When is 585 horsepower, really 585 h.p.?

What about the Jeep SRT8s that will run 12.9 100% stock? I've seen it. Any SRT8 will break into the 13s stock. My 5.7 Ram ran 14.8 100% stock with stock tires. That's a Ram, 4800 lbs and only "345 hp". Subtrack about 1200 lbs and add 80 hp. That's 13s easy.

Don't forget that new HP numbers are SAE. So if your 455 stage 1 is rated at 360 hp, SAE ratings would only be around 300-320. Assuming that "360" is the actual hp number which it probbaly isn't. It's probably higher but you see my point.

And if you use HP calculators by ET or by MPH, it puts my truck at right around 300 hp at the wheels. That's with bolt ons and a programmer.

Which reminds me of another guy on this forum who said he's never seen a new hemi run 14s. I still haven't got a reply after I showed him my 14.81 STOCK time slip.

 

Hi Robert,

Thanks for the response. Are the SRT8s rated @ 425h.p. @ 6200 r.p.m., as in the Dodge Challenger? If the 2008 Challenger runs a 13.3 @ 108 m.p.h., with a curb weight of 4189 lbs., does the h.p. rating reflect the e.t.?
Any large truck running those kind of e.t.s is a contender. Keep her in tune!

Take care,

Nando.

 

Yes, All SRT8s are rated at 425 hp.

According to my calculations 108 in the 1/4 and 4350 lbs (including 150 lbs driver) = 427 hp.

Calculating by ET you get 365 hp. The calculator says "on the pavement horse power" which I assume is rear wheel.

Keeping in mind that these come with 3.06 gears. I don't think 425 hp is enough for those highway gears and big ass rims and tires.

Using my truck to compare figures I come up with 4800 lbs 14.52@ 92.5 I get 310 hp by ET and 296 by speed. Which should be pretty close for rear wheel hp for my truck.

Here it is, play around with it. some of the online calculators are right on with my truck.
http://www.dsm.org/tools/calchp.htm

My truck stock

4800*, 14.81@90.52

292 by ET
278 by mph

Most dyno charts Ive seen for stock hemis are in the 260-280 hp at the wheels range

Here are my results working backwards.
4800 lbs, 345 hp = 14.77 not far off from 14.81
http://robrobinette.com/et.htm

 

Hi Robert,

Appreciate the web link. Have you heard of new Apple iPhones with the neat optional feature of GPS? Some are using the GPS to calculate all sorts of speed-related info while driving such : as 0-60, e.t.s. Anyone verify their accuracy versus some of the acceleratomers?

Talk later,

Nando.

 

I think nowadays, advertised h.p. figures sell cars, and some of these manufacturers' figures are bogus. You know, 425 h.p. SRTs, which might crack into the 13s. Any other examples, domesic or import, you can name?

the US DOT ( or FHTSA or whatever .gov acronym is in charge of that ) tightened up their testing procedures for torque and power ratings a couple of years ago and all of the Japanese manufacturers had to drop their advertised ratings 5-10%. US car companies kept almost identical numbers pre and post change.

there was a little bit of a stink about it at the time.

i don't think it really had much effect though. people don't typically buy Japanese cars to leave black stripes on the pavement.

 

http://videos.streetfire.net/video/iPhone-Dynolicious-More_175854.htm?Ref=Newsletter
http://videos.streetfire.net/video/iPhone-Dynolicious-video_174587.htm
:TU:

 

I've seen that second one before. Pretty cool. Too bad his car isn't that fast.

 

Hi Wes,

Thanks for the links to the video clips. Seems like a worth-while feature to have for an iPhone. Is it a 1x cost, or a monthly cost to have this feature?

Take care,

Nando.

 

one time cost :TU:

 

Gotta love torque! :3gears:

 

Hi Wes,

Thanks for the info. Seems like a great feature, that'll save the expense of that $100 dyno test @ the local shop, when upgrading with speed parts.

Talk later,

Nando.

 

There are other factors that make that thing not so accurate as far as HP calculator. Wheel spin is the biggest for me. I can run a 6.5 0-60 and then get bad tire spin on the next one and run a 7.5. I don't think it's quite a substitute for a real dyno but I bet it's fun to play around on.

 

Hi all,

Along the same vein: about fudging the #s in some of those early road tests of the '60s-'70s, Joe Oldham's new release, titled "Muscle Car Confidential", seems like a great read. Will be ordering a copy next week through the Buick GSCA, if there are still copies available.
Wish more editors would come forward, and tell it like it really was.

Talk later,

Nando.