[drphoto]

GTI is a turbo car.  from Mk 4 onward 1.8T then the 2.0T from Mk5 to present.  Yeah, the early variants were NA.

All replies pretty spot on. You can get some big power gains on turbo cars w/ ECM refresh, though it generally means running higher octane fuel.

Yeah most the HP gains claimed by the manufacturers of CAI & Catbacks are hype.As stated you might get 10-15HP at crank for an outlay of $1500.

But as crazy audiophiles we spend a lot of money on dubious things like 'magic' wire.  So maybe 'magic' piping on a car makes sense. 

I wrestled w/ this very question for my VW GSW/JSW 2.5. Probably not worth the money.

Now by front strut bar,  did you mean front strut tower brace, or front sway bar? Strut brace would be good if you are really pushing car hard. If you meant sway bar, I would ask how does the car handle now? If it seems to understeer, then going to a stiffer rear sway bar can help w/ that.

All that being said, I've read that Ingen makes a fine product, especially for Japanese cars, and they are somewhat less expensive that other. The sell the type that does not locate the intake down low where you have to worry about hydrolocking. I understand the urge to upgrade. I've got a box full of suspension parts waiting to go under my wagon, just haven't had time to install.

[rif]

Strut device - its the simple one that connects across the top of engine bay. Sorry for the wrong terminology. See picture.

[DaveC113]

I wouldn't do it. It'll make the car much noisier when accelerating and might cause issues with proper MAF readings which is a big deal. Not only the oil on the filter is an issue but also turbulence at the MAF. If you want to be safe any modifications should be followed up with a dyno run with a wideband O2 setup and datalogging. It's likely your car would require a different ECU program than stock to account for the differences.

Think about what you really want, then find the car closest to that and buy it.

Some vehicles do need to be slightly adjusted to drive as intended, like the Subaru WRX/STi, but the Maxima isn't really one of those cars a few mods will make a big difference with. On a WRX you can make 50+ HP and even more torque very easily while also improving driveability and fuel economy just by buying a downpipe and a tuning device. If you want to get into tuning and working on a car buy one where it'll make a difference and there's some real performance potential. Subaru is my choice... the WRX/STi are great cars, lots of fun to drive, practical, AWD, and hold their value. Most modern muscle cars are much more powerful, but usually aren't as practical. If I could have a pure toy though I might go for a Vette... I drove the previous gen Z06 and it was spectacular.

[zybar]

GTI is a turbo car.  from Mk 4 onward 1.8T then the 2.0T from Mk5 to present.  Yeah, the early variants were NA.

All replies pretty spot on. You can get some big power gains on turbo cars w/ ECM refresh, though it generally means running higher octane fuel.

Yeah most the HP gains claimed by the manufacturers of CAI & Catbacks are hype.As stated you might get 10-15HP at crank for an outlay of $1500.

But as crazy audiophiles we spend a lot of money on dubious things like 'magic' wire.  So maybe 'magic' piping on a car makes sense. 

I wrestled w/ this very question for my VW GSW/JSW 2.5. Probably not worth the money.

Now by front strut bar,  did you mean front strut tower brace, or front sway bar? Strut brace would be good if you are really pushing car hard. If you meant sway bar, I would ask how does the car handle now? If it seems to understeer, then going to a stiffer rear sway bar can help w/ that.

All that being said, I've read that Ingen makes a fine product, especially for Japanese cars, and they are somewhat less expensive that other. The sell the type that does not locate the intake down low where you have to worry about hydrolocking. I understand the urge to upgrade. I've got a box full of suspension parts waiting to go under my wagon, just haven't had time to install.

My GTI's were VR6's - no turbo.

I should have stated that.

George

[Dieterle Tool]

I have no experience with Nissan's but pretty sure a tune is not required when replacing stock air box with a CAI system. This is a "plug-and-play" modification, same as the strut brace. 

You really should sign up with a Nissan forum if you want to start dabbling with your whip. But I think your on the right track for simple mods that make you want to jump in the driver seat for every errand.

Dieter

[S Clark]

When my daughter got her license in 2003, I bought her a 97 Acura Integra that had an AEM cold air intake installed as I wanted her to learn on a stick shift.  I was going to remove the CAI, but to go back stock was going to be around $400.  So I left it in- mistake.  When she drove through water that was only about 8" deep and hydrolocked the engine  we had to rebuild it.  A piston had to be replaced, so we went ahead and put new rings and bearings in throughout $$$$.  I've still got it sort of as a back up vehicle.   But I'll never put a CAI in anything that meant for transportation. 

