hi gang,
couple of questions for ya.

i've tried the MT ET street radials. like them so far. but its getting time to swap for some new ones. these dropped my 60ft down from 1.9-2.1's to 1.6's and 1.7's.
i would like to try "slicks".
1) would this be a wise or worth while move?
2) what are u guys running?
3) any issues?
4) rims sizes?
i had to purchase a pair of 17in wheels (rims) to install the ET Streets.
5) would i have to buy another set of rims to run slicks?

any and all help would be appreciated.
thanks,

 

A "slick" has more rolling resistance and will slow you down somewhat. I run faster on a radial, by 2-3mph. If you do not have traction problems than it may just slow you down. If you could leave harder with a true slick and improve your 60' significantly it may be worth more than you'll lose on the top end.

To the best of my knowledge you will not find a 17" slick. You will need (in most cases) a 15" rim.

 

thanks,
just spent the past couple of hours researching this issue...i have a c5. using the MT Et street radials. was looking to lower my 60ft and overall et.
my best pull to date is 1.68 60ft and 11.45 at the end. was trying to better that. traction seems to be ok. minimal spin depending on the burn out...just notice others using slicks and getting 1.5 60ft's or so. and getting really close to the 11.0 at the end.
didnt realize that they had 15in wheels. i've made about 15 passes on the current tires and may need to re-shoe the rear and didnt want to waste any $$$, especially if i could get something that could get me into the 1.5 60ft range..

thanks again,
dan

 

If you can really hammer it off the line, a good biting slick might get you that 1.5x 60'. This is however kind of hard to do with an automatic unless you run a brake. Are the other cars your looking at A4s?

At 11.45 I am going to guess your not running the stock converter.

EDIT: You sould be able to get a LOT more than 15 passes out of a set of tires. I made 12 full passes two weeks ago in under 1 hour and have a total of 30 or so passes on my slicks and I even bought them used with 75% tread and they look like they'll last the rest of the season pretty easily.

 

hi, yank2800 is my tc. also running a maggy setup. runs really strong on the last half of the track. im still learning. been doing this for just over 1 month now..been to the 1/4mi track twice. 1/8mi track twice. dont really want to change anything else on the car. really happy with it. was thinking that if i can get into the 1.5's i might be able to get a better shot at the lower 11's...not interested in getting into the 10's (yet). i have the rollbar setup but not interested in installing a full cage. i drive the car to work, grocery store, etc. not a dd but use it as my cruiser..
as for the other cars. yes. several are auto's. running about the same hp/tq as mine. 466/455t..probably need some more track time. learning i guess.
thanks for the response, im always looking for helpful hints and info.

peace

 

Well, as luck would have it the stupid forum erased my post when I was trying to post it....

OK, I'll try this again. I am surpised that CFI-EFI has not posted about the "hook factor"

The hook factor is a measure of how quick (ET) the car is for a given MPH. You multiply the ET by the MPH to get your hook factor. A well set up car will have a hook factor at or near 1320. I am assuming you are trapping at 120-122MPH, so your 11.45 ET will yield a hook factor of 1374.

This is one reason you will see "race" cars run quicker with less MPH. The chassis is setup to optimize the first 60-330' (this is where you spend most of your time). For the ideal hook factor, a MPH of 120 would yield an ET of 11.0.

As far as launch technique, how are you currently launching the car? Some have reported that leaving off idle and letting the torque converter flash will lower your 60's. The maggie should make plenty of torque from idle the mid range so you may want to try that. If traction becomes the problem and you cannot leave under WOT a slick will help, but make sure your drivetrain is in good condition... A dead hook with can create a dead rear end... Also, as minimal as the effect may be, if you stage real shallow you will get a short run at the light before you break the beam. It's not worth a lot, but every little bit counts, no?

Good Luck!

 

wow. there so much i dont know yet...
take a look at the links. i was launching at about 1900-2000rpms. with tract/con off. in competive mode the car would start to "chug" while reving up on the line at about 1500. so i tried turning it all off and it did better. here's the links:
http://pg.photos.yahoo.com/ph/usd2si...&.dnm=6116.jpg

here's my #'s:
http://pg.photos.yahoo.com/ph/usd2si...9d.jpg&.src=ph

this past friday night. i let my 17yr old daughter try it out. with tract/contr on. she started off the line and spun, lifted and re-rolled into it. her 60ft was 3.1sec, her speed was 117, with a 14.6 et.
i was thinking that this was one of of those fluke readings on the tickets until i went back and looked at her first 3 runs. all were right around the same mph. but the diff was the 60ft and over all et..

IM SO CONFUSED

any and all advise is appreciated. would i be better off with putting the stock torque converter back in???

EDIT: i forgot to add my ride has 3:15's in the rear, and the hardened output shaft.

 

Some torque converters will brake-stall well, while others will try to move the car as low as 1500rpm. Why don't you try launching at or near idle, or ~1000rpm. When you see that last yellow light, hammer it. If you get a LOT of spin some slicks might help. Also, I have managed 60's as low as 1.72 on Falken 245/45/17 tires, but I certainly can't leave the line at WOT. Here is what I do: When I see the last yellow bulb I hit the gas and flash the converter, once I have broken the beam and the car is rolling I let off the gas slightly and lean back into it feeling how the car is hooking and apply throttle accordingly. The important part to remember when trying to control spin is you need to relax your body so you can feel what the car is doing.

