TRD 2 way clutch LSD

[kngrsll]

Well, i havent had my poor egg for a week due to an LSD install. I got a used 2 way clutch LSD by TRD for $400 on ebay, and i had a friend install it. Going to pick up the car tomorrow and take it for a spin! :D

I dont know how much ill be able to tell you it improves the handling quite yet. The star specs are nearly shot and the alignment is hell right now. I havent done a proper alignment since i installed the 6kg rear fit springs and removed the 23mm rear sway bar. Although that wouldnt have a huge effect, i also removed my SPC shims and installed the PG spacers with the washer, and i think the alignment is not quite right back there now. Either way, with that set up, i took 2nd in ST at a detroit region autox and the tires were way past their racing life.

So next up, slot the upper bolt holes in the front struts for a little more camber (shooting for 2.5-3.0*), change the rear beam pitch, and get the thing realigned front and rear. And hopefully beat up more corvettes and vipers :D

[blacksandiegovitz]

+2 !!!
What was your reason for taking off the rear 23mm sway bar? I just installed mine and the car's just feels so "on-point" .

[kngrsll]

Originally Posted by blacksandiegovitz

+2 !!!
What was your reason for taking off the rear 23mm sway bar? I just installed mine and the car's just feels so "on-point" .

The yaris strut/rear beam suspension is nearly identical to that of old VWs. there are two schools of thought in the VW world in regards to rear beam suspensions.

1. normal springs rates that either are close to matching front to rear or have a slight front balance, like the Yaris. Then use a big rear bar to make up the difference.

2. no rear bar and use really stiff rear springs (100lbs or 2kg higher rear) compared to the fronts.

Now the advantage to #1 is its easy and cheap. The supposed advantage to #2 is that it allows the rear beam to do the work it was intended to. They argue that the rear beam is designed to twist (which it is, as the yaris does as well), which keeps more rubber on the ground, also changing camber/toe in the process. They also say that the big rear bar increases oversteer by decreasing overall rear grip by removing the torsion beam from twisting. the increase in rear spring rate does not decrease rear grip, but rather increases the total grip the car has.

I can tell you, ive drive both set ups, and they both feel good. I have only autox'd the second set up, and it was good. i am going to play with both to really figure it out. I am experimenting bc i am bored and thats just what i like to do...

For now, the proven set up is springs, shocks, and big rear bar. i think that set up is great, i just want to see what else is out there potentially. :)

if you do the math, the rear bar should be worth about 145 lbs of spring, which is nearly the same as the springs i am using. In effect, the roll resistance is nearly the same! but, you have now allowed the rear beam to twist, doing the job it is engineered to do, as well as removed the weight of that sway bar. we will see how it works :)

[advocate]

Originally Posted by kngrsll

if you do the math, the rear bar should be worth about 145 lbs of spring, which is nearly the same as the springs i am using. In effect, the roll resistance is nearly the same! but, you have now allowed the rear beam to twist, doing the job it is engineered to do, as well as removed the weight of that sway bar. we will see how it works :)

Certainly sounds logical. Let us know how it turns out!

[kngrsll]

i certainly will... i can tell you this, it FEELS different for sure. just dont know how to quantify that. and that was before the LSD.

i know what times i run at the track, so thats where we will find out for sure

[kngrsll]

haha, what an awesome mod!!

so i picked my car up this weekend after getting the LSD installed. it was a used LSD, but we decided to follow the break-in anyways.

the first thing i noticed is that the steering felt a little heavier. this may be due to the increased friction caused by the LSD, or may just be my imagination lol. my friend said he thought the same, and he had driven it on track nearly ever event i go to. while driving around town, you dont even notice it. it isnt noisy, doesnt chatter, or irritate you. this is good, i was kinda worried about that being that it is a clutch pack, and 2 way.

the first drive i did, i just went up and down some local on ramps to see how it felt. it feels REALLY smooth, a little bit of throttle causes the car to track out just slightly, while coming off throttle just a little causing the car to pull inward. this is what you normal, even without an LSD, but it is more smooth and easier to do.

