Wnts2Go10O

iTrader: (12)

yea, i know. ive seen the video. i just didnt know that: sidewall = tire spin control. you learn somethin everyday

flintwrench69

iTrader: (11)

When I had my 10 bolt one of the reasons I slipped the clutch was to avoid shocking the tiny rear & breaking. After getting some track time in I do understand the concept of slipping the clutch & wheelspin to avoid bogging.

Me & a buddy of mine were talking about the downside of slipping the clutch & that is the creation of heat & the effects it has on the clutch fluid. This happened to me this past weekend on my 1st track outing with the 9 inch.
I figured since I got the near indestructive 9 inch & 4.11s I wouldnt need to slip the clutch at all but that proved to be unsuccessful. I was spinning bad off the line & I understand why after reading this. The Nittos I was running had a much softer sidewall than the MT DRs I am running now. I didnt slip the clutch & still it had an effect on my clutch pedal feel at the end of each run & I couldnt shift the car for a few minutes. Changing the fluid might help that problem. I would imagine the LS7 clutch is not considered to be a slipper clutch? I have never heard of such a thing. The info posted here was very helpful & hopefully should get a much better 60 time on my next outing.

flintwrench69

iTrader: (11)

Whats it good for?

blue99fbody

iTrader: (5)

I kinda skimmed through this thread and see the slipper clutch keeps coming up and while ideal its expensive and not at all Ment for any street driving. Ill stick to slicks and dumping the clutch, radials suck with the stick and slipping the clutch promotes extensive wear.

Bitemark46

I've done both and I was a pro-dumper but after testing it I have found that by slipping it, yields a better 60'(for me atleast). I can come out at least 200-400 rpms higher with a slip.

I think the biggest reason on why it worked for me is because there wasn't any slop in the drivetrain. And on a lil tire (26") I didn't have much forgiveness on the sidewall.

Introducing massive wheel speed on a stationary object at 100% power is going to go up into a spin faster than say applying the same wheel speed at say 90% power. But either way you should have adequate IC and AS values.

Slicks can get away with a longer IC and lower AS. DR's need a short IC and a high AS due to a stiffer sidewall.

-Mark

98blueSScamaro

iTrader: (14)

slippers can be driven on the street i know alot of people doing it.but there are a solid steal type clutch so there make a ton of noise. I still do not have a slipper tho wish i did.

I am running a Tex oz700 with 25thousand miles on the street and over 200 track passes. Still grabbed hard and i do the fast slip to help preload.

But what do i know i cant drive stick i only got my junk to go 10.88 with a cam and stock junk LS6 heads and factory stock 6speed.

BrianSF-GA

I am glad to see your OZ700 is holding up well. I have roughly 5,000 street miles on one (no racing) and it's about to become primarily a track car. Are you running an aftermarket "master" ... Tick / McLeod ?

98blueSScamaro

iTrader: (14)

Nope still the stock 98 masterbut i up graded tothe tick this year so we will see if it helps

CaMaRo67RS355

iTrader: (75)

Few questions whats the reason behind using a broom handle to keep the clutch engaged when sitting? Also what is the difference between a regular alignment and a drag racing alignment?

98blueSScamaro

iTrader: (14)

the alignment with street tires and fat's and skinnys is way differnt. the front end contact pad change's on the tire. i found out the hard way after wasting a set of fronts

and the handle is by hand if some some is taking forever too stage togive my leg a rest so i can hit my shifts better. Some auto guys like to play games with us stick cars.

MYSTIC-1SC

iTrader: (14)

We sure do Robert! LOL!

Tally TransAm

iTrader: (17)

i personally dont slip the clutch at the track. depending on conditions i dump it between 5000-5500 on the two step. i get alot of axle movement which i know is a result of my shitty rear shocks but the car hooks up fairly well and cuts pretty consistent low-mid 1.5's. pretty confident after i get some rear shocks and a sway bar i should be able to bump the rpm/boost level and drop into the 1.4's

Camaro9969

iTrader: (12)

I have a question on shift point i'm looking at my Dyno sheet and the torque starts going down at 5200 rpms that seems low to me and it falls steady all the way to 6700 rpms so where should i shift at 5500?? highest torque is at 5000rpm but that seems low for a cammed LS1 what do you guys think?? the sheet is 394rwhp with 375tq max. thanks

vetteboy2k

iTrader: (5)

You should shift over peak rwhp. If your car peaks @ 6700 try shifting @ 7000(as long as your car is built for that rpm) and change 100 each time to see if you pickup.

