PDA

View Full Version : What Am I Doing Wrong??(bad Day At The Track)



WELTERRACER
09-25-2004, 11:20 AM
I just got back from Tristate raceway in Iowa!! Best time i ran was a 13.02 at 109.38mph!!

My car is a 1984 chevy camaro with updated body panels!! 355engine 10.1 comp. Dart pro 1 heads (ported) Dart cool can intake, 750 demon carb.. crank scraper, windage tray, Crane cam with 234/244 duration 488/498 duration and 112 centerline.. i am also using harland sharp 1.65 roller rockers and Stud girdle!! I have underdrive pulleys and 1 5/8 headers running threw single 3inch exhaust with a dump cutout!! T-56 6 speed with zoom clutch, 4.10 gears and 275/50/15 quick time drag radials! I am guessing the car with me in it weights about 3800lbs!The car picked up 3 tenths of a second and 2.5mph with the exhaust dump removed!!

No matter what i did i couldnt get it to come out of the hole very well,, My 60 foot times were 2.02-2.200 .. car would either hook to hard and almost kill motor or i would BLOW the tires away!!(made 7 passes)

I was pulling about 6000rpms threw the traps and shifting at 6500 in each gear!!

I was hoping it would have run a 12.50 or better!!(car had previously ran 12.80s with a TH350 and a 2500 stall convertor on streat tires!

My buddys 87 pontiac fiero (which has a LT1 in it dynoed at 300hp at the wheels) went 12.5 at 116 on first run... His second run Broke the LR axle in TWO!!

My car looks like this one.... :camaro:

ProdigyCustoms
09-25-2004, 01:30 PM
Most of it is in your starting line ratio, first gear ratio X rear ratio. As you are finding out, it is nearly imposible to launch. Those short times are bad, a stock late model does that with 13.80 to 14.20s. If you got it to dead hook, and could side step the clutch at 3500 or so, she would probably go 1.75 short times and pick up .5 total at the big end.
Your Automatic had a taller first gear and a a softer hit, so it actually would 60 better. I have a car similar right now (84 HO Z28 with a almost indentical motor) that has the same kind of problem, first gear is so low (T5 and 3.73) we cannot throttle down anytime in first without blowing the 255/50 tires off at 2500. We have a set of Quick time Pros to post a number at the track, but in a stop light war it will get is azz handed to it by slower cars.
Buy some slicks, and see if you can brake something, LOL!

TurboLark
09-26-2004, 07:53 AM
Whats you rwhp? What rpm were you launching at? Did yo slip the clutch or dump it?
Your 60's just suck. I'd get some real race tires(slicks or ET Streets) and drive it like you stole it.
My old 88 Mustang GT ran 12.90's with only 227rwhp. Slicks and a 5100rpm clutch dump got it into the 1.6 60's.
And work on dumping some weight.

CAMAROBOY69
09-26-2004, 10:51 AM
Yup you need real race slicks period. With 109mph trap speed you must have just a little more HP than me so you should be running real close to 12.5 like you mentioned. The only difference I see from your TH350 will be weight. The T-56 is a heavy beast and adds weight thus slows you down .10 for every 100#. It is definetly your tires. If you ran really good slicks and launched about 3,000rpm you should have no problems breaking into the mid 12's again with a 60' around 1.70 or 1.80.

CAMAROBOY69
09-26-2004, 10:54 AM
I just noticed something else.. 25.8" x 10.8" That tire height is going to suck with 4.11 gears. If you can go taller try that. I had 28" x 10.5 on my car.

WELTERRACER
09-27-2004, 04:55 AM
Whats you rwhp? What rpm were you launching at? Did yo slip the clutch or dump it?
Your 60's just suck. I'd get some real race tires(slicks or ET Streets) and drive it like you stole it.
My old 88 Mustang GT ran 12.90's with only 227rwhp. Slicks and a 5100rpm clutch dump got it into the 1.6 60's.
And work on dumping some weight.

