player_1

wrong our 18" are forged aluminum, which is part of the reason they are so light. approx 21-22lb the factory Perelli's are 23-24lbs.

I have no Idea about the Red line.

djt81185

http://72.14.203.104/search?q=cache:...ient=firefox-a

No they are cast

the recaros and forged wheels on even the base redlines were like consolation gifts for buying the saturn

hatrickstu

iTrader: (1)

thank you someone finally sees that its not which wheels are bigger when it comes to affecting the ratio that only effects rotating inertia depending on weight, its the overall tire height, come on guys common sense

hatrickstu

iTrader: (1)

an inch actually does make a big difference

ggarcia86

xenox did you feel a difference with the zzp highflow cat/downpipe and was it the 2.5" or 3"

djt81185

you'll find that is lacking here

vandy0419

Oh come on...its not an INCH DIFFERENCE!!! In diameter yeah, but the wheel (not including tire thickness) on a RL has a diameter of 226.86" while the Cobalt SS is 254.34"

d=Pi x (r x r) <~~can't get the squared symbol but same thing!

So every one revolution of the cobalt, it travels an extra 28" than it does on a RL...but don't forget the cobalt and RL have different VSS (variable speed sensor) calculations.

hatrickstu

iTrader: (1)

except your numbers are wrong. its more like 812.5 for the 215/45/18 and 844 for the 215/45/17 taken directly from pirelli's website

hatrickstu

iTrader: (1)

yes it is an inch difference do the simple math man a 215/45/18 tire is about 25.6 inches in overall diameter, a 215/45/17 is about 24.6 inches in diameter. my gosh people

vandy0419

I said yes it is in diameter but the actual amount of travel is completely different for each revolution of the two wheels.

hatrickstu, do you not read a full post?

djt81185

same width plus same aspect ratio means same tire sidewall height...17" vs 18" 1 inch difference omgwtfbbq 1" diff in diameter.they are different and it is enuf to effect it

told u common sense is lacking lol

vandy0419

I know, lol, everyone overlooked that I said it was a 1" difference in diameter but the actual area traveled is a HUGE difference! When are those 12 second times coming dan?

hatrickstu

iTrader: (1)

we arent talking about how many more inches is takes for the tire to travel, we are talking about overall diameter we have already established that an inch difference makes a large difference in how far the tire travels. i misread your post sorry

djt81185

ill be getting my 13.3 when i get my damned shift cables fixed

hatrickstu

iTrader: (1)

hey thats about what im running!

djt81185

u must have killer traction and 60' then

i ran 14.0 @ 109 lol lost .7 due to shift cables not allowing me to engage 2nd fast

hatrickstu

iTrader: (1)

not a great 60 foot, 2.16. holy cow you must have been spinning like hell though to trap 109 in a 14.0 run

Tomtwtwtw

I went by Tirerack.com, and used the OEM tire (which for the Redline is a Dunlop, not a Pirelli). Clicky.

Not all tires are the same, even if the sizes are, but I'll agree that it's a far cry from Pirelli's 844, so who knows? Even at the numbers you say, that's not enough difference to make up for the difference in shift points.

djt81185

no...I just make lots of power

my shifter cables/clutch prevent me from shifting 1-2 fast...my datalogs show im losing .7 seconds on teh 1-2 alone

also that is with a 2.3 60'

if I had a 2.1 id be in the 12s...what tires u running?

hatrickstu

iTrader: (1)

i realize all tires of the same size arent the same height, but the size of the tire you gave and the pirelli are both 24.6 inches high, and i would put money on pirelli being more accurate over tire rack any day, especially considering dunlop doesnt even have the revs per mile on their site. i still think it would effect ratio somewhat, but not by as large of a margin that this particular thread starter is talking about

hatrickstu

iTrader: (1)

stock pirelli's son!

Tomtwtwtw

That's exactly what I said in the 2nd paragraph! But you're right, the numbers don't match up either way. If the Cobalt's tires are 812 revs/mi, then for the Redline to shift at 64 vs 72, the tires would have to be in the neighborhood of 900 revs/mi. I still say he's spinning.

Xenozx

the 64 vs 72 may be 65 vs 70 or 64 vs 71, I dont know exact, especially his car, but I know mine seems to be @ or above 70, and he says is his below 65.

I am running the 2.5 HFC, and to be honest, I would have rather bought a header then the HFC. There may have been some gains from it, but I dont believe it to be as much as you would get from a header. It may complement a header though, as I think it did with my bro's car. It does make an odd noise, so you may want to think twice before you purchase. Mine is very non noticable, but my brothers is f00king anoying.

As far as rim weight, I believe the Cobalt w/ tires weighs in at 24 lbs, and the Redline at 21 lbs per rim.

Rims alone are 21 for cobalt and 18 for Redline.

Hes not really faster then me though, he only seem to be faster when I am way out of my power band. a 20 MPH roll in 2nd means I am sitting at like 2000 RPM's. He pulls from this kinda launch. From a 40 where we both are peak power, we are neck and neck except when he shifts and then I start pulling.

The dood w/ the 2.6 inch pulley. Obviously you have bigger mods then us. You would have had to get tuned w/ the 2.6, where as me and my bro are on the stock GM stage 2 tune. You better be faster then us or I would feel sorry for you. I ran 13.7 on stock BALD perelli's (still on my car) w/ a 2.25 60 foot in blistering heat. IM sure I could hit very low 13's w/ the tires in my closet and normal temps out.

Blown 4-banger

Thats strange, I thought they would have use a slighly taller tire profile. Like a 215/50/R17. To make up for the smaller rim.

Darksun

Well...... after cooler blew up and had been dumping coolant through my motor and like an ass since i didnt know where the coolant was going i kept refilling it like a noob. But if i didnt the intake temps would hit in the 300's and the car wouldn't want to move period. it was like the motor had no supercharger it could barley pull it self. plus dealer used air tools on my car last time they replaced my exhaust system so now when trying to fix my cat again since the coolant running through it burnt it out i guess the studs cross threaded in the header and they came out one last time. Plus the dumbasses cross threaded the 15mm bolts onto the studs so you had no choice but to back them out. Good times folks. I might have to lemon law the car cause it looking like my cars gonna be gonna another 2 months thats 4 1/2 months outta 06 i would have been with out my car thats a No go on that one i cant have that. There mad they droped 14-15grand on repairs into my car already and dont wanna fix it again properly it seems. I have a base coupe as a rental and the gas milage is superb so im not complaining too much at this point. My cobalt s/c was down to 18mpgs highway and god knows what city so i rather not be driving it right now with the current gas prices anyway. I can get the parts to be fast again at the drop of a hat with cobalt addiction only 15 miles away from me plus so many cobalts with used parts they dont need but if i do get my car back in any decent shape i may have to leave it stock fo good, its to damn fragile at this point.