[jupiterboy]

It will be car dependent. Some give more top end power, some more low end. Some can cause CEL, so do go to a specialist forum and see what the wisdom is.

Good tires are a much better investment. Good progressive springs and better brake pads would be my first moves.

[rif]

Ok,  I think you guys have convinced me to not get a CAI.  I might still get the strut brace thing since its cheap enough.

So I'll look into getting WRX Limited or STI Limited in the next year or two.  That should give me time to learn to drive a stick.

[DaveC113]

Ok,  I think you guys have convinced me to not get a CAI.  I might still get the strut brace thing since its cheap enough.

So I'll look into getting WRX Limited or STI Limited in the next year or two.  That should give me time to learn to drive a stick.

I just got a '16 STi Limited as a result of a distracted driver totaling my '14 WRX hatch... she blew through a red light and plowed into me from the side going about 40 mph! Luckily Subarus are safe cars, I walked away with only minor injuries.

It was used with 600 miles on it, previous owner spent $5k+ on upgrades then returned it to the dealer after the family complained. I got it for $3k under blue book and got the $5k worth of extras too, otherwise I'd probably own another WRX. I have a 2nd set of very expensive wheels with Blizzaks, tint and clear bra (entire front of car is done!), $1k lojack system, chin spoiler, all weather mats, SPT exhaust, short throw shifter, wheel locks... lol. It was too good a deal to pass up!   

The newest generation of WRX/STi are excellent cars... while they look similar try to test drive both, they are VERY different cars from the driver's seat! 

[Early B.]

Ok,  I think you guys have convinced me to not get a CAI.

Yep. They talked me out of it, too. 

Yesterday, I was looking at changing out my shocks along with a lift kit, but decided not to do anything else. I've already installed new rims, tires, and running boards on my truck, so I'm gonna give my wallet a break and just enjoy what I have (although the Pedal Commander is still on my wishlist). 

[drphoto]

Doh......forgot about the VW VR6's. 

To OP, I agree w/ the recommendations if you just have to mod something to look at suspension and/or tires and wheels. But that being said, I don't think a strut tower brace is gonna do anything for you unless you are driving at the limit.

If you want cool, then think wheels. If you want handling think shock/struts and springs. Plus performance tires. Bigger rims, while looking cool offer potentially  better handling as they have less sidewall flex and generally get wider, but the do weigh more. More unsprung weight hurts acceleration and puts more stress on brakes.

 Personally I think it's more fun to have a car that you can flog around and have fun at relatively low speeds, than one that just goes fast. Just going way fast will either get you tickets or worse....get you hurt.

 But just another free opinion from the 'net. 

[Johnny2Bad]

Most "Cold Air Intakes" don't suck cold air and absolutely have no Ram Air effect, and in some cases they remove the factory Helmholtz Resonator effect that can improve low-to-midrange torque that small displacement motors tend to lack. You need to use a manometer or at least wool tufts to find out where your low pressure intake area is ... it is NOT always at the windshield/hood interface but critically dependent on the shape of the front third of the vehicle. On almost every vehicle the area where the front license plate normally resides is the best spot for intake air (have something to keep water out or allow it to drain as this is close to the road surface and vehicles in front of you will spray water there more than higher up).

The front strut brace is helpful if:
It is actually rigid rather than decorative
You have a MacPherson Strut front suspension geometry. It does help with a front Shock geometry but much, much less so and may not be cost effective in that case.

Sway bars significantly affect handling. The stiffness and to a lesser extent weight (solid vs tubular) are important factors. You should consider changes to the rear suspension with regard to sway bars (some cars have none in the rear, some cars benefit from removing a rear sway bar, others by stiffening it) in concert with changes to the front sway. Any changes to sway bars will affect the car's tendency with regard to oversteer/understeer, so the first thing to do is decide which tendency at the limit you prefer. FWD typically will understeer but there could be a transition point which might be abrupt and difficult to correct for. None the less a sway bar change will move the handling one way or the other, even if a FWD vehicle that will always understeer regardless, you have an opportunity to make it understeer less or more, as the case may be.

In some cars you can also add a rear bar to stiffen the MacPherson struts or Shock mount towers. Are the towers visible from inside the trunk in your car?