I at one time had the formula for weight and ETs and it said my car made 360hp at the Wheels..(atleast thats what the formula said it takes to push my car into the 12.80s)

I was launching at varied rpms.. i tired 2500, 3000, 3500... the the rpms almost killed the engine when i dumped the clutch and the 3500 launch smoked the tires..

I thought my tires were GOOD SLICKS??

CAMARO BOY!! ADDING taller tires would drop my rpms threw the traps thus causing me to have slower times!! My motor pulls to about 6550rpms.. I am only hitting 6000-6100 threw the tramps

WELTERRACER
09-27-2004, 04:57 AM
Yup you need real race slicks period. With 109mph trap speed you must have just a little more HP than me so you should be running real close to 12.5 like you mentioned. The only difference I see from your TH350 will be weight. The T-56 is a heavy beast and adds weight thus slows you down .10 for every 100#. It is definetly your tires. If you ran really good slicks and launched about 3,000rpm you should have no problems breaking into the mid 12's again with a 60' around 1.70 or 1.80.

The T56 Is alot lighter than the 700r4 i had in my car last year and i could only launch at 1500rpms and i still got the car to run 13.05 at 107mph (last year..)

CAMAROBOY69
09-27-2004, 04:58 AM
Adding a taller tire allows you to rev higher since your almost killing your engine at 3,000 but at 3,500 burns them. Plus by the time you are reving 6,100 I am sure your out of your torque band.
The taller tire would get you traction and with a 3,500rpm launch.

CAMAROBOY69
09-27-2004, 05:00 AM
car had previously ran 12.80s with a TH350 and a 2500 stall convertor on streat tires
This is what you said in your first post.
Now you said 700r4. :dunno: Anyway I was just suggesting taller tire if you want to get rid of that 2.20 60ft time. I increased my 60ft and my trap speed by going from a 25" tire to a 28".

WELTERRACER
09-27-2004, 05:15 AM
This is what you said in your first post.
Now you said 700r4. :dunno: Anyway I was just suggesting taller tire if you want to get rid of that 2.20 60ft time. I increased my 60ft and my trap speed by going from a 25" tire to a 28".

Four years ago i had the TH350.. Then i installed the 700r4 because i was sick of driving on the highway at 4000rpms.. The 700r4 was a heavy pig and robbed lots of power.. It finally took a crap! and i went to a T56 after seeing My friend install his in his 67 camaro (protc)

Like i said i only got to make 7 runs and the stick is pretty new to me.. AUTOS ARE WAY EASYIER TO DRIVE..LOL!

It was hard for me to keep the rpms up off the line without breaking the tires loose!! When i did hook up it felt like a 11second car.. I even got 3 gear rubber with the slicks!

CAMAROBOY69
09-27-2004, 05:28 AM
I even got 3 gear rubber with the slicks!
You are using radial drag slicks.
Not trying to offend you, but like it was mentioned in this thread already by myself and everyone else...."Get some real slicks" then your problems will be cured. Period. :) :icon996:

LS1NOVA
09-27-2004, 06:15 AM
Antoher Vote For The Slicks. Also Make Sure Your Driveshaft And Rear Are Up To The Task, Then Dump The Clutch At 5000 Rpm And Have Fun.

TurboLark
09-27-2004, 06:52 AM
I at one time had the formula for weight and ETs and it said my car made 360hp at the Wheels..(atleast thats what the formula said it takes to push my car into the 12.80s)

I was launching at varied rpms.. i tired 2500, 3000, 3500... the the rpms almost killed the engine when i dumped the clutch and the 3500 launch smoked the tires..

I thought my tires were GOOD SLICKS??

CAMARO BOY!! ADDING taller tires would drop my rpms threw the traps thus causing me to have slower times!! My motor pulls to about 6550rpms.. I am only hitting 6000-6100 threw the tramps
Drag radials are NOT slicks. They are streetrace tires, and specific class tires. Using drag radials when not required to is like running a horse race with only 3 legs. I understad some folks like to drive to the track and not swap tires, fine, then use ET Streets or Quicktime Pros.
I dont think changing tire size is gonna do alot for you. You could put a 28x9 slick(actual height is 27") and hook up a 9 second car. You should have no problem with either a 26x8.5 or a 26x10 slick. If your drivetrain can hold together, try dumpng the clutch at 4000 or so. Of course ya gotta play with it to find the sweet spot.

