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Pirelli P Zero slicks, Forgeline wheels, vs stock wheels and street tires
Some data and photos comparing Pirelli P Zero slicks, Michelin Pilot Sport Cup 2, and Michelin Pilot Super Sport NON runflat tires.
Wheels are:
OEM Z06 For the street/DOT tires
19x10 front, 26.31 pounds
20x12 rear. 30.03pounds For the street DOT tires.
Forgeline GS1R For the slicks
18x11 front, 20.97 pounds
18x12 rear, 21.48 pounds Medium Bronze Anodized Power color.
Tires are: size/section and diameter/weight
Michelin Pilot Sport Cup 2, stock
Front 285/30/19 303x645 28.62 pounds
Rear 335/25/20 340x665 33.86 pounds
Michelin Pilot Super Sport, NON runflat
Front 285/35/19 290x675
Rear 335/30/20 340x705
Pirelli P Zero slicks
Front 305/680/18 DHA 295x680 22.84 pounds not mounted
Front 315/680/18 DH 310x675 27.15 pounds mounted
Rear 325/705/18 DHC 325x695 24-25 pounds mounted
Picture of all tires: left to right--front Cup 2, front SS, rear Cup 2, rear SS, rear P Zero, front/rear 315 P Zero, front 305 P Zero
Super Sports on the car
Pirelli P Zero slicks on the car
The MPSSs are the tallest tires, and I think I hear a rear rub occasionally when I am in Tour mode on the free with full fuel and passenger, but not enough to cause me worry. I have run them on the track in Track mode, and don't think they ever rubbed. They ride smoother, as they are taller section and non runflat, than the Cup 2s. I got them to travel with.
The Pirelli P Zeros on the Forgelines don't appear to rub (highway Tour mode and parking lot lock to lock testing) but I haven't had them on the track to say that 100%. On the highway (I know, they aren't street legal) they are softer than the MPSSs. But the transient response seems better than the Cup 2s, but they don't really even get warm on the road. Just felt crisper so I thought I would mention it.
The Forgeline/315 fills the front wheel well as fully as I think is possible. The Forgeline/325 is actually narrower than the Cup 2, and could maybe move out 10-12 mm. Might consider getting some new ones to do this, but right now my wheel/tire budget is depleted
Thanks to Gerry at CW4L. Prompt and easy to work with.
That front 680 is going to rub at the track. My 660s on ccws rub with compression.
We'll find out. So far with a passenger, full tank, tour mode, and a maximal stop on a 5% down grade, nothing has rubbed. You might have a little different offset on the CCWs.
We'll find out. So far with a passenger, full tank, tour mode, and a maximal stop on a 5% down grade, nothing has rubbed. You might have a little different offset on the CCWs.
Would really like an update on the larger slicks to see if the rub after tracking. I am sure the snow is gone from Utah by now.
Would really like an update on the larger slicks to see if the rub after tracking. I am sure the snow is gone from Utah by now.
Snow is gone
Unfortunately as of right now the forecast for Saturday, Opem track at Utah Motorsports Campus is for RAIN all day long, high temp of 56
I have the Pirelli Pilot Super Sports on the car now, not even the Cup2s
But the slicks are ready and if the forecast is wrong I will give them a shake down. But rain and low temps are likely to delay that. If it happens I will give an update.
Next Track day is May 20th. I am keeping my fingers crossed.
I envy you guys further south that don't have to put up with this weather. When I retire in a couple years I will be snowbirding to the southern territory for car and bike track days
Unfortunately as of right now the forecast for Saturday, Opem track at Utah Motorsports Campus is for RAIN all day long, high temp of 56
I have the Pirelli Pilot Super Sports on the car now, not even the Cup2s
But the slicks are ready and if the forecast is wrong I will give them a shake down. But rain and low temps are likely to delay that. If it happens I will give an update.
Next Track day is May 20th. I am keeping my fingers crossed.
I envy you guys further south that don't have to put up with this weather. When I retire in a couple years I will be snowbirding to the southern territory for car and bike track days
Head down this way. I am sure we can find a dry track for you in Texas...
Pirelli P Zero 315/680/18 on Forgeline 18x11 at the front
We took the Z06 to Utah Motorsports Campus yesterday. Raining in the AM, so mounted Michelin Pilot Super Sports, non-run flat, in the sizes noted above. Marilynn and I each did one 20 minute and two 30 minute sessions in the rain on those tires (a real experience but that is a whole nother thread).
