Anyone have info on a LSD for the sedan? I autocrossed for the first time this past weekend, spent a lot of time not putting the power down, I knew I should have waited for an 04!

I'm guessing I could get and 04 Infinity LSD put in at the dealer, but also guessing that is the most expensive way to go and probably not the best from a performance standpoint.

Am I guessing right?

What's the best way to go?

Thanks!


Mize

 

Not to mention, you won't qualify for the Solo2 stock class anymore, since an LSD isn't available on the '03's.

 

True, but I'm thinking STX, PAX factor is 0.795 vs. 0.794 for DS, I think mods can make up for no R tires so I can run in what we call 'sportsman' locally in Phoenix, any car is allowed, winner determined by PAX adjusted time. STX is now a full blown nationally recognized class for 04, so if I'm inclined to go to nationals I can go and don't have to worry about driving 1000 miles on R tires or hauling them...

Thinking I'll get some springs/shocks/sway bars, either 17x8 (with 245/45 Falkens) or 18x8 (with 245/40 Kumho Ecsta MX or BFG g-Force T/A KD) wheels pushed out to the corners as much as I can, maybe a few engine mods and I'm there.

I ran a 931 PAX first time out in my bone stock 6 speed, plus with the encouraging words from others on the board, I think the potential is there...


So... where do I get a LSD? Are there a lot of choices? What are the factors/different types avail?

recommendations?

Thanks,

Mize

 

Quaife America is supposedly working on a version of their automatic torque biasing differential for the G35. It works with gears, so there are no clutches nor variably-viscous fluids to degrade. It's a "bullet-proof" unit that is guaranteed for life, even under racing conditions. When/If they actually produce it, I'd guess it would sell in the $1,500 price range. I had a Quaife ATB differential on my '95 Maxima SE 5-spd, and it was outstanding.

'03 G35 5AT Sedan, Garnet Fire/Willow
18x8 SSR GT1/Bridgestone PP S03 225/45/18Y
Eibach Pro-Kit Springs & Anti-Sway Kit
Stillen Cat-Back Dual Exhaust System

 

Search in the Technical & Modification section. There's a Nismo LSD that a couple have fit.. but it's not a direct drop-in and requires a couple of mix-n-match parts to make work. Kaaz has one that I think someone has tried.

Ahh, yes.. STX. Glad that made it in, but I'll stick with DS for now. Partly because I'm not good enough for mods to affect my times yet (gotta reach the limits of the car in stock form before throwing money at it), and partly because it's a lease and I'm not so sure I'm going to want to keep it in a couple of years with all the new competition in the sports sedan field these days.

 

ryoken,

I ran in STX this last week. I totally blew it though because I ran with "R" tires and their not allowed. I didn't know. So I'm on my way back to ESP. Jason said I should send an email to SCCA to get them to classify the G35 sedan like the coupe. They have it listed in BS right? Maybe I could get them to allow me to run BSP. ESP is a tough class. I think that BSP may be better. What do youthink. Man I really need to get a SCCA Solo II rules book. BTW I say John out at the event this weekend, it was a real treat to drive in the rain. It started just as my run group went out for the practice.

Base 6MT Silver sedan
Stillen Exhaust
Stillen CAI
Eibach Pro Kit
Eibach Sway Bars

 

You don't want it classed like the coupe. The coupe runs BS stock, the sedan runs DS stock. DS does not equal DSP, BS does not equal BSP. Actually, since the coupe is not yet classified, I think it falls under ASP by the catch-all rules.. which is not a good place for it.

We run in ESP with mods because the G35 Sedan is not specifically classified, and falls under the "Sedans, over 3.0L" description. Different cars are competitive in different places in different years.

Yes, the ST classes are for Street Touring.. hence, street tires, as you've discovered. Locally, we run Improved Street classes with racing rubber allowed.. you'd be in IS1, unfortunately running against stiff competition there, as the local rules equate twin cam = forced induction or 2 extra cylinders. There's at least one Corvette running IS1.