WELTERRACER
09-27-2004, 11:52 AM
The tires i am using are HOOSIER QUICK TIME Drag D.O.T!

I drove to the track on these tires, although they are a little squirelly at highway speeds!!

CAMAROBOY69
09-27-2004, 11:58 AM
275/50/15 quick time drag radials!
That was your original quote in your first thread. It would really help if you had your posts correct when you are looking for help. :hah: :hah: :slap: :poke:

TurboLark
09-27-2004, 01:37 PM
The tires i am using are HOOSIER QUICK TIME Drag D.O.T!

I drove to the track on these tires, although they are a little squirelly at highway speeds!!
Ok, those arent radials. What pressure were you running at the track? What is your rear suspension setup? What is the tire size really? they dont make those in metric sizes.

WELTERRACER
09-28-2004, 06:24 AM
The tire size is 275 50 15

I started at 37lbs and lowered them to 35 with no difference and ended up at 32lbs on my last run but they went up in smoke off the line..

I have tubular lower control arms and panhard rod and lower control arm relocation brackets(which got rid of the wheel hop i usta have) and finally.. lowering springs (i realize it is setup more for handling than traction

Maybe i just needed more time and practice off the line!!

WELTERRACER
09-28-2004, 06:24 AM
The tires get way too squirelly for me below 30psi

TurboLark
09-28-2004, 06:41 AM
The tire size is 275 50 15

I started at 37lbs and lowered them to 35 with no difference and ended up at 32lbs on my last run but they went up in smoke off the line..

I have tubular lower control arms and panhard rod and lower control arm relocation brackets(which got rid of the wheel hop i usta have) and finally.. lowering springs (i realize it is setup more for handling than traction

Maybe i just needed more time and practice off the line!!
If you run that kind of pressure at the track, you may as well race on ice.
Now, I want to make sure what tires you actually have. Are they Quicktimeshttps://static1.pt-content.com/images/noimg.gif
or Quicktime PROShttps://static1.pt-content.com/images/noimg.gif

If you have the Pros, you need to run the pressure down to as low as 15. the regular QT's could probably go that low also. The pressure at the track is your problem. You just need to find someone with air at the track, or drive slowly to the nearest gas station to fill em up for the drive home.

WELTERRACER
09-28-2004, 06:55 AM
Its the top ones!

TurboLark
09-28-2004, 07:14 AM
Ok, now that thats straightened out..LOL.
Go back to the track and try 18 or 20lbs. try launching at 3500rpm. if you bog, raise the rpm 500 and try again. raise rpm until you spin, then drop the pressure another lb or 2. You will just need to adjust rpm and pressure until you find what gets you the best times.

WELTERRACER
09-28-2004, 09:31 AM
turbo lark.. do you have any experience with these tires?? are they any good.. I got em used but they are like new!!


I was scared to try them at that low of pressure as the car gets very quirelly at highway speed at 35psi..

THANKS FOR THE HELP!!,..,.Brian

TurboLark
09-28-2004, 03:30 PM
turbo lark.. do you have any experience with these tires?? are they any good.. I got em used but they are like new!!


I was scared to try them at that low of pressure as the car gets very quirelly at highway speed at 35psi..

THANKS FOR THE HELP!!,..,.Brian
Actually yes, I have had them. But, mine were the 31" tall 15" wide ones, so traction wasnt much of a problem for that car. It's been a while but they worked great for the midnight drags :3gears:
I normally use drag slicks at anywhere from 12-18lbs, DOT drag tires(bias ply like yours) at 15-20lbs, and drag radials at around 18lbs.

ProdigyCustoms
09-28-2004, 05:04 PM
My radial friends run a lot less pressure then that. Almost run them like bias tires in the mid teens or so. You should have no squirrly (spelling?) problems at 15 to 18lbs. We run 10lbs in QTPs (bias) on the street, no problem, and on the track at much greater speeds.
It still will not be as fast as the TH350 though.