Rain stopped and partial sun dried the track so I put on the Pirelli 315F/325R slicks on the Forgelines. Temps in mid to high 50's. Kept adding air pressure from 24psi to begin with but never got above 27 when hot, because they never really got hot. The slicks vs DOT tires-whole new world! I did 3 thirty minute sessions and Marilynn did 4. In the afternoon they were back to back so the Z was being hammered and never skipped a beat
But the question at hand is did they rub anything. Couldn't hear any rubbing, but driving with the windows open it could have been missed. Look for rub marks. The rears rubbed a little in the mid-to-inner rear fender liner but didn't appear to be a big area. There doesn't seem to be anything hard beneath that area when I push on it, but I didn't take the liner off to see. It seemed pretty minor. It may eventually wear through the liner, but the liner is getting chewed up pretty bad by, I think, all the rubber debris the tires kick up.
The fronts on both sides rubbed on the mid rear side of the liner and a little on the inner one fourth of the lower lip of the plastic "flare" on the back of the wheel well. Seems pretty minimal.
The tires themselves don't show any signs of rubbing.
So I think these tires on the 18" wheels with whatever offset CW4L built for me (I need to remember to ask Gerry) are reasonable because I don't mind a little rubbin'. I will keep running them. When the fronts need replacing I will try the 305's with the 325's on the rear and see how that goes. When the rears wear out I will try the 315's on the rear, 305's in the front, or even 315 square.
Hope this helps someone out there trying to decide what to do. Paul
We took the Z06 to Utah Motorsports Campus yesterday. Raining in the AM, so mounted Michelin Pilot Super Sports, non-run flat, in the sizes noted above. Marilynn and I each did one 20 minute and two 30 minute sessions in the rain on those tires (a real experience but that is a whole nother thread).
Rain stopped and partial sun dried the track so I put on the Pirelli 315F/325R slicks on the Forgelines. Temps in mid to high 50's. Kept adding air pressure from 24psi to begin with but never got above 27 when hot, because they never really got hot. The slicks vs DOT tires-whole new world! I did 3 thirty minute sessions and Marilynn did 4. In the afternoon they were back to back so the Z was being hammered and never skipped a beat
But the question at hand is did they rub anything. Couldn't hear any rubbing, but driving with the windows open it could have been missed. Look for rub marks. The rears rubbed a little in the mid-to-inner rear fender liner but didn't appear to be a big area. There doesn't seem to be anything hard beneath that area when I push on it, but I didn't take the liner off to see. It seemed pretty minor. It may eventually wear through the liner, but the liner is getting chewed up pretty bad by, I think, all the rubber debris the tires kick up.
The fronts on both sides rubbed on the mid rear side of the liner and a little on the inner one fourth of the lower lip of the plastic "flare" on the back of the wheel well. Seems pretty minimal.
The tires themselves don't show any signs of rubbing.
So I think these tires on the 18" wheels with whatever offset CW4L built for me (I need to remember to ask Gerry) are reasonable because I don't mind a little rubbin'. I will keep running them. When the fronts need replacing I will try the 305's with the 325's on the rear and see how that goes. When the rears wear out I will try the 315's on the rear, 305's in the front, or even 315 square.
Hope this helps someone out there trying to decide what to do. Paul
All good information. Thanks Paul. I don't know this but I would guess the square set up would make the computer mad. I am hoping we can get away with 685 front and 705 rear like you did. I bet the 305 front width would be better. There seem to be plenty of these PZero's out there. Our next track day is the casual fun of the Corvette Classic in Ft. Worth this coming weekend. Guess I will put on the Cup 2's.
Had to go out in garage and measure the Forgeline 18x11F and 18x12R wheels to calculate offsets, which I thought I should add to this info thread.
Measured/calculated OEM 19x10 and 20x12 wheels and got offsets of 44/59mm, compared to known OEM spec of 43/59. So I think I know what I am doing.
Forgeline 18x11F, one inch wider than OEM used on front, had positive offset of 47.5mm, meaning the wheel was moved in 4.5mm but is still a little wider both inside and outside. From the pictures, I think this is good. Neither wheel or tire appear to contact any suspension parts.
Forgeline 18x12R, same width as OEM used on rear, had positive offset of 51mm, meaning whole wheel was moved 8mm closer to outside of rear wheel well. From the pictures, it could probably go a little further. But there should still be clearance with Hoosier 345 x 18 slicks with this offset.
