Yes Doc you can have two identical cars driven by the very same driver racing the clock and get two different times. That's a given. But drag racing an NA SLK automatic vs an NA Crossfire automatic is essentially a point and shoot competition. Put the car into 1st. and let the tranny do the rest. Neither car is a tire smoking monster by nature (unless you want to make it look like it is) but one would think the Crossfire would at least be able to pull a little bit of a hole shot on the Merc right out of the hole thanks to it's massive tires. But as Road & Track pointed out. Getting those massive tires to spin takes more H.P. than it does to get the smaller SLK tires to get rolling. The Stat sheet presented both cars as being identical mechanically, with the same exact H.P. and gear ratios.

KDW4Him, yes they list slalom runs. 66.0 mph for the Crossfire vs 62.8 mph for the SLK.
Skid pad #'s were 0,87 Crossfire vs 0.81 for the Mercedes.

Interestingly, three months later they tested a 6 speed Crossfire and did the slalom at 69.6 mph. with a 0.89 skidpad. (which by the way bested the speed and times of the SRT-6 Roadster they tested). Faster thru the slalom than the mid-engined Ford GT as well. (But don't tell anybody.)

 

I see your point Mike... 19's vs 16's I believe, will change the gearing and would make a few tenths difference. As for the N/A vs the SRT6 in a slalom, the SRT is at a disadvantage. When playing in the curves of TN, the 6 speed's gearing will stay with or even pull a stock SRT6. The reason, is I think the low end HP is probably the same. We need the boost to get going, and those short bursts just doesn't give you time to bring on the heat, until a straight a way...then it changes....lol

 

I pointed you to the Crossfire engineers You Tube video remember?
What I was getting at was many will just read this statement and question it, when making statements like that it is best to give something to refer back to.

 

I did hyperlink back to the original conversation in my earlier post...

Of course I remember the video you linked in the referenced thread (and again posted here by syfi)

I enjoyed the video very much, but not the esoteric browbeating in both threads.

 

Lots of great info I learned in this thread!

I also found an older thread that kind of sparked my interest, too directly relating to this topic.

In this thread Eurocharged dynod the STOCK NA at 258hp and 285ft of TQ!
I am very sure Mercedes didn't go through the hassle of detuning engines...Pretty sure they sent exactly the same engine to Karmann for both SRT and NA and solely switched the "sticker"!

 

https://www.crossfireforum.org/forum...p-results.htmlCompare apples to apples the car in question was an SRT6.
The hp is at the wheels.
Here is the thread done at that time.

 

Totally my bad. I figured something had to be wrong here!
How do you convert HP at the wheel to total HP if that is even possible?

 

Its mostly a guess/ estimate.

Take the motor out and test it by itself is the only true way to test.

Here is a guesstimate calculator:

Wheel Horsepower to Crankshaft Horsepower Guestimator

other references

How to Calculate and Convert Rear Wheel Horsepower - CarsDirect

The absurdity of fixed percentage drivetrain loss - TDIClub Forums

 

This thread is indeed informative. I'm going to craft my own take-a-way.

The NA Crossie HP is same as the Merc - 255 from factory. That means, all my mods have added about another 45 hp, which brings me up to 300 hp. No wonder my car feels so darn quick now.

It always felt quicker than the advertised 215 anyway. Whether it's true or not, I'm going to say I'm now a 300hp car!!!!!!!!

 

Get you a "FUEL INJECTED MERCEDES V6 300 HP" bumper sticker made.

 

It is what it is.... Each will go after their HP the way they see fit. I grew up with big block Chevys in the beginning switching to small block 350's... Think about how many ways you can mod a 350 small block Chevy. It is endless.... Be glad we have such a limited numbers of mods....lol As for the BS in these car discussions...that will always be there. Everyone has an opinion...

 

I'm having them printed as we speak....

 

Thank you for your response. The converter is very helpful. Is there a converter that can give the real output of torque, too? I assume the dyno results that show HP/Torque are both for the rear wheel then and so how would I convert the Torque values to engine torque?

 

One thing about HP and cars..... I have ran against cars with a lot more HP, in fact, I am out gunned in about every race at the local drag strip and half mile runs that I have done. It really isn't all that important as much as how you deliver that HP to the track..... So many factors to contend with...drive train, suspension, weight, transfer of weight, wheel size, tire size, tire type, track conditions, weather....etc etc... Bottom line for me is who crosses that finish line first, and if I didn't what do I need to do to improve. Right now for me, is the rear end gear change if that is ever possible. Right now it isn't.
I might add one more thing, is those who have been successful with Nitrous Oxide injection. They push the parameters of a car's HP instantly for just a few seconds. The bottom end of an AMG motor has said to have been rated up to 800 hp. So they can take it. I just don't get into arguing numbers as much as arguing times in the 1/4 or 1/2 mile. If you have done you homework and can turn those numbers time and time again...then you have done all you can do until the next modification comes along.

 

If I add up the advertised claims for each mod then my car is making over 500 HP LOL. You can't really know without a dyno and even then different dynos, different numbers. Consistent #s at the track will give you the most accurate test of the effectiveness of your mods.

 

Engine torque to Wheel torque calculation


http://horsepowersports.com/torque.php

 

Hey. Which modes have you done?

 

The last post was in 2015, just sayin.

 

Old post but my mods are the Needswings Dual Cold Air system and the Eurocharge Tune. I still hsve the car and still love it. I still run our Maryland group and am active with other owners and their groups as well. Regardless of the true Horspower, the car runs well, drives extremely well on the twisties and brings together many people. I did buy a higher horsepower power car as well...love my F Type S AWD as well!😎😁

 

Okay. So i i stall needswings dual and eurocharge tune then how mucb will it change my car power? How many hp did it give u? Did u measure like accelaration 0-100km/h and difference?