Edmunds: New STI vs Shelby GT

[LonghornTX]

So upgrading an already F/I car's turbo is more difficult than adding an aftermarket turbo kit to a N/A car?

No but adding oil coolers, replacing injectors, intercoolers, etc (plus installing the new turbos), is going to be pretty much the same thing in the end as adding a turbo kit.  It might still be easier for the stock FI car, especially if it does not need some of that stuff, but the preconception that stock FI cars are always easier to modify sometimes isn't true IMO.

[SVT666]

I really love the new STI, and hope to own one in four years, but I have to say this comparo is really only good at pointing out how one dimensional and overpriced the whole Shelby Mustang thing is.

That said, the basic Mustang Gt V8 is still one of the best performance bargains of this decade.  300+hp for ~$26k anyone?

You are absolutely correct.  The Shelby GT is beyond being overpriced.  The Bullitt is a better car and costs substantially less.  You're overpaying for a name...that's it.

[LonghornTX]

not to be the RX8 whore here, but i'm failing to see some of the logic... (but i'll say up front i respect your goals for your car and like them a lot)

I'll just take this from the RX8 perspective since i know it best (i'm sure the same applies to most or all of the cars in this range)... stock on that platform you have double wishbones up front, multilink rear, generous caster/camber/toe adjustment on all four corners, the ability to fit a 10" wheel on all 4 corners stock, and a car that weighs 2900-3030lbs depending on options.

A double adjustable coilover suspension from KYW can be had for $1,600 and isn't even really needed (or you could go with about a dozen other coilovers offered - one of which is as little as $600).  There is enough adjustment in the stock suspension to keep the camber/toe/cster in spec as low as you want to go.  The top B-stock auto-x teams and a bunch of track day junkies just use 4 koni yellows for $600 total and they are set.  If you really want to play with sway bars afterwards, a set of adjustable front and rears from progressive will set you back $400 for the set.  None of which cost any more then Mustang aftermarket parts offered and you save a ton by not having to try to change the piss poor stock suspension components as all the suspensions arms are already cast aluminum and there is nothing to be gained.

The stock brakes already outstop pretty much anything on the market.  The stock rotors and calipers are used by Speedsource for their touring cars.  Weight savings can be had with a 2 piece setup offered for some $ but all thats really needed for a track day is a set of pads.  Again checking the prices, if you want to have your eyeballs pop out of your head you can get a 2 piece rotor and aluminum 4 pot caliper upgrade for the RX8 for less then $2k, which is right in line with the Mustang kits.

Power does come at a price with the half a dozen forced induction kits ranging from 260rwhp to 400 rwhp for $3-7k... the cheapest being the greddy kit ($3k) which hits full boost around 3k rpms and with some tuning is hitting a little over 300 to the wheels.  The one disadvantge, but given the weight advantage.... eh

Thanks for taking the time to write a good post.

So it seems that the power and acceleration goals would be a lot easier to attain on the Mustang than on the RX-8, but the suspension mods would probably be a crap shoot.  I felt that the RX8 needed a stiffer suspension when I drove it so I would definitley upgrade it.  The thing with Mustang brakes, though, is you can upgrade to the Brembo GT500 kit for $950, so that is a steal.  The range of suspension adjustments available for the RX8 would surely save some money in the comparison as well.

I definitely did not know that the RX-8 could fit such wide wheels stock, that is pretty bad ass and it is a much lighter car.  In the end, the RX8 is just a more expensive car though, with worse fuel mileage (from what I hear at least), and even though some of the upgrades might be of comparable price, the car itself is like 5k more expensive than the Mustang.  There were some other reasons why, but most of them are personal and probably mean little to other people (like styling).  It is a great car though and the engine is probably one of the more unique powerplants that I have had a chance to drive, though a bit strained with what I felt was pretty tall gearing stock.  Speaking of exhaust notes, the buzz saw whip of the rotary definitely has its own appeal.

