[1LE caSSper]

Driveshaft delivered installed & dyno tested from gforce1320.com manual transmission only

Finally got to check a lightweight driveshaft off my automotive bucket list. Overall I'm very pleased with the results before and after. Very very noticeable differences. Dyno test actually showed zero gain in whp I was surprised. We know driveshafts don't create hp but some say it 'frees' up hp like lightweight underdrive pulleys & flywheels etc.

Initial impressions: for $950 delivered the driveshaft out of the box from gforce engineering is beautiful, made to order looked great quality. Couldn't find any corners cut on production. It was solid! 1 piece , not nearly as lightweight as I anticipated or assumed, but the bicep test it was noticeably lighter than oem but not much. Side by side with oem it appears HUGE. Now I don't want to knock the stock driveshaft, which I forgot to take pictures of, is built well. I was shocked how well it appeared made honestly. The GForce shaft seems to save weight by eliminating the oem two piece design. Oem is basically 2 small driveshaft coupled together in the center with u-joints for flexibility and absorb harshness I assume..

Weight: oem driveshaft 20lbs - connecting plates & bolts 3.5lbs total 23
Aluminum driveshaft 17lbs - adaptor plates & anodized hardware 3lbs - total savings on rotational mass 3lb.
Install: very easy. NEED a lift & NEED a partner tho.
Drop the cat back exhaust, unclip npp valves & muffler hangers, unbolt passenger side pipes and wrestle the driver side slip in point in front of secondary cats and it's free. Couple small braces under the driveshaft and you have access, 30 minutes work to this point. The driveshaft removal & install requirea a a set of racheting wrenches 16 17 18 mm 10mm hex socket & torx50 socket I believe. Unbolt & replace it's very simple install. Total time 1.5 hour with beer breaks.

Driving tangibles: idle and revving and throttle response are much better. Car feels smoother and more natural. Was not able to read any mpg improvements I only put put to work down the street. Letting out the clutch normal driving 700-2500rpm the beast feels between 400 & 600 lbs lighter! Yes no exaggeration here. It's unbelievable the difference. Spirited driving I can tell no difference or top end gain on butt dyno. But low end feels great. The best comparison I can make is my track mode throttle now feels like a smoother twin of touring mode throttle map in normal traffic driving. Car feels very light from a stand still. Also able to use 6th gear at about 45mph without lugging or stressing the engine as opposed to about 47-48mph for anyone who care.

Cons: zero gripes, one thing as I expected -example engine braking in 3rd gear @ 0% throttle and quickly getting back on it not rolling info the gas there's a huge kick / shock. This driveshaft is solllllllid. Although overall driving and shifting gear engagement is smother, choppiness is less forgiving.

Great product gforce, wish it were lighter but no complaints I'll trust what they made 100%
9/10 review with couple pics of the install came out sideways I'm too lazy to flip em sorry lol

[EV2DEMON]

Driving tangibles: idle and revving and throttle response are much better

Maybe I'm misunderstanding. Are you saying that in neutral at idle, the car now revs more quickly?

[DFW1LE]

Why the weld at one end of the shaft vs a continuous seamless shaft? Seems like another point where it might fail.

[mjk3888]

Originally Posted by EV2DEMON

Maybe I'm misunderstanding. Are you saying that in neutral at idle, the car now revs more quickly?

If so that makes zero sense. The drive shaft has no effect on the car unless the car is rolling in gear.

[1LE caSSper]

Originally Posted by EV2DEMON

Maybe I'm misunderstanding. Are you saying that in neutral at idle, the car now revs more quickly?

I meant from idle @ stop light normal driving & shifting in traffic up to cruising speeds 40-55mph; car feels at least 400-600 lbs lighter...........

Full throttle applications I noticed no difference albeit the butt dyno is sooooooooo accurate right?

[Gville1LE]

Is there a carbon shaft on the market yet to compare it to? Bet it would be near double that price however.

[1LE caSSper]

I think only the automatic cars have one applicable I saw on phastek about it 12-1400 but doesn't work for 1LE's......

