So I was doing some surfing this morning and ran into an advert about a racing performance shop offering services in welding the differential. This is what they reported; "We use an 1/8 inch thick square of steel to weld in between the spider gears so there is no possible way the welds will break. This is a cheap alternative to buying an expensive LSD and works great for drifting and drag racing with both wheels locking to the ground." Wondering if anyone has ever heard of this, as I know many people have upgraded their LSD on the SC430 for more torque (ie. power to the wheels). Looking forward to hearing everyone's thoughts. Thanks!

 

It's fine if you just use the car on the track. It would be a real nightmare on the street. An lsd still allows for the inside wheel to turn slower during a turn. You won't have that with a welded differential. You will be chirping that inside tire when turning.

 

remember the old Ford 9in Detroit Locker?

 

If I understand you post, it sounds like they are permanently locking the differential. For drag racing, this would work well. For every day driving, it would be a disaster.

First a basic discussion of what a differential does. You drive shaft transfers power from the transmission the a rack and pinion gear. This turns the power 90 degrees to the drive axel which connects to the wheels. This works well when driving straight down the road as both rear wheel are turning at the same rate. The problem comes when you need to turn. If you picture you car making a tight circle, the rear wheels will make 2 circles. The circle made by the tire on the inner side will be smaller than the tire on the outer side. Therefor to make a turn the outer tire will have to travel further (turn more) than the inner tire. If you have a solid axel with no differential something will have to give. So one tire will have to be dragged across the pavement. Every time you went around a turn the tires would squeal and your tire life would be very short. An open differential allows the wheels to spin at different rates. There are other sites that will show you exactly how they work. The bad part of an open differential is that it is uncontrolled. If you loose traction on one rear wheel (like snow) it will spin while the other remains stopped. From a performance point of view, When you try to put 300 HP to the ground all at once, you are limited by the adhesion of the tires to the road. With an open differential once that limit is exceeded on one tire, the tire spins and all the power is transferred to the spinning wheel. A limited slip differential (LSD) is just that. It has a way of locking the differential once significant slippage is detected. There are several types. So when you put 300 hp to the wheels power is always transferred to both wheels so you have more grip and more go. However, when making a turn the LSD will allow the wheels to turn at a different rate, sparing you tires. Of course you can apply enough power and overcome the traction on both wheels and this is where electronic traction control come in.

As to welding the spider gears. If you have a dedicated drag car, one you transport on a trailer to the strip, this might be an option. Otherwise no.

 

<br /><br /><br /><br />they still unlock during turns. A welded differential would not allow that.

 

true, the conversation reminded me of the old locker and I knew you would remember them ;-)...I heard they would still chirp the tires during turns.

 

a lot of broken axels too. Great for off-roading though.

 

Yeah don't do it for a car on the street. I know a lot of budget drift guys who do it. But those cars on the street churp doing low turns. Also in the rain a welded diff will likely cause you to spin out.