Diff Gears

[06vzcalais]

ive heard alot of people talking to me about diff gears modifying them blah blah blah it would be good to get some opinions on this matter, next year i am looking at supercharging my car as ive said before it will be pushing around 440-450kw.i am waiting on sure shift to get back to me about kits from them. if i push this much power will i need to mod my diff

[impulsesv6]

ive heard alot of people talking to me about diff gears modifying them blah blah blah it would be good to get some opinions on this matter, next year i am looking at supercharging my car as ive said before it will be pushing around 440-450kw.i am waiting on sure shift to get back to me about kits from them. if i push this much power will i need to mod my diff

i think the better option would be to see if you make that much power first...

how bout calling sureshift if you are that serious???

[06vzcalais]

this much power has been gaurenteed with the quote and has been done by C.A.P.A before, but i dont wanna go throwing all my money into the charger if the gearbox and diff wont hold long enough for me to get home. i work 0630 to 1730 mon-fri No phone contact at these times is the reason for not ringing

[06vzcalais]

a mate of mine has a VZ with a T trim C.A.P.A kit on it, it is making 395kw at the fly with fuel problems, needs to take his car to CHE i think. his confidence in the tuner wasn't real reasuring (trying to get him on this forum but hes not real computer literate and isnt real interested)

[Vt_vic]

if its an auto 3.9 will be a huge difference im not sure what the stock vz is and get lsd and im not sure if lsd came on the vz or if its a option.regarding the gearbox the vz isnt the 4l60e is it cos in a ls1 the box would be on its way very shortly with 400kw at the engine

[06vzcalais]

no its a 5 speed. my mates box takes it well little bit rough between changes but is to be expected

[wikky]

no its a 5 speed. my mates box takes it well little bit rough between changes but is to be expected

Is your mate's gearbox an auto? If it has rough gear changes, that can be tuned (as long as the box isn't shagged and that's what's causing the rough changes.)
If you're going to be pushing that much power through the engine, I'd be looking at having a strengthened diff, not just doing the gears. A Harrop TrueTrac is rated to approx 500rwkw and the Eaton TrueTrac is rated to approx 500rwhp (~370rwkw). In regards to gears, maybe 3.7s would be a good compromise, but depends what you want to do with the car.

[06vzcalais]

Is your mate's gearbox an auto? If it has rough gear changes, that can be tuned (as long as the box isn't shagged and that's what's causing the rough changes.)
If you're going to be pushing that much power through the engine, I'd be looking at having a strengthened diff, not just doing the gears. A Harrop TrueTrac is rated to approx 500rwkw and the Eaton TrueTrac is rated to approx 500rwhp (~370rwkw). In regards to gears, maybe 3.7s would be a good compromise, but depends what you want to do with the car.

thanks mate this info will be useful
the problem with my mates car is the tune, the tune C.A.P.A provided isn't good enough he is looking at replacing the ECU with an aftermarket system and getting someone like CHE to tune it in

[impulsive]

i would like to see some REAL dyno readouts, and some hard evidence.. i have not heard of, or seen anything with the alloytec motor make that much power before.

[bigdaddycool]

twin turbo alloytech makes some serious powers.

Dyno Sheet >
VZ Alloytec Twin Turbo 252rwkw @ 10psi - Project Cars - HFV6.com - GM Alloytec HFV6 Forum

[impulsive]

250rwkw has been done a couple of times, supercharged and recently single turbo, i was talking about the so called whopping 395 FWKW, which i assume would be about 320rwkw..

Im not a fan of the Twin turbo setup how ever, pipes going every where. And what do they mean by custom Turbo Manifolds? are these the exhaust manifolds?

[Corbs1234]

Capa do offer a system, supercharged intercooled running at 14PSI, which they guarantee will deliver 440KW or 440rwhp from a 175 alloytec
Although they do recommend upgraded internals for this kit...so there's another few G

[impulsive]

with an aftermarket piggyback ECU, where are these cars? DO THEY EXIST?

[Corbs1234]

They'd be strip weapons Impulsive; the people who own them would not be driving them on the street.
After the 12K cost of this CAPA kit, and the costs of upgraded trans, internals, exhaust etc...the age old argument (which i firmly believe in now...yes i've been converted...) is why spend all this money on a V6 when a V8 can get the same power for a 1/4 of the price?
And also, lol the people who own these cars would not be spending their time on an internet forum...they'd be out working their asses of to pay for these cars..

[tanner892]

cant the 5 speeds only take like 340nm of torque...?

oh and yeh ur gonna need some internal upgrades :P

[blnls1]

After the 12K cost of this CAPA kit, and the costs of upgraded trans, internals, exhaust etc...the age old argument (which i firmly believe in now...yes i've been converted...) is why spend all this money on a V6 when a V8 can get the same power for a 1/4 of the price?
And also, lol the people who own these cars would not be spending their time on an internet forum...they'd be out working their asses of to pay for these cars..

Yes agree totally. not to mention the extra torque you get from an ls1 , ls2 , ls3 ect

Why waste your money on trying to get big power out of a v6? And then having to upgrade and strengthin every other part of the drive line to cope with it? I just dont see the point!
When you could spend the same $$ on any of the LSx's and definetly get more power with more reliability! And if it was a T56 6 speed all you have to do is put a decent clutch in it for drive line reliability and you done. My car is a VZ SS Ls1, Stock except for a harrop blower and a ceramic clutch and when last on Autotechniques (vcm performance) dyno it made 315rwkw and 800nm of torque at the wheels. Now i'm not saying it's a absolute power house but it's no slouch.

BUT an answer to the OP for his original question....Yes you will have to upgrade just about every part of the V6 driveline INCLUDING THE DIFF. If you get close to your claimed power figure.

[Corbs1234]

[QUOTE=blnls1;1444386]My car is a VZ SS Ls1, Stock except for a harrop blower and a ceramic clutch and when last on Autotechniques (vcm performance) dyno it made 315rwkw and 800nm of torque at the wheels. Now i'm not saying it's a absolute power house but it's no slouch.
QUOTE]

BLNLS1, i want your car haha.
And yes, in answer to the original Question for the poor digga who asked it..
find yourself a reconditioned HSV LSD diff, prob 3.07 for all round performance and from a VY or VZ, nothing earlier. you'll prob end up paying between 1000-1500 for it but it will last, and give you a hassle free run.
good luck

[06vzcalais]

the reason for him not working the LS motors is cause EVERYONE is doing it, after all it is his car his money and his choice. He has upgraded cams and a list of other custom interals this car is not a complete project as of yet, he drove it 500m and the running gear crapped itself. it seems alott of companies these days have the same attitude as half the people on this forum dont believe it till they see it. he however wants to keep this car as a weekender not a strip weapon.........