Do not underestimate the value of low unsprung weight per corner. It will affect handling more than changes to the front sway, for example, and at the same time, any benefits a front sway adds will be enhanced with low unsprung weight. Run, don't walk, from any aftermarket wheel that does not list the weight in the size you are considering. That is not a guideline, that is a Directive From Above. No exceptions. Do not buy any wheel/tire combo that is not lighter than the OEM figures.

Also determine the weight of the tire you can fit to any wheel, and don't forget the weight of lug nuts. DO NOT compromise strength when selecting lug nuts, but do choose lighter variants. Also the valve stem can be lighter which makes balance and handling improvements.

After the wheel / tire / lugnuts / valve stem weight, you can move to aftermarket brake calipers or two-piece brake rotors. There will typically be perhaps 6+ pounds of unsprung weight you can remove there for an import car. Check out the OEM calipers you may be able to pick up cheaply from a wrecker that were offered on high performance variants of your car or interchange with your geometry. Buy good (but street, not race type) brake pads.

Any bolt-on suspension / frame braces that were offered for your make / model but were not installed on your option level should be added if they exist.

You should replace any bushings involved in any suspension work you do, but perhaps consider if you are willing to put in a whole-car poly bushing kit ... they are a lot of work to install. They will add noise and stiffen everything, making the ride less comfortable. People will always tell you to go poly but you may find simply replacing the OEM rubber bushings offer enough improvement (they are a wear item) without affecting Noise Vibration Handling (NVH) as much so you still have a comfortable ride for the wife & kids to suffer in, and for a daily driver.

[Folsom]

Do very many cars have strut tower shapes but not have actual coilovers?

[jupiterboy]

Do not underestimate the value of low unsprung weight per corner. It will affect handling more than changes to the front sway, for example, and at the same time, any benefits a front sway adds will be enhanced with low unsprung weight. Run, don't walk, from any aftermarket wheel that does not list the weight in the size you are considering. That is not a guideline, that is a Directive From Above. No exceptions. Do not buy any wheel/tire combo that is not lighter than the OEM figures.

Also determine the weight of the tire you can fit to any wheel, and don't forget the weight of lug nuts. DO NOT compromise strength when selecting lug nuts, but do choose lighter variants. Also the valve stem can be lighter which makes balance and handling improvements.

Good advice in my experience. I have a low-torque, high rpm engine made by Yamaha. Best thing I did for it was to get some nice aluminum wheels right at 13lbs each. Now with tires (slightly wider than stock) and lugs I'm still right at factory spec weight, although it's not exactly the same because of the weight distribution.

After that, I got a slightly lighter flywheel (not unsprung) and improved the brakes and suspension and I'm set. No need to goofy bolt ons.

[yeldarb]

I bought a 2011 Hyundai Sonata when they came out.  Lot of high strength steel in the body.  Which, I theorize, rang like a bell.  I added an inexpensive strut bar to improve the steering and handling and it also made the car quieter.  Shark Racing had lots of stuff.

[Peter J]

Most "Cold Air Intakes" don't suck cold air and absolutely have no Ram Air effect, and in some cases they remove the factory Helmholtz Resonator effect that can improve low-to-midrange torque that small displacement motors tend to lack. You need to use a manometer or at least wool tufts to find out where your low pressure intake area is ... it is NOT always at the windshield/hood interface but critically dependent on the shape of the front third of the vehicle. On almost every vehicle the area where the front license plate normally resides is the best spot for intake air (have something to keep water out or allow it to drain as this is close to the road surface and vehicles in front of you will spray water there more than higher up).

The front strut brace is helpful if:
It is actually rigid rather than decorative
You have a MacPherson Strut front suspension geometry. It does help with a front Shock geometry but much, much less so and may not be cost effective in that case.

Sway bars significantly affect handling. The stiffness and to a lesser extent weight (solid vs tubular) are important factors. You should consider changes to the rear suspension with regard to sway bars (some cars have none in the rear, some cars benefit from removing a rear sway bar, others by stiffening it) in concert with changes to the front sway. Any changes to sway bars will affect the car's tendency with regard to oversteer/understeer, so the first thing to do is decide which tendency at the limit you prefer. FWD typically will understeer but there could be a transition point which might be abrupt and difficult to correct for. None the less a sway bar change will move the handling one way or the other, even if a FWD vehicle that will always understeer regardless, you have an opportunity to make it understeer less or more, as the case may be.