I want to take this car to the open track, so that is why power is something that remains important to me.  If I were strictly autoxing, the RX8, 350z, or STi may have been as good or better of a choice, for various reasons of course. 

It just frustrates me when people look at the Mustang as some POS that cannot do anything well, especially corner carving.  Sure, stock it is pretty tame, armed with all season tires and urethane bushings, but give it a little love and you can chase C6s (base model of course) and pass M3s (e46) if you are a good enough driver. I guess you can make any car into a corner carver with enough money (like the RR that Chris posted the other day), but the Mustang is better at it than most assume.

[LonghornTX]

Look, mustangs suck.

Period. From their soldi rear axles to their low output V8's(4.6L v8 with 300HP?????? hello ford, meet infiniti 19 fucking 90).

If you meatheads want to cuddle up with your furd at night and wisper sweet nothings into its ear then go ahead.

I personally want nothing to do with that POS. I haven't owned a vehicle with a solid rear axle since a brief stint in a 1995 S10. I was unaware of such things as SRA and drum brakes. Good ol domestics cutting corners and saving a few penies at the expense of quality product, then again if the customer is to stupid to notice then why bother. It reminds me of when i sold basile to all the stupid middle school kids. They got high and were too stupid to notice.

HAHA

[LonghornTX]

Ford, its like buying a dime bag of basil. Your just too damn stupid to notice.

So that is why I didn't get the munchies last night?  Basil eh? Haha

[Nethead]

That's cool, but in this case, I'm not demanding you like it either.

I'm just saying its hypocritical for someone to look at that and say "oh what a ricy, silly piece of racer boy wannabe shit," when they would make excuses for a non-functional scoop on another carthat they happen to like.

Soup DeVille: SoupDude, if you read my postings you'll see that the Nethead here does not like hoodscoops on anything, functional or not. History's best-looking functional hoodscoop was the one on the '67 Corvette Tri-Power 427--the car would look diminished without it. It is the only hoodscoop I approve of, and the only one that added something to the car it is on. 

A long, long time ago, it was established that the hood is poor placement for an air intake--because air pushed upwards by the front end tends to partially overshoot the hoodscoop at speed (which is one of the reasons why you see such tall scoops on many racecars--to get the inlet up into that air that would overshoot a lower hoodscoop).  For awhile, this situation was improved by cowl induction--air hitting the windshield generated a pressure build-up that could be ducted through a cowl induction scoop.  Then, windshield slanting got so great that cowl induction lost a lot of effectiveness because of the proportional drop in air pressure build-up in front of the heavily-slanted windshields. Oldsmobile once had a W31 option, I think it was called, on 4-4-2s that mounted dual scoops under the front bumper and this was a big improvement even though the air down near the pavement is warmer than air higher up--and there is a gravel/burger wrapper issue in that location. Arguably the best location is in the grille, and even that has a few issues with radiator/headlight clearance but otherwise offers most of the air pressure advantages of the 4-4-2's W31 hardware while far enough above the pavement to avoid most of the heat/gravel/trash issues.  I call this "arguably the best location" because really tall hoodscoops might me somewhat better still--if the narrowed field of vision is not an issue. The common wheelwell induction systems seen today are at least better than no effort at all to avoid hot engine compartment air being the only source of intake air for an engine. Western Motor Sports of Calgary offers an over-the-radiator CAI that intakes air from the area underneath the hood forward of the radiator, which is an idea that may catch on in designs that have worthwhile clearance between the top of the radiator and the underside of the hood. Time will tell...

[r0tor]

the RX8 intake is in front of the radiator behind the bumper... works pretty good

[Soup DeVille]

Soup DeVille: SoupDude, if you read my postings you'll see that the Nethead here does not like hoodscoops on anything, functional or not. History's best-looking functional hoodscoop was the one on the '67 Corvette Tri-Power 427--the car would look diminished without it. It is the only hoodscoop I approve of, and the only one that added something to the car it is on. 

