Any Reason Why I Can't Go 245/45 Rubber On The Fronts?

[superspit]

Hey Guys,

as per the title....any technical issues that I haven't bothered to search for?

I'm planning on putting 245/45 rubber (as per currently on the rear) to the fronts.

What is the reasoning behind utilising smaller rubber at the fronts, is it one of handling?

I believe the rim widths are the same, front and rear. (?)...are these 8"?

I have the standard 7 spoke 18" 'track' wheels.....obviously on my 2003 V35 6M.

Thankyou.

[iamhe77]

If the rim widths are the same, why would the tire sizes be any different?

[n15m0]

245/45 tires on an 8" rim is OK. I'm no expert but I believe having wider rears than fronts has something to do with improving handling charateristics of a vehicle. If I had 8" rims all around, I would probably go 235s on all rather than 245s. but thats just me. Never had a 245 on an 8" but I would assume there would be a bit more tire bulge compared to a 225 or 235.

[superspit]

245/45 tires on an 8" rim is OK. I'm no expert but I believe having wider rears than fronts has something to do with improving handling charateristics of a vehicle. If I had 8" rims all around, I would probably go 235s on all rather than 245s. but thats just me. Never had a 245 on an 8" but I would assume there would be a bit more tire bulge compared to a 225 or 235.

I'm pretty sure now that all my rims (standard V35 18") are all 8"W.

I also believe (?) these cars come from the factory with 245's on those rears, and they look perfect..no bulging as such....it's just the fronts that look a tad gay at the moment.....hence my question on scaling up to 245 on the fronts (symmetry).....are there technical issues and such with this.(?)

Cheers.

[scathing]

as per the title....any technical issues that I haven't bothered to search for?

Just the effect on your ABS and TCS/VDC (whatever you've got).

What is the reasoning behind utilising smaller rubber at the fronts, is it one of handling?

I'd say so. The car understeers more with the staggered setup, which is "safe".

I went to using the same sized tyres all round on my Z33. I noticed I picked up a bit more front end grip, but the tail didn't get any looser as a result. I found the front more eager to turn in, and I could pick up the throttle just as aggressively as ever on the way out of the corner without having to add a dab of oppo.

VDC/TCS is the only thing heavily affected, in my experience. My Z33 has TCS. When I ran the same sized tyres all round I found the TCS kicking in when I throttled hard (3rd gear rolling when stock in the dry, so no chance of actual wheelspin) and the problem was even worse when trying to accelerate out of a corner. Even mild throttle openings would trigger the TCS. My ABS worked fine, however.

I've heard similar complaints from VDC-equipped Z owners who've done the same thing.

[rs73]

yes, but the car's electronic brain is expecting that:

- On a coupe: the front tyres is smaller - thus 225/45 front and 245/45 rear

- On a sedan: front and rear all same sizes

if the difference are too big, the electronic brain might get confused and might stuff up the vehicle dynamic stability control in the long run...

too much electronic in cars these days...

[superspit]

woah!....guys....if even you are only partially correct, this is amazing!

All that?....from stepping upto 245 at the front?.....oh my.

Good thing I'm not into pushin' it too hard!

Seriously, so all I have to worry about is potential changes in 'upper envelope dynamics'?......I don't go there anyways,

nowadays.

I'm thinking that as long as there's no rubbing, scraping or the like, (which you guys haven't mentioned) I should be fine.....

oh, I never drive with VDC on, that, in my humble opinion, is only good for turning this car into a deathtrap.

I've had more issues with VDC ON than I've ever had in my history of driving ANY CAR....and my VDC checks out perfectly, according to Nissan, and their diagnostics.....I'm organising VDC to be de-activated from my car on it's next service, I won't be putting up with it any longer (I sometimes forget to hit the switch, then get caught out)......

Passive EBD is brilliant in this car though....go figure! I've been told I can have this done (VDC bypass) without affecting EBD or any other system within the car....we'll see.

Thankyou so much guys for your feedback, I really appreciate it!...Oh HI to LUKEB.

[rs73]

VDC On = turning the car into a deathtrap?

I think VDC OFF is turning the car into a deathtrap... the car has enough torque to send the rear end skirming in the wet...

If you press the button and you got the VDC warning on your dash , that means VDC if off, not on.

When VDC is on you don't see any warning on the dash.

Keep your VDC ON as it saves life... it helps your car gets 'glued' more in the wet...

I wouldn't deactivate it, it's a feature of the car why you would pay to remove it?

The only exception is if you are transforming your car to be a track only racing machine, you would want to disable any form of VDC or ABS,

as they may kick in too early... and the purpose on the track is to shave off lap time...

[superspit]

If you press the button and you got the VDC warning on your dash , that means VDC if off, not on.

When VDC is on you don't see any warning on the dash.

yes, you are quite correct.

I want to see that light on....permanently.

In other cars I've owned/driven, (and they have generally been faster cars than my V), they've never had provision for VDC.

But I've have never 'spun them around'.....guess I must suck at driving.......

Anyway, horses for courses I guess!..

Cheers.

[scathing]

CHGLDN001094875

if the difference are too big, the electronic brain might get confused and might stuff up the vehicle dynamic stability control in the long run...

I've driven my Z33 around for 3-4 years with the same sized tyres all round, with no issues.

I'd agree with you that VDC being on is a better thing for safety, though, if you're not driving the car hard. I've had a couple of "moments" where TCS has aided me. When I'm going for it my mind is tuned in to driving, so I can catch those little moments. The VDC/TCS is more of a hinderance in this situation.

When I'm cruising around, though, I'm not in "the zone" and something unexpected (like a patch of dropped oil at night, or leaves/gravel mid corner) can catch you unawares. In that instance it'd be a good thing. VDC never gets distracted.

