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1/4 mile times

so what kind of times are you guys getting in the 1/4 mile.must be some quick times since i see some nice mods on here.mine im getting in the mid 11's around 127mph.im doing the efi route now.cant wait to go play with(race) a friends ford gt.
Old 04-15-2007, 02:07 PM
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this isnt me.anyone from this group?if not thought you guys would enjoy it.and i dont know if it was posted before.im kinda new here.hi my name is steve and i have an addiction its called a porsche 930 lol

http://videos.streetfire.net/category/Porsche/16/0C0ED1CA-B912-4B42-871C-15FF88A6A51F.htm
Old 04-15-2007, 02:12 PM
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I'm not sure how quick my 934 replica will be, but it should be quicker than my GT2 GT700 because it will have similar power and 7-800 fewer pounds. Here is a video of the GT2 GT700.

http://videos.streetfire.net/video/000af64b-cb21-4de1-bcb0-982d01404c2a.htm

Cleve
Old 04-15-2007, 02:59 PM
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RG5, what were you runniong to get mid 11's out of the car without efi? That is pretty impressive. I have a bunch of stuff done to my 930 and EFI and Im hoping for mid to high 10's.
I hope you stomp your friends GT - I got the pleasure of smacking one around on the highway with my fathers Evolution tuned twin turbo. The guy got really mad.

Do you have the stock 4 speed? If so- how do you come out of the hole with it? I have not gotten to launch my car yet and need advice as to what I should do for the best 60' times.
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Old 04-16-2007, 05:55 AM
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yes he just bought the gt(gt40) last fall.didnt have a chance to run him yet.all he talks about is the hp it has.i know another guy that has a mustang with around the same spec.510rwhp convertable so it weights about the same as the gt.i beat him.i have the 4 speed but the final drive is changed.forget what it is but top end is around 160mph at redline.im just doing the efi right now.i dont usually drag race but other cars worth mensioning 01porsche turbo and roll ons with a friends 600bike f4i.he smoked me off the line though.
Old 04-16-2007, 07:32 AM
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I wish I knew my accurate 1/4 mile time.....the previous owner had a friend with a Viper and his Porsche was definitely faster 0-60 and such. Only above 120 mph, the Viper was faster, because 930 aerodynamics stink.

I was able to beat a supercharged Mustang. I didn't abuse the clutch, I just let it out like normal. So the Mustang got a jump, but my car was faster ultimately. I found out more about the Mustang from some friends around town, the guy that owns the car is a mechanic and his car is supposed to be a major build. The hood was huge on that thing, it was all bulged out. My P-car just weighs so much less and has short gearing, no real secret tricks up my sleeve.

I don't think that you need to dump the clutch at all to launch a 930, just let the clutch out like normal and then step on the gas just hard enough to get going but not hard enough to spin the tires. In fact, if you are gentle and smooth letting off the clutch and then give it the proper amount of throttle, you can be quick and consistent in your starts with no drivetrain abuse. And you can practice all the time, at every red light if you want. The less dramatic you are with the clutch, the smoother and quicker you can get off the line. Dumping the clutch will only get you a repair bill.

Traction is very important to fast starts, and if you can find a sweet spot where you are accelerating fast but not spinning your tires, you are going to be at maximum acceleration.
Old 04-16-2007, 11:30 AM
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yes on launch i dont dump the clutch.just let it slip abit trying to keep the revs above 3-3300.i do have a ceramic 6 puck clutch now.i love it but never tried launching with it yet.
Old 04-16-2007, 12:32 PM
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Rg5- which clutch did you use? I got a 4 puck ceramic from Clutch masters
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Old 04-16-2007, 05:34 PM
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i dont know what kind it is.the pressure plate is a kep.how do you like the 4 puck.
Old 04-16-2007, 09:03 PM
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I will be firing my car up for the first time since having it in a few weeks, I will let you know. I just finished the build and am waiting for the tuner to load the map into the car so I could start it. Its times like these that feel like an eternity.
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Old 04-16-2007, 09:46 PM
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the clutch does make a little noise sometimes.doesnt bother me.shifting gears is better to.have to watch though,i saw a telephone pole in front of me as i shifted into second as it decided it wanted to go sideways.cool day didnt help
Old 04-16-2007, 09:54 PM
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Quote:
Originally posted by DDDD
I
The less dramatic you are with the clutch, the smoother and quicker you can get off the line.
Sorry, have to disagree. The more dramatic the takeoff the faster you will accelerate, sure you'll have wheelspin, but if you can hold it you will out accelerate a clutch-slipping takeoff. 500-600RWHP turbo cars will spin on boost regardless. If I clutch-slip a takeoff against a friends very warm WRX he gets me initially. If I rev 6-7k and dump the clutch he can't get anywhere near me. I get wheelspin, but I am accelerating quickly too. I doubt whether you'd find a clutch slipping drag racer.
I have owned some 10-11sec street cars and was into drag racing some time ago ( modded 'street ' cars ) and I can't ever remember slipping the clutch to get a better time. It's dump and burn man.
Yes you risk the drivetrain, but smoking clutches are'nt pretty either, to the disc or the flywheel. If you've seen the in car vid of Juan Riez? pull a 10.4, there ain't no clutch slipping there.
Old 04-17-2007, 01:23 AM
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Dewolf, What I usually did with my other cars (Modded Galant VR-4, 89' C4/930) is as soon as the light drops, I would slid them at about 4500 rpm for a split sec, and then dump it. The reason for this is that I wanted to preload the drivetrain first. Would you use this tactic or would you just dump it. I just dont like the idea of dumping the clutch, it seems like the mechanical version of rape- Not right

