ET vs Weight - Moparts Forums

Register Log In Moparts Forums Unlawfl's Race & Engine Tech ET vs Weight

Print Thread

Page 1 of 2

1

2

ET vs Weight #1321688 10/17/12 09:40 AM 10/17/12 09:40 AM
Joined: Jul 2012 Posts: 323 Endicott, NY, USA crazyjjk OP enthusiast
crazyjjk OP enthusiast Joined: Jul 2012 Posts: 323 Endicott, NY, USA	Hypothetically if someone had a 4000 lb car and gave it a diet removing a total of 500 lbs how much would this lower ET per 100 lb loss of weight assuming everything else was the same?

Re: ET vs Weight [Re: crazyjjk] #1321689 10/17/12 09:45 AM 10/17/12 09:45 AM
Joined: May 2008 Posts: 1,238 North Cackilacky S sdaurity pro stock
sdaurity pro stock S Joined: May 2008 Posts: 1,238 North Cackilacky	You cannot go by the old school 100lb is a tenth mess unless you have a 11 sec bracket car. In my small tire car running mid 8's in 1/4 100 lbs would slow it down about 3 numbers at most. One day I will have something cool here.

Re: ET vs Weight [Re: crazyjjk] #1321690 10/17/12 10:25 AM 10/17/12 10:25 AM
Joined: Jan 2003 Posts: 24,562 Brookeville, Md Mr.Yuck Not enough dumb comments...yet
Mr.Yuck Not enough dumb comments...yet Joined: Jan 2003 Posts: 24,562 Brookeville, Md	Quote: Hypothetically if someone had a 4000 lb car and gave it a diet removing a total of 500 lbs how much would this lower ET per 100 lb loss of weight assuming everything else was the same? only advice I can give you is this. I had a 67 coronet w/ a mild 440. It ran 12.90's, I lost the power steering, switched from heavy heavy cragars in the front to 14x5.5 rims and smaller lighter tires, removed the ac stuff and the car went....12.90. My 60 foot was a tad better but et and mph were pretty much the same. At that point the car weghed 3850 w/ me and 1/2 tank of gas. [IMG]http://i66.tinypic.com/pui5j.jpg[/IMG] Coming soon!!!!

Re: ET vs Weight [Re: Mr.Yuck] #1321691 10/17/12 11:01 AM 10/17/12 11:01 AM
Joined: Jan 2003 Posts: 27,421 Balt. Md 3 383man Too Many Posts
383man Too Many Posts 3 Joined: Jan 2003 Posts: 27,421 Balt. Md	Here is how I look at it. No matter what removing weight is always a smart move in a drag car to go faster but I think its is over inflated some times as how much et you will pick up up. All I have for info is in my old 340 Dart that I had in the very early 80's at the track one day I ran 12.15 on a time trail run. It was a Co-driver day where you could take a pass for a ride with proper seat belts. I put my 115 lb girlfriend in my 340 Dart which was a 4-speed and ran 12.16 with her in the car. So I only picked up .001 that day instead of the normally claimed .010. The car ran in the 12.12 to 12.17 range the rest of the day. So yes any weight lost helps but I would not bet the house on a tenth for 100 lbs every time. Ron Last edited by 383man; 10/17/12 11:05 AM.

Re: ET vs Weight [Re: crazyjjk] #1321692 10/17/12 11:18 AM 10/17/12 11:18 AM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	Quote: Hypothetically if someone had a 4000 lb car and gave it a diet removing a total of 500 lbs how much would this lower ET per 100 lb loss of weight assuming everything else was the same? You have to stipulate a ET to start with... as the car gets light it takes more power to run .1 quicker... its on a bell curve... also the .1 for every 100# is on a sorted out car... just because some say they didnt go quicker doesnt mean anything, because they werent running a sorted out car... spend a few bucks and get a Moroso Power Speed Calculator 89650 and play with it to see what it should run

Re: ET vs Weight [Re: MR_P_BODY] #1321693 10/17/12 11:25 AM 10/17/12 11:25 AM
Joined: Jan 2003 Posts: 3,505 DFW M mr_340 master
mr_340 master M Joined: Jan 2003 Posts: 3,505 DFW	I use the formula: ET^3=200*Weight/HP It's not perfect, but is close for most bracket cars. Floyd Lippencott IV

Re: ET vs Weight [Re: mr_340] #1321694 10/17/12 11:41 AM 10/17/12 11:41 AM
Joined: Oct 2007 Posts: 156 Southern California B BIG DRAG member
BIG DRAG member B Joined: Oct 2007 Posts: 156 Southern California	The best thing you can do is to take that weight that you removed and put it as far back in the trunk as you can. (to a point obviously - scale the car and get it about 48% in the front and 52% in the back on a leaf spring car) I used to have 2 100lb weight bars in my bracket car, sure it would have gone quicker but on the crapy tracks that i had to run on it made the car way more consistent than the et was worth. And afterall most people are running brackets

