F1technical.net

r101 wrote: ↑

18 Jan 2018, 23:26

Just a naive question: If on Renault engine all elements are outside the 'V', why cannot both turbine and everything else be much lower than on Merc/Honda? Is it illegal to do so, or there simply isn't any space in the packaging?

As you lower the compressor/turbine/MGU-H assembly at the back of the engine it will hit the top of the little clutch assembly. You can move the comp/turb/MGUH 50 mm further back to clear the clutch and lower it further until it hits the shaft between the clutch and the transmission. At that point you need to severely kink the exhaust upward to clear over the transmission. And the space you've lowered the c/t/H into is already very tight because the cars all use inboard transmissions with the gear clusters ahead of the final drive. Also, generally, the more you lower the c/t/H, the more you create an awkward structure on the top of the bellhousing and transmission, and that surface is important for rigidly connecting all the rear suspension and rear wing loads into the engine and forward part of the car.

All ultimately tradeoffs. The Merc/Honda approach makes the engine-rear more tidy, but the front is a packaging and structural mess. The Ferrari/Renault approach goes for the opposite tradeoffs.

FPV GTHO wrote: ↑

18 Jan 2018, 12:51

Moving the MGUH out of the v seems like a backwards step. What would it benefit, more room for the variable trumpets?

That's one of the main reasons IMO... more room for the VLIM and for the odd shaped compressor airbox?
That part seems to be (atleast partly) inside the V since 2017.

Blackout wrote: ↑

18 Jan 2018, 09:35

Do you know how a 2017 MGUH looks? Tim Goss said something strange about the Renault; according to him the H hangs between the compressor and the turbine... but it's hard to believe because some pictures show that the space between the C and the T is quite tiny... so if this is true, the H should look like a disc or a camembert box whereas the 2014 H was a KERS-like long cylinder and did sit in the V... Is that possible?
And the rules suggest that the H units are much lignter than the K...
https://pbs.twimg.com/media/C0yC6BAWEAAlsJU.jpg:large

It is best not to assume the 2017 and 2018 engines will have a similar mguh layout.

Isn't the 2018 Renault MGU-h supposed to be a reliable 2017 mgu-h unit?

Blackout wrote: ↑

18 Jan 2018, 09:35

Do you know how a 2017 MGUH looks? Tim Goss said something strange about the Renault; according to him the H hangs between the compressor and the turbine... but it's hard to believe because some pictures show that the space between the C and the T is quite tiny... so if this is true, the H should look like a disc or a camembert box whereas the 2014 H was a KERS-like long cylinder and did sit in the V... Is that possible?
And the rules suggest that the H units are much lignter than the K...
https://pbs.twimg.com/media/C0yC6BAWEAAlsJU.jpg:large

That also struck me as odd. I thought the MGU was in the vee. Photos and cad suggest so. A split turbo fully behind the engine would be quite long and encroach upon the transmission housing.

















Granted, this is an older engine. 2014 I believe. But it gives a sense of how long the MGU-H is, and how much farther the turbine would have to be pushed back into the transmission housing in order to accommodate a split-turbo arrangement.

Worth noting here, since it came up in the other threads recently, that the fuel rails are atop the centerline of the cam covers, as you might expect them to be. More recent Merc engines appear to have theirs running below the exhaust ports.

Man these engines really have come a long way, if you saw what they're doing now today, it's on a completely different league. 4 years of development goes a really long way, and it's not the engine block, but the ERS and cooling, the control electronics, the energy store itself has come some way, although there's not much more they can squeeze out of current tech.

godlameroso wrote: ↑

22 Jan 2018, 05:57

Man these engines really have come a long way, if you saw what they're doing now today, it's on a completely different league. 4 years of development goes a really long way, and it's not the engine block, but the ERS and cooling, the control electronics, the energy store itself has come some way, although there's not much more they can squeeze out of current tech.

Do you mean squeeze out of the current tech, or current regulations glm ?

I was referring to the energy store, there's still plenty of scope for developing the power unit.

I notice that the COG of this engine is no worse than the Mercedes. Both have the MGUH as low as possible.
In fact if Renault wanted to they could put the MGUH further away from the compressor and closer to the oil tank, or they can even copy mercedes with the frontal compressor.
The main draw back with their design is compressor housing temps. It doesn't seem to suffer much drawbacks.

Compressor housing diameter may be restricted by clutch diameter in the Renault/Ferrari arrangement. To enlarge the compressor assembly would then entail raising its centerline, along with the MGU, at detriment to CoG. I'd want a straight shot into the compressor inlet as well, like the Merc.

Years ago I toyed around with the concept of a reverse Merc setup. Turbine in the front, compressor in the back.

Advantages: Longer, gentler 180* sweep into the compressor inlet from the intake trumpet; no exhaust pipes through the gearbox casing; exhaust header spaghetti lump moved forward i.e. the widest part of the engine moved further forward; heaviest turbo components moved toward polar center.
Disadvantages: Longer, heavier post-turbine exhaust pipe proximal to intake runners & MGUH; exhaust heat near safety cell; compressor diameter tradeoffs as with the Renault/Ferrari setup.

but then you'd have to run the turbine outlet pipe and wastegate pipes back to the rear. Not only they are hot as hell but inconel is denser than steel..

roon wrote: ↑

23 Jan 2018, 19:37

Compressor housing diameter may be restricted by clutch diameter in the Renault/Ferrari arrangement. To enlarge the compressor assembly would then entail raising its centerline, along with the MGU, at detriment to CoG. I'd want a straight shot into the compressor inlet as well, like the Merc.

Years ago I toyed around with the concept of a reverse Merc setup. Turbine in the front, compressor in the back.

Advantages: Longer, gentler 180* sweep into the compressor inlet from the intake trumpet; no exhaust pipes through the gearbox casing; exhaust header spaghetti lump moved forward i.e. the widest part of the engine moved further forward; heaviest turbo components moved toward polar center.
Disadvantages: Longer, heavier post-turbine exhaust pipe proximal to intake runners & MGUH; exhaust heat near safety cell; compressor diameter tradeoffs as with the Renault/Ferrari setup.

What happens to the exhaust pipe? and the air intake?
hah.

PlatinumZealot wrote: ↑

24 Jan 2018, 00:35

What happens to the exhaust pipe? and the air intake?
hah.

It's a non-selectable seat heater.

Really split turbo, or turbo at the back are your only options. The difference between the two at this point is purely academic. I don't think the different setups have a big difference in CoG, or giving space for aero.

Well, I never claimed it to be a particularly good idea. Perhaps I should have emboldened or underlined the "disadvantages" section in my previous post. Here's a sketch. Pardon the quality, I'm in a library; all I had available was those 3" long eraser-less pencils and small pieces of note paper. Enjoy!



The arrow & bracket is simply to signify the more forward placement of the widest part of the engine. The compressor outlets are hidden at this angle--you'd either route the charge lines above/through the vee or around the sides/floor.