A long, long time ago, it was established that the hood is poor placement for an air intake--because air pushed upwards by the front end tends to partially overshoot the hoodscoop at speed (which is one of the reasons why you see such tall scoops on many racecars--to get the inlet up into that air that would overshoot a lower hoodscoop).  For awhile, this situation was improved by cowl induction--air hitting the windshield generated a pressure build-up that could be ducted through a cowl induction scoop.  Then, windshield slanting got so great that cowl induction lost a lot of effectiveness because of the proportional drop in air pressure build-up in front of the heavily-slanted windshields. Oldsmobile once had a W31 option, I think it was called, on 4-4-2s that mounted dual scoops under the front bumper and this was a big improvement even though the air down near the pavement is warmer than air higher up--and there is a gravel/burger wrapper issue in that location. Arguably the best location is in the grille, and even that has a few issues with radiator/headlight clearance but otherwise offers most of the air pressure advantages of the 4-4-2's W31 hardware while far enough above the pavement to avoid most of the heat/gravel/trash issues.  I call this "arguably the best location" because really tall hoodscoops might me somewhat better still--if the narrowed field of vision is not an issue. The common wheelwell induction systems seen today are at least better than no effort at all to avoid hot engine compartment air being the only source of intake air for an engine. Western Motor Sports of Calgary offers an over-the-radiator CAI that intakes air from the area underneath the hood forward of the radiator, which is an idea that may catch on in designs that have worthwhile clearance between the top of the radiator and the underside of the hood. Time will tell...

That's all wonderful: except the STi's hoodscoop is not for the air intake, but for venting the intercooler.

[Nethead]

That's all wonderful: except the STi's hoodscoop is not for the air intake, but for venting the intercooler.

SoupDude:  The atmosphere neither knows nor cares what will be done with the air taken in by the hoodscoop(s) of any vehicle--the air being forced upwards by the forward motion of the vehicle will partially overshoot an intercooler scoop the same as it would an air intake scoop.   

[S204STi]

SoupDude:  The atmosphere neither knows nor cares what will be done with the air taken in by the hoodscoop(s) of any vehicle--the air being forced upwards by the forward motion of the vehicle will partially overshoot an intercooler scoop the same as it would an air intake scoop.   

No it won't.  On a cold morning I can observe ice forming on the rear of my hoodscoop, and nowhere else, indicating that air is in fact being caught and forced through it.

Besides, most engineers aren't armchair racers, they tend to actually know what they're doing.

[Soup DeVille]

SoupDude:  The atmosphere neither knows nor cares what will be done with the air taken in by the hoodscoop(s) of any vehicle--the air being forced upwards by the forward motion of the vehicle will partially overshoot an intercooler scoop the same as it would an air intake scoop.   

Once again, it's not an air intake, it's a vent. It doesn't need stable or increased pressure, it just needs to dissipate heat.

[Nethead]

No it won't.  On a cold morning I can observe ice forming on the rear of my hoodscoop, and nowhere else, indicating that air is in fact being caught and forced through it.

Besides, most engineers aren't armchair racers, they tend to actually know what they're doing.

SoupDude:  So, does it scoop air in or does it vent air out? You've stated both so far:

"Once again, it's not an air intake, it's a vent."

"...indicating that air is in fact being caught and forced through it."

Call the STi hotline--as you say, the engineers surely know which one this "scoopvent" does, but apparently you do not. Or is it a "ventscoop"?

OTOH, the STi has one, whether you know if it's venting hot air away from the intercooler or if it's scooping outside air to the intercooler. It ain't likely that it's doin' both. Whichever it does evidently works well enough or they'll modify it eventually.                 

[Raza]

No it won't.  On a cold morning I can observe ice forming on the rear of my hoodscoop, and nowhere else, indicating that air is in fact being caught and forced through it.

Besides, most engineers aren't armchair racers, they tend to actually know what they're doing.

Yep, it's the marketers that do silly things like put useless scoops; like on the last generation Mustang or the current generation Mini Cooper S. 

[Raza]

SoupDude:  So, does it scoop air in or does it vent air out? You've stated both so far:

"Once again, it's not an air intake, it's a vent."

