slower at track...

[V8MUSCLE]

when i had only a slp loudmouth catback done to the car the fastest track time a ran was 12.8 at 109 with a 2.1 60'. with Michelin pilot sport 245/50/16 with the original rims.

i now have 275/40/17 sumitomo htrz on black machined c6-zo6 wheels, full exhaust but am still untuned. new plugs,nkg tr55's gaped to whatever mr. luos said to gap em at .055 if i remember correctly, new msd wires, fresh fluids oil/trans/diff/coolant/wiper/power steering/headlight... the fastest i could turn out was 13.5 at 102 with a 2.3 60' and that was flatfooting it all the way down the track... the others were 13.7-13.8 trapping 98-100 with 2.3 60'

the whole tire/rim when weighs a little more than the originals, maybe 8 lbs each, but i cant imagine it slowing me down that much.

i checked compression and each was where they were when i got the car.

the only other thing i can think of is ive been using sarges voodoo 2cycle oil in the gas. 1oz per 5 gallons. running shell v power.

the weather was pretty close to the same, maybe a little hotter but it was only 87, night runs.

what gives...

[shady milkman]

sumitomo tires suck dick bad...that is your problem ...id change that and see what you run..however with full exhaust you should have picked something up.


bad track prep, weather changes (aka humidity) all play a factor

[V8MUSCLE]

it didnt feel like i spun much if at all, im launching at 2500, a little higher than i was with the Michelins. yea, everything plays a factor, but a full second, i could understand a half second at the most thats a little much isnt it?

[shady milkman]

yeah it is. but if track prep was shit also..

[V8MUSCLE]

the people i was with were running a bit slower than usual, but nowhere near as much as me. i kinda looked like a douche bag cause i was runnnig my mouth predicting a 12.6-.7 and ran a 13.8. he has a a4 camaro that usually runs 13.4 and was running 13.6-.7.

[V8MUSCLE]

im a m6, forgot to mention that earlier.

[shady milkman]

well add heavier rims and shitty tires and it is understandable ...especially considering you were dumping higher than normal

[V8MUSCLE]

dumping at 2500 was my fastest. lower and it bogged, faster it wouldnt catch and id just spin like a douche. i guess ill throw the old rims on, i still got some meat on those tires and see what i run on friday.

[shady milkman]

dumping at 2500 was my fastest. lower and it bogged, faster it wouldnt catch and id just spin like a douche. i guess ill throw the old rims on, i still got some meat on those tires and see what i run on friday.

sounds like a plan.

[35th-ANV-SS]

If you were slower by two tenths on your 60' time, that would easily result in a 0.4 slower overall ET.

Did you try changing your tire pressure at all? And like said, those tires are shit. I've never used them, but have heard pretty much nothing but negative feedback on them from this site.

[V8MUSCLE]

i aired them down to 25. they hook a little better than the michilins i had, but they are also wider. im not breaking loose on any of the shifts, a chirp in 2nd and 3rd, thats it. with the michilins if i launched at 2500 i would just sit there and spin. the sumitomos as soon as i start to move mash the gas and it hooks. the people i was with said i wasnt spinning much if any.

[35th-ANV-SS]

Well if you had a 2.3 60' time either you were a) spinning or b) you car was bogging down badly.

[V8MUSCLE]

ill know a little more on friday, im gonna take the michilins on the old rims and see what they can do.

[BLK2KSS]

Well if you had a 2.3 60' time either you were a) spinning or b) you car was bogging down badly.

I concur

[rkvette]

why not try drag radials, on your old lighter wheels !! ? also get the drag tires a little shorter/not as tall /to help your rear gear /slightly lower, wont hurt !! rkvette

[Mr. Luos]

Weight in the wheels is HUGE!
It is rolling resistance. 8 pounds per wheel is enough for damn near a tenth.

And yeah....SumiHomo's suck. I have them on the back of mine right now. It is like driving on ice.

[shady milkman]

Weight in the wheels is HUGE!
It is rolling resistance. 8 pounds per wheel is enough for damn near a tenth.

And yeah....SumiHomo's suck. I have them on the back of mine right now. It is like driving on ice.

sumihomo ...i didnt know you had them on your car....im sorry

[Mr. Luos]

sumihomo ...i didnt know you had them on your car....im sorry

Just to get through the next month or so....then the car gets parked.

Will be burning them off soon....

[Firebirdjones]

when i had only a slp loudmouth catback done to the car the fastest track time a ran was 12.8 at 109 with a 2.1 60'. with Michelin pilot sport 245/50/16 with the original rims.

i now have 275/40/17 sumitomo htrz on black machined c6-zo6 wheels, full exhaust but am still untuned. new plugs,nkg tr55's gaped to whatever mr. luos said to gap em at .055 if i remember correctly, new msd wires, fresh fluids oil/trans/diff/coolant/wiper/power steering/headlight... the fastest i could turn out was 13.5 at 102 with a 2.3 60' and that was flatfooting it all the way down the track...

You say you are launcing harder now, without spin, and hooking better with the new wheels/tires, but your difference in 60 foot times aren't showing that.

Yes the weight in wheels are a double whammy. You have additional weight, but that's not just dead weight, it's also rotational mass, so it hits you twice as hard. I don't see a full second difference though.

There is so much that could be going on it's almost impossible to nail it down from the internet.

But the first things that come to my mind for one,,,,DA numbers. They change from 1 hour to the next and are never the same from day to day. Without knowing them, it's impossible to compare track times. You say your temps might have been the same, but that doesn't account for the humidity, dew points, (amount of moisture in the air) etc...can change the DA a couple thousand feet for any given temp range.

Other things that might be going on,,,possibly fuel pump getting weak, low fuel pressure?? Or any number of other minor mechanical issues. Or like has been mentioned, track prep?

Frankly, I wouldn't even worry about it. Make your changes and experiment. Have some fun.

[c5z28]

I lost .2et going from my 16's to 18" wheels. Circumference and rotational mass make a huge difference. You think all those homeboys with the 22" donks are any faster?