do wider rims slow you down if i go from the stock 18 to 19's with a width of 8.5- 9.5 will it make a big difference

red 6mt prem navi

 

If they are heavier, yes.

2003 TwBlue 5AT Sedan, sunroof,
Graphite Leather, splashguards, HKS exhaust,
14 wire Grounding kit, 350Z duct, Stillen CAI
Underbody rear diffusers, Drilled alum pedals

 

but if they are lighter than the dtock ones but just wider then there is no problem?


red 6mt prem navi

 

correct...a wider rim means more rubber is on the ground which = less chance of spinning the tires and more chance of a better launch. That's why Porsche Turbo's have such a wide stance in the back. Anyone else want to add?

2 G or NOT 2 G, there is no question!

 

Wide is good for straights but too wide at the rear and you have a slip angle problem that Turbos suffer. The cars plow like crazy because the fronts give up before the rears. Don't go bigs and littles and then wonder why your car sucks in the corners.

03.5 Sedan/B.Sil/Prem/Wntr/Aero/Tint/Rims/Hotchkis Sways--WHRER ARE OUR PARTS!
69 Chevelle Hard Top BB/4.11's/Posi

 

IQ, good points...depends on what type of driving you're doing.

2 G or NOT 2 G, there is no question!

 

well help me out then

i was thinking about putting 19X8.5 all around from the stock 18's just was wondering if that will make me alot slower

red 6mt prem navi

 

Most likely not slower but you have to keep your stagger under control if you want the car to be quick in all areas. My Chevelle is an all around car but I do have a big and little set up to run at the drags. The big and little set up consists of 295/60 15s in the rear(rolled fender) and 205/65 15 fronts-this is not the most extreme set up be ut the car can't corner for $hit with those tires. I also have 15x 8 Rallye's that run 235/60 all the way around for street duty. Meats out back are good but too much is bad..just like most things in life. Try to keep close to the factory stagger and you will be just fine for an improvement try matching the front to the rear and see what the handling is like...better!

03.5 Sedan/B.Sil/Prem/Wntr/Aero/Tint/Rims/Hotchkis Sways--WHRER ARE OUR PARTS!
69 Chevelle Hard Top BB/4.11's/Posi

 

lol 15's

 

Slower, in a straight line...no. Will you tend to lose your rear end a lot more, yes. (when cornering)

2 G or NOT 2 G, there is no question!

 

I just bought some Enkei RPF1 rims:

18x8.5 35mm offset front
18x9.5 15mm offset rear (pretty aggressive offset, but recommended by Enkei)

245/40-18 front
275/40-18 rear

The rims are pretty light weight at 17-18lbs per rim.

Right before the change I consistently got 6.2-6.3 on my G-timer (I have a 5AT). Now, right after the change (same strip of road) I'm getting 6.5-6.6. They say that the tires haven't broken in yet. I hope that's the reason why I'm slower now.

2004 Twilight Blue G35C / 5AT
Z-tube / Clear Corners / Racing Pedals
Enkei RPF1/ Falken FK-451 245/40 F 275/40 R

 

Did you record the temperature, humidity, and barometric pressure during each run?

You will have more rolling resistance, however you will also have more contact patch for traction.

One thing I've noticed with the G tech is that you must do the first 20 foot run to calibrate it to zero Gs, and you will also get widely varying times (as you should) due to temperature, humidity, and pressure. Make sure you do your runs on the exact same road as gradient will also effect the G Tech heavily.

2004.5 Coupe/5AT/Ivory/Everything but front spoiler/Nismo CAI/Crawford V5/Crawford Cats/ Service Engine Soon

 

Did you record the temperature, humidity, and barometric pressure during each run? At 55 degrees I do a 14.22, at 75 degrees I do a 14.6 for instance. At 90 degrees your ECU will start screwing with the timing.

You will have more rolling resistance, however you will also have more contact patch for traction.

One thing I've noticed with the G tech is that you must do the first 20 foot run to calibrate it to zero Gs, and you will also get widely varying times (as you should) due to temperature, humidity, and pressure. Make sure you do your runs on the exact same road (looks like you've done this) as gradient will also effect the G Tech heavily, and also record your winds.

Also, do you know what the tires weight? The stock Pilot Sports are extremely sticky and extremely light. You've picked up around 3 pounds by going from 225 to 245 and probably another 3 pounds going from 245 to 275 but I can't confirm that I'm just guessing based on the Toyo Proxes weight differences, that I'm assuming are similar to the Pilots (as far as weight difference between the sizes).

Keep in mind that 3 pounds at the tire will have a greater effect than 3 pounds at the wheel. By putting a heavier weight at the tire you may have counteracted the lighter weight of the wheel, and then some because the weight is farther from the axis.

2004.5 Coupe/5AT/Ivory/Everything but front spoiler/Nismo CAI/Crawford V5/Crawford Cats/ Service Engine Soon

 

Unfortunately, I did not for my previous runs. But yesterday it was:

89 degrees
55% humidity
29.85 inches

I'll need to get into the habit of recording the weather.
Makes sense about the tires though, as torque=force * distance. I'm not sure about the actual weight of the tire. I was in such a hurry to get my rims that the only choices I had was Nitto-555's and Falken FK-451's. I went with the Falken's since I heard the Nitto's are questionable in the rain. The car felt like it had a tad more oversteer this morning (which I like). Discount tire told me to break in the tires for ~500 miles before testing the performance limits.

2004 Twilight Blue G35C / 5AT
Z-tube / Clear Corners / Racing Pedals
Enkei RPF1/ Falken FK-451 245/40 F 275/40 R

 

Temp makes a HUGE difference.

The configuration you did should create more UNDERSTEER. The ratio of back to front wideness has increased. Your front is a little wider and the rear is a little more wider. Back gets more traction now at a greater rate than the front.

I like tire shoping at www.edgeracing.com because they list the tire weights for those they sell. Yours are on there, go check it out. Unfortunately I don't know the exact weights of the Pilots, but you'll see by checking different combos that you can pick up quite a bit of weight going wider.

Keep in mind that you're also picking up traction. With an automatic you probably have more traction than you do power. Thus, if both tires offer equal traction in a straight line with the pedal floored, the lighter tire would be preferable, in my opinion. That opinion changes when there is more power than traction, or when you're in the twisties. Then it all gets more complicated.

2004.5 Coupe/5AT/Ivory/Everything but front spoiler/Nismo CAI/Crawford V5/Crawford Cats/ Service Engine Soon