For the Racers out there

[86bluecobra]

Ok i have a question. If you have cars of equal wieght one a auto one a stick both running 150hp shot of juice. one car (stick) runs a 7.74 1/8 mile @ 94 mph the other car (auto with sloshy shifts) runs a 8.2 sec 1/8 mile @ 96 mph . which car makes more hp? using the hp calculators the car running the higher mph has more hp can this be right since he is slower? the 8.2 sec car hooks very well and takes off the car running 7.7 spins through 1st and 2nd gear. I'd like to hear your theory's and why.

 

[bobcatv8]

From all I've ever heard with car weights being equal the car with the higher MPH is making the most power.

 

[mackey]

The 8.2 is losing alot of time in the sloshy shifts.

 

[bobcatv8]

Or a rotten 60 ft time too.

 

[gt40_2003wes]

the reason the stick is runnin slower is because its loss of traction.

 

[bimmertech]

the auto only has 4 forward gears where as the stick has 5. this means the stick has a greater torque multiplication factor and is able to achieve its trap speed quicker. when you race 1/8 mile, gears are very important.

the diff in mph may be attributed to diff in the motor itself. maybe the auto car has been maintained a bit better and has less blowby.

my team leader bracket races a pro-comp rail car and he can actually trap a higher mph if he spins a little off the line.

 

[IntenseBlue]

The MPH on those seem way off.

 

[bluevenom867]

The mph is because of converter slipage......

The motor will "spin up" faster into its powerband sorta acting like a larger gear.

But thats same reason the mph is high with the auto is why its et sucks.

 

[86bluecobra]

ok i forgot to mention the stick has 3.73's and the auto was running 4.10's. yes the shifts in the auto are very sloshy. ok i know the mph don't add up. the 7.74 was acheved in my mustang at our local air port with no traction availible for my car (i ran the same mph at a 1/4 mile track at 1700ft for my 1/8 but the et was a 7.3). we were both running slicks but like i said i spin. the other car is a 67 dart hard-top with a 360 in it on the same 150 hp shot of juice.

 

[86bluecobra]

i would hate to think the 360 is making more hp then me since all that motor has done to it is a cam and intake a 750 edelbrock carb and long tube headers. in which case all my horse dollars (otherwise known as hp) are failing me at the local track.

 

[Euphoric306]

The MPH on those seem way off.

was thinkin the same thing

 

[Michael Yount]

You can't compare the way you're trying to with two different cars -- different weight and different aerodynamics. If you're trying to make HP comparisons between two cars based on trap speeds, the cars have to weigh the same and present similar aero profiles.

Bimmertech - I suspect total number of gears in the tranny has little bearing on this as both are probably only using the first 3 gears in the 1/8 mile. However, the ratios of the gears they're using has some bearing -- the 5 speed's first 3 gears are closer together ratio-wise than the auto's are.

Having said all that - since the Dart is likely heavier, is less aerodynamic, is likely losing HP through a slipping tranny-- I'd suspect he's making more HP than you.....just a guess though.

Why does this bother you --- you're beating him to the other end by 1/2 a second in the 1/8th - probably by over a second in the 1/4. What's the problem?

 

[86bluecobra]

the problem is that my 351w has aluminum heads ud pulleys msd ignition coil and distributor etc etc etc his is a stockish 360 with only a cam a intake and long tube headers. he is running the factory heads with no work done to them at all. He just got a set of edelbrock heads for his car and i would hate to thik that this dart is going to make more hp then me. the cars do weigh the same. i wouldn't think the areo on them would be much different my 4 eyed fox is pretty much a box just like his hard top.

 

[IntenseBlue]

Mopars have been known to make more power most of the time. It seems that every time there's an engine comparo between Mopar, GM, and Ford with same class engines, Mopar seems to come out on top. Him having an auto is a big advantage, also.

 

[Michael Yount]

Intense - him having an auto may provide a consistency advantage compared to someone that's not so good at launching or shifting a stick when racing at the strip. But all things equal an auto puts LESS power to the ground than a manual because there's always some slippage due to the torque converter.

 

[IntenseBlue]

I understand how they work. I know we put a C4 and my buddy's Mustang to replace his T5 and it felt alot faster. He had ported X303s with a TFS Stage 3 cam on a 306. Had 3.73s.

 

[86bluecobra]

It just sux to go to the after market and get all the good stuff for your own engine and to have your bro-inlaw give a 360 a tremclad rebuid (otherwise known as painting an old engine) and actually make more hp then me.

 

[bluevenom867]

It just sux to go to the after market and get all the good stuff for your own engine and to have your bro-inlaw give a 360 a tremclad rebuid (otherwise known as painting an old engine) and actually make more hp then me.

I believe the Mopars have pretty decent factroy heads (big valves).