That said, I did have a moment once where the tail aquaplaned around a corner while I was "taking it easy" and I corrected it...only to have the TCS kick in, unbalance the car, and cause it to slide more. If the TCS had just left well enough alone I would have been fine, but with it present I had to work harder to bring the car back.

Unless you live in an area with very low grip (like snow) I don't see it as being necessary for an Australian car driven by a competent and sensible driver (even if they're not paying 100% attention).

[rs73]

yes, you are quite correct.

I want to see that light on....permanently.

In other cars I've owned/driven, (and they have generally been faster cars than my V), they've never had provision for VDC.

But I've have never 'spun them around'.....guess I must suck at driving.......

Anyway, horses for courses I guess!..

Cheers.

Find the fuse to the VDC computer and pull it out. that should turn off VDC permanently ?

[rs73]

That said, I did have a moment once where the tail aquaplaned around a corner while I was "taking it easy" and I corrected it...only to have the TCS kick in, unbalance the car, and cause it to slide more. If the TCS had just left well enough alone I would have been fine, but with it present I had to work harder to bring the car back.

the only thing something like that happened to me is when the road is on a slant angle like going downhill the wrong way against the turn...

and probably because of my shitty Nankang NS-II... and I did boot the accelerator very hard in that corner.

other than that it works beautifully, probably because my front to rear ratio are kept to the same ratio to stock sizes front to back,

the VDC might work properly that way... also I found with most cars, usually VDC OFF position is not 100% OFF...

it will still kicks in if it senses extreme conditions. It's like turning it off just bring the treshhold level higher or much later.

The V35, like previous Skylines, does have 4 wheel steering system, which needs some getting used to...

Dunno what they call them now, but it was called HICAS in R32/R33/R34.

I did on a few hard cornering felt the rear was swinging weirdly but it was the HICAS keeping things together,

took some time getting used to, e.g. NOT correcting the car as early, kept the steering angle a tad longer than usual

with little to no correction at all, let the rear sort itself out, then before you know it the car's already out of the corner

back to the straight line...

On my old R33 I took it to the track with HICAS and had no issue and I was used to that weird feeling at the back.

Managed to drift it ok as well on the skidpan, even with HICAS.

But again I had no intention to pursue that last 0.001 second of lap times, so I couldn't be bothered to have it

disabled /deleted with HICAS delete kit like other people did.

Not sure if 350Z has similar HICAS thing or not...

[Touge Kyousou]

The v35 coupe has hicas ???

I've never felt it on mine, nor see anything linked to 4ws/hicas. The rear end feels solid to me ?!? =/

I thought only some of the sedan variants had hicas.

245 f, 275 r here. No problems whatsoever.

[rs73]

same tyre sizes on mine....

the japanese brochure I had mentioned the HICAS system. I would guess it is part of the whole VDC system on all V35.

but it will not be triggered unless some condition is met e.g. corner speed and the steering angle,

a word of warning - don't try this at home... race track/skidpan is best to test those limits....

[180 wanabe]

Im pretty sure iv read somewhere that becaue the V35 has VDC the HICAS was no longer needed and was dumped

read it here

Edited September 16, 2009 by 180 wanabe

[mosoto]

http://nissanskyline.6te.net/HICAS.htm

Oh and you guys wanting to de-activate the VDC, consult your insurance company first. Most claims will be rejected if VDC is found to have been turned off at the time of the accident.

Food for thought

[Touge Kyousou]

Seems American G coupes have the hicas/rear active steer as an option on their cars after some googling.

I've had my V on the hoist a fair few times and can definitely not see any linkages/electric actuators for adjusting the rear wheels angles.

Interesting..

[Touge Kyousou]

Im pretty sure iv read somewhere that becaue the V35 has VDC the HICAS was no longer needed and was dumped

read it here

Cheers, pretty sure i read that as well before i actually bought my V.

Almost certain no hicas.

On another note, i wouldn't be disabling VDC for insurance purposes etc.

If you really wanna run around without vdc to test it out, simply unplug the abs power plug. You will lose vdc, abs, ebd and eba however. Do at your own risk.

[superspit]

Cheers, pretty sure i read that as well before i actually bought my V.

Almost certain no hicas.

On another note, i wouldn't be disabling VDC for insurance purposes etc.

If you really wanna run around without vdc to test it out, simply unplug the abs power plug. You will lose vdc, abs, ebd and eba however. Do at your own risk.

please do read my points relating to this.....I wish to have Nissan remove my VDC only, without affecting EBD/ABS!

Pulling a 'fuse' (as suggested by someone) is not an option, as it can 'cross-disable' other critical functions.

The best tests that I've made (other than historical with other cars without VDC) is the fact that I'm enjoying driving this car when I remember to shut down VDC....it's also far safer, as I'm not stuck out in the middle of an intersection with a car that's 'bogged down' then allows power to come in when I've almost beed T-Boned.

Please note, again, that all the close calls I've seemed to have had (in this of car) have been ones where I've been left stranded in a 'pull out' maneuver..

As for my insurance company?......they don't even know wtf VDC is....

I think I'll leave this post at that, I've got the info I need with regards to tyres at the front of my car, the rest has been fun!

245's at the front it is!!.....Should look a lot nicer.

Cheers guys!

[Touge Kyousou]

Don't worry, i did read lol. Just sharing how i managed to not have vdc come on with car.

Iirc, there was some American product/service that made the car start up with VDC always off, then if you want it on, you had to press the button. Might be worth asking around the American forums...or if Nissan do it for you, that's pretty cool too. Wouldn't have thought Nissan would do such a thing but there it is!