Rg5, yea racing clutchs are always going to be noisy. No good about that telephone pole though. Im just having bad thoughts about my car when I start driving it with all that power and girlish tires (275 rear).
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Old 04-17-2007, 05:57 AM
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Quote:
Originally posted by dewolf
Sorry, have to disagree. The more dramatic the takeoff the faster you will accelerate, sure you'll have wheelspin, but if you can hold it you will out accelerate a clutch-slipping takeoff. 500-600RWHP turbo cars will spin on boost regardless. If I clutch-slip a takeoff against a friends very warm WRX he gets me initially. If I rev 6-7k and dump the clutch he can't get anywhere near me. I get wheelspin, but I am accelerating quickly too. I doubt whether you'd find a clutch slipping drag racer.
I have owned some 10-11sec street cars and was into drag racing some time ago ( modded 'street ' cars ) and I can't ever remember slipping the clutch to get a better time. It's dump and burn man.
Yes you risk the drivetrain, but smoking clutches are'nt pretty either, to the disc or the flywheel. If you've seen the in car vid of Juan Riez? pull a 10.4, there ain't no clutch slipping there.
Not to be a smarta$$, but is dead wrong - the fastest 1/4 cars (top fuel and pro stock) have ALWAYS used clutch slippage rather than wheelspin to create the fastest 0-60 times. Once your tires really break traction, you will either continue to spin the wheels until the power curve drops (and hope they hook up before the next gear breaks them loose again since a slipping tire wants to keep slipping vs hooking up), or you have to back out of it.

This is the ONLY part of 1/4 mi. racing that requires any driver skill IMO - getting the right mix of clutch/torque converter slip to turn the tires over and get them to bite. The gear multiplication in lower gears allows the clutch to slip then grab MUCH easier and more effectively than tires, which in turn easily go up in smoke because of that same gearing.

I grew up in one of the biggest 1/4 mi. garage in the US, and have seen tooo many of these cars. I'm totally NOT a fan of drag racing (IMO it is much more a test of engine building and to a lesser extent chassis tuning skill than driving, but that's a debate for a different day), there was a time when I lived in this arena.

Pat Kelley
Old 04-17-2007, 06:20 AM
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with the telephone pole i think that was the closest i ever came.maybe another time that scared me i was on it in third in the rain and i think it went throught a puddle.car went sideways a little.on a wet road,ditch on each side doing that speed wasnt fun,kinda stupid to.i had the car for around 14 years and most of the time it does what i want.just with that clutch before when i quick shifted into second the clutch gave a little.this one doesnt.as for drag racing yes thats what i do preload the drivetrain and get the weight transfering to the back.my old clutch would never be able to take a drop the clutch.it would just keep spinning.when i took the clutch out last year it was toast.and as for tire size.i never looked into it but what i heard its not the size but the tire compound.dont know if its true.one day ill look into it.
Old 04-17-2007, 10:28 AM
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Kellcats521,
Sorry, have to disagree. Regardless of your background, and I mean no disrespect to you or your knowledge of cars or drag racing but, did you race yourself?. Race clutches are usually on or off, there really is'nt much 'slip' in them. If you've got a lightning fast reaction time and 60ft time is good you did not slip the clutch.
I am still sort of in drag arena as friends still race heavily, one in fact has a top fuel door slammer, 6.1secs at 380kph and I can tell you that is pop the clutch and go.
Once the car is off the line and moving you can then regulate wheelspin with throttle control, but the most important thing is to get the launch right. You've seen cars pull wheelies off the line right from the get go, that ain't clutch slip.
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Old 04-17-2007, 02:16 PM
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Quote:
Originally posted by dewolf
Kellcats521,
Sorry, have to disagree. Regardless of your background, and I mean no disrespect to you or your knowledge of cars or drag racing but, did you race yourself?. Race clutches are usually on or off, there really is'nt much 'slip' in them. If you've got a lightning fast reaction time and 60ft time is good you did not slip the clutch.
I am still sort of in drag arena as friends still race heavily, one in fact has a top fuel door slammer, 6.1secs at 380kph and I can tell you that is pop the clutch and go.
Once the car is off the line and moving you can then regulate wheelspin with throttle control, but the most important thing is to get the launch right. You've seen cars pull wheelies off the line right from the get go, that ain't clutch slip.
I'm sure you are aware of the fact that the clutches in Top Fuel cars never fully engage...they slip the entire run (this is a MAJOR part of car set up...too much slip=slow...too little=no traction). If they do fully engage the tires go up in smoke OR if there was enough traction and all 7000+HP made it to the ground, the car would probably go through the traps at 1000+MPH!

