james12345pt

iTrader: (5)

I got a chance to ride in a 350z with a Greddy Twin turbo kit on it this weekend and was blown away by the power but noticed the car could not find traction in first and second gear. I know twin turbos create alot of torque down low but it was ridiculous how little traction the car could get. The car had a 3.5 gear with vlsd and 275 tires on the back. What is the traction like with a vortech kit? Also, how much does the 3.9 gear changes things?

Cux350z

iTrader: (162)

i get traction fine with my out of the box setup. I run 275 in the rear which may help a bit.

james12345pt

iTrader: (5)

I'm going Vortech in March and hope to achieve 430-440 hp and 350-360 torq while at the same time I'm planning new tire purchase but don't want to go too big that it affects handling or gas mileage. I though 275s would do the trick but was shocked how littel traction that 350z got even with that size of tire.

sentry65

iTrader: (11)

the vortech will have better traction because it won't generate as much tq so early in the powerband to upset the tires. The shape of the tq curve lends itself well to traction because of how it reaches peak power at the top of each gear. So as power increases, your speed increases and that helps manage traction not to mention giving you more time to react. This is the same thing why larger turbos are better with traction since they spool later in the powerband once you've gotten more speed built up

with my setup, I can get full WOT traction in 2nd gear if the tires are warm and it's 100-110 degrees outside with my 455whp map. I have the 3.9 FD, 295 tires, nismo LSD. I can go WOT in 1st gear up to about 4000 rpms, then have to reduce throttle to about 50% at redline

when I had around 390-400whp, I did have full WOT traction in 1st gear

however when it's 50-60 degrees outside and I use my 477whp map, I usually can't get full WOT traction in 1st-3rd gears, and sometimes 4th loses traction too depending on if my tires are warmed up or not

It's VERY easy to manage the traction. I can go WOT after each gear change and leave my foot at WOT for a couple seconds and then can start to feel when it's about to overpower the tires because it's a gradual loss of traction. So my method is to go WOT right after changing gears and then gradually start reducing throttle a little.

A strong TT setup I'd imagine would be an absolute animal to try to control. I'm not sure you'd ever really be able to go WOT at all until higher gears.


275 tires are way too small for FI. They work fine for NA though. Hell I think 295's are too small for FI on this car

I think the 3.9 FD works great with the vortech if you have a good tire setup and 400-420whp. It really makes the car come alive.
I'm considering 315 kumho V710 or 305 toyo R888 tires for the rear when I get my next set of tires
I hate losing traction. It completely sucks

pimpsahab

iTrader: (1)

Yea im TT on a stock block 9psi and cant get traction in 1st and most of second and i have 275's in the rear also..but i believe 295's BFG Dr's should cure that..or atleast make it a lot more managable

carrera4s

I'm TT and I lose complete traction in 1st. In 2nd if i'm higher up on the powerband I will have full traction but if I do a 35mph roll in 2nd I'll be in spin city

rcdash

iTrader: (18)

Yep, TT makes gear 1 and most of 2 pretty much useless. Need electronics to help out - can't wait to try some traction control solutions...

Triple8Sol

iTrader: (218)

As of a couple weeks ago, I'm now running a 3.9FD with my Vortech. Definitely easier to get wheel hop in 1st/2nd. Improvement in acceleration in around town driving is awesome, though. Unfortunately, I think the shorter gearing did hurt my peak #'s on the dyno...

Nexx

iTrader: (41)

i get the slip light in 3rd, 1st and 2nd are pretty much worthless unless its really warm and the tires are sticky and even then 1st is useless.

james12345pt

iTrader: (5)

What width tires are you guys running and what is your numbers? I'm doing all of my research prior to any new purchases. I am planning to buy new tires just prior to my install in March.

Quamen

iTrader: (14)

I got 275 Falken GRB FK-451's in the rear of my Z and I am hoping they are enough for my Vortech. I will hit over 400whp no problem and I may throw in our boost limiters to get more torque in the midrange.

athenG

iTrader: (2)

edit.....

Glex25

iTrader: (11)

I'm in the same boat.

Tonight I'm swapping out my 3.5FD to a 3.3FD and installing Cusco RS LSD.

Hopefully that will fix some of those issues

athenG

iTrader: (2)

I think I really need to dyno my car again. I have 285 19's KDW2 and I have full traction on 1st to 2nd. I do loose traction if launch the car but I get full traction if I just floor the car from a roll. I think my clutch doesn't grab that hard anymore so that could be a reason too.

MUZZY

iTrader: (28)

i had 285 in rear with 410rwhp still couldnt get tracktion... i upgraded to 345 series... there is enough now

sentry65

iTrader: (11)

you have 345 tires? you have a widebody or something?

edit:
ah a veilside V3 kit
that makes sense

rcdash

iTrader: (18)

Shorter gears shouldn't hurt whp on the dyno - that's odd. If the dyno is completely uncorrected a swap to shorter gears (higher ratio) should bump up wtq in any given gear.

sentry65

iTrader: (11)

it shouldn't really even have an drastic effect on tq on a dyno

the main thing is shorter diff gear ratios have higher parasitic loss because the gear is physically larger and has more teeth

booger

iTrader: (6)

Hey Sentry
You posted a video a while back of you doing a WOT run from 2nd with your 3.9 rear gears and 455whp tune . You had full traction in 2nd with the 3.9 rear gears .
If I remember right....wasnt this video done at night time when temps woul;dnt have been hot and the street surface would have cooled off ?

booger

iTrader: (6)

It doesnt show up on the dyno , but it has a huge difference on the street . I had a 3.5 on my AT5 and traction wasnt there at all in 2nd gear . I went back to the 3.3 because of it . WHy have a 5 or 6 speed tranny if you can use all the gears . You give up 1st gear if the rear gears are to low . Which puts you in 2nd gear to start off in . For a street car.....no thanks !

And to add....having wider and better tires would help some . But unless you live in 115 degree weather that bakes the street . Wider tires wouldnt help in 90% of the country with power levels much over 400whp