"...indicating that air is in fact being caught and forced through it."

Call the STi hotline--as you say, the engineers surely know which one this "scoopvent" does, but apparently you do not. Or is it a "ventscoop"?

OTOH, the STi has one, whether you know if it's venting hot air away from the intercooler or if it's scooping outside air to the intercooler. It ain't likely that it's doin' both. Whichever it does evidently works well enough or they'll modify it eventually.                 

Nethead, sometimes it seems you need a vent to let out some hot air yourself.  And R-inge is decidedly not Soup DeVille; you're quoting two people and crediting one.

[FlatBlackCaddy]

This is a pretty pathetic arguement.

Subaru has been placing hood scoops to feed their intercooler on their cars for decades.

I'm guessing that it works just fine.

[Nethead]

Nethead, sometimes it seems you need a vent to let out some hot air yourself.  And R-inge is decidedly not Soup DeVille; you're quoting two people and crediting one.

RazDude: Thank you for catching the miscrediting of R-inge's quote to Soup DeVille! Apologies as necessary!  So, RazDude, do YOU know if it vents hot air out or scoops air in? FlatBlackCaddy & R-inge state that the hoodscoop feeds it in, and I agree. And R-inge apparently has an STi so he's the one with the revolver at the card table.

[Raza]

RazDude: Thank you for catching the miscrediting of R-inge's quote to Soup DeVille! Apologies as necessary!  So, RazDude, do YOU know if it vents hot air out or scoops air in? FlatBlackCaddy & R-inge state that the hoodscoop feeds it in, and I agree. And R-inge apparently has an STi so he's the one with the revolver at the card table.

Roy has a 2007 WRX, not an STI, but the hood scoops on that model year are identical.  I think it's fairly obvious that a forward facing gaping hole in the hood of the car is going to take in air, but I don't know for what it's designed. 

[S204STi]

Soup is correct in that it's primary function is to force air over the intercooler subsequently venting behind the engine to the underside of the car.

Semantics. 

The conclusion here is that it is not a useless appendage as it is on the Mustang, and many other vehicles on the market. 

[S204STi]

Some corrections are needed here anyway.  First of all, I like to call it a Reverse Spoiler, creating the extra lift I need at highway speed to be able to jump the Grand Canyon someday.

Second of all, it is indeed smaller on both models as of the 2006  model year because Subaru engineers improved the aerodynamics of the nose sufficiently (the airplane nose works!) to improve airflow into the hood scoop.

The latest Impreza is even better at it, you can see from pics that rather than sticking out into the airstream it is recessed into the hood.

[Soup DeVille]

SoupDude:  So, does it scoop air in or does it vent air out? You've stated both so far:

"Once again, it's not an air intake, it's a vent."

"...indicating that air is in fact being caught and forced through it."

Call the STi hotline--as you say, the engineers surely know which one this "scoopvent" does, but apparently you do not. Or is it a "ventscoop"?

OTOH, the STi has one, whether you know if it's venting hot air away from the intercooler or if it's scooping outside air to the intercooler. It ain't likely that it's doin' both. Whichever it does evidently works well enough or they'll modify it eventually.                

Wow, you must be fun at parties.

On one hand, you're mind-numbingly verbose; on the other, you're so full of yourself it hurts.

[S204STi]

lol!

[MrH]

SoupDude:  The atmosphere neither knows nor cares what will be done with the air taken in by the hoodscoop(s) of any vehicle--the air being forced upwards by the forward motion of the vehicle will partially overshoot an intercooler scoop the same as it would an air intake scoop.   

I think you're answering your own question here.  Surely, some of the air overshoots the thing, but you admit yourself only some of it does.  Where does the rest go you ask?  You mean, it actually works as it's intended, and goes into the hood scoop?  Who would've thunk it?!

Silly me, who am I to argue with Nethead's banter on aerodynamics?

