Need more traction (and your opinions)!

[freakyjason]

I'm not quite sure where to post this seeing as it could arguably be put in suspension/wheels, brakes/tires or engine/drivetrain so I'm going to post in here. Anyway, I just got back from the track for the second time and and realized that i was not quite pleased with my cars performance through the turns. Fisrt of all, it's an s13 hatch with toyo t1r's on the rear (245/40/17), stance gr+ coilovers, front and rear strut tower braces, front tension arm brace, stock differential and rear sub-frame brace. I'm running about 2.5 degrees of camber in the rear. The problem i had was when i went into a really tight turn and then began to accelerate through the apex, the inside tire (one with least traction) would start to slip like crazy and the other tire would do nothing. My first thought was the differential. But then i started thinking that it might be a number of things including the drastic shift in the cars weight. I was thinking of experimenting with different spring rates (i am running the 8/6 setup right now), maybe something along the lines of a 12/10. I was also looking at the s15 hlsd. Is this a good diff for grip driving? I saw this http://cgi.ebay.com/ebaymotors...ories for sale on ebay and figured that I could just buy this and drop it into my pumkin (since it was made for an r200) and still have the same final drive as I do now which is what i want. Is there any reason why this would not work? Also, i really want to continue to run these tires until their dead which will probably be a while. I know they're not ideal. Sorry for the ramblingness of this post.

[AZ89two4Tsx]

Wow, I doubt anyone but a few in 240gen would have any idea how to help you.

I would try posting this in the 240sx tech or maybe even gen chat.

[freakyjason]

Wow, You're all over my threads today!

Wow, I doubt anyone but a few in 240gen would have any idea how to help you.

I would try posting this in the 240sx tech or maybe even gen chat.

True, I guess I'll do that. Hope the mods don't yell at me for posting it twice

[adrianfromthecastle]

its your differential... plain and simple as that.

If your serious about racing, I wouldn't even consider getting a VLSD, as those are really only good at locking for a short period of time (till the diff oil gets hot and loses its viscosity).

hlsd, or some kind of mechanical LSD is what you should look for. and in your case, probably a 1.5 way diff.

[freakyjason]

its your differential... plain and simple as that.

That's kinda what I figured, but I didn't want to dump a whole lot of money into a diff and realize there was really some other aspect of the car I could have addressed before that would have made a considerable difference. Is the s15 hlsd a good option in that case?

[adrianfromthecastle]

well, there are other factors such as subframe bushings, differential bushings, etc. that'll help your wheels stay on the ground and get more traction... but your situation does sound like its the diff itself.

Is the s15 hlsd a good option in that case?

yes. Made for gripping, not for oversteering

[RMerritts]

i would try a stiffer rear sway bar or stiffer rear springs, could also toy with the valving some with the coilovers, i have the SSD's from stance on mine with the stiffer springs, you could also try that, the stiffer springs are only like $40/ea or something like that.

[maryjane]

it your diff, im using a kaaz 1.5 way, cant complain about its performance but its noisy as hell for a d/d

[sr20power]

I would suggest the differential first. Cuz even if you upgrade all the bushing/sway bar/springs or whatever. Your differential will NOT change the way its supposed to act.

To cure the wheel slipping during hard cornering you are going to need some type of LSD. Cheapest I would suggest is the stock VLSD.

[freakyjason]

Cheapest I would suggest is the stock VLSD.

I am on a budget, but I don't want to cheap out with a vlsd. I'm pretty serious about making this thing into a force to be reckoned with on the track while also being a somewhat streetable ride. I'm going to look into the kaaz 1.5 way and the s15 hlsd some more. Are all s15 diffs the same ore is there a difference between models like the different spec s15's?

[sr20power]

Don't take my word for it, but I believe they are all the same. Doesn't matter about the model.

[Space Monkey]

I think they are all the same. I would go for the Helical Diff. Made for grip and it works 100% of the time your driving! It does not run out like a clutch type or VLSD either. It should last the life of your car is treated with care. I mean change the diff fluids frequently if you're tracking it.

[Nismo775]

Don't take my word for it, but I believe they are all the same. Doesn't matter about the model.

ditto. i just got a n/a 93 300zx vlsd for 140 and i cannot complain. 10000 better then open dif

[supreamS14]

For road racing I would get a s15 hlsd. The outside wheel will get most of the power and the inside wheel will still get some power. That makes for great turning balance. A 1.5 or 2.0 clutch type lsd will lock your wheels together so both wheels get 50/50 power split.

