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73-87 Chevy _ GMC Trucks => Performance => Topic started by: mikewb on August 13, 2008, 04:12:38 pm

Title: horse power
Post by: mikewb on August 13, 2008, 04:12:38 pm
How much horse power would you say i have to go 15.0 in a quarter with my swb weighing 3900?
Title: Re: horse power
Post by: HAULIN IT on August 13, 2008, 05:12:10 pm
Mike, There are many factors that are involved that will effect this slightly. Plugging your numbers into a couple calculators comes up with 230-240 HP, remember this is at the rear wheels. You can do a search for....HORSEPOWER TO WEIGHT CALCULATORS & come up with several. Hope this helps, Lorne
Title: Re: horse power
Post by: SRK-087 on August 13, 2008, 07:37:43 pm
i run 11.89s with 500 + hp weighing 3700
Title: Re: horse power
Post by: 82Shortbed on August 15, 2008, 01:38:47 am
I would THINK that umm....250hp and a decent gear/converter combo would easily put you into 15s maybe high 14s. 
Title: Re: horse power
Post by: SUX2BU99 on August 15, 2008, 02:28:56 pm
250-ish to the wheels with gears in the 3's and traction should do it. It's pretty easy and cheap these days to get a 350 to make 350 crank HP, would should get 250 to the wheels without much issue.

My stock 00 Dakota R/T with 250 crank HP, 3.92 gears and 255/55-17 tires went 15.12 in the 1/4 and it was a 4300 lb extended cab.
Title: Re: horse power
Post by: mikewb on August 15, 2008, 04:07:23 pm
it went 15.33 with a 3.73 no stall
Title: Re: horse power
Post by: mikewb on August 15, 2008, 04:08:05 pm
why exactly is soo much power lost on the way to the rear
Title: Re: horse power
Post by: team39763 on August 18, 2008, 05:41:49 pm
From what I've been reading, it's parasitic loss.  Like the TH350 transmission takes 35HP to turn(got that # from a mustang site), and the rear diff may gobble up a few more horses aswell as the driveshaft. 
Title: Re: horse power
Post by: SUX2BU99 on August 19, 2008, 10:57:51 am
Horsepower is just energy and when energy transfers from one medium to another, it can get 'lost'. In reality it just gets converted into something else other than what is needed to turn the tires, and that's heat. It takes power to turn the transmission, the driveshaft, the rearend, the axles, all of the front end accessories like the water pump, power steering pump and alternator. Friction is there all along the way to eat up horsepower by turning it into heat. That's why there can be such big differences between crank HP and wheel HP. Plus, it can be misleading seeing engine dyno power numbers because you don't know how many accessories they have on the engine. It's like the old gross power ratings of the 60's compared to the net power ratings of the 70's (smog equipment and changes notwithstanding). Could have been the same motor but made 'less' power because it was rated with all of the engine accessories.

Anyway, what is your motor combo? 15.33 ain't so bad.
Title: Re: horse power
Post by: Lt.Del on August 25, 2008, 08:33:10 pm
Quote
Friction is there all along the way to eat up horsepower by turning it into heat.

hmmmm, so that's why we have global warming, huh Gore?  The solution, outlaw V8's so there will not be too much horsepower anymore.  We don't want all that heat, do we?
Title: Re: horse power
Post by: HAULIN IT on August 25, 2008, 08:39:10 pm
Andy, I'm assuming that you were teasing when you said that, however I do believe that there are many lobbying for that very thing. And if their not, lets not give them any ideas, I think our hobby is getting controlled quite adequately Thank You. Lorne
Title: Re: horse power
Post by: Lt.Del on August 25, 2008, 10:55:37 pm
Yeah Lorne, everything is being controlled too much if you ask me.  Less gov't is better gov't.

Title: Re: horse power
Post by: JJSZABO on August 29, 2008, 08:15:45 am
Quote
Friction is there all along the way to eat up horsepower by turning it into heat.

hmmmm, so that's why we have global warming, huh Gore?  The solution, outlaw V8's so there will not be too much horsepower anymore.  We don't want all that heat, do we?

Hey wait a minute - what am I going to use to tow my travel trailer?  Smart vehicles wont do it >:(
Title: Re: horse power
Post by: Lt.Del on August 30, 2008, 10:38:38 am
Quote
Hey wait a minute - what am I going to use to tow my travel trailer?  Smart vehicles wont do it


I know whay ya mean.  I have two trucks.  They are both V8's, and they both pull my 30' camper without problem.

(http://www.delbridge.net/cmpr5.jpg)(http://www.delbridge.net/graves1.jpg)

I don't think a Prius would do this.
Title: Re: horse power
Post by: SUX2BU99 on September 14, 2008, 01:40:46 am
I just ran a 14.994 @ 91 in the 1/4 last Friday. My combo is mostly listed in my sig and my track is at 24' above sea level.