Tuesday, June 8, 2010

The next time you think of selling your NSX, READ THIS!

"Everyone is different, but I can say that after owning an NSX, I 'get it'. I understand the exclusiveness when it comes to the rarity of the car, the aluminum body panels, the Senna influence. I truly feel that it is one of the last greatest sportscars to come out of Japan."

What a great quote, taken from a thread on NSX Prime called "The NSX is stupid!!!", a sarcastic admission by an ex-NSX owner crying over why he still misses his NSX after selling it a while ago. The writer in this case is a guy who sold his NSX, bought a Ferrari, realized he made a mistake and is about to sell the F-car for another NSX in the coming weeks. Hahaha!

Thread is here

Wednesday, June 2, 2010

New fluids,better handling, less restrictions, MOAR NSX!

Took the NSX to Mike and Derek at Autovation last Friday for a 2 day jobber and car came home feeling noticeably better.

At NSXPO last year it was stressed upon us that the MTF needs frequent changing in these cars, which for some reason accumulates a lot of gunk in it in a short amount of time. We were also told that the best fluid is Honda white cap. So, stopped off at Honda, picked up a box of the stuff, a new filter, a few litres of Mobil One 10W30 and a crush washer. :)

I also ordered a set of Dali 1" front and rear swaybars (in fancy anodized red) and picked up a used set of Prospeed HiFlow Cats from Big_D on NSXPrime.

What a nice improvement. First thing I notice is the SOUND. A nice, deeper grumble in low rpms and a nice wail at high revs. Nice. Handling, the car is noticibly crisper. I had them set the rears at full soft and front at 50%, as recommended by a few people on Prime with the sways. I'll report back on them after the next track session in mid-June.

A bit of sage advice from "shrddr on Prime re: sways:
think about what a sway bar does... it connects the spring/shock from one side to the other. the logical question to ask would be "why would we want to do that in the first place?" well, the answer to that is that we would like to limit excessive body roll, but we want to do so without sacrificing ride quality. so instead of using crazy stiff springs to limit body roll, which would also make the ride really stiff and bouncy... car manufacturers can use more reasonable spring rates which keep the ride compliant, and use a sway bar to effectively get a higher spring rate when the car is cornering.

you with me?

so now... think about what happens because of a sway bar when the car corners. let's say you are taking a right turn... which means the car will lean/roll towards the left. so the left side springs will be forced to compress, and the right side springs will extend. BUT... since the 2 sides are connected by a sway bar... the forces oppose each other! the extension of the right side spring make it harder for the left side springs to compress... and similarly... the compression of the left side springs makes it harder for the right side springs to extend. the net result is that the since the springs extend/compress less... the car leans less i.e. less roll!

let's clear up one common point of confusion. body roll and weight transfer are NOT the same thing. you can eliminate body roll 100%, but guess what, weight transfer is still going to happen.

now that we have that cleared up... here's the critical thing to understand. a sway bar actually transfer even MORE weight from one side to the other. the way to imagine this is to think about it as if your car had no sway bar at all. when you take that right turn, the left side spring will compress, and the right will extend, and both tires will maintain a good connection with the ground. but with a sway bar in place... recall that the extension of the right side (inside wheel) is limited because of the sway bar which is connected on the other side to a spring that is compressing... and so the inside tire ends up with LESS weight on it. which means the outside tire has to support MORE of the car's weight. and hence... greater weight transfer.

more weight transfer means... LESS GRIP! the gain in traction that the left/outside gets from the additional weight on it is less than the loss in traction that the right/inside get from the weight taken off. you would think the gain/loss would be equal... but turns out that is not true due to the properties of rubber and how it adheres to the road.

so the net result is that a bigger sway bar causes more weight transfer... and thus REDUCES grip.

a bigger front bar will reduce front grip... and thus reduce oversteer or increase understeer.

a bigger rear bar will reduce rear grip... and thus reduce understeer or increase oversteer.