Cleve
Old 04-17-2007, 02:46 PM
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I won't beat this dead horse, but I guess the SAE is clueless too....

SAE Technical Papers
Title: Potential for a Ground-Effects Top Fuel Dragster
Document Number: 2002-01-3348

Author(s):
Murf McKinney - McKinney Corp.
L. Daniel Metz - Metz Engineering & Racing

Abstract:
The current performance of a top fuel (T/F) dragster racing car is very high. The cars can accelerate from a standing start to well over 330 mph (528 km/h) in \ml 4.6 seconds! The engine of a T/F dragster can make considerably more power than can be put down to the track surface. Intentional clutch slippage prevents wheelspin for most of the 1/4-mile (0.4 km) standard length racing run. Even though the drive tires used are highly specialized and specifically designed for this type of racing environment, more traction is needed. To create more traction, especially during the second 1/2 of the run, external wings have been employed by the designers of such cars. The size and configuration of the wings is limited according to sanctioning rules.

Titan - one of the biggest 1/4 mile clutch companies is prolly also clueless on what it takes to drag race.....

The automotive clutch was originally designed to disengage the driver (engine) from the driven (transmission). Drag racers learned that the clutch could be manually feathered — i.e., slipped — by a skilled driver's foot against the clutch pedal. This allowed the drive tires to spin less, yielding quicker elapsed times. By the mid-Sixties, Top Fuel teams were starting to experiment with clutches that had a certain amount of slip designed in, enabling a car to run quicker and repeat more consistently.

The long-style pedal clutch, which uses a combination of spring pressure plus centrifugal clamping to make the unit lock up, was used initially because it was a simple matter to make the springs adjustable and the counterweight adjustable. Eventually clutches appeared with their springs located behind the cover, instead of between the cover and the pressure plate (drive shoe). These became known as "'Glide" clutches, and allowed a driver to remove his/her foot from the clutch pedal before leaving the starting line. As engine rpm increases, the counterweighted levers overcome the static springs, and the clutch locks up. This system allows the tuner to put a fixed amount of load on the engine at idle (also referred to as "stall").

Both pedal- and 'Glide-type clutches can be operated in multiple stages. In these applications, pressure is applied to the drive shoe by a few of the many levers available. As the throwout bearing is allowed by the clutch controller to move back, more and more of the levers engage, adding squeeze to the clutch pack. Most Top Fuelers and AA/Funny Cars use multistage, 'Glide-type clutches. Most Top Alcohol Dragsters and Funny Cars, Pro Modifieds and Pro Stockers, plus many nostalgia cars, run single-stage, pedal-type clutches.

Here's a link to their site - maybe they can bring more credibility than I do.

Titan

And, to answer your question, I did previously own two 1/4 mile cars - one was a true 11 sec bracket mustang and the other was a 10.19 index 1970 Camaro. But, beyond that, I BUILT too many of these engine/clutch-trans (or automatic)/chassis setups to start to describe. The shop I spend my high school (and some college) summers at had 15 dedicated drag cars in the shop every day.

Pat Kelley
Old 04-17-2007, 02:58 PM
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Quote:
Originally posted by cgmeredithjr
I'm sure you are aware of the fact that the clutches in Top Fuel cars never fully engage...they slip the entire run (this is a MAJOR part of car set up...too much slip=slow...too little=no traction). If they do fully engage the tires go up in smoke OR if there was enough traction and all 7000+HP made it to the ground, the car would probably go through the traps at 1000+MPH!

Cleve
Cleve,

Maybe they do it differently down under.....
Old 04-17-2007, 03:00 PM
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Okay, I'll concede. Only to fact that your talking about 3500-7000HP machines. I think we're all aware that these are particulary extraordinary machines that require very different measures to get the power to the ground, and yes I am aware of multi-stage clutches etc. We are talking about 300-600HP cars. I think they are very different. In fact I know they are very different.
Kellcats, do have a 930? Try your own shootout doing clutch slip and clutch drop. Get a friend to do a stopwatch start time, not the best I know, but you'll be surprised. Given two identical powered street cars ( 930's in this case, and not 750-900HP track weapons) with exactly the same setup I bet that the clutch slip would lose every time. My 930 is basically stock apart from exhaust and 1.0bar. I cannot beat a friends '05 GT3 off the line no matter how many times I try if do a 'soft' start. If I do the very cool burnout, 2 black lines down the road type start I can keep with him, just. And the smoking tyres start does look the best,lol .
And I'm not having a go at you nor is it a personal attack so please don't get agitated.

And yes, we do do things different down under
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Last edited by dewolf; 04-17-2007 at 05:33 PM..
Old 04-17-2007, 04:03 PM
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