Hi all,

 

my ride is giving me hard time... i don't blame it for traction but the issue is going extreme jumps side ways when ever the throttle is aggressively pressed.

 

 

my current setup is as following..

 

1JZ-GTE

81 SR-5

R-154,

3.737 diff. LSD.

255/45/R17

boost 1.2 bar..hx35(8 blade)

 

I am in a assumption that if change the diff. from LSD to non LSD, the issue of jumping will be minimized , moreover the diff ratio is also very high, i should also change it to 4.1:! instead of 3.737:1,

 

 

reduced the boost from 1.2 to .8 bar...

 

Your valued experience is welcomed....

i will also upload a video as well,,,,

Yes, non-LSD will stop it jumping sideways, but will spin the inside wheel or the driven all the time instead. Terrible idea!

 

Fit traction control instead. You'll just need an ABS setup, a computer, and fly-by-wire throttle... :laff:

 

The 4.1 diff will light up the tyres even more too, although reducing boost will help stop it sliding.

bouncing sideways in the way you are describing is suspension that is too stiff, or shocks that are not strong enough to match the stiffness of your springs

And 4.1 is a lower diff ratio than 3.737.

 

The higher the number the lower the ratio.

i think if you think its too powerful with an LSD, the best option is to turn down the power, or train your right foot to not be so agressive.

 

or perhaps look into,

 

better tyres, wheel alignemnt, check all the bushes in the car - especailly the rear end.

are you running crap tyres. That could well reduce some of your concerns.

 

You can run rev-controlled traction control with a lot of aftermarket ECU's now, doesn't need ABS.

bouncing sideways in the way you are describing is suspension that is too stiff, or shocks that are not strong enough to match the stiffness of your springs

 

I have the same problem, and I know that it is cause of this, as mine is setup for track work, and drive it on the street alot and i have the same diff gears,

 

soften up the rear

have change the rare spring to 10% soft ones... driveability is much batter..

its not bouncing, it jumps to left(60deg) when i shifts to 2nd and press the throttle.. Yes If i can train my foot it will get batter,,, but I want to run 1.5 bar boost. so that i can race,

I tried controlling the throttle but it works but It cost me race,

 

my friends 5RFHE turbo, 1.1 bar, takes the lead while i am controlling the throttle .... at .8 bar of boost.. and at third gear i can't catch him. under a 1/4 mile...

 

tires are NanKang, just 2 month old.

 

how worse will it get if i uninstall the LSD??

lol nankang...

what is your rear spring rate now?

and how tight is the limo?

Nankang........they aren't tyres. They are ice skates.

 

I had nankang ns2 on my s15, absolutely useless tyres.

 

Grab some toyo r888 to go with that engine/car combo!

Nankang........they aren't tyres. They are ice skates.

 

I had nankang ns2 on my s15, absolutely useless tires.

 

Grab some toyo r888 to go with that engine/car combo!

 

YES, they are NS2, in my current condition i was capable of buying those, but I failed...

the next tires that i have order are Nitto NT555, which from my friends exprience are batter then aDvan neova ad08...

 

I don't know my spring rate??

 

http://youtu.be/AtCzHw6yK98

The diff ratio you need depends on how fast you are going to drag to. Ideally I'd say you need to win the race just before you change gear again, so you are using 1st and 2nd to their best potential without changing gear again and losing time.

 

3.7 will mean you go faster in each gear before you change. A 4.3 will give the motor more revs but you will change gear more to get to the same speed.

 

Smaller wheels have the same effect as larger diff numbers. If you use 13" they will spin very fast and you will change gear often, while 17" go faster for the same revs and you spend longer in each gear.

all things aside, nice looking car mate!!!

 

but yeah definately look into some better tyres, any of those optiosn up there will be a huge improvement over the NS2's.

 

just have to watch the prices in that tyre size.

 

i would even look at dropping the wheel size down to 15 or 16" to reduce the cost of tyres. 185/60/R13 toyo R888's do an amazing job of handling the ~320hp of my mates turbo rotary. but even that size were ~$300 each tyre.

yup, we get a tire for another 100 or more because of shipment and duty... :/

 

i want tires for 500whp.

in this video i lunched the car at 1500 rev. and slowly slowly pressed the throttle. but in second gear it jumped.. !!!

 

currently i am reaching 182-185km/h on 1/4 mile.. at 1.2 bar.. i will be running 1.5 or more..

 

I was thinking may be if there is a cheaper way of getting the traction.. tries are expensive here...

 

 

 

 

http://www.youtube.com/watch?v=-SSVDnADl-c&list=UUCTFj97W1obChf_sQphRvJg&index=1&feature=plcp

softer springs will help, that car really doesnt squat much, there are calculators online to calculate your spring rate if you can't get it from your manufacturer.

 

I'm trying to understand how you know you softened rear springs by 10% without knowing the spring rate?