Originally Posted by SpeedOften
You compare peak tq values, but that's like comparing power only at 7200 rpm. The total area under that tq line is the usable tq. In the cars you used for examples, their peak tq while not an outstandingly high number were all very flat tq curves, and or have their peake tq come much much sooner than the SVT.
Take two SVT's one with less hp and the other with more tq. The one with more tq will win in the 1/4, as well as on a road course b/c it'll be able to accelerate faster. Who cares who has the higher top speed, it's who gets there first right? You'll get there first with the greater overall useable tq.
As an example: 70 charger running down a Ferrari GTP:
Who's got the tq?
I'm sure the Ferrari has the hp advantage at 12000 rpms.. but...
Tom came up with the idea of lowering the rpm at which the IM switchs runners when he first started tuning the cars so it's not a new idea.
As far as the coil, you're not going to push it any more than someone who's pushing 300whp out of their engine. I'll believe a 3-5whp gain when I see a dyno comparing the two.. My opinion is that it's a placebo effect. It may improve the overall smoothness of the engine, but it's not going to give the any gains.
Yep you are correct about the usable powerband on the SVT (It sucks in stock form).
But what do you think would happen if the SVT with more hp and less torque had proper gearing to take advantage of the different powerband? Only through proper gearing can an engine take advantage of the power it produces out on the open road (no matter what an engine or chassis dyno says). Dynos are a great "tuning" asset but means very little out on the road where many other variables must be considered. Hence my 800hp Supra v.s. 520hp Corvette comparison.
Comparing a 70's musclecar and *ANY* exotic is like comparing an F1 open style race car to a NASCAR Nextel stock car (it's silly). Put the same two cars on several different types of tracks and the results would favor the Ferrari. It's not built just to go in a straight line and make a lot of noise!
I've seen that video before and it bores me to death.
And like I said before (if you actually read everything I wrote), horsepower and torque are only ONE
of many variables. Having a peaky hp/tq powerband works just fine *IF* you have gearing that is properly designed to drop each gear change into the sweet spot of the engine on each upshift. It's called PROPER gear spacing. This is the sole reason a 6-speed transmission is better than a 5-speed transmission. The gears have better spacing and can provide increased performance (in theory). The Focus SVT uses a 6-speed transmission but it feels like 4th through 6th gears are all overdrives (I don't have the exact ratios in front of me). On upshifts @ WOT, The SVT gearing drops the rpm well below the sweet spot in the powerband, especially with the stock tune.
Most of my direct "comparisons" were cars in the same class and same dollar range as the SVT, making them "direct competition". My comparisons of lightweight but "lower" horsepower cars that perform really well were used as examples of good engineering. Most of those super lightweight cars have peaky powerbands, but because they are geared right from the factory they can take on cars with twice as much horsepower ratings on paper! A powerband as shown on a "dyno" (ie: on paper) means nothing if you can't get it to the ground or the transmission isn't geared correctly to take advatage of the power. This is one of the SVT's limiters. The gearing isn't even close to optimal. However, taking 1,000 pounds of weight out of the car would make more of a difference than changing the gearing (but think about what you could probably achieve if you could do both).
I would lump just about any $18,000-$20,000 "performance oriented" economy based pocket rocket into the same competition as the SVT. The truth of the matter is, the SVT sits at the bottom of the class in power AND good usable engine upgrades (unless of course you want to go forced induction). People rant and rave about the SVT Focus being so technologically advanced but it isn't at all. Ford didn't do anything with the SVT that hasn't been done many times before on production cars. Don't get me wrong, I love the handling of the SVT (another benefit of a low weight platform) but the power delivery is not very good. Much of the blame there can be attributed to the gearing (and a horrible stock tune).
I'm fully aware that lowering the rpm of the switchover from long to short runners is nothing novel and that Tom does this with his tune. I only mentioned it because it will no doubt make for a much more pleasant powerband compared to the abrupt and peaky transition of the stock switchover. This "abrupt" and rather high rpm switchover shows up on the dyno curve and is very noticeable (on a basically stock car as mine)...
As for the MSD coil: You obviously do not have any clue as to what I am talking about.
The coil all by it's self doesn't do anything as far as power (as I stated before). The power increase is from indexing and modifying the plugs. This is an old trick racers of any "combustable engine" have tried and proved for over a 100 years (it's nothing new and is a PROVEN engine blueprinting technique that will almost always increase power just a little). You can't do the "MOD" without the coil (or some other way of increasing spark strength)
. The modified electrode is nothing new either. The coil is just 1/3rd of the equation to make this work. Without it, the engine runs poorly and misses at lower rpm due to the much larger spark gap.
So, back to the weight issue....
Anybody care to guess how much difference a properly tuned N/A Focus SVT will perform (ie acceleration, handling etc) by taking out 700-1,000 pounds? I'm somewhat surprised no has done a project like this before.