The thing about autocross is that you either go to have fun, or you specifically prep your car for a particular class to race in. Your best bet would probably be to put the stock intake back on the car and drop to DS, if you're worried about competition. I wouldn't worry about it at this point, just run in ESP and wait until you can run at the limits of the car before figuring out where you might be competitive. Just worry about getting some seat time and improving your skills for awhile.

 

A couple of you have the Eibach springs and sway bars, how are they? What did you do if anything for alignment? Is camber adjustable on our cars?

 

thanks for the info, I emailed quaife for an update...

why do you have 225s instead of 245s on your 8 inch rims?

any pics of the ssr gt1s?

Thanks,

Mize

 

The stock viscous limited slip diff would probably slip too much for your autocrossing needs. The Nismo kit on performancenissanparts.com will fit, and has all the parts you need assuming you have a 6MT. If you have a 5AT, I think that site sells a kit over the phone that has the extra stuff you need.

I watched the guys on Spike TV's Power block install a posi-differential on some muscle car. Definitely not a DIY.

Drew
2003 G35 Sedan 6MT / Black / Graphite / Prem / Aero

 

Thanks!

Yeah, have a 6 speed. So the Nismo will be better than the 04 stock LSD? Would the Quaife be better than the Nismo if it existed?

Mize
Silver 03 6 Speed/Willow/Premium

 

Ok, a lot of info to cover, sorry if this is long, pm me or post a reply if any part isn't as clear as you'd like

I did the oem viscous swap on my 03 6mt sedan. And two other members have done it as well. Their is of course two ways to accomplish the swap.

1. Somehow get ahold of a complete diff assembly out of a donor Z or G, good luck finding a whole diff to do this, how gurgenpb located one for his car is beyond me (hat's of to ya man). I was told that to buy the complete diff at the Nissan parts counter of cost me $1300.

2. Swap in the specific parts required into your diff, which is what I did. I stumbled onto a oem vicous diff core assembly for $100, it came off of a showroom car so it only had maybe 15 miles tops, same part at the Nissan parts counter cost's $600 at a discount. To that, with my car being a 6mt, you have to add, new stub axles, part numbers 38220-AR011 and 38220-AR010. 2 Oil Seals ment for a stock limited slip equipped diff part number 38342-P9010 And 2 Differential Bearing assemblies, also ment for a limited slip equipped diff part number 38440-0C000, total cost in extra parts is $400, not including the $100 I paid for the vicous assembly. Cost to remove my diff, swap the parts in and adjust (critical) cost $400. My total VLS parts swap was $900(*see note below)

Now, if you have a automatic equipped car and you are doing the parts swap or installing a clutch type aftermarket LSD you have to also swap in the ring and pinion gear set off of a 6mt car, additional cost for those part is $500. This is in addition to all the above noted cost's.

* When we talk about doing oem LSD swap's into these cars one thing I have to say is, IMO the return on net investment with the oem vicous system, does not come close to matching your costs to net improvement ratio. I did not get $900 worth of improvement, not even close. Yes it's better than an open diff, but $900 better, no way. It allow's way to much slip, keeping in mind that is HAS to, since that allowed slippage is how the visous medium stiffen's to lock up, but in the mean time the slippage it does allow, is to much.

Ok, so now what? You can swap in a clutch type LSD, which is a superior device for limiting slip(has some drawbacks, will discuse in a little bit) or you can wait in hopes for Quiffe to come up with a gear type LSD, I for one certainly hope Quiffe does bring one out.

What are the drawback's to the clutch type LSD? First thing to know is that they require break in procedure that is long and involved, failing to do the break in can result in premenant damage to the diff and excess noise for the life of the diff. Even when broken in properly, a clutch type LSD will make noise in slow speed parking lot manuver's. This noise issue gave us the 3rd person that has a oem viscous swap, Lead_Foot. He had the Nismo LSD, but he couldn't stand the noise it created in daily life and he found a Z local Z owner and swapped out for his oem VLS. Another fact about the clutch type LSD is that they do need regular changing of the diff oil, much more important than on the oem diff, reports vary on how offten, from changing it every 15k to 3K.

