OxSMSxO

I see a lot of talk about this lately, and would like to get a technical perspective, couldn't find a thread that could answer my questions. This upgrade doesn't increase horsepower per say, but it does cut down on weight, and specifically rotating weight which from my understanding is the worst. So making the upgrade to a lighter driveshaft, lets say half the weight of stock, how much of a return would you see. You can put it in terms of equivalent to a ?HP gain, or how much time it would cut off a flawless stock 1/4 mile run. Just curious to know how much this upgrade helps, and is the return exponential?(As in the More HP you have, the better results it will yield). Sorry if my phrasing of these questions confuses you.

CrazyAl

As far as raw, constant, HP is concerned the driveshaft upgrade will give you zero. As you wrote, it is NOT actually changing the HP of the car it is reducing weight (inertia). Therefore the drag-limited top speed of your car will be unchanged. However, the reduced rotating mass will give you improved acceleration. I belive it is equivalent to 20-30 HP in a strict acceleration sense (in the 1/4). The return has little to do with how much HP you have. However, it does become more important as your operating RPM go up. So, if you had a modded car with a higher-than-normal redline, then it would become an even larger factor.

Lucy2005

Think of it as lowering your interest rate. Your "Principal" is your HP at the crank. The interest rate is the amount of HP you lose in the drive train before the power gets to the pavement. Lowering inertial weight, with things like driveshaft, lightened flywheel, and even wheels and tires, to an extent, reduces your "interest rate" and gets more of your HP to the ground. Similarly, other mods dont actually "Create" HP, but reduce strain on your engine, resulting in more HP, such as Turbo vs. Supercharging, electroc water pump, UD pulleys for those N/A out there, etc. Forced induction, for example, increases your actual HP. But turning the S/C actually eats up some of your potential HP. Thus, a more efficient S/C, with nothing else different in the amount of boost, will perform better, all else being equal, because it is less of a drag on the motor.

OxSMSxO

For the money then, why don't people do this more if in a acceleration sense its 20-30HP. If those numbers are accurate, for the money, this would be pretty much the 2nd best upgrade after Intake/Tune. Or is it because it doesn't acctually yield any HP, they don't get their bragging rights?

01RobGT

I know the drive shaft is my next mod after I do suspension. I have no idea why more people dont get it. Isnt it like 12-15 more hp at the wheels, Id like to see some dynos after driveshaft install. I know like to utilize the power my car already makes first. I got 4.10s 3 weeks ago and I love every min of them.

CrazyAl

I'd like to mention that I am not sure about that 20-30 HP number. That is what I have stuck in my head after reading about this for a while. There are past posts about the subject, hit the search and see. It may not be quite that high. 20-30 could be clutch+flywheel in addition to the driveshaft...

I think that a lot of people don't do it becasue it's not a very glamourous mod. A lot of people want mods that are plainly visible or sound powerful when they brag to their friends. A new air intake sounds a lot more impressive than a 1-pc driveshaft.

This happens all the time in car audio. People LOVE to buy new speakers/amps and so on, when a much better bang-for-the-buck deal is a sound deadening job, such as Dynamat. It's just not as "cool" to say that they deadened ther car as it is to say "I just bought new pioneers".

RED121572

Actually, my thinking is the opposite. The reason I havent gone with a driveshaft is because the cost is high for my wallet.

lukoi66

with drive shafts being 600-1000$ and the HP gains being spoken of being under 10HP in some case (alot of it depends on who's claiming the numbers I've seen on these forums), the cost/HP isn't as good as many would like especially when you factor in cost of installation for the more casual drivers out here or less experienced/technically savvy ones.

I'm one of the guys who doesn't have the mechanical skills to install one and be confident it's ok to drive, so I'm in that camp, but I'm definitely interested in the driveshaft option, just not at the cost/HP ratio it represents for me. I'll get much better bang for my buck with my current plans.

randy78045

I personally dont believe these claims of 20-30 hp gain... Nevertheless, there is a benifit... but it is a costly one for the little return one might receive... just my humble opinion...

Lucy2005

I think of it like this: Any mods that cut the drivetrain drag are going to be great mods, because you probably wont need to re-work them if you upgrade the motor more and more as you go along. Also, remember, that drivetrain mods are going to be necessary as you increase your BHP, because at some point stock parts are going to start breaking. Im not that heavy on BHP, but I already see the need for a clutch. If the clutch is out, it only makes sense to reinstall a lighter flywheel, and a lighter, or smaller, clutch, with a heavier pressure pate and better quality clutch disc. Same with Driveshaft- also, if you like to race, many tracks are going to require a driveshaft loop fairly quickly as your times drop- it usually comes right about the time they require you wear a helmet. May as well do it together. The driveshafts have been out for a few months, now, so the prices should be (and are) dropping as competition gets into the sale of the item, so shop around, and find a company you are comfortable with, and go fo it.