Next time out, stage shallow. Just as you light the first pre-stage bulb, inch forward really slow until the second bulb starts to flicker, roll just enough to get it solid. This will get you staged shallow. Bring the RPM up to ~1000rpm, or leave it at idle. When you see that last yellow, nail it.

And no, you wouldn't be better off with the stock torque converter. The torque converter is allowing the engine to operate where it makes more torque/HP.

How much air are you running in the tires?

Also, when do you plan to head back out? I will be looking for results...



EDIT: Just a word of caution, if the car starts to get a squirrely the best thing you can do is get out of it sooner, rather than later. There are a couple of "C5 nailed the wall" threads around and you have plenty of power to put you there on a bad run. My car tracks really straight so I can usually ride out most wheel spin. I suppose it is a decision you'll have to make, just be careful and have fun.

EDIT 2: Gearing will have a lot to do with your 60', assuming you can hook the car up. With a 3.15 I feel your leaving a lot on the table, 3.73's, or 3.42's may be the way to go, but you'll find real quick that your going to have to sacrifice driveability for ET.

 

Most Corvette are running the 16" rim's with the slicks
I have Hoosier 28/10/16. I have not run them yet. but with the nitto DR's I got a best of 1.89 60 and a 11.20 131.56mph so I need slicks. But it really sounds like you have a good package running 11.4's at 120 and not breaking anything. I would stay with the DR's, If you only have 15 passes on them they will be good for at least 100 passes. If anything my BFG DR were hooking better at 100 passes. Use them until your 60' times fall off and make sure it is not just bad track prep.
Thanks Chuck

 

hi, im happy with my setup. just was on the train of thought that if i can get into the 1.5xx range i might be able to get into the lower 11's... traction seems ok when launching. heat up the tires until i see smoke rising up then let it roll out. line lock helps alot. taking in the input from vetdrms and yourself is leading me to believe that im ok..just need to learn some more about the sport. practice, practice...
the shop that helped me set it all up has been great. great advise. they know im a squid (newbie) to this stuff. i wanted a mid 11sec daily driver and that is exactly what i have. wouldnt change a thing...
havent been back to the track yet to try the helpful hints out. but im itchin to go.. ..gonna try and make the event on the 18th here in the dfw area. not expecting a whole lot. but dont want to look like to much of a dummy either..
gonna try it off idle like vtdrms suggested.
i had no idea that u could get that many passes out of the tires..see, another squidly perception. i've been running the tires at 17lbs. tried 18 and spun them, tried 16 and didnt like the way they launched. something didnt feel right..and felt squirrely(sp?) at the end..so 17 it is..
i am always looking for advise...
thanks all.

 

oh yeah. i forgot to ask. where do u find 16in rims/wheels to fit a c5?
i also did a major search for some front skinnys to fit. but only found the ccw package. to much $$ for me. hard to justify that kind of dough on something that i would rarely use...are your 16in ers a straight bolt on? or did u have to do the fbody brake thingy?

thanks,
dan


EDIT: BTW. if u looked at those tickets you'll see reaction times of .7xx or .8xx. they had instant greens... never knew how to react. or when the green would hit...sometimes right after staging, others a couple of seconds later...thought they were playin with us..

 

FWIW..........On my 97' I run the BFG 345/30/18 drs.................1.52-1.55 60' all day long, 6.99 1/8 and 10.97 @ 122+.
tubbed and on a 18 x 12 rim
I just wore out my 1st set after 64+ passes and 2000 miles
Just picked up another used set and need to swap them as I started to get a tad bit of wheel hop.............

 

thats awesome!
wow!

 

As far as the 16" rims go, any late model Camaro or Firebird rim will fit as long as you grind down the top of the rear spindle on your C5. I have two sets of 16" wheels and tires (28"x 10.5" Hossiers and 26"x10" MT Et Streets) both run fine on the car after grinding down about a 1/4' or so of the corners and top of the rear spindle to gain clearence for the inside of the rim.
My 28" diameter tires will rub a little on the inside of the well area on a hard launch but not to bad.

 

I have used both the ET Street bias ply (11.5/16) and MT ET Street Radial and found my 60' is about the same on each. The bias ply may be .01 better but that could be because of the lighter wheels (CCW Drag package).


the drag radial can get 1.5s and you seem to have the rwhp to get it but I think you might need more converter and/or more gear.

my current setup is 3.90 rear and 5000 stall converter.
Car gets plenty of street use (250 each way to once a week) and 60's high 1.5s to low 1.6s with 405 or so rwhp.

Perfect the radial launch.

One thing to keep in mind with bias ply is that a bias ply rear tire combined with a radial front tire, will produce some sway at the top end. Since you were uncomfortable with the 16 psi radial, you will likely not be comfortable with the bias/radial combination. I wasn't and I trap 117-120

 

Looks like my "hook" factor is pretty decent... 11.05 @ 120.82 mph...

 

thanks everybody...this place is awesome...great info all around...