Full capacity or turbo parity?

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
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coaster
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Full capacity or turbo parity?

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Hi,
Looking for an opinion on which option is best;
1/ 2000cc naturally aspirated, unlimited mods.
2/ 1170cc single turbo with a 36mm restricter.

The 1.7 capacity factor and 36mm restricter are unchangeable.

All out boost?
Or upper mid range cubic capacity?
Are they about equal do you think?

Rodak
Rodak
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Re: Full capacity or turbo parity?

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Sort of depends on what you're doing. What are you doing?

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coaster
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Re: Full capacity or turbo parity?

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To be more specific, a 2 litre MZR duratec with itbs, cam and headers or a Suzuki M13a with 54mm stroke crank, 145mm rods with a hitachi turbo and 36mm throat velocity stack.
Mostly hillclimb and timed events.

(Edit, the V8 Cbr idea is bunkum)

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Zynerji
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Re: Full capacity or turbo parity?

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Short of altitude playing a part, wouldn't the NA be more responsive and have less peaky drivability? Since they are both 4cyl, does the added weight/complexity of the turbo setup really help?

With unlimited mods on the 2L, what's the fuel-per-minute burn rate difference if you de-stroke with the 1.8L L8 crank to raise RPM, then punch the bore to bring it back to 2.0L?

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coaster
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Re: Full capacity or turbo parity?

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Sadly, the 1.8 and 2.0 share the 83.1 stroke.
Buying a 2.0 acheives the same result, 83 bore increased to 87.5.
The mzr has a list a mile long of devolpment parts available.

The turbo option for me brings into question the gearbox, without any mid range a 6 or 7 speed sequential much like a sports motorcycle.
The constant need for fast, multiple shifts to stay in a narrow power band.

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Big Tea
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Re: Full capacity or turbo parity?

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coaster wrote:
Sun Oct 17, 2021 5:07 am
Sadly, the 1.8 and 2.0 share the 83.1 stroke.
Buying a 2.0 acheives the same result, 83 bore increased to 87.5.
The mzr has a list a mile long of devolpment parts available.

The turbo option for me brings into question the gearbox, without any mid range a 6 or 7 speed sequential much like a sports motorcycle.
The constant need for fast, multiple shifts to stay in a narrow power band.
I suppose CVT is not an option?
When arguing with a fool, be sure the other person is not doing the same thing.

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Stu
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Re: Full capacity or turbo parity?

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What style of car is this going in? Packaging could be a concern.

30 years ago Daihatsu rallied a turbo 993cc triple cylinder in club level UK gravel rallying in the ‘up to 2000cc’ class with some success (it was group N if my memory serves me correctly).

Are you planning to short UK style Hillclimbs or longer, Continental type events.

Or…
Is there a 1600cc category that you can de-stroke the 2L engine down to (short-stroke screamer!!)
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coaster
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Re: Full capacity or turbo parity?

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Destroke is nice with a short deck height, most 2 litres will end with a 165ish conrod similar to a vintage small block chevy.
The fiesta zetec and the suzuki m16a are nice little motors well suited to the 1600 role aside from the cheesy crankshaft in the suzi (its hollow cast).
Most of the 1600 guys stretch the hayabusa with a stroker crank to 1500 and get the benefit of the sequential trans, the road going 1600 (2.0 destroke) has no chance against the busa, the valvetrain must be totally redone with motorcycle parts to catch them which sorta brings you back to the old busa engine.

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BassVirolla
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Re: Full capacity or turbo parity?

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I would start with some (possibly) known variables:

How much rpm / compression ratio can stand the tuned 2.0? At what rpms a tuned 2.0 achieves the maximum torque?

How much boost (MAP) can stand the 1170? At what rpms? What air speed is needed to achieve this air flow through 36mm diameter? What loose of pressure charge will produce such air speed through the restrictor? What ratio of turbine / compressor will achieve this "plenum" pressure at such air flow rate?

...

The turbo tuning has plenty of (starting!) questions to answer. But, while trying to answer them, the final decision could fall in place by itself.

I know I don't give you any answer, but I hope I've helped you, somewhat or sort of.

gruntguru
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Re: Full capacity or turbo parity?

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I suspect they will make similar power - around 250 - 300 hp.

The turbo engine will have a wider power band - can use much wider gear ratios - less gear shifting required. However it will have poor throttle response after a period of zero throttle (lag). If an anti-lag system is available - go turbo.

The NA engine will be more peaky and require more gear changes but will have instant throttle response.

Getting the turbo engine sorted will take more time and more skill.
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Jolle
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Re: Full capacity or turbo parity?

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Lot of variables to take into account. How long does the engine has to last and what’s the budget?
With the turbo being restricted in air (and therefore power), it’s easier and cheaper to get closer to its peak performance and made more durable with less trade-offs (because rpm is less of a thing). With the NA you won’t have a power ceiling as long as you can go for higher RPM’s, which are exponentially expensive and effect durability.

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coaster
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Re: Full capacity or turbo parity?

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Probably more towards budget with in house machining, bi metal motorcycle valves, steel buckets to replace hyd lifters, reduced base circle on cam, beryl copper bar stock probably cant be cheap, forged pistons cant be either.
Water jet cut single plane crank, forged factory rods with fresh bolts and resized bores.
Alloy flywheel diy.

Tommy Cookers
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Re: Full capacity or turbo parity?

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coaster wrote:
Tue Oct 19, 2021 11:41 am
.... beryl copper bar stock probably cant be cheap .....
for valve seats ?
or valve guides ?

I regularly ordered the stuff (well sheet or strip mostly) - but never had any idea about the cost
my last contact was about a special billet to XH heat treatment - maybe 10" dia x 60" long (didn't go ahead)

I think they now go to c. 2.8% beryllium (not in F1 use of course)

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coaster
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Re: Full capacity or turbo parity?

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Just the seats, guides are pretty cheap, not worth making and i can live with bronze.
Copper is strange stuff, its soft and yet if its struck in a flywheel press it wears the machinery at moderate pace.
It seems a natural choice for a seat and its heat transfer properties also.

Tommy Cookers
Tommy Cookers
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Re: Full capacity or turbo parity?

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coaster wrote:
Tue Oct 19, 2021 8:37 pm
Just the seats, guides are pretty cheap, not worth making and i can live with bronze.
Copper is strange stuff, its soft and yet if its struck in a flywheel press it wears the machinery at moderate pace.
It seems a natural choice for a seat and its heat transfer properties also.
well .... copper beryllium isn't much like copper
(iirc copper isn't hardenable by heat treatment)

it is/was also called beryllium bronze or spring copper
(older type bronzes may or not have had a substantial tin content - but CuBe doesn't)
the 2.5% or lower Be content was/is the limit of the 'carcinogen rules'

outstandingly strong and hard as well as very high in thermal conductivity - so favoured for valve seats
especially with titanium valves as it's non-galling

mostly I used the hardest grades but machining was good
or unhardened for forming it was then easily hardened by low heat (age hardening)

hardened and cold-worked I could take it to c.10000 ppm of elastic strain - better than any steel
so it might allow bigger valves than would any other insert materials