Prior to 1972 American cars list their horsepower as SAE gross. That's horsepower at the flywheel, with no accessories other than the carb, fuel pump, oil pump, and water pump. After that, US manufacturers used SAE net ratings. That's a full exhaust system, all pumps, the alternator, the starter, and emissions controls. The SAE net runs somewhere around 80% of gross, but that's a really rough estimate. DIN numbers are found in European and Asian cars. They're net. Because of variations between metric and US numbers, you can usually divide the DIN number by 1.0139 to get an SAE net number. Of course, all of this is at the flywheel. Depending on your transmission and rear end (not to mention how honest the factory was in its rating), rear wheel horsepower can be 10 to 20% lower. Has anyone here done any dyno runs? Can you compare them against the factory rating? I'd be curious about all kinds of engines, from built flattys to crate motors. Also, how do you find a good dyno shop in your area? Thanks, Matt
i have a 327 sbc that is mostly stock, with a little bit of cam , a four barrel afb, and short headers. running through a th350, the car made 191 rear wheel hp. at 4000 rpm.
My 406 SBC with a th400 and 4.11 geared 9" made 400 HP and 503 ft/lb at the rear wheels, on pump gas, through the mufflers. It was 102 degrees that day and the kid that was tuning it didn't know what he was doing! (he didn't even put probes in the exhaust!?!) Since then, I've figured out that my rings were allowing a ton of blowby, and the compression and quench figures were not what they should've been. It's in the process of being put together correctly, including gapless rings and fully porting the intake. I am scheduled for the chassis dyno mid Feb... I'll keep you guys posted!
the only car I ever dyno'd is my '71 Datsun 510... I know it's not 'on-topic' but I don't care... 99% of this car is custom... It has a hybrid 4-cyl engine... napZ block('81 Nissan truck) '89 Nissan 240sx head(crossflow design, off of a GT4 race car) 44mm dual Mikunis custom header 2250cc built STRONG, like for nitrous strong.. blah blah blah... anyway, engine on the stand, 230hp... and at the rear wheels, 180hp... ZX 5-spd, 4.11 lsd, this car hauls ASS..!! 130+ mph no problem... On-topic... I'm planning on dyno-ing my '65 Rivi with it's 425 once I get the TA Performance headers and mandrel-bent exhaust... I'll let everyone know what happens... Later, Snacks...
yesterday for the hell of it, I dynoed my truck. yeah it's not a rod, cause my rod is for sale, but anyways. 279hp 693lb/ft AT THE REAR WHEELS... This is a bone stock '92 Dodge Ram Cummins Turbo Diesel BHAF (Air Intake) 4" straight pipe exhaust into 5" outlet, 16cm2 turbine housing upgrade. thats all. I get 23mpg on the highway. Future mods including: F1 "EDM" Injectors Custom Holset HX-35W Turbocharger 3200 RPM Governer Spring Kit & VE44 Injection Pump tweaks in the near future should net around 375hp at the rear wheels, 900+ lb/ft, while still maintaining over 23mpg. You just can't beat a Cummins Diesel... PS ...SNACKY6, i wanna see the FIVETEN, i love those cars, had one myself...
Do G-Tech runs count? If so, the Stout Auto Club's '54 Desoto witha '56 330 Hemi made 143 HP at the wheels, and ran an 18.5 second 1/4. -Bugman Jeff
My 355 (more or less) made over 4 and 444 ft lbs at the wheels. Thats, single 4, Hedmann Hustlers, 3" exhaust. 350 turbo, 11", aluminum wheels and a 10 bolt. I guess no accessories. Can't say how accurate the dyno guy was, shouldn't make more that 375 the way it's built. By my way of thinking its like stocks n bonds, just numbers on a paper. The real test, can you feel it in the seat of you pants? Do you pee when you let it out?
1st one is a shot of the 408 (based on a 360 Magnum) that I built and dyno'd for the truck. And yes,that is me running the valves. i used a 4 in stroke crank and a .030 over bore with 9.5 to 1 compression,stock head castings(oversize intake valves only) and a VERY mild roller camshaft. Idles like a stocker. 450ftlbs of torque and just over 400 hp. Second shot is the same engine AFTER paint and bolted in the chassis.
TexasHardcore... I have some good pics on a disc somewhere... if it gets sunny on my days off I'll try to snap off a few newer pics... you'll be stoked..!!! Later...Snacks...
