Mods to reduce drivetrain power loss?
 

Been thinking about mods that could help reduce drivetrain power loss (I think stock is about ~15%?) for these cars...

1. Lightweight driveshaft (leaning toward CF to reduce rattling, ~9lbs lighter than stock)
2. Lightweight wheels/tires (TWS T66-F 17inch and Dunlop SportMaxx RT, should reduce about 9lbs per wheels compared to stock)
3. Possible lightweight pulley set (not sure how this will impact the car, but not planning on touching the flywheel which may make the car harder to drive in traffic)

Any other ideas? :iono:

Lose weight yourself, then gut out your car. Replace body parts with carbon fiber, lexan glass.

If your still worried about power loss, sell car get a motorcycle.

Convert to a transverse mounted I4 engine with transaxle gearbox for best reduction in drivetrain power loss...

:lol:


Flywheel is a great mod, I've yet to do it for the FR-S, but do plan on it...won't ruin daily driveability. Had an 8lb ACT Prolite in an Integra before and it was perfectly well mannered and daily driveable...even in stop and go traffic jams. Lot more getup and go in the first 2 gears....2nd gear was a blast!

Other than that the only other things possible for driveline loss reduction is the driveshafts, bearings, and fluids (engine oil, transmission, and differential)....

Mods to reduce drivetrain power loss?
 

Do 1 & 2. Light weight pulley don't do anything other then makes you feel good. 😁

Rear axle too. Any other stuff is super expensive.


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Well you did mention wanting to keep the car easier to drive in traffic so I assume you are looking to improve performance and not mess too much with its daily driver appeal ie NVH levels and ride?

I'd research some basic weight reduction ie removing the spare wheel or switching it to a space saver, if you have a full size wheel in the boot (like my BRZ does). I hear switching the battery out for a lighter one is a good move too.

Then look to the drive shaft, as you mentioned, but I was thinking of an aluminium one rather than CF. You mentioned they rattle? First I heard of this and CF ones are a good deal dearer and not much lighter.

I'm a big fan of upgrading the FD ratio. That speeds up each gear like a 4.556 makes each gear roughly 10~11% faster or so.

Then look to lighter wheels / tires and possibly coil overs with a bias towards better ride (more of an NVH impact).

None of the things you mentioned actually reduce the drivetrain losses. They only reduce drivetrain inertia. Which is good, you'll get a performance benefit from it. But to actually decrease drivetrain loss is much more difficult, and kind of tricky. You're looking for ways to decrease friction in the engine block between the rods, pistons, cylinder walls, transmission gears, rear end gears, etc. Aside from using different viscosity oils, you would have to be willing to rebuild the whole engine and drivetrain. Your drivetrain losses are pretty much set from the factory.

The FR-S will be a DD for me, I want to improve the performance of it with mostly bolt-on parts (at least for now) and don't want to mess with the drive-ability or NVH much.

I have been reading about after market driveshaft and looks like the aluminum one is a little lighter than the CF ones, but the CF ones are said to be better at absorbing rattling and vibration compared to aluminum, both should be considerably lighter (8-9lbs) compared to stock. I will keep the car NA so I think CF should be sufficient.

Already thought of wheels and wires, TWS T66-F wheels, 17x8, et42, weighs about 13.95lbs, and should clear BBK and discs up to 345mm. Will probably go with 225/45/17 Dunlop SportMaxx RT, which weighs about 3lbs less than stock Primacy HP.




I think drivetrain losses is not the accurate word here(I sucks at physics), what I meant was to reduce the drivetrain inertia and therefore improve the WHP and responsiveness because of less rotational mass....fail on my part :lol:



Thanks, I did some more reading about pulley and looks like they are a waste of money like you said, probably will cross those off my list now :D



I heard some light weight flywheel may mess with driveability, if you ever do it for your FR-S, I'd like to hear your experience :D


Working on losing weight myself now :bellyroll:

Lol my fatass needs to start working out

get motor mounts. less wheel spin and I swear i feel a little regained power shifting into 2 with wot

Just like TorqueMan777 mentioned, thread title is misleading, as most posts were more about reducing rotational and rotational unsprung weight. It will net better acceleration/braking, but none of that is related to drivetrain power losses, which is mostly made up from friction in engine parts/gearbox/diff/multiple bearings/rotational resistance of tires. Most of those with exception of maybe tires are not easily changeable (and stock oem primacy tires to begin with are eco low rolling resistance tires, so most probably tires with higher grip and wider thread width will add to those losses).

But regarding to reducing rotational & rotational unsprung weight most including you were writing of:
1) go for TWS T66-F 16" wheels for even more weight savings (imho there are lighter forged wheels then these in 17" size), don't go for too wide wheels and too wide tires.
2) add aftermarket BBK kit to save weight also on brakes
3) your mentioned CF driveshaft
4) lightweight crank pulley. Little to no gains from other small ones.

And few other generic weight reduction items:
1) aftermarket exhaust (gaining also extra power/torque alongside)
2) soundtube delete
3) reduced volume window washer liquid tank
4) lightweight battery
5) lighter suspension components
6) lighter body CF components like roof/doors/bonnet/side mirrors and so on ..

Rest of items to reducing weight depending on how far you are willing to go/how much comfort you are willing to give up:
0) generic choice of car at lower trim with unheated cloth seats/without fog lights/few other extras of higher trims
1) racing seats (maybe just one, with delete of passenger seat)
2) rear seats delete
3) AC delete
4) audio delete
5) sound proofing delete
6) interrior panels delete

As last batch is usually done for track-only cars, then there probably will be some weight added back by installing rollcage, possibly some aero elements (like wing, splitter, side skirts), brake ducts, oil (and maybe diff) rad addition, possibly wider tires then stock.

What are the lighter forged wheels that you mentioned? These were the lightest one I could find from a reputable brand that's known to be compatible with BRZ/FRS and BBK. 16s would be sweet but thought that may put a lot more limitation on the BBK setup that I could go with.

My dream set of wheels - BBS RF 17x7.5 +48

http://www.ft86club.com/forums/showthread.php?t=12621

http://www.tirerack.com/wheels/Wheel...+Black+Painted

$515 USD a wheel on tirerack - 14.3lbs (Forged)

You can fit the existing 215's on them and, once you use up their tread, go to 225. Both will comfortably fit on that rim and its design with thin spokes makes it look like an 18" without being one. Also reading through the thread you will see they clear Brembo's.

Thanks for the info, that's definitely a set of wheels that I would look into besides the T66-F. As for BBK I'd probably go with some Project Mu stuff instead of Brembo :D

Low-friction wheel bearing.

SKF is now OEM supplier for Mazda2 and Honda Civic with low friction wheel bearing, see:

http://www.bearing-news.com/the-new-...s-co2-savings/

I have not see any low-friction wheel bearing mod available specifically for FT86, but there are racing shops that offer to install low-friction ceramic balls to fit any OEM wheel bearing.

Light-weight lug nut. OEM lug nuts weigh about 60g each (if I remember correctly), a set of ultra-light lug nuts, at 25g each, will save about 175g (about 6 oz) of rotational and unsprung mass per wheel.

One last item: a friction modifier, eg CERATEC by Liqui Moly. I know, it sounds like snake oil. Anyway, it is cheap and should not do any damage. I actually tried it myself, and it seems to work. I did not take a pre- and post mod dyno comparison, but fuel consumption did improve (under similar driving condition), so I conclude this snake oil works (since there is no change in all other variables).

In principle, these (fairly inexpensive) items should help reduce power loss in the drivetrain.