Re: ET vs Weight [Re: crazyjjk] #1321695 10/17/12 02:58 PM 10/17/12 02:58 PM
Joined: Mar 2008 Posts: 5,746 Ontario, Canada Dodgem master
Dodgem master Joined: Mar 2008 Posts: 5,746 Ontario, Canada	My car was always right at .10 per hundered pounds when it was 13's mid 12's and low twelves and high 11's If I took a passanger when we were aloud ride alongs 220 lb crew would knock me down .22 my buddy's wife at 140 .140 so my car was always true to the .10 for every 100 lbs

Re: ET vs Weight [Re: mr_340] #1321696 10/17/12 03:23 PM 10/17/12 03:23 PM
Joined: Jan 2003 Posts: 16,928 NC 440Jim I Live Here
440Jim I Live Here Joined: Jan 2003 Posts: 16,928 NC	Quote: I use the formula: ET^3=200*Weight/HP It's not perfect, but is close for most bracket cars. Good for estimates. 4000 lb original weight 500 lb change Assume 13.00 at original weight (ET2)^3 / (ET1)^3 = Weight2/Weight1 other numbers cancel (ET2)^3 = (13.00)^3 x 3500/4000 = 1922.375 ET2 = (1922.375)^0.3333 = 12.43

Re: ET vs Weight [Re: crazyjjk] #1321697 10/17/12 04:17 PM 10/17/12 04:17 PM
Joined: Feb 2003 Posts: 6,849 F fullmetaljacket master
fullmetaljacket master F Joined: Feb 2003 Posts: 6,849	500 LBS is going to net you at the very least 3-4 tenths. Could be more or less depending on how the car is already calibrated as stated above. Some slow cars react very well to weight reduction after a 100 LBS or so has been removed and some fast cars don't see as much as a tenth or less with the same amount of weight taken out. As well, some cars just plainly like for the weight to be moved around, preferably to the extreme rear. It has always been easy to remove the first 100-200 LBS off a car that has all the comforts, but it takes a mad Scientist to remove the micro weight that after so long, amounts to a lot. I believe that most cars have a tipping point to be found where you can remove so and so much weight and nothing happens, but as you go along further in the reduction, something tips to the other side of the fence and all of a sudden the car reacts amazingly to the weight loss just because you breached that tipping point.

Re: ET vs Weight [Re: crazyjjk] #1321698 10/17/12 04:24 PM 10/17/12 04:24 PM
Joined: Nov 2005 Posts: 690 New Hampshire, USA O oldiron mopar
oldiron mopar O Joined: Nov 2005 Posts: 690 New Hampshire, USA	66 belvedere vert jerico 3950 lbs w/me, 4.10 gears best 10.57 @129 relocated engine/trans to barracuda 3340 w/me, 4.56 gears best 9.95 @135 66 Belvedere Vert, 4 Speed/Jerico, slowly, very slowly, getting faster - NA LD Wedge New New Best: 10.56 @129 68 B'cuda 4 gear Jerico - Another New Best of 9.86 & Trying to slow up https://www.youtube.com/watch?v=T4jDLKwd9Gs

Re: ET vs Weight [Re: fullmetaljacket] #1321699 10/17/12 05:45 PM 10/17/12 05:45 PM
Joined: Oct 2007 Posts: 4,209 New York polyspheric master
polyspheric master Joined: Oct 2007 Posts: 4,209 New York	all of a sudden the car reacts amazingly to the weight loss just because you breached that tipping point And the reason is...? Boffin Emeritus

Re: ET vs Weight [Re: polyspheric] #1321700 10/17/12 05:52 PM 10/17/12 05:52 PM
Joined: Mar 2009 Posts: 2,467 Sydney,Australia tex013 top fuel
tex013 top fuel Joined: Mar 2009 Posts: 2,467 Sydney,Australia	i do have to agree with full metaljacket. as i reduced weight,wheels tyres glass front bumper liteweight battery it seemed to do little with 20-30 odd lbs but when i got to around 60 plus lbs it became noticeable with et gain. in the last month i have reduced race weight by around 80-90 lbs i picked up around 0.06. Tex New best ET 10.259@129.65 . New best MPH 130.32 Finally fitted a solid cam, stepped it up a bit more 3690lbs through the mufflers New World block 3780lbs 10.278@130.80 . Wowser 10.253@130.24 footbraking from 1500rpm Power by Tex's Automotive

