N/a Dyno 318 H/p 279 Ft/torque

[jayro]

Are you talking at the crank or at the wheels? At the crank, there have been some. At the wheels....not really.

The sho in this thread is much more than just a high hp # though.

So has anyone else built a 300hp n/a sho motor?

 

[zach44102]

this is at the wheels on a mustang dyno!

 

[SeanMc]

I was supposed to go out there this year to watch Ernie run, but he had a stroke, and had to cancel . He's doing much better though, and will try to get out there again next year.

 

[Off Road SHO]

Holy cow! Can he have any more bad luck?

Tom

 

[Geek SHO]

Don't forget about tuning. And you could probably spend half that on exhaust.

 

[sho4life]

So back in the day Yamaha built the SHO engine at 300hp. Or thats a myth. Anyways so it wouldnt surpass the stang. So basically after doing everthing possible to a N/A sho engine it would be the equivalant to a C32b Honda nsx engine. Anyone every driven one of those?

 

[SHOtime2511]

Hate to be a Debbie downer but...

this is at the wheels on a mustang dyno!

So has anyone else built a 300hp n/a sho motor? All it would take is this right?

cams $700
pistions $700
throttle body $100
maf $25
exhaust $500
intake manifold $500
udps $125
bigger valves ?

head work

so about $3000

The posted numbers were at the wheels no? 280 ft/lbs @ the tires is a heck of a lot more than 262 ft/lb at the crank (per the M3 engine).

An N/A engine can only make so much torque (VE) period. Even a $5 million 3.0L V10 F1 engine, best estimates put those at about 270 ft/lb peak (granted the short stroke ain't what you want for big torque numbers but you get the point).

hp per cube (RPM) is a LOT different than torque per cube (VE). 300+ ft/lb from 182 CI (n/a) with a SHO stroke/bore is going to need VE out of this world to get 1.65 ft/lb + per cube.

Here's a great primer on the relationship between volumetric efficiency, air flow, HP and torque: http://www.epi-eng.com/ET-VolEff.htm

I'm too lazy to do the math, but my guess is (as Mark mentioned) you'll see some pretty high VE numbers required to get that kind of power from a 3.0L N/A motor.

Dave Kegel

If you can get ~1.85 ft/lbs of torque per cubic inch (if we are factoring in ~ 280 measured at the wheels) from a 3.0L *atmospheric breathing* engine, with a ~89mm bore and ~80mm stroke, on pump gas...there's some F1 teams over in Europe that would gladly pay you millions of euro's to come head their engine building programs

I of course want 20%, as your agent, since I "discovered" you...

Correct me if Im wrong, but
(input torque) x (gear ratio) = output torque?
3rd gear has a ratio of 1.38 to 1.
(input torque) x 1.38 = 279ft*lbs as read on the dyno
That means actual input torque (un-multiplied by the gearing) would be
279/1.38=202.173 ft*lbs
So if you did a 4th gear pull (gear ratio of 1.02 to 1) you should get closer to the 202.173 number. This seems more realistic.

 

[sho4life]

Id have to say i just saw the new v-6 mustang commercial and i cant believe thats even possible. 31mpg out of a 305 hp v-6. technology is wonderful

 

[SuperHO]

oh for the love of all that is good and blessed let this go! to build a 300whp N/A SHO, you need an abundance of two things...time and money. if you can afford it, likely as not you'd have done it already...

 

[tool88]

I'm sure it will take more money and time than most people are willing to put in.


but it is still awesome as s#!t

 

[zach44102]

hey!.....somebody had to do it.

 

[Chuckblvd]

My brother had alittle over 300hp N/A like 4 or 5 yrs ago it was dynoed in central Mass. It can happen with about 13K. It was a 3.2L w/big cams in 3.0L heads lots of tunning and head work. Not very streetable kept detonating around 3K at part trhottle. He sold the car and the kid he sold it to got t-boned in it like 2 or 3yrs ago. He is looking for a dyno sheet so I can post it. Fred from NESHO sold him alot of parts so he may remember it.

Chuck

 

[dohcsable]

just add and hide a direct port nitrous setup under the manifold.......much cheaper/easier.....unless you like throwing large sums of money at things....

 

[revhardSHO]

A n/a engine can only make so much torque for it's displacement, at any rpm, period. It only has the resonance tuning of it's intake to acheive good cylinder fill and a high VE number. Since there is no aid of extra oxygen/fuel through adding more via a turbo, supercharger or N20, an n/a engine is forced to make high hp numbers by making "hp" by using high rpm. It's that simple. It may not have a hp "limit, or an RPM limit, but it WILL have a torque limit.

You can see he has changed his compression ratio stroke and bore. All your calculations go out the window with that + race fuel.

 

[jonheese]

You can see he has changed his compression ratio stroke and bore. All your calculations go out the window with that + race fuel.

Race fuel might give you a little bit more energy (BTUs), which will raise your maximum theoretical torque ceiling a little, but compression ratio doesn't have any effect whatsoever on it. It's still ingesting X amount of air and fuel, and unless you compress it down to a singularity (i.e. black hole seed), you won't get any more energy out of it than you put in.

Also remember that higher octane fuel doesn't necessarily have any more energy per unit mass than lower octane fuel; it's just more resistant to detonation. I don't know if "race fuel" has any more energy per unit mass than regular pump gas, but it will certainly allow one to run a higher CR due it its increased detonation resistance. But the fuel all by itself may not actually increase the power/torque at all.

The stroke and bore values are what is used to determine the engine displacement, so he already covered that when he said "for its displacement".