Y2KevSE

iTrader: (13)

Difference between viscous, quaiffe (sp?), and helical LSD?
http://forums.maxima.org/showthread.php?threadid=45787

What does the valvebody recalibration do and why do I need a cooler?
http://forums.maxima.org/showthread.php?threadid=45794

How can a torque converter improve my performance and what does it do?
http://forums.maxima.org/showthread.php?threadid=45795

Why should I get wider tires? Does it improve my handing?
http://forums.maxima.org/showthread.php?threadid=45797

Do slotted or cross drilled rotors give me better braking power? Or is it just for show?
http://forums.maxima.org/showthread.php?threadid=45798

What purpose do stainless steel braided brakes lines serve?
http://forums.maxima.org/showthread.php?threadid=45799

Do coilovers make my car handle better than aftermarket springs? Why is that?
http://forums.maxima.org/showthread.php?threadid=46034

Answers will be FAQ'ed and credit will be given. Thanks!

Sprint

iTrader: (10)

Y2KevSE

iTrader: (13)

<SprintMax in action>
*slurp* *slurp* *slurp*
</SprintMax in action>

Jeff92se

iTrader: (82)

$20!

gtr_rider

iTrader: (50)

PM me when your done

Dave B

Answers:

Differentials:
There are LSDs, helical, open, and locker differentials. LSD means "limited slip differential" which means the wheel that is not spinning will have a certain percentage of power directed to it. LSDs are viscous (sp) which means they operate with fluid clutches. Only about 20-30% of the power (torque) is directed to the wheel that isn't slipping. A helical differetial directs even more torque to the non-spinning wheel therefore making it a notch better than the LSD. I believe the helical is a gear driven setup (ie no clutches). Locker differentials are used in drag cars. Locker means the both axles are tied together making for perfect straightline acceleration (dragster use these). Lockers aren't streetable because you can't turn. Open differentials are what most cars use including most Maximas. When one wheel begins the spin, more power is directed to the wheel that's spinning making the spin even worse (not good for drag racing or on a slick surface).

Valvebody upgrade:
This adjustment makes for quicker shifts reducing the wear on the clutches. Shift feel is improved, but with an increase in harshness. This setup is actually better for the tranny than stock because less heat is involved on each shift (stock = more slip, more heat). A tranny cooler isn't necessary because of the upgrade. A tranny cooler should be a standard piece on ANY automatic. Period.

Torque Converter:
An automatic is not mechanically connected to the transmission output shaft like a 5 speed unless the torque converter is "locked" while cruising in 3rd or 4th. The auto relies on hydraulic fluid to accelerate the wheels not mechanical gears like the 5 speed. The auto does this by way of torque converter (torque multiplier). Torque converters are extremely complex. The higher the stall speed, the higher the WOT launch rpm. Stall speed is the rpm at which the torque converter begins to accelerate the car at WOT. Inside the torque converter are to propeller vains. Vision two fans facing each other. When you turn one fan on, the other will start to spin. The same thing applies to the torque converter. Instead of air being the media, fluid is the media which turns the propellers. One propeller is connected to the tranny and the other to the motor. Higher the stall speed, the more resistant the propeller is to spin intially therefore giving more torque multiplication. A byproduct is more heat and this is why you need a cooler. Higher stall converters increase launch ability, but they make the car feel a bit sluggish at part throttle because the converter is always slipping a little until you go WOT. Torque converters only help on launch. At cruise, the car is drive no differently than stock. Buying a high quality torque converter ($500) is mandatory. A cheap one will slip way too much and possibly destroy the tranny.

Wider tires:
Wide low-profile tires are good for cornering. The contact patch is wide, but narrow. Wide-low profile tires aren't good for off-the-line acceleration (look at dragsters) because they lack the ability to bite off the line. Narrow and taller tires have a long and narrow contact patch which is good off the line acceleration and driving in the snow. Which do you want? I'd say the best handling setup for the Maxima would be a 215/55R16 with Z-rated tires.

Slotted and cross-drilled rotors:
Pretty much for show unless you consistently stop from 120-70mph on a regular basis. Cross-drilled and slotted rotors have been shown to increase 70-0mph stops, but with little fade. From a 120-70mph stop, they are superior, but how many people drive like this and WHERE? THese "big brake" kits are also heavy which means more unsprung weight and slower acceleration. Buying a cheap set of cross-drilled and slotted rotors is a no-no. You get what you pay for.

Stainless steel brake line:
They work. They improve brake feel, application, and heat transfer. A definate best buy and worthy upgrade.


Dave

Y2KevSE

iTrader: (13)

Thanks Dave.

Jeff92se

iTrader: (82)

Dave. It was under my impression that some of these "big brake kits" are actually lighter than the stock cast iron single brake set-ups. The Wilwoods are aluminum correct? I know the 300z TT brakes are available in cast iron(heavy) and aluminum.

Sprint

iTrader: (10)

dave.. Bill will be proud of your use of the search feature

Y2KevSE

iTrader: (13)

Bump

Y2KevSE

iTrader: (13)

Any other input?

bill99gxe

iTrader: (1)

<tears of joy for Dave's research>



</tears of joy for Dave's research>