Hlsd will act like an open diff if you over steer and if you get 1 wheel in the air you won't be going anywhere.

Vlsd is better than an open diff but it leaves much to be desired.

1.5 or 2.0 clutch type lsd is my choice but I mostly drift.

[freakyjason]

Yeah, the s15 hlsd is pretty appealing. I think I read that the s15 diff can split the torque up to a 5:1 ratio (wheel with grip:wheel that's slipping) between the wheels. It is possible to simply drop the diff into my pumpkin and still use my same gearing in the diff so that I have the same ratios, right?

[supreamS14]

Yes you should use the same ring gear. But you will need a dial indicator and the correct shims to set the backlash correctly. You might as well get new bearings and axle seals. You might be able to find a kit that comes with bearings, seals and shims.

[S14toRPS13]

Yeah, the s15 hlsd is pretty appealing. I think I read that the s15 diff can split the torque up to a 5:1 ratio (wheel with grip:wheel that's slipping) between the wheels. It is possible to simply drop the diff into my pumpkin and still use my same gearing in the diff so that I have the same ratios, right?

As long as you're using the same ring gear, your gear ratios shouldn't change. I had the same issues you had because I had an open diff. Once I installed the HLSD, I can feel the rear end fighting a lot harder for traction coming out of corners. You'll notice the difference immediately. I still don't get the traction that I want though, but that's also because I'm only running 205's.

[ventrex]

i agree with everyone else, S15 Helical is your best bet for grip, i think it will solve your problem and its pretty easy to install. If your not on a budget and are serious about racing i would definitly look into a QLSD (Quaife LSD).

[Nacho_240]

If you go the s15 helical route, be sure to get both left and right flanges. Like this one:

http://cgi.ebay.com/ebaymotors...ories

[freakyjason]

How bout this one?:http://cgi.ebay.com/ebaymotors...ories

Just to be sure, that's all I need (besides new seals and fluid), right?

[mech_E]

I wouldn't only look at a diff, but at sway bars. Sway bars will give you the option to balance the car a little better in cornering. If you are looking to perform better in cornering, I would say go with about a 2-5% lateral load transfer distribution making your car want to understeer a little bit. The lateral load tranfer distribution is your weight transfer front over your total weight transfer. The weight transfer is effected by the roll stiffness distribution of the vehicle. The sway bars will also effect the roll gradient of the vehicle. The roll gradient is how many degrees the car is going to roll per g of lateral acceleration. So the lower your roll gradient, the more responsive your car will be while the higher the roll gradient, the more mechanical grip your car is going to have. But all this is to a certain point based on the tire. You can also effect the roll stiffness of your car with the 12/10 springs. That combination doesn't effect the roll stiffness distribution, so you do not have that option with your spring inventory, therefore a sway bar would be necessary. I would say, throw them on and see if you like them. I hope some of this made sense and it might be hard to perform such calculation without knowing the roll centers and cg height of the vehicle, but it might be fun to try. You can find ways to calculate these things from http://www.optimumg.com/Optimu....html. It has calculations and description on how to help set up your car with springs and dampers. Good Luck.

[freakyjason]

Wow! That's a pretty good link! Thanks for the info! Sounds like I have a lot more research to do on the subject. After all, I am a beginner on the track.

[simmode1]

It's sad, but as soon as I read the first post, I knew it was the differential based on Gran Tursimo 4's discriptions of LSD tendencies... lol

[Koshin]

1.5 way lsd isnt bad...if you drive your car on the street, this is a good choice...I run a carbon ATS 2-way on my s13...its pretty much a track car that I rarely drive on the street...its pretty annoying fro street driving but is the s*** for grip/drift...

either a quality 1.5 way diff

or an s15 HLSD would do you best...

I've had a bunch of different ones...it may be a trial and error thing beofre you find exactly what you want

[AZ89two4Tsx]

Wow, I stand corrected.

I guess some people in 240gen actually know what they're talking about. Or they appear to be.

[1_bad_4_door]

yea i would do pos diff for sure and adjust your suspenion

[freakyjason]

Okay, I just ordered my s15 HLSD with output shafts. Can't wait to get it in before my next PDA event in October at Watkins Glen! I'll let you guys know how it works when I get it in!

[ray666]

i would get roll center adjusters too.

[freakyjason]

Roll center adjusters? What are they? Never heard of such things.

[91rs13]

Well I know this goes against most of what you guys posted --but I dropped the rear sway bar after I installed the LSD ( Nismo 1.5) and it made a huge difference in the rear handling.

Where did you notice it? Was it at WGI? If so --what corner?