Also from my research carbon fiber shafts weight slightly more than the aluminum but as well are still 150% more resistant to
Snapping than aluminum units. Probably in the future coming with one I imagine

[TrackClub]

Butt dyno accurate? Not IMO.
Heck of a way to eliminate a 5 year power train warranty tho

[Chevy71]

Originally Posted by TrackClub

Butt dyno accurate? Not IMO.
Heck of a way to eliminate a 5 year power train warranty tho

Who gives a shit! I never trusted them to work on my cars anyway and it's a warranty to cover faulty parts like this two piece OEM driveshaft

[Snowblind]

Thanks for sharing

I am surprised the weight savings is only 3lbs.

[TrackClub]

Originally Posted by Chevy71

Who gives a shit! I never trusted them to work on my cars anyway and it's a warranty to cover faulty parts like this two piece OEM driveshaft

I don't like that weld on this "one piece" shaft - not in the least.
And $1000 plus install to save 3lb is pretty nuts if u ask me even if this didn't void a whole warranty.
But hey, that's just IMO. Peace

[RUQWIKR]

Originally Posted by TrackClub

I don't like that weld on this "one piece" shaft - not in the least.
And $1000 plus install to save 3lb is pretty nuts if u ask me even if this didn't void a whole warranty.
But hey, that's just IMO. Peace

Agree - 3#'s along a small diameter long shaft does not gain you much.

Critical speed will be MUCH less than the 2-piece stock shaft. The 13/ 14 GT500 had a large 4" diameter carbon fiber shaft to get around the critical speed, and it only had 3.31 gears. Remember that with a 0.50 6th gear, the driveshaft is spinning twice engine speed. It's spinning one-to-one in 4th. They say the shaft is good to "around 160" - probably in 4th. Read up on critical speed. A driveshaft coming apart at speed won't be a good thing. Not saying it will for you, but, it's your car and your mods.

FYI - it is much more expensive for an OEM to have two piece props with center carrier bearings than old school one piece. With the two piece really being two short one piece shafts from a critical / limiting speed, that's why there are in such things as our cars, ZL1's, CTS-V's, etc.

[crazydmc]

Originally Posted by RUQWIKR

Agree - 3#'s along a small diameter long shaft does not gain you much.

Critical speed will be MUCH less than the 2-piece stock shaft. The 13/ 14 GT500 had a large 4" diameter carbon fiber shaft to get around the critical speed, and it only had 3.31 gears. Remember that with a 0.50 6th gear, the driveshaft is spinning twice engine speed. It's spinning one-to-one in 4th. They say the shaft is good to "around 160" - probably in 4th. Read up on critical speed. A driveshaft coming apart at speed won't be a good thing. Not saying it will for you, but, it's your car and your mods.

FYI - it is much more expensive for an OEM to have two piece props with center carrier bearings than old school one piece. With the two piece really being two short one piece shafts from a critical / limiting speed, that's why there are in such things as our cars, ZL1's, CTS-V's, etc.

I never thought about "critical" speed...(maximum rpm's the drive shaft can handle I assume) The rear diff ratio is all that matters here... at 160mph it doesn't matter if you are in 4th or 6th... the drive shaft is still spinning the same speed.

[RUQWIKR]

Originally Posted by crazydmc

I never thought about "critical" speed...(maximum rpm's the drive shaft can handle I assume) The rear diff ratio is all that matters here... at 160mph it doesn't matter if you are in 4th or 6th... the drive shaft is still spinning the same speed.

Wrong. Your driveshaft speed on a rear drive (trans in front) is your engine speed divided by your trans ratio. So, in first gear, it is spinning significantly less than engine speed, in fourth (ours is 1.00 ratio), it is the same, but in 0.50 ratio 6th, it is spinning twice as fast.

That's why it is called overdrive because the trans output shaft connected to the driveshaft spins faster than the trans input shaft on the engine side.

With no clutch or torque converter slippage: Engine RPM / trans ratio = Driveshaft Speed