[CALL_911]

I think you're answering your own question here.  Surely, some of the air overshoots the thing, but you admit yourself only some of it does.  Where does the rest go you ask?  You mean, it actually works as it's intended, and goes into the hood scoop?  Who would've thunk it?!

Silly me, who am I to argue with Nethead's banter on aerodynamics?

You probably took Physics, did you take B or C?

[S204STi]

It doesn't take physics to figure this all out...

[MX793]

Sweet fancy Moses, we're still going through this hood scoop nonsense?

Firstly, one major point of confusion is that the Netdude is mixing up scoops intended for the engine's intake tract with scoops intended for cooling purposes.  Not all functional scoops have the same function and scoops with different functions have different airflow requirements.

The hood scoops that were pretty prominant on performance cars through to the 1970s were intended to feed the engine's intake tract.  In those days, most motors were carburated with the carbs, and the engine's airfilter and intake, set atop the motor.  The initial premise behind a forward opening scoop in those days was to try to generate a "ram air" effect in the engine's intake tract, force-feeding air into the engine and improving intake efficiency, and power, at speed.  In order to really take advantage of ram air, the scoop has to be in the free-stream air flow where it can take in air at a high velocity.  The nature of airflow over a car is that the nose tends to throw the free-stream up over the hood, so in order to get a scoop into the free-stream flow it either needs to be at the nose of the car or elevated some ways up off the hood.  Otherwise it just sits in relatively slow moving air and there is little to no ram air effect, though it could still function as a cold air intake.  It should be pointed out, though, that today's cars are much better aerodynamically than the cars of the 50s, 60s and 70s.  Blunter noses on the cars of those decades would call for either a nose mounted intake scoop or a rather tall scoop.  Sleeker cars can get away with lower profile scoops mounted further back on the hood. 

The scoop on the WRX is not intended to achieve any sort of ram air effect, nor is it to feed the engine with air at all.  It's a duct for passing air over a heat exchanger (the intercooler).  Unlike scoops intended for ram-air induction, cooling scoops don't need to harness the full brunt of the free stream air flow, it just needs some air flow.  In fact, blasting air over a heat exchanger too quickly could decreases its effectiveness by way of convection inhibiting flow separations on the cooling fins.  Thus, the WRX's scoop works similarly to brake cooling scoops you see on the rear quarters of cars like the Corvette Z06 (which also aren't likely fully exposed to the free-stream airflow).

[S204STi]

Thanks for the clarification, MX! 

[Nethead]

SoupDude:
"...you're so full of yourself it hurts."
Ya got me there, SoupDude!

MX793: We're saying the same thing here, only you have put it more eloquently than I.   

But all this fuss leaves the impression that hoodscoops are bestowed upon us by God himself--they were good on '67 Tri-Power Corvettes but they look rice on everything else, whether they function or not. I gotta admit: they fit right in with the wings on the rears of WRXs...

[MrH]

You probably took Physics, did you take B or C?

I'm in college.  I've taken a hell of a lot of Physics.  And that's not really a Physics kind of topic.

[CALL_911]

I'm in college.  I've taken a hell of a lot of Physics.  And that's not really a Physics kind of topic.

I know, but I remember you saying something about it, and you are an engineering major.

[MX793]

SoupDude:
"...you're so full of yourself it hurts."
Ya got me there, SoupDude!

MX793: We're saying the same thing here, only you have put it more eloquently than I.   

But all this fuss leaves the impression that hoodscoops are bestowed upon us by God himself--they were good on '67 Tri-Power Corvettes but they look rice on everything else, whether they function or not. I gotta admit: they fit right in with the wings on the rears of WRXs...

No, we're not saying the same thing.  The hood scoop on the WRX is fully functional and entirely necessary, although it serves a completely different purpose from the functional hood scoops of old.  The WRX's intercooler is mounted atop the engine, the only way to get cold air directly to it is to channel it through the hood.

The Mustang's hood scoop is entirely aesthetic.  It does not feed the engine with air, it does not provide air for a heat exchanger (I don't think there's even a hole in the hood).