In some cars you can also add a rear bar to stiffen the MacPherson struts or Shock mount towers. Are the towers visible from inside the trunk in your car?

Do not underestimate the value of low unsprung weight per corner. It will affect handling more than changes to the front sway, for example, and at the same time, any benefits a front sway adds will be enhanced with low unsprung weight. Run, don't walk, from any aftermarket wheel that does not list the weight in the size you are considering. That is not a guideline, that is a Directive From Above. No exceptions. Do not buy any wheel/tire combo that is not lighter than the OEM figures.

Also determine the weight of the tire you can fit to any wheel, and don't forget the weight of lug nuts. DO NOT compromise strength when selecting lug nuts, but do choose lighter variants. Also the valve stem can be lighter which makes balance and handling improvements.

After the wheel / tire / lugnuts / valve stem weight, you can move to aftermarket brake calipers or two-piece brake rotors. There will typically be perhaps 6+ pounds of unsprung weight you can remove there for an import car. Check out the OEM calipers you may be able to pick up cheaply from a wrecker that were offered on high performance variants of your car or interchange with your geometry. Buy good (but street, not race type) brake pads.

Any bolt-on suspension / frame braces that were offered for your make / model but were not installed on your option level should be added if they exist.

You should replace any bushings involved in any suspension work you do, but perhaps consider if you are willing to put in a whole-car poly bushing kit ... they are a lot of work to install. They will add noise and stiffen everything, making the ride less comfortable. People will always tell you to go poly but you may find simply replacing the OEM rubber bushings offer enough improvement (they are a wear item) without affecting Noise Vibration Handling (NVH) as much so you still have a comfortable ride for the wife & kids to suffer in, and for a daily driver.

That is some really intelligent  and coherent advice. The aftermarket mods market is driven largely by hyperbole and looks. Now, don't get me wrong, there's good stuff among the chaff, but it amazes me sometimes that people will disregard the considerable engineering that goes into making an automobile and substitute hearsay and BS they read on web forums. Can you make it better in a specific application? Probably, but other things will change as a result.

And when a company bothers to actually quantify performance gains, it's often miniscule not applicable to cars driven on the street. When was the last time you drove your ride at wide open throttle for say, 10 minutes? Yet that's where the HP gains are most likely going to be had.

With electronic engine controls, bringing a given engine up to it's potential is much easier and that's different than it was 25+ years ago. While there would be other considerations like longevity and drivability, engineers just won't be leaving 30-40 HP on the table in many cases.

 

[srb]

Now, don't get me wrong, there's good stuff among the chaff, but it amazes me sometimes that people will disregard the considerable engineering that goes into making an automobile and substitute hearsay and BS they read on web forums.

I'm not amazed because that kind of thinking isn't limited to the automotive world ..... you could easily replace "audio components" for "an automobile" in the above sentence. 

[Peter J]

I'm not amazed because that kind of thinking isn't limited to the automotive world ..... you could easily replace "audio components" for "an automobile" in the above sentence. 

True dat! It occurred to me as I wrote it that's not a new phenomenon...just a different arena.

[rif]

True dat! It occurred to me as I wrote it that's not a new phenomenon...just a different arena.

Probably like that for most hobbies - guys who overclock their computers or get massively powerful graphics cards, amatuer astronomers paying $$$ for parts, model train builders, quilters, knitters, backyard gardeners ... antything.  There will always people so deep into it an outsider would think they're a little crazy.

Now some of these "hacks" are legit, but as said above there are tradeoffs.

[DaveC113]

Lots of mistakes here...

The aftermarket has a much easier job vs the mfgr because of emissions. Basically, modern cars are saddled with a lot of emissions control gear to avoid pollution before the car warms up. If you do just enough to pass emissions when the car is warm you can remove some huge, expensive and very restrictive cats and replace them with much less restrictive units. This can free up 20% or so more power (turbo cars) and increase efficiency without increasing boost pressures. There's lots more stuff like this in ecu programming as well. Also, gains tend to be at low to mid rpms and greatly improve driveability. Don't believe me? Check out Cobb's dyno charts. My STi gets a massive boost in power and turbo response down low but little up top.

Unlike audio this stuff is easily measured and quantifiable, anyone can look up dyno charts on the net these days.