3 beats Miata?

I'll try to make this short and succinct...

My 2010 2.5L Mazda 3 with fewer go-fast parts beats my '94R Miata on my 2 mile home track .  Both have Koni yellows, stiffer springs, updated sway bars, Carbotech XP8 brakes, Falken 660s.  3 has a K&N cone filter, Miata has intake, header, full exhaust, '99 head, etc. to dyno at 131HP WHP on a calibrated dyno.   If I do the math, the 3 is about 18lb/HP and the Miata 15.8lb/HP.  And of course the vaunted Miata handling vs. an open diff FWD econobox...

Yet on the home track the 3 turns time trial times that are over a second faster, and as a sanity check the difference to the nearest competitive car is even greater from event to event.  The 3 and Miata are in the same class.

I don't get it.  I'm thinking that the all the time and money I just put into new bushings, alignment, calipers, tires, hubs, etc. on the Miata was wasted and I should have just put a header/exhaust/tune on the 3.

The 3 probably makes way, way more than 131hp at the wheels, and the midrange punch of the 2.5 probably works better on those courses with OE gear ratios.

I also would not discount the chassis.  I forget if it was done by Mazda, Ford, or Volvo, but it's a really good chassis. 

What tire sizes are they?  Wider on the 3?  Any idea where on the track you are faster?  Straightaways, corners, or both?

I agree with Pete on the 2.5 having a lot more midrange than the Miata's engine.

+1, the 2.5 is going to have more torque than the 1.8, but that shouldn't be enough.  

How do your Miata times compare to other similarly prepped Miatas at the same track?  Have you used a timing app to compare the Miata vs. the 3 to see where it's making time on the Miata?  

Miatas make their time in the corners +entry/exit.  I would look at that data compared to the 3.

But which one made you smile more?

If it's a faster track, power/drag becomes more important than power/weight. A 12 year old hatch has better aero than a 28 year old convertible that has frankly crap drag numbers. You're also looking at peak numbers and that 2.5 has a whole lot more area under the curve plus probably more rubber under the fenders.

Progress happens :)

Maybe you're a better FWD driver?

I know I am. I prefer RWD, but am rarely competitive against other RWD drivers. But I can hang with the top dogs if we are all driving FWD. 

I still have more fun with RWD. 

A 1-2 second difference is still within the realm of setup adjustments. has the Miata been properly corner weighted and aligned?  Grip and driving dynamics should matter more than power in either of those cars. 

This thing just puzzles me.  By the numbers and car characteristics the 3 should be in the same class as the Miata - but it's FASTER.  Both cars are on 225 width RT660 tires.  The Miata just was aligned.  -2.2F/-2.1R camber, .05F/.06R combined toe and is on FM springs/Konis/bumpstops per Keith's recommendation.  The 3 was partially aligned, the rear was too rusty to break the bolts free but it looks OK.

I've been a Miata/Exocet driver for fifteen years, with maybe a year of FWD in 3s, and this is my home track with bazillions of laps/events.  The Miata runs top of class and has the class record at the Milwaukee mile which is a pretty fast track.  Compared with the results from prior years, it would almost always have won the prepared class it runs in, and is generally two seconds faster than the fastest stock class Miata times (shocks, brakes, and two points for mods allowed).  I beat the other Miata running yesterday which I consider pretty well prepped and driven by over a second.  I think the Miata is healthy and fast.  I left the track app phone and GPS  on the desk at home charging.  That would have answered a lot. 

This is a pretty good Miata track.   1.95 miles.

What tires are on each, including sizes and age?

In reply to Floating Doc (Forum Supporter) :

Both Falken RT660 new this year.  225 width on 8" wheels.  Might also be worth noting that the Miata times are pretty consistent with the previous Rival S that were aged out after 3 seasons.

When I was racing sports cars, the ruling organization elected to amalgamate some sedan classes with us (it was a production limited modification class).

It turned out that the sedans had a handling advantage because they had rigid chassis so that a 1600 cc sedan often turned in faster lap times than the same engine in a roadster.

In reply to wspohn :

Huh.  All this comes with a good dose of irritation.  I'm thinking this is my last all-in season of time trials/autocross/track stuff and I just put a couple $K and a bunch of work into the Miata.  I love that car, but it looks like like I chose the wrong car.  I'm really sure the 3 built to class with a header and exhaust will annihilate the Miatas.  Wonder why there's not a lot more Mazda3s on the track?

In reply to jwagner (Forum Supporter) :

They rust like they were Italian?

That track map makes me think horsepower is the determining factor here.  3A is the only corner that really plays to the Miata's handling advantage in changing directions.