how hard is it to change the wheel studs out? How did you know which spacer to use? How much did everything cost?

2003 G35 Coupe 6mt Diamond Graphite
AIM= bkchang79
http://www.sounddomain.com/id/bkchang79

 

Catatafish,
Re: the consequences of running wider rear tires...

I'm getting Racing Hart CPF-Tune's which are 19x9 front and 19x10.5 rear (kinda pricey, but one of the lightest forged 19's out there...) So I had to really consider all of the implications of what that set-up would do to the G's balance.

On the plus-side, the fatter rears would give better grip for launches off the line and during any acceleration where there's any "squat" (weight transfer) over the rears.

On the down-side, like you said, it would exacerbate the G's tendency for understeer at the limit. Despite that, I figure that in real-world driving conditions, my G encounters power oversteer a lot more than at-the-limit understeer.

The classic scenario, for example -- after you spank someone off the lights you forget to turn your VDC back on... you take a corner aggressively and Woa!! you break the rear end loose and hopefully can catch it and steer/ throttle your way out of your power oversteer...

Anyway, that's the kind of oversteer the better rear-grip would remedy to some degree.

I'd say that the understeer problem created by the wider rears could be a detriment when I'm running laps at the track, which I plan on doing soon with the G... so I'll have to make adjustments for the car's tendency to push, especially coming into corners just before turning into the apex, where a bit of oversteer can come in real handy.

But that's only on the odd weekends. On the street, even with spirited driving, we don't usually corner at the car's true limit so we usually don't feel that understeer... and when we do, it's a lot safer than oversteer when other traffic's around.

On the street, it's more likely we'd occasionally power-oversteer. These fatter rears should balance that out a bit, and they'll give me a better launch of the line (always good! ;-)

So all in all, I'd say that for my particular needs, the better grip trumps the extra understeer, so I'm going for it!


G35Coupe 6MT + Nav

 

Rugratcoupe, looks great!!!

I was going to get the same Nismo LM-4's as you (my coupe's same color as yours) but after my own humming-and-hawing I went with the polished superblack RacingHart CPF-Tune's instead.

For me to get the same effect as you (within 1 or 2 mm) I'd have to use a 15mm spacer up front. (The offsets on the RacingHarts are +26mm front and +22mm rear). My offsets will work in the rear as is with the deep lip I got (2mm off your setup), but I'll be about 16mm further in on the fronts.

(Before I saw your car, I was pretty content, lol!
Now that I see how much more aggressive your car's stance is, I want that too! ;-)

Anyway, my one concern is that when you put bigger and bigger spacers on the front (besides rubbing, which you don't seem to be getting), you end up putting some slight additional stresses on the front suspension -- since what your suspension "sees" is the center of mass (wheel plus tire) pushed further outboard of the mounting plane.

From the suspension's point of view --whether it's a really deep-dish wheel with negative offset, or a big spacer-- the extended leverage effect places a greater load on the wheel-bearings, ball-joints, control arms, etc.

I have no idea at what point it becomes a problem... but I figure 15mm can't be enough to be significant. I think it only would matter if you used a deep negative offset wheel. That would probably result in some steering-wheel kickback as well.

With the 15mm front spacers, do you feel any changes in the steering at all?

It's good that you had the wheels for a while, because now you'll know if changes in handling, steering, tracking etc. are from the wheels or the spacers.

Anyway, the new setup/ stance look GREAT!!!



G35Coupe 6MT + Nav

 

Hey Rugrat. I sent you a PM, could you let me know what you think? Thanks

'03.5 Silver AT Sedan, Premium, Aero Kit/Package, Sport, Winter, Stillen Air Box, Z pipe, Polk Tweeters, Clifford RSX 3.5, 19" Gram Light 57F Pro's, Hotchkis sways, Borla

 

Meta,
Now we're cookin with butter!

THANK YOU for the analysis. Sort of what I intuitively figured but your explanation was great. I too love those CPFs, especially that seductive black chrome, but wow those are expensive. And, from what I'm told buy a couple of wheel guys, the Tire Pressure Monitor system will not work in anything but the Nismos.

I was also seriously considering the Volk CE28N but again, TPM imcompatibility. Do you know otherwise? What does the Tire Pressure Monitor depend on that makes the Nismo and stock wheel work with it?

One more tidbit. Wouldn't you still be able to tune back the desired neutrality or less understeer/more oversteer with adjustable sways?

Thanks again for the great thoughts. I've been trying for weeks to drum up a good discussion about performance effects on wheels.

