real HP v6-v8

[tarpumn]

I know some of you out there know how to figure true HP of these engines.
There is so little difference in performance difference that I thought back to the 70's when one of the popular car mags published how to calculate HP buy using weight, and top speed generated thru 1/4 mile.
It seems to me that the v8 performance is about right for listed HP. BUT the v6 seems to be generating more HP then listed.
Anybody know what I'm trying to say? Anybody even seen dyno results for v6-v8?
I'm convinced the v6 really puts out more then 300HP, perhaps up to 320?

 

[thom000001]

If you google

ET calculators

It will give you an idea of hp based on weight and 1/4 performance.

Remember that the V8 may be rated at 375hp
And the V6 at 290HP

But there is somewhere around a 400lb difference in the 2 cars. They have physically larger suspension pieces on the V8 (to handle tq better) and more added to frame to help quell twist from that tq.

I'm not sure if the gearing is the same between the v6 and v8 trans's but that would adjust things too.

Tom

I know some of you out there know how to figure true HP of these engines.
There is so little difference in performance difference that I thought back to the 70's when one of the popular car mags published how to calculate HP buy using weight, and top speed generated thru 1/4 mile.
It seems to me that the v8 performance is about right for listed HP. BUT the v6 seems to be generating more HP then listed.
Anybody know what I'm trying to say? Anybody even seen dyno results for v6-v8?
I'm convinced the v6 really puts out more then 300HP, perhaps up to 320?

 

[yuhaze]

I have a 2009 v8 with K&N filter and Borla exhaust.
I've been playing around with a new "toy" that gives me torque and HP. really cool device.
I've only dared the 0-60 timing so far, and during such a run, and have not registered more than 226 hp being released. I did this in auto, not manually changing gears
If I find a good stretch, I'd like to try the 1/4 mile and see what my peak hp is there.

 

[tjc78]

That 226 HP would be at the wheels though right? The listed HP of 290 is at the crankshaft. That would be around a 25% driveline loss, which I believe to be about right.

 

[yuhaze]

Well, here is what happens when my two little braincells start rubbing against each other:

The 226 hp is because of the:
1. rpm and speed (velocity)
2. auto control - rpm is lower and torque is dominant (even after several training trips)
3. velocity. i am of the opinion that you won't see the 400 hp unless you're doing 160mph in top gear at max rpm.

Mine is the v8 4.6l, rated at 375 hp. roughly 400 hp with the added mods
Maybe I'll take 'er to the local drag strip and try the 1/4 mile, should show more hp and torque

N.B. there's a video of someone taking the genesis to 160 mph in a tunnel - kewl

 

[motorsportsauthority]

Yeah it all sounds about right with the powertrain loss. Here's my V8 on the stock run:

intake flap delete on same day/conditions:

 

[tarpumn]

OK, My point was I think the V-6 puts out a better % of power then the V-8. IE, it is under rated or the V-8 is over rated.

Using the Google calculator the following results we shown for several cars:
Gen. 4.6, 308hp vs 375hp rated, 82% =18% loss
Gen. 3.8, 255hp vs 290hp rated, 88% = 12% loss
Equuas 4.6, 304hp vs 385hp rated, 80% = 21% loss
ZR-1 482hp vs 638hp rated, 76% = 24% loss

Shows me what I thought, V-6 puts out more hp per what ever then v-8.
Also DON'T SPEND THE EXTRA $20K + FOR A ZR-1

 

[Sayantsi]

The V6 has more aggressive gearing so that factors in - its more complicated than back in the day when you had one trans and just bolted an engine to it.

 

[wallymn]

OK, My point was I think the V-6 puts out a better % of power then the V-8. IE, it is under rated or the V-8 is over rated.

Using the Google calculator the following results we shown for several cars:
Gen. 4.6, 308hp vs 375hp rated, 82% =18% loss
Gen. 3.8, 255hp vs 290hp rated, 88% = 12% loss
Equuas 4.6, 304hp vs 385hp rated, 80% = 21% loss
ZR-1 482hp vs 638hp rated, 76% = 24% loss

Shows me what I thought, V-6 puts out more hp per what ever then v-8.
Also DON'T SPEND THE EXTRA $20K + FOR A ZR-1

the problem isnt power but traction... I have the v8 and I can't use it because the ECS nanny can't be defeated and the 255s I have on the rear can't hold the pavement, (neither could the stock 235s).... if you can't use the power it doesn't matter how much you have...