next, i took it up to the mountains for a quick blast through. the car felt really good, the lsd has shifted the grip forward some, so the car had a slight bit more understeer than before. this can be tuned out with tire pressure though, it wasnt much. i noticed a couple things, the turn in felt alot better off throttle, and coming out of the corner, you could use alot more throttle. being that it is a 2 way, you would expect both of these things, so thats good, lol. the only problem with that is the car felt more underpowered than it did before haha. because you could get back on throttle sooner, you were carrying more speed, but it felt slower, if that makes sense. you only noticed on the really tight 2nd gear stuff though.

i cant wait to try it on the track, i am curious to see how it will work. i noticed it is alot easier to pick the line you want using the throttle now, so i think i will be much more consistent. the biggest difference will be in the slow speed stuff, with less of a difference as the corner speed increases. I have times from my last even, without the LSD, and i just got another set of star specs, so the tires will be consistent.

anyways, hope that helps. i love this thing, really transforms the car! they are on Ebay all the time, mine came from a starlet GT turbo, while the ae92 works as well. just make sure you know someone who is comfortable opening a tranny, that is tough stuff.

[cali yaris]

the lsd has shifted the grip forward some, so the car had a slight bit more understeer than before

If the "grip" is shifted forward, that would be LESS understeer.

[kngrsll]

meh, i dunno how to explain it. the grip is higher in the front, but it understeers a tiny bit more. and its in a good way!

[ozmdd]

Cool. Been interested in the LSD, but bummed at what it does to your autoX classing. Good luck in SM. :)
I went around a tight sweeper last weekend on concrete that had the inside wheel spinning so long that I threw-up a smoke screen! The LSD would have been nice then.

[kngrsll]

Originally Posted by ozmdd

Cool. Been interested in the LSD, but bummed at what it does to your autoX classing. Good luck in SM. :)
I went around a tight sweeper last weekend on concrete that had the inside wheel spinning so long that I threw-up a smoke screen! The LSD would have been nice then.

you dont have to run SM. i am going to run FSP or STX. If i get slicks, ill run FSP, if not, ill run STX on street tires. I am not real concerned about autox classing, more concerned about points tally for NASA time trials. thats what i really want to do.

[ddongbap]

You can't gas the middle of a turn and expect the LSD to fix it. Its mostly going to help you during the power out of a turn.

[kngrsll]

Originally Posted by ddongbap

You can't gas the middle of a turn and expect the LSD to fix it. Its mostly going to help you during the power out of a turn.

haha, thanks... i knew i was doing something wrong.

[ddongbap]

Originally Posted by kngrsll

haha, thanks... i knew i was doing something wrong.

Well, I didn't mean to sound like, HEY YOU'RE DOING IT WRONG. I meant it more like a question. Cause I was reading your thread, thinking what I wrote.

[kngrsll]

Originally Posted by ddongbap

Well, I didn't mean to sound like, HEY YOU'RE DOING IT WRONG. I meant it more like a question. Cause I was reading your thread, thinking what I wrote.

:rofl: yeah, you dont just jam the throttle down and let the LSD sort it. bc it doesnt work that way.

so after you start to enter a corner, you aim for the apex, off throttle, right? well, once you hit the apex, you start to pick the throttle back up by pressing the gas. without a diff, you send power to one of these wheels. with an LSD, you will send power to both wheels. this is where you will really notice the diff, you have both wheels driving your forward, instead of just one. since it is a 2 way, you will notice it off power heading into the corner too, which i like, but is more difficult to control.

does that help at all?

[cali yaris]

Before I made more power with the Yaris, I accelerated my car way before the apex. Not enough power to get a top exit speed with this car if you coast into the apex. So I would brake a little late (past the turn-in), then hit it right through the apex. As long as the rear is stiff enough (and the front wheels are grabbing, which you now have ) it will come around just fine. (My strategy will have to be a little different now, of course).

Here is a good article on trail-braking (braking past the turn-in point) and the point at which acceleration begins. I bought this book a long time ago, and it's the best single book I've ever found for studying race technique.

http://www.bentleypublishers.com/rac...ry-831-14.html