2004.5 Coupe/5AT/Ivory/Everything but front spoiler/Nismo CAI/Crawford V5

 

I just installed the Spacers so I haven't had a chance to drive the car at it's limits yet. I'm not too concerned with the offset causing wear problems, I've tracked the car 3 times now so I have the Performance shop I use put it on the lift to tighten & check things out every once in a while. So I try to stay on top of things. Yes it seems with this new setup with the spacers, the turn in at the track would be more noticeable.
About tire stagger causing understeer(pushing) It has more to do with your suspension set-up. When I installed the Eibach springs & especially the NISMO Sway bars it solved the pushing problem at the track. The car is very Neutral now, very flat in the corners & if i choose to, I can induce oversteer with my Throttle & kick the tail end out just for fun . Here's a few pics at Little Taladega speedway, a tight 1.3 mile road course....This first pic I'm in a tight turn the tires just beginning to let go, notice how Flat the "G" is in the turn...



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Turning around to go Counter-clock wise, a little wheel spin...



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Going down the front straight. look closely & you can spot my in car Video-Cam...



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bkchang79 (you asked?) How hard is it to change the wheel studs out? How did you know which spacer to use? How much did everything cost? (RugRat) I had a Wheel/Tire shop Change out the Wheel Bolts(studs) You have to hammer the old ones out & have a Press or large vise to press the new ones in. I determined which size spacer to use by Measuring the outermost part of the top sidewall of the tire to the inner lip of the wheel well. That way it gives you an idea of your clearance. Plus, when the wheels compress upward while driving they camber in which gives you a little more room to play with. The 5mm spacers were $65.00 & the 15mm spacers were $111.00. Both are H & R hubcentric spacers sold in Pairs and come with longer Hub bolts(studs). Purchased from Performance Nissan. They came down on the internet price a little, because Options Auto Salon Online had them Cheaper.

 

I'd better give some credit to "MARVIN"(here's a Pic) my co-driver who has helped me out at the track...



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oops!!! Wrong Pic... This is the one I meant to post.
Oh yea... He likes wearing my helmet & Hey...That's My Last Coke!!!!



270974-P5090006.JPG

 

Rugratcoupe,

Lol! great pics!! Glad to hear that your car feels neutral with your setup... now I'm going to consider a 10 - 15mm spacer on my front.
Thanks again! I wouldn't have thought of that until I saw what you did and how great it looks.


Catatafish,

Thanks for that info! The TPM system is a bit of a mystery to me, I always thought the sensor sat behind the valve stem and could be swapped into another wheel/tire set... but like you said, maybe it's dedicated to a specific type of wheel?

I'll have to ask the guys at the Infiniti service dept. next time I'm there. I think it's a shame to lose that function -- but in the worst case, if need be I could live without it since I usually check the pressure manually about once a week anyway. Plus the TPMS sensitivity is 5 lbs (I think?), and I figure my "butt sensor" could tell me if my tire pressure dropped that much during driving ;-)

Re: the sway bars...
I was looking at a set of Hotchkis adjustables -- with the various settings you can definitely tune the car's balance, like you suggested.

If I softened the front sway and stiffened the rear to medium or hard, that would counteract some of the understeer induced by the fatter rear tires. If I end up going with coilovers, I could similarly reduce the push by softening the front suspension and tightening the rear. Another way to do it would be to increase the front negative camber -- which would happen if you softened the front suspension anyway.

I think a good front lip could also add a bit of downforce over the front end which would further reduce the tendency to understeer, especially at the track coming very fast into a corner... (at least in principle, assuming you're carrying enough speed).

I've been looking at the Data Systems lip for that purpose -- we'll see...
(The wish-list can sure grow fast!! ;-)




G35Coupe 6MT + Nav

 

metasystem...let me know if your able to find a 10mm hubcentric spacer. Performance Nissan told me I could stack two 5mm H&R spacers, but that didn't work. When you stack the two 5mm spacers it is no longer Hub-Centric.There is no hub lip for the wheel to fit in...

 

H&R only makes spacers for our cars in 5mm, 15mm, 20mm, and 25mm. You'd have to get one custom made if you're looking for a 10mm. I am using a 15mm in the rear for a final offset of 20. I've used all of the other sizes before with other wheels and was always satisfied with all but the 5mm size because it doesn't have that "lip" like on the 15mm and up sizes for your wheel to sit on. The 5mm reduces your bore size.

Black on Black 5AT Coupe, Navi
Falken Koblenz 19x8.5 F 19x9.5 R
Falken FK-451 245/35 F 285/35 R
HKS Legamax Exhaust
350Z Duct
Stillen Hi Flow
7 Wire Hypergrounding Kit

 

So could someone please tell me what I woudl use? I want front and rear H&R wheel spacers, I have 19x8.5 on a +40 offset on my sedan. Should I use the same setup? Im also running 245 all the way around. Thanks, martin


Martin
2003.5 BS G35
Full Aero/Sport Package
Injen CAI
B+G Springs
Clear Corners
ADR M-Classic 19's FINALLY!