I want to explain why someone would want to go with a clutch type, someone not willing to wait in hope for a Quiffe type. The limitations I describe, I very much run into and are why I'm less then thrilled with my $900 investment, I was hoping it would perform much better than it does. Also, keep in find that my assement does not come from the track, nor do I have "R" compound tires, just everyday spirited driving.

The stock viscous limited slip works by immersing a series of round plates, alternately attached to an axle or the differential housing, in a fancy viscous goo. The plates in a viscous limited slip don't actually touch each other. Instead, they are separated by a thin film of this viscous goo. When you go around a corner, and theplates start turning at different speeds, the goo trapped between them heats up. The viscious goo expands and thickens under this shear load,
making it more difficult for the plates to go different speeds. While the fluid tries to lock the plates together, the tires try to rip them apart. At low speeds and gentle turns, the fluid doesn't get thickened much and the tires win (remember that point). Boot it at a stop and try to spin one tire and the plates suddenly are going dramatically different speeds. The fluid thickens just as dramatically and, with the stock tires, the fluid wins, locking both rear tires together. A little less throttle and you have the smooth, seamless acceleration Nissan engineers had in mind. If you have really sticky tires, though, the tires win, and the long, gooey molecules of the stock
diff's viscious snot get sheared into smaller, less thermo reactive visco-thickening stuff(I think this is all to easy to accomplish). Apply power in a corner results in a moment of inner tire spin before the sheared and demoralized fluid gathers the courage to rein in the inner tire. Viscous limited slips have inherent limitations in how much torque they can transfer through their fluid medium. Conventional, clutch-type limited slips, however, can be built to handle the massive torque loads of racecars on slicks. They tend to be less refined and seamless than viscous units, but they are more capable since the real magic of a clutch-type limited slip,
however, is how the clutches are pressed together harder under load The more torque you apply, the harder the clutch plates grab. This is the fundamental difference between a clutch-type and a viscous limited slip. The stock viscous diff responds to a difference in wheel speeds, relying on the slipping plates to heat the fluid and tighten, which means it must react to wheelspin after it begins. The the clutch type responds to torque, so it reacts before the inside tire
has a chance to spin and is hence more effective as a slip limiting device.

Sorry for the long post.







"All that's necessary for the forces of evil to win in the world is for enough good men to do nothing.”
Edmund Burke

G35 6mt

 

cwmizner ()
02/17/04 08:56 AM

Thanks!

Yeah, have a 6 speed. So the Nismo will be better than the 04 stock LSD? Would the Quaife be better than the Nismo if it existed?
__________________________________________________ _
Yes and yes(not really wanting to get into a gear type vs clutch type debate, but I'll still side with the Quiffe gear type).

For 03 owners the Nismo LSD come's with all those extra parts required to do the swap ( any year of automatic equipped car will still have to purchase a MT ring and pinion gear set).

"All that's necessary for the forces of evil to win in the world is for enough good men to do nothing.”
Edmund Burke

G35 6mt

 

I'm personally going to get the stock viscous LSD when I upgrade. I've already set something up with a 350z owner looking to upgrade his stock lsd. Before Gsedan35 jumps on my *** about this one, I'm only going to do it if the price is right and he'll include the stub axles and differential bearings. If not, then no deal, I'll get the Nismo and turn my stereo up.

Drew
2003 G35 Sedan 6MT / Black / Graphite / Prem / Aero

 

Awesome info, thanks!

Is the Quaife noisy also? Is there any down side to the Quaife (besides price and the fact it doesn't exist, )

Mize
Silver 03 6 Speed/Willow/Premium