Torsen into the LS400 UCF10 / UCF20

[Spinnetti]

that link you sent me shows a 1999 LS diff but it isnt... the '99 diff has 2 mounting lugs at the front of the diff housing and the one in the picture only has one eg:UCF10 diff.....

easy enough to find - just look at Kaaz or TRD or other and see which part fits your car. Then compare that part number to the known Supra part (10 or 12 bolt).. that should tell you what you want to know. The AT supra is 10 and the 6 speed 12.

 

[Skullface]

What's DHP ? and your talk about good turn ins and good responsive drive, are you refering to the LSD ?.... i'm not sure what your talking about....

DHP = Dynamic Handling Pack .. you'll find good pictures and some description here...

http://retrorides.proboards.com/index.cgi?board=FSW&action=display&thread=70200&page=1

But the story goes like this...
The Chief Honcho at Lexus UK is obliged to drive the top lexus available at all times. The man on top during the introduction of the VVTi LS400 actually wanted something of a drivers car and found the over plush ride lacking for use on our english country lanes. So he got a chassis expert in to take a look what could be done. Settled on 10% uprated spring weight, 10mm lower front and rear, standard dampers, and a 1mm thicker rear anti roll bar (sway bar - this to IMPROVE RESPONSE AND AID TURN IN) and special 17" Alloys with 245-50-17 tyres. So impressed were the other dealers that got to drive it, that it was available as a special dealer option througout the UK.

I have a DHP 1999 VVTi AND also a 1998 VVTi normal model. The difference is penomenal. From what i remember of bmw's i've driven, the LS now feels somewhere between a 5 series normal model and a 5 series sport of the same era. (closer to 5 series normal really) It really does turn in sharp as a tack. It's loads easier to hit an apex, still a little up and over movement flicking a tight line through a roundabout but I can now do it and be confident in its road holding. As Spinnetti says, rear sway to aid turn in.

 

[fastegg]

DHP..... well you learn something every day... i never thought about a bigger bar at the back as i figured with all the weight in the motor at the front that you'd first put a bigger bar at the front but you guys are telling me different.... maybe i should bite the bullet and get some custom coilovers... check these out :

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=110585143962&ssPageName=ADME:X:RTQ:AU:1123

These guys reckon $800 base price and if you want adjustments for both damping and rebound on remote reservoirs extra $280... So for say $1,200, you get ride height adjustment, pre-load adjustment, camber/caster adjustment, duel springs of your choice, damper & rebound adjustment on remote canisters. Now i spent 20 years building and racing road racing bikes, everything from GP to production to superbikes so i'm familular with going from totally unadjustable suspension to fully adjustable and the difference that it makes.... Ive just never done it to a car... so i'm quite looking forward to it....

 

[Spinnetti]

DHP..... well you learn something every day... i never thought about a bigger bar at the back as i figured with all the weight in the motor at the front that you'd first put a bigger bar at the front but you guys are telling me different.... maybe i should bite the bullet and get some custom coilovers... check these out :

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=110585143962&ssPageName=ADME:X:RTQ:AU:1123

These guys reckon $800 base price and if you want adjustments for both damping and rebound on remote reservoirs extra $280... So for say $1,200, you get ride height adjustment, pre-load adjustment, camber/caster adjustment, duel springs of your choice, damper & rebound adjustment on remote canisters. Now i spent 20 years building and racing road racing bikes, everything from GP to production to superbikes so i'm familular with going from totally unadjustable suspension to fully adjustable and the difference that it makes.... Ive just never done it to a car... so i'm quite looking forward to it....

Well, coilovers are not sway bars. They perform different, but of course related functions. You need to consider all of the components to really get it right. FWIW, I spent $34 total for coilovers for my Lex with some random kit for a Honda or Neon or something off fleabay, but I've been doing race car suspension (club level) for a long time. Anyway, there's probably some good on-line references, but before you spend big $, you might want to go over to Amazon and buy a couple books on suspension - Carrol Smith, Paul Valkenburg etc...... Just sayin...

 

[fastegg]

Rear sway bars

Since talking to you guys about sway bars etc ive read lots of stuff ..... i thought a 1mm rear bar would do bugger all but i did read this :

Whilst 1mm may seem insignificant, it should be noted that this will increase the effective sway bar rate torsion by a minimum of 20%. The actual increase in sway bar torsion is disproportional to the increase in bar diameter. This meaning, a small increase in bar diameter will result in a large increase in sway bar torsion.

It also said "If your car doesn't have a rear sway bar, put one on"

 

[Skullface]

swapping out the mounts for harder polybush sway mounts will also make the sway bar effect come in sooner, taking up the slop of worn softer rubber bushes. I know you can do the whole car in poly, but sway mounts alone shouldnt have any NVH issues as a compromise.

 

[fastegg]

What's NVH ?

 

[fastegg]

sway bars

Do you guys think its worth the extra $$ to get adjustable sway bars ?

 

[Skullface]

:thinkerg:

Do you guys think its worth the extra $$ to get adjustable sway bars ?

would that be to compensate for a heavily lowered geometry?

NVH is noise-vibration-harshness ... engineering term

 

[Spinnetti]

Do you guys think its worth the extra $$ to get adjustable sway bars ?

Well, that's normally for racing adjustments per track, but in your case, you don't know how stiff you want it, so I'd say yes. Start on full soft, then try full hard, then see where to go from there... If you have winter where you are, full soft in the winter and full hard in the summer might be the way to go... (they build in understeer for a reason - its safer in normal conditions)

I went 1mm larger bar on my Audi, but it wasn't enough... All depends on your goals and what tradeoffs you want, and there's always a tradeoff.

Poly bushings are ok, but stiffer rubber is better.. Maybe TRD has something?

 

[fastegg]

sway bars

Well i'm so glad i mentioned the word 'sway bar' on this forum. Before that, i would have gone out and put the biggest bar i could get on the front thinking it would solve my problem. I never would have considered a rear bar, but after googling 'sway bar theory', ive spent the last couple of nights reading lots of stuff from lots of people and i must say i have a totally different concept now of car suspension and handling issues... I now have a much better understanding of why my VVTi handles the way it does and what i have to do to change that...

::: heres a sway bar conversion chart showing % upgrade in stiffness...