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I have a question regarding this video and please be nice as I'm a Nooby!

http://www.youtube.com/watch?v=dI9WdTS10C8

I also don't have a Drag strip where I live so I have absolutly no experience on Drag racing! (However, I do enjoy watching Pinks!)

Even though this guy is on the street and beating the crap out of his car, isn't this how people launch when at the drag strip?

Also, when people upgrade their turbo's to G35 and are making 450whp, say like the guys from Big Valley, have they changed their drive shafts? Because there are lots of vids of guys dragging their STI's against Vetts and Lambos who don't seem to break their drive shafts.... (Or am I wrong and they do?)

SO what's the different with this guy? What is he doing different here than someone would at the track?

He did like 5-6 hard pulls back to back, but is that any different than doing 5-6 hard pulls at the track over a weekend?

I have heard a lot of people talk about their 60ft times and it needing to be down in the 1.7sec area (I think). Well getting a time of 0-60 in 4.0sec, wouldn't that get you a pretty good 60ft time?

What kind of mods did this STI have? Say Cobb Stage 2? Well there area lot of other STI which are makeing WAY more hp... do they have issues with Drive Shafts?

The reason why I ask is because everyone always talkes about upgrading their turbos and maxing HP, but I have NEVER heard of anyone upgrading their Drive Shafts!!!!

So if this guy can break his drive shaft so easily, why haven't we heard more people doing the same with crazy HP STI's??

I just want to make sure I know the difference between what this guy is doing wrong to break his STI, and what the guys at the Track are doing Right NOT to break their STI's!



Anyways thanks for any imput!

Jay
 

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I can't check the video out from work but if it's of the black STi snapping a half-shaft, then there are quite a few reasons that could have happened. First off, that guy was definitely dropping the clutch. You can tell because the tire goes from completely static to instant rotation. With a quick-slip you'll see the wheel move slightly (or a 1/4 turn) and then spin.

It is well known that our rear half-shafts are designed with a weak point in them to apparently "save" the rear diff and tranny from harm. No one really knows exactly what causes the half-shaft to snap, but its very likely due to:

- drivetrain slack and then a clutch drop

and/or:

- too much traction and power being applied too quickly

Basically the half-shafts can only take so much twisting force before failing. Furthermore, like any automotive part, half-shafts can "fatigue" over time, finally reaching a point where they fail. This could be on your 100th launch or your 10th.

You can minimize the stress placed on the shafts by:

- increasing your tire pressure to reduce traction

- reducing traction by other means (i.e. wet tires)

- preloading the drivetrain before letting fully off the clutch; i.e. quick-slip vs clutch drop

- don't bog! Massive bogging when launching is horrible and very hard on your car. Pump the throttle to modulate the RPMs which allows you to launch harder.

As for Big Valley, they've broken tons of half-shafts (and even tranny gears) and are now running driveshafts from The DriveShaft Shop (http://www.driveshaftshop.com). If you want to make big power and continually do big launches (less than 1.8 60fts) you will probably want to upgrade your half-shafts.

For the most part though, drag racing *will* eventually break something, whether it is your tranny (unlikely in the 6spd unless you have BIG power), diffs, shafts, CV joints, engine components, etc. That old cliche saying "you've got to pay to play" holds true here. You want the best ET? Be prepared to cover the cost of an axle or diff.

Edit: I should point out that breaking stuff is not restricted to AWD cars. RWD and FWD cars suffer similar mechanical failures, though less frequently than an AWD equipped car.
 
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