I welcome forum members to critique my findings and comments as I wouldn't want someone to drop 6k on a set of wheels and discover I was fos
Do you have PDR data and what were the lateral G's you were pulling? Is your car a Z07? The stiffer Z07 springs definitely help and how hard you are leaning on the car will make a big difference. With my FE6 car I was running the liners with 660 fronts and 680 rears.
You have to be careful as in the front you will wear through the plastic spat and eventually be hitting the fender lip itself. On the rears, there is a metal bracket behind the push pin towards the rear of the of the fender and I wore all the way through the push pin and liner.
I'm all in on the 305/660 and 315/680 setup at this point.
Do you have PDR data and what were the lateral G's you were pulling? Is your car a Z07? The stiffer Z07 springs definitely help and how hard you are leaning on the car will make a big difference. With my FE6 car I was running the liners with 660 fronts and 680 rears.
Car is 2017 Z06/Z07equipped Fantastic car, couldn't be happier.
You have to be careful as in the front you will wear through the plastic spat and eventually be hitting the fender lip itself. On the rears, there is a metal bracket behind the push pin towards the rear of the of the fender and I wore all the way through the push pin and liner.
I'm all in on the 305/660 and 315/680 setup at this point.
Sorry, I don't have any PDR info. I can do that soon, hopefully, going back to track this coming Sunday and will turn it on. Saturday the track was damp for a couple of sessions that I ran the slicks, and temp never above 56, and it was my first time on slicks so I was creeping up on how they handle, which to say the least is amazing. I started at 24PSI and kept adding some air, but never got "warm" pressure above 27, probably because the tires never really got warm. I need to work on getting that set a little better. My butt accelerometer said I was cornering harder than the Cup 2s. And I was holding my own in corners with other good cars that I know are on slicks, that I couldn't keep up with on the Cup 2s. But the bottom line is I haven't used them hard enough to be a test of your good question. I think I did see rub at all the points you describe though.
Will post an update on this thread when I have more info. Thanks for sharing your experience too I may well wind up with your recommendation. paul
Do you have PDR data and what were the lateral G's you were pulling? Is your car a Z07? The stiffer Z07 springs definitely help and how hard you are leaning on the car will make a big difference. With my FE6 car I was running the liners with 660 fronts and 680 rears.
You have to be careful as in the front you will wear through the plastic spat and eventually be hitting the fender lip itself. On the rears, there is a metal bracket behind the push pin towards the rear of the of the fender and I wore all the way through the push pin and liner.
I'm all in on the 305/660 and 315/680 setup at this point.
Dang Poor-sha would you quit buying all of the used slicks out there.
Did you make another track day today? Curious how those sizes worked. Our track day got rained out.
Brad
Pirelli P Zero slicks, 315/380/18F
325/705/18R
These tires, as anticipated, will take the Cup 2s lunch. I am some 45-70mph corners 3-6mph faster without feeling I have reached the Zeros full capacity.
These sizes will also eat your soft wheel liners
Probably a combination of rubbin on full bump and track debris thrown up/rubbin. They do not appear to rub on anything solid to speak of. Can't see any wear on the tires themselves.
I don't think I have gotten them up to full capacity, as I am still working on optimal pressure, and it was only in to the mid 60s on Sunday, and then we were rained out too. But they did peg the g-bubble on the PDR!
I will keep running them and when they wear out will go to the 305F/315R combo that Poor-sha likes. That may well be the ticket.
I finally got to run my new track wheels and tires for my stock 2017 GS. I have steel brakes and run the DSC controller (a must for DD). I bought the BC Forged RZ05's from PK Auto Designs. They did a great job with their recommendations and the wheels look great. I had them mount the R888R's on them. 315/80-18 front and 335/30-18 rear. I ran them last weekend at MSR Houston during a Chin track day. I saw no unusual intervention from the traction control or nannies running in Track mode with PTM set to Sport 1.
I am not a real hard charger but I thought the tires felt great compared to the Cup 2's, the only other tire I have run on the track. These size tires rub at full lock on the front but my wheel well liners don't show any wear after the track day. The wheels are 18x11 front and 18x12.5 rear. I drove the car for several days on the street to heat cycle them as best as I could. I remember one comment on another post about them sounding like snow tires and I would say that is pretty accurate. I started at 26psi on a 95 degree day and they heated up to about 33psi after each track session. They wore very evenly. It looks like one track day might have taken about 20-25% of the tread. After these tires are gone I will likely go to used slicks provided Poor-Sha hasn't bought all of them up.
