Toddcod

I was surfing and found this table for Ls1 years and horsepower.

Toddcod

You have to click on it a few times to make it large enough.

UrbanSoot

i heard that most gm motors are underrated from factory. fbody cars usually see around 300whp when new.

skidude

Good find, but too bad it doesn't go past 2003. :-(

fmowry

Only real difference in the 5.7 aluminum blocks is the intake, heads and cam. The LS6 intake is good for 20whp and is the first mod. You can swap a Z06 cam into any LS1 and they run $120 used at the corvette forum. The LS6 heads flow a bit better and the Z06 heads have sodium filled valves.

LS2 V8 Miata

GM used a couple of different HP Torque evaluation methodologies, from 98 - on.

Does anybody know HOW theses numbers were derived? At the Crank, Rear Wheels, SAE, Brake, WHAT?

rupzuk

Good info,
up to current year of production would be nice, and for this endevour I'd love to know the weights on the various different models.
Are all the LSx motors the same physical size(ie:4.8 to 6.0 just like a 289 & 302?-externally)
Thanks

irishvol

All manfucturers began using SAE ratings in 1972 (I believe) as government mandated. Ratings are obtained with the engines under load but are not near actual wheel HP. General rule of thumb is RWH is about 30% less than manufacturer advertised HP. For example, my Lexus is advertised at 300hp. It dyno'd at 214 rwh. 70% of 300 is 210.

MRM331

So if my last Ford conversion made 240 whp I should have sold it as a 312 hp Miata?

-Jason

LS2 V8 Miata

So my car actually dynoed 350.3 RWHP and 362.6 Ft/Lbs @ 5687 RPM

and by the SAE calcs (+30%) you cite, my Flywheel should be 455.3 HP

we'd previously calculated conservatively, 25% with M/T 438 HP

I've learned most after-market Parts manufacturers / suppliers Lie and that most calibrated, maintained Dynos don't Lie

My Two Cents

MRM331

So what is the accepted percentage of driveline loss in a V8 Miata? I've heard as low as 12% and as high as 25%. 30% seems a little ridiculous.

-Jason

rupzuk

To many variables involved to nail down a set figure.
Anyone stating a percentage is guestimating at best.
Anyone dyno the motor on a stand then run it on a chassis dyno?
They'd know, for their setup anyway.
Just my 2 cents,YMMV

MRM331

I assume the best estimate for us Ford guys would be if there is a figure stated somewhere for a 5.0 Thunderbird with a T-5. The only difference in the driveline would be about 2 feet less of driveshaft.

-Jason

irishvol

All dynos are not the same. It can be an advantage to an operator to exagerate results. If my dyno says you've got 300hp and Joe's says you've got 330....who ya gonna believe? And Who are you gonna recommend to your buddies for their tests?

Hp can also be calculated with math formulas. Using the given factors of weight, 1/4 mile time and 1/4 speed HP can be determined. For example it takes about 360hp to run a 3300lb car through at 13.4 secs. @ 106mph. Obviously any of these factors can be determined depending upon which factors are givens. None of these methods are certain but they put us in the ball park. There are too many varibles like weather, driver, gear rations and transmissions, tires...not to mention the efficiency of the performance of your motor. So be it.....it's all a good time!!

LS2 V8 Miata

IMO the HP and Torque at the rear wheels is what everybody I associate with seems interested in and recognizes as an accurate asessment.

The Dyno (Rollers, Manufacturers & Calibration) variation argument probably has some merit, however Real World I've used two different Dyna-Packs (Bolts directly in place of rear wheels) at two different shops and the results were so similar as to be within the margins of deviation in 4 runs, as if ALL done on the same machine. THAT'S ACCURACY in my book, if anybody wants to quibble over 5 HP here or there as making any REAL difference in our Miatas Go for it, doesn't make sense to me.

Evan

Even 4wd Subarus only lose about 25% through the drivetrain. FWD Hondas typically lose 10-15%.

irishvol

That's because you're special......the rest of us have to deal with reality, lol

Evan

Who are you talking to?

MRM331

Are you referring to the apparent "un-dyno-ability" of 4-wheel drive platforms? If so check this out:

http://www.jscspeed.com/pages/jsc_bbq.html

-Jason

ls1miata

rwd has more driveline loss than fwd but less than awd. Automatics have significantly more loss than manuals (due to both "slipping" in the trans as well as the parasitic pumping loss for trans fluid). General number (more than guestimate, more like an average) for rwd manual is 20%. For rwd auto figure 25%.

For a more up-to-date hp/tq figures for lsx: http://www.pirate4x4.com/tech/billav...otorsAtaGlance