Shelby Super Car - unbelievable MEP?

[mbtoloczko]

This car was built in the town where I live, and I got a chance to see it during a car show in town last weekend:

http://www.sscautos.com/

Its looks just as awesome in real-life. Anyhow, I got to looking at the HP specs, and decided to calculate the now infamous "MEP". The specs from the website are, N/A motor, 6.2 liters, 782 HP at 6500 rpm. So,

MEP = 782/(6.2*6.5) = 19.1

That's almost 40% higher than anything else out there. Kinda makes me wonder if the HP number isn't a little inflated.

[SVXer95]

6600 rom on the website. Still comes out to 19.1 though. All this on 91 oct pump gas??!?!?!!

[Chiketkd]

Drool...

MSRP of $239K, 0-60 in 3.11, 1/4 of 10.98 @ 126mph and a top speed of 249!!!

I'm in! I must have a 1/4 million in change buried in my couch by now...

-Chike

P.S. With a trap speed of 126mph in the 1/4, I also doubt that hp claim. The Enzo has a lower hp rating (650) and higher curb weight (3200) and trapped at 133mph when Road and Track tested it.

[SVXer95]

Originally posted by Chiketkd

P.S. With a trap speed of 126mph in the 1/4, I also doubt that hp claim. The Enzo has a lower hp rating (650) and higher curb weight (3200) and trapped at 133mph when Road and Track tested it.

Thats a pretty bold statement. Gearing could be much different.

[Chiketkd]

It is. However, my statement has some merit. Both cars are mid-engine rwd and while gearing is most likely different, it can't account for a trap speed difference of 7mph.

Even Mychailo mentioned that he suspects that figure to be inflated...

-Chike

Originally posted by SVXer95
Thats a pretty bold statement. Gearing could be much different.

[Shadow248]

Originally posted by Chiketkd
Even Mychailo mentioned that he suspects that figure to be inflated...

It is. Remember that Ford is notorious for inflating horsepower numbers, they've been doing it for a long time, so it would be no surprise that a Shelby car would be the same. I looked up some specs on that car and there's no way that can work. It's at least 100hp overrated. Probably more. After some quick math, i'd say about 605hp would get pretty close to the test numbers and an MEP that is at least close to believable.

As for the gearing argument - remember this car can reach 250mph, and to do that it must have a fairly tall final drive.

[Chiketkd]

Very well put!

-Chike

Originally posted by Shadow248
It is. Remember that Ford is notorious for inflating horsepower numbers, they've been doing it for a long time, so it would be no surprise that a Shelby car would be the same. I looked up some specs on that car and there's no way that can work. It's at least 100hp overrated. Probably more. After some quick math, i'd say about 605hp would get pretty close to the test numbers and an MEP that is at least close to believable.

As for the gearing argument - remember this car can reach 250mph, and to do that it must have a fairly tall final drive.

[mikecg]

Ya sure it's an N/A engine. The 8T in the name could mean it's an 8 cylinder, turbo. The only thing I noticed is the compression might be a little high for a turbo at 9.5 to 1.

A turbo would account for alot of what your not believing. Turbo spoiling up could hinder quater mile speeds and through off your calculations while allowing a high HP on pump gas. It doesnt says it's a turbo, but it doesnt say it's not either.

[mbtoloczko]

Yeah, they make absolutely no mention of a turbo on the website, but if the car really is making 782 HP, it must have a turbo. The "T" in the name is a good tipoff. I didn't see that.

[Chiketkd]

That could definitely explain their results. I imagine the single 'T' in the name represents one turbo, so if it's really large in displacement, it could take a while to spool up to maximum boost!

-Chike

Originally posted by mikecg
Turbo spoiling up could hinder quater mile speeds and through off your calculations while allowing a high HP on pump gas.

[Shadow248]

It's supercharged. So forget MEP. But using good-ole physics to figure this out shows several things.

1 - There is no way that car has 782bhp. Not a chance in hell. Using the fact that the car reaches 249mph as a guide for gearing, you would only need about 550bhp in a 2700lb car to run 10.98. Hell a 3000lb Supercharged Z06 vette runs low 10's with 550hp. Granted that car is geared to run only about 200mph top end, but it makes a good point.

2 - The trap speed doesn't jive with the ET. The tires must have been spinning clear through second gear to trap 126mph and only pull a 10.98 ET. Unlikely for a setup that should be very easy to launch off the line.

I would put a good amount of money on the fact that this car is grossly overrated. If you take the 782bhp as power at the crank, that gets you about 620hp at the wheels...which is very close to what I surmised was really the output of the car. Plus that would account for the gearing difference and put the MEP right in the range of alot of high-output supercharged motors. So yeah MAYBE I could see 782 as crank hp, but then that means the car has a pretty inefficient driveline for a MR configuration. Ok enough of this.

By the way, MEP can be used for FI applications, you just have to take into account the amount of boost vs. the compression ratio of the motor - and i'm not about to go any further into this because i've already wasted too much time. Hopefully someone finds this interesting.