I guess I should have elaborated a little more when I mentioned the 11 year old Motor Trend article.
The 03 SLK was mechanically identical to the 04 Crossfire. H.P. and gear ratio.
Speedy 4x4 clarified what I meant by saying the SLK had smaller wheels, this is how Motor Trend put it.

From the starting line, the SLK showed a slight acceleration advantage, which increased throughout the run. The Crossfire is about 100lbs lighter overall, but its wheels are much more massive, creating more rotating inertia.

Those very same "smaller" tires that help improve the 0 to 60 (and 1/4 mile) times of the NA SLK over the NA Crossfire, may just have a detrimental effect on the "Supercharged" version of the SLK. Because the smaller width of the 225/50/16" tires don't lay down the footprint of the Crossfire's big meats.

 

Makes perfect sense. It is why I would change my rears to 18s for a run at the drag strip. 4" less rotation at the pavement per revolution of the wheel. Maybe 3% to 5%more power delivered to the pavement.

 

Great Franc, 18's are only as far away as your Wife's SRT.

 

Didnt chevy do that with 90 ish camero ss? like it was ac LS1 but they didnt wanna advertise it had the same hp as theyre pride corvette?

 

Single piece aluminum drive shaft and rotary formed wheels with the right tires would have a noticeable difference (different tires of the same size weigh different). And why in "most" vechicles a manual transmission has more rear wheel hp and better mpg due to rotational mass, the auto torque converter filled with oil is it's downfall.
The ls and lt engines in 3&4 Gen camaros where 30-50 hp less than in the corvette, which had a little better cam and more airflow. And the Vette where alittle lighter.
More compared the the corvette and the fiero, the reason Chevy would not put a small standard v6 in the fiero the first year is due to it outperformed the corvette in there testing.
If only they would have done more with the AWESOME LT5

 

Better, I have a full set on NA wheels with rubber.

 

In 1970 Pontiac had two 400s with different camshafts (one a bit more agressive than the other for M/T cars) but otherwise identical. In the F body both were rated at 330 hp, in the A body both were 350 hp, in the B body 360 hp. Almost pure marketing.


ps the Firebird did have a throttle stop. Was bent almost immeciately.

 

Yes so I guess in conclusion we can point to two things that make sense. Wheels and marketing.
If you can just claim whatever the hell you wish in marketing, does that mean I can expect a lot of cars to not really output the amount, the manufacturer claimed?

 

The Crossfire looks better!

 

My 70's were 3 Camaros and 4 corvettes. Young and single, lol. Motors back then being all mechanical and no ECU help, could be of the same displacement, but camshafts and lifters varied. A 70 Vette motor, which I later bought and put in a '71 Camaro, could be had with a hydraulic cam or a solid lifter cam. Could be as much as 30 hp difference with the cam alone, same motor. In fact, the short block I bought had the solid, and I changed out to a more aggressive hydraulic. Less I had to do to adjust the valves that way. Those were some fun days of experimentation of gaining hp. Today, you let a computer do it for the most part. Go figure. Well, I better add, I know it isn't quite that simple.
As for wheels, just remember the wheels sensors, deviate too much, and you are in limp mode. The puter knows better. I run 17" wheels and drag radials which are the same height as an 18" wheel and tire or close to it. Those who experimented with wheels sizes didn't find much of anything as Jim can attest to...

 

do 10 runs at the 1/4 mile and you will have 10 different #'s

 

Have to agree. Rarely will you repeat the same numbers....too many factors as the day or night goes along.

 

There used to be a joke that the F*rd 390 made a good boat anchor and the only way one ever hit 335 hp was to wind it tight, dump the clutch on the dyno and see how far the needle on the Toledo swung.


OTOH the sideoiler 427 and the 429 were probably underrated significantly just like the Z-28 and L-88/89.


ps back in the daze a set of hydraulics were good for about 5,500 rpm and backed off a quarter turn would go another 500. Solids were good until a rod came through the block. Then Rhodes lifters appeared and everything changed.


pps with a computer and an automagic I could make a car turn near exactly yhe same time on every run. That is why they were outlawed in some classes. I never believed in bracket racing anyway, the whole idea of losing because you ran too fast is just WRONG.

 

Heads up is the only way to go.

 

just how much faster does it feel ??? I know when I just put in the K & N filters, mine felt alot faster !!!! : ) And I dont care what anyone one else says or thinks I like the sound better too !!!

 

when i had a x fire did the sl5oo air box swap with kn filters really liked it

 

I hate to bracket race, and that is my only option. NHRA refuses to put the car in the class it belongs in. It is in a class of it's own being only 3.2 liters, and I end up with 5.0's or better....so, it is bracket race or get killed with full blown race cars....that is why I haven't raced this year, as I am still lobbying for a class.