft of torque too.

JLv3.0 wrote: Wed May 22, 2019 8:33 am

DeskJockey wrote: Wed May 22, 2019 8:14 am One of the 'Murican mags put one on the dyno and it apparently had a lot more power and torque than quoted.

339 bhp at the wheels apparently which is a substantial jump on the quoted 335 at the crank.

That’d be getting on for something like 400 at the crank. That’s more like it!

Although they don’t look that quick in any of the YouTube reviews.

IanF wrote: Wed May 22, 2019 8:24 am

Simon wrote: Tue May 21, 2019 10:55 pm It causes confusion in a lot of people who lift a BMW bonnet and see 'twin-power turbo' written and assume that means two turbos..

But RIC in his description.

Didn’t the first 335i have two turbos, then it dropped to one, but kept a very similar name?

The N54 x35i engines were twin turbo, then they went single, twin-scroll for the N55 and B58 engines.

NotoriousREV wrote: Wed May 22, 2019 9:35 am

IanF wrote: Wed May 22, 2019 8:24 am

Simon wrote: Tue May 21, 2019 10:55 pm It causes confusion in a lot of people who lift a BMW bonnet and see 'twin-power turbo' written and assume that means two turbos..

But RIC in his description.

Didn’t the first 335i have two turbos, then it dropped to one, but kept a very similar name?

The N54 x35i engines were twin turbo, then they went single, twin-scroll for the N55 and B58 engines.

I argued this once with the owner of a 335i in the waiting room of a tyre shop.

He wasn't having it

NotoriousREV wrote: Tue May 21, 2019 8:15 pm

McSwede wrote: Tue May 21, 2019 7:56 pm

GG. wrote: Tue May 21, 2019 4:30 pm

Which this one still doesn't quite as its an inferior single turbo set up whereas the prior lump was a twin turbo! 15hp more from 25 years of advancement

It isn't a single turbo. It's a twin impeller turbo with each impeller looking after 3 cylinders. Very quick spool up and lots of torque. Mine for example was running just over 400lb/ft as standard which is a fair amount.

That’s not how Twin-scroll turbos work. It’s a single impeller but with the exhaust gasses split in two and delivered separately to it at different angles, with the blades angled to make efficient use of the flow from each nozzle. One nozzle works best for response, the other for high boost. Overall you end up with a turbo with great response and great top end flow.

Ok - but presumably boost limited because of the overall size of the single turbo despite the fact that the exhaust gasses are delivered in two streams to minimise lag - i.e. less tuning potential? I would also imagine swapping to a bigger turbo would not be easy unless compatible with the twin scroll setup?

Sounds like a clever solution to minimise cost whilst not succumbing to the lag typical of a single turbo. I expect fiddling with the exhaust plumbing upstream from the turbo is cheaper than fitting two which was the main driver behind doing that.

And of course, back to my overall point, ditching Toyota tech in favour of using a BMW setup.

DeskJockey wrote: Wed May 22, 2019 8:14 am One of the 'Murican mags put one on the dyno and it apparently had a lot more power and torque than quoted.

American dyno though.

Almost as trustworthy as a Brexit Party candidate.

Simon wrote: Wed May 22, 2019 10:16 am

DeskJockey wrote: Wed May 22, 2019 8:14 am One of the 'Murican mags put one on the dyno and it apparently had a lot more power and torque than quoted.

American dyno though.

Almost as trustworthy as a Brexit Party candidate.

Car and Driver is usually quite good in my opinion.

https://www.caranddriver.com/news/a2754 ... orsepower/

NotoriousREV wrote: Tue May 21, 2019 9:49 pm

McSwede wrote: Tue May 21, 2019 9:21 pm That's not my understanding after watching the Engineering Explained video. It's described as a twin scroll and each scroll is fed by a separate half of the engine. Cylinders 1-3 go via 1 manifold to one scroll and cylinders 4-6 go via a different manifold to the other scroll. I might be understanding it incorrectly but see link below from 6.45.

https://youtu.be/z_7aTQzpIOI

Your explanation is correct, but a scroll is not an impeller. Each “scroll” is the path taken by the split exhaust gasses to the single impeller.

Thanks for clearing that up.

With regards to power output, the B58 is quite healthy even with PPF. Mine did up to 360hp and 405lb/ft on the 4 Dyno runs it did when I got it. It's plenty fast