It seemed like researching this wasn't as simple as I thought. So hopefully someone looking to do the same thing with the same car will have another helpful piece of data from which to make their decision. Thanks for all of those who posted before me with their experiences. It helped me order the new wheels and tires "mostly" with confidence.
Next track: COTA in October. Should be a real kick.
Had to go out in garage and measure the Forgeline 18x11F and 18x12R wheels to calculate offsets, which I thought I should add to this info thread.
Measured/calculated OEM 19x10 and 20x12 wheels and got offsets of 44/59mm, compared to known OEM spec of 43/59. So I think I know what I am doing.
Forgeline 18x11F, one inch wider than OEM used on front, had positive offset of 47.5mm, meaning the wheel was moved in 4.5mm but is still a little wider both inside and outside. From the pictures, I think this is good. Neither wheel or tire appear to contact any suspension parts.
Forgeline 18x12R, same width as OEM used on rear, had positive offset of 51mm, meaning whole wheel was moved 8mm closer to outside of rear wheel well. From the pictures, it could probably go a little further. But there should still be clearance with Hoosier 345 x 18 slicks with this offset.
I welcome forum members to critique my findings and comments as I wouldn't want someone to drop 6k on a set of wheels and discover I was fos
Bumping this thread, as I'm looking at options for slicks and wheels. The offset you measured for the 18x11 front is 47.5 mm. That's 10 mm inboard from what Signature wheels uses, as well as Forgestar. Any rubbing during the track season last year?
I'm in on this conversation as well. I've got 17 Z07. Just installed Hoosiers R7 on my stock wheels, only heat cycled them. Gonna do -3 camber front and -2.7 rear and try them out. Anybody tried these? comments? Would doing the CW special offset wheels and the Pirelli 18" slicks work best, or just a little better? or? Bout to have to buy rotors? Should I bite the bullet and do Girodisc steel replacement rotors? Or just go all out with the AP Racing steel setup ($8000+). These CCB rotors @$1300 each and pads @ $550 front sets are killing me!! Tough decisions and $$$. Seems with my 07 springs (FE7)etc., the standard wheels w Hoosiers, and my CCB brakes, I should be maxed out in the performance setup? Is there a clear benefit of the 18" wheels and the Pirelli's? Anybody running this stock wheel setup w Hoosiers? Seems Poor-sha has the FE6 and 18" w pirellis.
My neighbor has a Z07 convert that will/can never see a track or speed limit. Why does GM even sell a car. that cannot be put on any track, with these CCB brakes and harsh suspension? Better yet- Why does anybody buy this??? Jeeeeezzz! But I just can't bring myself to tell her I'll swap out rotors with you and give you $3000, she would not understand.
18s are lighter, and there are more affordable tire options. Search the forum and you’ll find that the Pirelli 305/660/18 F and 315/680/18 R is the hot setup. Signature (Competition Carbon now) wheels makes a track setup 18x11 F, 18x12 1/2 R that will be about 45 lbs lighter than stock with tires. BCForged also makes track 18s, and Forgestar F14 is a cheaper flow-forged option. Forgelines are American made, and more expensive.
I have steel brakes, non Z07. A buddy of mine has a Z07 and he cringes when he buys brakes. Was a great deal at Summit Racing for the ceramic rotors, I believe he paid $1050 each. From what I’ve read AP is a much better long term setup. 1” thick pads last long, and act as a heat sink, reducing brake temps.
X25 has a great build thread, he just bought a Z07. Poorsha is building a high powered GS, documented in the “autocross & roadracing “ section of the forum. It’s under general topics.
Good luck. 👍
Guys our competition wheels from Forgeline are build for the Track, warrantied for the track and made to be tracked. All the proper testing is done on these, and made with performance in mind first. They are load rated and we can assist with anyone whom needs a set. 18/18, 18/19, 19/19 and so on.
CALL/TEXT 440-915-6166
18X11 start at around 19 lbs
18x12 start at around 20 lbs
Few of the wheels we track and a great article about Forgeline and racing..
04-25-2018, 10:21 AM
Pirelli P Zero slicks, Forgeline wheels, vs stock wheels and street tires