My small block makes 489# of torque @ 4600 rpm and 515 HP @ 5600 RPM..... oh, 100% street, pump gas, tunnel ram, in my old primered Willys.
Come to the HAMB Drags and find out.... Numbers get tossed around alot...but for example..a "502 Horse" 502 Chevvie crate motor will make about 270 hp on a REAL chassis dyno. ( that figure is a hot rod w/ a TH400, 11 inch converter and 3:25 9inch w/ 30 inch tall tires.) So, if you think your car makes 400 horse at the rear wheels, you are probally WAAAY the hell off... In a properly equipped 2500# car, 400 rear wheel horse will get you DEEP in to the 10 second zone. MY car isn't even that fast and it's a PONTIAC!! -Abone.
Bone stock 100 horse 8BA is about 85 true according to several who have tested them. My best pull with a fresh built 276 is 192 but that is with a pair of 2300's at 600 cfm. Not streetable the way it was set up and well on the rich side which a flattie favors. Got another 276 with several intake changes to evaluate as well as a built 292 Y scheduled for a few weekends in March.
My Chrysler weighs 4200lbs and is rated at 250hp. My mom's '91 Nissan Maxima is rated at 165hp I believe and weighs about 3,000lbs. It's WAY faster from a standstill, and I don't think it's just the weight difference. I'm pretty sure if I swapped the 2-speed Powerflite auto for a 4 or 5 speed manual it'd be way, way faster without touching the engine.
FLAMED got it. Take it to the Drags your MPH will tell you your horsepower based on your vehicle weight. ET will tell you how effecient youre chassis is.--Feder
[ QUOTE ] So, if you think your car makes 400 horse at the rear wheels, you are probally WAAAY the hell off... [/ QUOTE ] Damn... you're right... I thought it said 400, but I bet it was 4.00. My car could NEVER beat a pontiac. They made those GTO's and stuff. Those ran 11's from the factory, right? God damn... some people...
Hot Rod to Hell. Oops, sorry. I wasn't talking about your 406. A 400 horse SBC is a pretty serious piece and you know how hard it is to make that number. I was talking about how most hot rod guys grossly overestimate thier horse power. As for my Poncho motor, it was the 2nd quickest car at the HAMB Drags. (Ryans bad ass skinny block got me by a few tenths) As quick as it is, It still doesn't make 400hp at the rear wheels. Yes, you CAN make 400 horse at the rear wheels, but those who have done it know how hard it is. You are absolutely right about the GTO comment. All those "11 seconds from the factory" runs were more like mid to high 14s. Just another example about how #s get ...fudged.. Goin fast ain't easy, -Abone.
Flamedabone is right 400HO at the rear wheels is smoe serious shit. - I was almost crushed when I saw the computer spit out the real numbers! I was thinking I had way more! I have put my car on a chassi dyno twice. Its got a 388 SBC, 700R4, 3:73 gears, 10:1, trick flow heads First time - Comp Cams 292H Magnum Hyd cam with a holley 750 double pumper Hp - 279.8, tq 359.9 Second time with a XE 268 H comp cam and 3 two barrels - I had to go to a smaller cam to have enough vacum to idle the rochester, which is the way it is now - Hp 230, tq 291.8 It feels pretty good - but a hydraulic roller cam and the four barrel may be going back on this summer before the HAMB drags. The real numbers kind of let you down becasue all these magazines talk flywheel HP and TQ. I had a 6 sp 98 Z-28 with an LS-1 that I chassi dyno'd and it had 297 HP and 302 Tq at the rear wheels. That car hauled ass. So I am happy with my numbers considering I put the engine together and all. It will stick you back in your seat. I just wish I had a little old bitty roadster to stick that motor in.
Yeah. I know what you're sayin guys... After people ride in my car, or watch me run, and they ask me how much horsepower, I tell 'em "bout 400 or so" and they all think I'm jokin! They say my car would HAVE to have 6-700 HP to run the way it does. And yes, I know how hard it is to make that kind of power. My goal for this season is 500 HP at the wheels We'll see what I can do, and I'll keep ya posted!
We've got a chassis dyno at the shop (shameless plug for our gd opening feb 7). I have volunteered my bucket for the first run. 255 in. '50 Merc, 3/4 cam, stock heads, Fenton 2 pot intake w/94's. Any guesses? I'm figuring 110-120. So prolly about 14 at the wheels?
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