Re: ET vs Weight [Re: oldiron] #1321701 10/17/12 06:07 PM 10/17/12 06:07 PM
Joined: Apr 2003 Posts: 1,627 anywhere@ anytime A actionange top fuel
actionange top fuel A Joined: Apr 2003 Posts: 1,627 anywhere@ anytime	Quote: 66 belvedere vert jerico 3950 lbs w/me, 4.10 gears best 10.57 @129 relocated engine/trans to barracuda 3340 w/me, 4.56 gears best 9.95 @135 Maybe I need to get a Cuda too...LOL

Re: ET vs Weight [Re: actionange] #1321702 10/17/12 06:13 PM 10/17/12 06:13 PM
Joined: Aug 2003 Posts: 4,055 Salina ks 572_dup2 Back On The Bumper!!
572_dup2 Back On The Bumper!! Joined: Aug 2003 Posts: 4,055 Salina ks	Ive taken weight out an really never seen anything. Shawn Jennings

Re: ET vs Weight [Re: polyspheric] #1321703 10/17/12 06:23 PM 10/17/12 06:23 PM
Joined: Feb 2003 Posts: 6,849 F fullmetaljacket master
fullmetaljacket master F Joined: Feb 2003 Posts: 6,849	It can be just a pound over that point that is when the car (and all cars are different in many ways) reacts to weight reduction and or distribute of such weight. It could almost be compared to center of gravity where a cars suspension reacts better than another based on where the point of the traction device contacts on a particular point on the chassis. I know, I've seen it myself. Every ounce counts as I say and if you want to have a lasting drive train with out the strain, go light and make might.

Re: ET vs Weight [Re: 572_dup2] #1321704 10/17/12 06:24 PM 10/17/12 06:24 PM
Joined: Aug 2007 Posts: 1,271 Vista, California 6 67Satty pro stock
67Satty pro stock 6 Joined: Aug 2007 Posts: 1,271 Vista, California	My '67 Satellite with iron-headed 440, full interior, full exhaust, all steel, steel wheels weighs 3600 pounds. Guy at the track I talk to has a '67 Belvedere with aluminum heads, gutted interior, open headers, fiberglass hood, fiberglass trunk lid, aluminum wheels weighs 3400 pounds. So it seemed to me like a lot of money and bother for two tenths at best.

Re: ET vs Weight [Re: 67Satty] #1321705 10/17/12 06:27 PM 10/17/12 06:27 PM
Joined: Jan 2003 Posts: 13,376 Marion, South Carolina [><] an8sec70cuda I Live Here
an8sec70cuda I Live Here Joined: Jan 2003 Posts: 13,376 Marion, South Carolina [><]	Quote: My '67 Satellite with iron-headed 440, full interior, full exhaust, all steel, steel wheels weighs 3600 pounds. Guy at the track I talk to has a '67 Belvedere with aluminum heads, gutted interior, open headers, fiberglass hood, fiberglass trunk lid, aluminum wheels weighs 3400 pounds. So it seemed to me like a lot of money and bother for two tenths at best. Way too many variables in that one. Different scales, different cars, not a good comparison any way you slice it. CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax

Re: ET vs Weight [Re: an8sec70cuda] #1321706 10/17/12 07:03 PM 10/17/12 07:03 PM
Joined: Aug 2007 Posts: 1,271 Vista, California 6 67Satty pro stock
67Satty pro stock 6 Joined: Aug 2007 Posts: 1,271 Vista, California	Well, the only variable is the scale. A '67 Satellite is the same car as a '67 Belvedere. A '67 Satellite, a '67 GTX, a '67 Belvedere, they are all '67 Belvederes, just different trim lines of a '67 Belvedere. They guy with the '67 Belvedere with 'glass hood, trunk lid, gutted interior, etc...is the one who told me he thought it was a waste of effort for only a couple hundred pounds and I kind of agree from a best bang-for-your-buck point of view. If you add up the cost of a 'glass hood, 'glass trunk lid, aluminum wheels, it seems like there might be better ways to spend that same amount of money to get you more than a few tenths off your ET.

Re: ET vs Weight [Re: 67Satty] #1321707 10/17/12 07:47 PM 10/17/12 07:47 PM
Joined: May 2004 Posts: 3,210 robin hood country deaks master
deaks master Joined: May 2004 Posts: 3,210 robin hood country	I dont know how fast you car is but it might matter more to you, if you were an et chaser and your car was running 11.1. My car is going on a diet over xmas. LOL Mick 69 Dart GTS 440 mopar .590 cam, Edelbrock heads, 3200# best et 6.45, 106.78, 10.14, 132.88 mph, 1.47 60ft best 60ft 1.36

Page 1 of 2

1

2

Moderated by Al_Alguire, Hotwheelsjr, moparts, not_a_charger, RangerDan440, tboomer

Hop To

Powered by UBB.threads™ PHP Forum Software 7.7.1