I hope she likes driving an STR car! What did she say about the drive in Jim's car in Moultrie?

 

Why wouldn't the diff work for an 06+? The differential assembly has the same part number (41100-PCZ-003). I heard that they strengthened the carrier mounts a bit.

EDIT: I looked into it, and it works for both the AP1 and AP2.

 

Who knows if she will like it... just last week, she seriously considered buying Carpenter's ASP car when it was for sale. Anyway, if she doesn't like it, I will sell my car and drive it.

 

With the 07 Si the condition is simply timing. But like I said it has a plethora of maps, more than the S2K in fact and none of them fit the bill as nicely as one would like, the problem is rare because most people have a stock or lightly modded car and like I said every car is different. We spent 3 hours tuning my NA car, no timing was added or removed from the stock map, picked up a lot mid range(30+ft lbs), vtec is at 4k, a/f is at 12.8:1. I ran 13.9 1/4 mile with 3/4 tank of gas and -3 degrees rear camber so should run a 13.7 on a good day with the right setup.

I built my diff personally with PuddyDad's help, and $600 in tools . If you AP1 guys replace the entire unit I would recommend an AP2 housing. The casting process was changed and Honda claims it is %40 stronger than the Mazda designed unit. To retrofit the unit you just need to change the drive shaft coupler, install a new crush sleeve and you are done, but while you're at it I would go ahead and install 10.9 grade metric cap bolts so that really the only failure possible is the caps themselves. But the amount of torque to break the new caps is pretty significant, so no worry for NA guys.

I run a J's 2 way LSD, its manufactured by KAAZ, I bought J's because I got a hookup on it. You can tell the diff works better than the OEM. 2 way is supposed to help rear stability under hard braking, so 1.5/2.0 way will be a preference thing for most drivers. Usually if you are an aggressive driver most racers I talked to suggest 2.0 way. Tom actually experimented in his AE86 last year, he went from 2 way to 1.5 way and went back to 2 way because that was faster for him. KAAZ or Cusco will be the best LSD's for the buck. I have over 25k miles on my diff with 0 problems. So I'm pretty happy with the results. Now to just get more racing in this year If you or Dave are interested in building a diff I can put one together in a couple hours. Clutch type has a long life as well, I run the Cusco fluid, its expensive ($36/L), but is miles better than Valvoline with additive, I have tested this as well

 

Not legal to run any AP2 diff parts on an AP1 unless the part number has been superceded by Honda. There is no allowance to replace anything in the diff with anything other than OEM parts unless specified in the FSM.


I wouldn't touch a Cusco/Kaaz or a 2way diff with a 10' pole in an autox car.


Carbon clutched ATS or OSGiken are light years better for a minimal increase in price. 2 way clutches lock up way too much under braking and will cause a nasty entry push.

 

[QUOTE=BrianGT,Dec 22 2009, 03:31 PM] Why wouldn't the diff work for an 06+?

 

There was talk on RRAX about something inside the diffs being superseded and now the same for all models.

 

You cannot simply blame the 2 way for creating push, this comes down to driver style and suspension setup, my car is tuned for it and I have 0 push with 245/255 setup, my diff locks 100% accel and decel. 255X4 next season, fingers crossed . For example ASM's time attack car runs Tsukuba in 58 seconds and has a 2 way LSD, it is the world record holder for an NA car at that track and is faster than TOP Fuel's 500+hp S2000 by over a second. AJR's car holds the record for BW Cfg 13, they run a 2 way LSD and their record is still unbeaten, even though they didn't return to racing this year. Apples to Oranges of course comparing track cars to autox cars, as far as autox I guess we will have to wait and see what the National winner(s) are using and what they claim works best. I think all that really matters is what will work best for you, no one else. Where the 1.5 way will shine is in super tight corners.

KAAZ is one of, if not the largest LSD manufacturer in the world, LSD's have been around since the 1930's, so none of these companies are recreating the wheel. Carbon simply dissipates heat better and wears half as much, if you want your diff to outlast your car then buy up, OS Giken is a great LSD from all that I've read about them. I'm happy with what works and what gives me the best bang for my buck, for me that was KAAZ. As far as being light years better, no way, there is clutch design and the rest is pretty much the same, the design characteristics are simply too limited, the Giken is more than likely better, but $500 better? For a few tenths gained I am leery, factor in tires and driver error and a few tenths is pretty negligible to those of us just having fun. Grassroots Motorsports did some testing and the conclusion was just that, a few tenths, Giken being the fastest, it was said to be a very small tight course. Unfortunately a test like this isn't ideal for us and a better conclusion could be had with better testing. A track size more related to a typical autox and a few seconds then it would be hands down.

I have the new Super Q which is supposed to be a better/stronger LSD. http://www.kaazusa.com/superq/

There is some great info in these links.
http://www.kaazusa.com/intro2.html
http://www.osgiken.net/products/superlock.html

We are racing for 1 minute here, we're not generating enough heat to worry about, especially since we are NA. If the car sits for 20 minutes the differential is already cooled almost to atmospheric and it can take upwards of 15-20 miles for the differential fluid to warm back up to the 200 degree range on the street and that is straight from PuddyDad himself. It would be interesting to monitor the diff temps to see what they reach at an autox, maybe I will do so this summer, or if someone else, who is willing and has a pyrometer on the west coast could see what the temps look like after each run and tell us results, might mean a lot.

As far as rules I have no idea, I am way too illegal for this class, right now anyways, I was just offering my opinion/knowledge to those who might be interested.

 

Thank you s2ki for the ignore button.

 

[QUOTE=ShocK,Dec 22 2009, 08:11 PM]Grassroots Motorsports did some testing and the conclusion was just that, a few tenths, Giken being the fastest, it was said to be a very small tight course.