A great way to get very close is to take an average of the hp under the curve in the area your car is racing in.

ie. If you shift at 7000rpms and your car drops to 4800rpms then add up all the rwhp numbers per 100 increments and come up with an average number.
Now do the same if you were to shift @ 6500 and drop down to 4300rpms and see what that averaged number is. Whatever is the highest value is where I would start and you will be close.
I also look at peak torque afterwards. It's nice if your shift recovery point lines up around peak torque.
The above is important for getting the best and often overlooked or misunderstood.

vetteboy2k

iTrader: (5)

Just to add.
Even with slicks it's often better to get some clutch slip whether it's done inherently by the clutch or executed by the driver's left foot.
The latter being more difficult and often less consistent than a full dump.

If when you dump the clutch and:

- the tires spin excessively than a slip will benefit by decreasing the amount of that wheelspin and maintain rpms which is critical.

- the tires spin on initial hit (spin-bog) and then bog further out then a slip of the clutch will benefit and prevent the motor from bogging and maintain rpm.

You want the car to launch like an auto with steady smooth force not a hard hit then recovery by the car/motor. If the tires are spinning and the clutch is slipping at a consistent steady rate the car will pull out of the hole best and maintain rpm.

This is not easy to achieve this via a convential or a slipper clutch but when figured out it will be very rewarding and produce the lowest 60' times.

If you can maintain rpms from going below peak torque you car will 60' great. This is very hard to do with a convential clutch hence why you see the big dogs that utilize high rpm for power running slipper clutches.

Now go a step further and dissect a shift. On the 1-2 most cars get alot of wheelspin whether they know it or not. We often saw a spike of 20+ mph on data logs on 450ish rwhp cars. Now introduce a slipper clutch and that 25 mph spike is reduced to 3-5 mph and the rpms are still maintained. Less tire spin and keeping the rpms in the ideal zone especially on the shift recovery is a great combination and the key to maximizing a combo.

With vettes, the rear differential are significantly weaker so slipping the clutch on the launch is almost imperative for driveline longevity.

There's so much more to it but that the general gist of it.

vetteboy2k

iTrader: (5)

The broom handle is the keep clutch parts from touching in an effort to cool the clutch. This theory is often debated on whether it works. Cooling the clutch between runs is a good idea however possible. Another great tip is flush through fresh clutch fluid after a few hard runs either via the reservior or a bleeder.

Drag race alignment is setup straighter to allow the car to roll better in a straght line in general.
Also one should consider what happens to the rear tires on the launch and compensate for that.
Also a drag race alignment should not be setup for a crown in the road like most street alignments are. (caster)

Street alignments take into account going around turns and have more negative camber built into for handling.

Have a professional do your alignment because if your not careful you can make the car unstable. Even on the drag strip you want some handling characteristics especially at high speeds for stability ( some toe in up front).

vetteboy2k

iTrader: (5)

Taners car is silly fast and his driving is great. I'm confident that car would pickup tenths in et with a properly setup slipper clutch.

fly pantera

iTrader: (9)

rob z is very good at getting the most out of his cars to bad he got banned,and his car was just h/c/i

98blueSScamaro

iTrader: (14)

There you go words from the man thanks for joining your info is always good info

Rob

TAGOES11S

iTrader: (13)

I personally think most people that slip a clutch need to inorder to compensate for a gear/suspension/power/tire combination that doesn't work great together. Get all that setup properly and working together and you can get launch hard with a dump. I dump a mcleod twin off a two step on nitrous and cut 1.40 60's. I plan on cutting 1.3x's this year as I dropped 170lbs off the front of the car.

Slipping a street clutch will add a lot of heat, wear it out much faster, and be inconsistant.

A high $$$ slipper clutch is Not good on the street, plus most that run them go through several sets before getting them setup to work properly.

Slipping a clutch, dumping a clutch, or using a slipper clutch unfortunetely isn't going to be as quick as a properly setup stalled auto.