Veloce Raptor

AGREED!!!!!!!!!!!!

J richard

....Bingo we have a winner...

techno99

But which curve?

mark kibort

Lets look at your car and those on this list of the things they have done to go faster. How many of them REALLY work. Electric superchargers have given 10hp net gains on the dyno on 200rwhp cars for years now. Not much more on more powerful cars due to basic aerodynamic limitations of the device. Now, if we see a proven .5 vacuum relieved in the air box and a .5psi pressurization in the airbox, for 300 bucks, wouldnt you use it if you could? 1psi is near 6%. on my higher hp car, its less than 2%, but It flattens out the HP curve at the top. (more area under the curve) Now, go make fun and insults (by the way, your comment below is no more insulting than what I have said hear about you, trying to PULL some facts out of you!)

Edited - BR
mk

mark kibort

VR, Here is the answer to your question regarding two cars coming off a turn one with greater torque than the other, but both engines have the same HP.

Read and make comments as this is what this thread was supposed to be about.!

Two engines in two same cars:

400hp 200ftlbs peak torque 7500rpm (redlinie 10,000rpm) coming off a corner in gear in the meat of its 3rd gear. (call it 75% rpm drop per shift)
vs
400hp 400ftlbs peak torque 3750rpm redline 5000rpm coming off a corner in the meat of its 3rd gear.

both cars are the same
both cars have the same gear spacing
both cars are in the same gear and traveling at the same speed.

What is the torque at the rear wheels that DETERMINES acceleration?

Lets say the speed is 70mph for both cars.
If we use a gear ratio that is 5:1 for the high torque car low rpm car, the same speed will be found at 10:1 for the low torque high rpm car.

The net acceleration force for both cars coming off the turn at 70mph would be 2000ft-lbs vs 2000ft-lbs! same same same .

Let me show the math:

200ft-lbs x 10:1 = 2000ft-lbs
400ft-lbs x 5:1 = 2000ft-lbs

Get it now???

answer your question?

read your answer and think about a response.


Mk

onefastviking

Mark, I am confused now.
In either yours,or your sponsors, ad for the electric supercharger it said I could get 27 GUARANTEED horsepower, now you are saying it is only 10 ? Which will I get ?
My Spec Miata could REALLY use the 27hp, it would even be worth it on the Porsche, but if it is really only 10hp I think I will just get one for the Spec Miata. So which truth is it ? I am beginning to possibly doubt what you are telling me with these contradictions you are making.

BTW - Electric superchargers have been tested and shown at a loss many times, low hp on a dyno with no moving air you might see a small gain, real world, dynamically, in the types of cars we drive in moving air = loss.

eclou

this debate is about as scientifically valid as Al Gore's global warming pitch.

wanna911

OK, now we are getting somewhere. Now let's apply it to paper so people who don't know what the terms mean can know what this looks like on a dyno sheet. Here are two antitypical dyno plots, one from a CTS-V and one from an M5. Which would you prefer on a track. Compare the baseline runs.

As you can see there is a 10 whp peak difference but a 120 whp difference in torque.

Mind you these cars are very close in performance, but the M5 tends to trap higher on the drag strip when tested on the same day.

Discuss.

CTS-V



M5

onefastviking

The BMW hands down !
Much nicer leather interior.

mark kibort

Its not as simple as the site would imply. The site talks about % gains but its not for all cars. Lots of factors. On the 3.2 200hp 911, we got 10hp gains, but on the sub 100hp hondas they got near 10%, which might be only around 10hp.

The 27Hp version is the dual inline model that puts two in series. (I think) Basic fan theory here, where it doubles the HP gain. I dont think it is 27hp though. I havent been on the site for awhile, so they might be talking about the new DC brushless versions that are getting near 2000watts, but require separate batteries, but include an installed charging system. This system is looking like near 2psi on some smaller cars.

Personally, I use on on my race car, but its not reall for positive pressure, but to change flow characteristics on my very ventilated air box. on the dyno it extended the HP curve at the higher rpms. On a spec miata, I would expect about 5-8hp realistically. I think this is a GREAT application before someone detects it and DQ's you for having it. but right now, its under the radar and there are a couple of them using them now and you cant see it during a normal tech inspection. If they did find it, there is not really a rule against it yet.

As far as dynamic performance at speed, we have done a lot of research there that shows that even with 120mph, and about .08psi of pressure generated due to ram effects, we add an additional .5psi. (almost 5x what is due to ram effects at 120mph!) This is probably its best feature in my opinion, that you basically get the ram effect of near 160mph at any speed.

The other nice thing about this mod, is its gurantee. put it on and go to the dyno if it doesnt work you can send it back for a refund. It does work on the AFM type cars very well. on my 928 V8 AFM version, it went from 236rwhp to 242rwhp. the cool thing about dyno'ing this type of mod, is that you can turn it on or off in the middle of a run. The curves are very telling having, not having , and pulling it off mid run.

Sorry for the slight hijack. Viking started it!

mk

eclou

I pick the car with the less complex motor and the better oiling system.

mark kibort

Here is how you do it.

Use the runs that show near the same hp. grab hp readings from redline to the post shift rpm. 500rpm increments. since we are trying to keep things the same, use a .73 rpm drop, since that really cant change in addressing the topic here.

If the CTSV has more average HP, then close the rpms for the BMW assuming that we could use a close ratio gear box at the track.

Certainly this is a good example of what the the answer could be. But, it could go either way, and that is the point of all this.

From what i know of both motors, i bet this one is pretty darn close.

Mk

onefastviking

There is clearly a rule against it, atleast in SM. I would never seriously dream of using it on any race car I owned, built or drove. I am much more familiar with intake pressures/vacuums than I care to admit publically. If in fact you do have customers using them on Spec Miatas you should inform them they are illegal. And now from 27 hp to 10 hp to 5-8 hp. WOW !

I apoligize to all for the hijack.

wanna911

Good stuff guys, great discussion.

mark kibort

Here is a rough approximation. both are very very close.

BMW from 6k to 8200rpm average 406hp.
CTSV from 4500 to 6200 average 402

the tie breaker really lies in HP-seconds. both of these cars would put down almost the same power at any speed.

Point is, the caddy has 420 torque and the bMW has 320torque.

Mark