I know this is a fairly general topic, but I'm curious and it doesn't seem to be something anyone has discussed before. Besides, it's snowing...

I'll set my "target demographic" at NA Hondas in the 2100-2500 lb range making 180 - 225 whp. I believe that encompasses quite a large number of us...

Basically I'm talking about 1/4 mile times. They're all over the map considering the similarities between NA motors and the popular platforms (usually an EG hatch). I can certainly attribute a lot to driving skill, traction, car setup, and even altitude, but the spread is still awfully large to me.

From what I've seen, cars that fall in the "test group" at the top of the post can run everything from mid 12's to mid 14's, and nobody is surprised at numbers anywhere in that range. That's confusing to me because we all know there's a *huge* difference between a 12.5 and 14.5. Another reason why NA cars stand out to me is because there isn't as much disparity in the amount of power they make. In this case I called the range 180 - 225 whp. That's a 45 hp spread, and I think encompasses a lot of good b series swaps out there in 2100-2500 lb street cars.

So what's going on here?

The 2 things I keep coming back to are driver and car setup.

Can a good driver really make that much difference? I'm not talking about an idiot vs. Lisa Kubo, but a guy (or girl) who knows their way around a drag strip vs. a real hot shoe.

The other thought was car prep, and I'm not talking about slicks HP or weight. Suspension tuning is grossly overlooked among weekend drag racers IMO.

I know it's probably impossible to pinpoint just one issue. I suppose given my scenario, a hot shoe in a 2100 lb NA car with 225 whp, slicks, and dialed suspension has a great shot at that 12.50, but that 2 second spread is still pretty surprising to me. Ideas? Thoughts? Maybe I shouldn't be surprised...

 

In a study that was done in South America on a race series that fields 150 cars that are all similarly prepared, the brakes were the culprit that are too often overlooked. It was found that up to 50 horsepower could be lost in brake systems that were unchecked. These were 375 horsepower cars so thats a 13% plus loss of power.
Makes you wonder why more attention isn't given to the brake systems, wheel bearings etc. on drag cars!!!!!!!!!
Alfred Nolan
Saenz Racing Transmissions

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dadwithgas &raquo;</TD></TR><TR><TD CLASS="quote">In a study that was done in South America on a race series that fields 150 cars that are all similarly prepared, the brakes were the culprit that are too often overlooked. It was found that up to 50 horsepower could be lost in brake systems that were unchecked. These were 375 horsepower cars so thats a 13% plus loss of power.
Makes you wonder why more attention isn't given to the brake systems, wheel bearings etc. on drag cars!!!!!!!!!
Alfred Nolan
Saenz Racing Transmissions</TD></TR></TABLE>


this is very very true, I have seen dyno differences between stock iron rotors and aftermarket two peice light weight rotors. people dont realise this but brakes can really slow you down (pun intended)

 

not all senarios invovle equally skill drivers, or equalivant track conditions

 

elevation

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boostage &raquo;</TD></TR><TR><TD CLASS="quote">
this is very very true, I have seen dyno differences between stock iron rotors and aftermarket two peice light weight rotors. </TD></TR></TABLE>

Wow, that would be a very interesting comparison. All this time and I never did give brakes more than a nod. I bled 'em regularly and ran good pads, but that was it.

So although there is the obvious "unsprung rotating" weight to deal with, is the parasitic drag effect of the pads sitting on the rotors that significant??? I'm concerned that simply jacking up the car and giving each wheel a spin by hand is not a sufficient test. Friction coefficients change quite a bit when the pad material heats up...

 

Wheel bearings is something i was thinking a lot of honda people forget about. I come from a karting background where everyone weighs the same and has almoast the exact same HP. Bearings and rotating mass were big things to us.

 

this is intresting.... i remember reading (i want to say late 90's) a article that general motors did a test on they're piston dust boot retracts the pistons(caliper) after the the brakes were depressed leaving no residual paristic load on the rotor... H'mmm bump i want to know!