The Nissan Altima and Altima Coupe may not be the fastest cars around. However, they can be great project cars to upgrade and modify. Modded Nissan Altimas with the 2.5 and 3.5 can offer good performance in a reliable and affordable package. That is a good combo for anyone, but it’s especially true for people newer to the aftermarket mods scene. In this article, we discuss some of the best Nissan Altima mods along with benefits, power gains, and more.
*Our primary focus in this article is 2002-2018 Altima’s with the 2.5L QR25DE engine and the 3.5L VQ35DE engine. Many of these mods are also good mods for older or newer models. However, the exact power gains, fitment, and other specifics may vary a lot.
Nissan Altima Engines
From 2002 through 2018 the Nissan Altima primarily used two engines – the 2.5L I4 and 3.5L V6. This span covers the 3rd, 4th, and 5th gen Altima. They’re both long-running engines that went through updates and changes over the years. As such, it’s important to lay out some background info for each engine. Which engine is in the Altima also has a large impact on results from tuning and modding.
This is the base engine for the Nissan Altima as found in the 2.5 S models. It delivers 170-179 horsepower and 175-180 lb-ft. Yes, the power is lacking a bit but it makes up for it with great fuel economy. The QR25DE engine also delivers good overall reliability. Early 02-06 engines can be a bit more problematic, but Nissan made some great updates over the years.
Some large updates took place in 2007+ QR25DE Altima engines. Check out the above link on reliability for specific info on some of the updates.
VQ35DE 3.5L V6
Are you familiar with the Nissan 350Z or Infiniti G35? If so, then you’re likely familiar with the VQ35DE engine. It’s known for being a very mod friendly engine, and many love those platforms. This engine also made it on the list of Ward’s 10 Best Engines for 6 years. The Altima is often overlooked, but it also uses this awesome 3.5L V6 engine.
If you’re looking for the most capable modded Nissan Altima then the 3.5 V6 is the clear choice. It offers up to 270hp and 251 lb-ft straight from the factory. That’s nearly a 100 horsepower advantage over the smaller inline-4 engine. VQ35DE engines are also more capable in the Nissan Altima mod for mod.
As with the QR25 engine this 3.5L engine also delivers good reliability. Check out our VQ35DE common problems guide for more info on reliability and issues.
Summary of Altima Engines
If you’re still looking to purchase an Altima and want power then it’s a good idea to look for the 3.5L engine. Chances are, a stock VQ35 engine is still quicker than a modded Altima 2.5 S. By the time you could get the smaller engine to the same or higher output you’ll have likely spent more.
The 3.5L Atima also generally responds better to mods thanks to the larger displacement. Of course, some may already own a 2.5 and are just looking for a bit more power. It’s still a capable engine, but reaching the performance of the VQ35 is going to take a lot of upgrades and money.
Best Nissan Altima Performance Upgrades
A few of the best modifications for the Altima 2.5 QR25DE and 3.5 VQ35DE engine include:
- Turbo Kit
- Lowering Springs
In this article we will take an in-depth look at each of the above Altima mods for power, performance, and handling. It’s by no means an exhaustive list. Tons of great aftermarket parts exist for the Nissan Altima. However, we believe these 6 mods are among the best options to improve power and performance.
Please note – any power gains we state are rough estimates. Actual results can vary significantly depending on many factors. Some Altima upgrades may not be legal in all 50 states, and are intended for off-road use only.
1) Nissan Altima Tuning
Tunes are often easy to purchase & install, and can offer solid power gains for the price. Unfortunately, that isn’t the case for the Altima 2.5 or 3.5 engines. Off-the-shelf tuning options don’t really exist for these engines. That doesn’t mean they can’t be tuned, but it’s usually not the first mod we would recommend.
With simple mods like an intake and exhaust a tune isn’t going to add much power or performance. You’ll maybe pick up an extra 3-7 horsepower. Some may see the value in tuning the Nissan Altima even with these basic mods. However, we don’t think it’s necessarily worth the cost or hassle.
However, start adding more mods like headers, throttle bodies, cams, etc. and tuning becomes a lot more valuable. In these cases you may see gains in the 10-20 horsepower ballpark from just the tune. Point is – Altima tunes can be a great mod, but it’s usually best to knock out the other upgrades first.
Best Altima Tuning Options
In the future, we’ll have a separate guide dedicated to tuning the Altima 2.5 and 3.5 engines. There are lots of different options depending on year and model, and we simply can’t cover everything here.
UpRev is a common tuning choice for many Nissan Altimas. These are going to be as close to the standard off-the-shelf tuning for most models. You might find a shop that can install the tune for about $300. Others may charge more or require the necessary cables from UpRev. Bully Dog is another popular tuning option.
Next, you’ll run across true engine management systems. Haltech is a good example as they have some engine management systems for the VQ35 engine. It will set you back at least $1,500 and that doesn’t even include the cost of install or actually tuning the engine. These systems are generally for those looking to make serious power, usually via forced induction.
2) Altima 2.5 & 3.5 Intake Upgrades
An intake is a standard upgrade that most car enthusiasts are into. It’s hard to find a modded Altima (or almost any other modded car) that doesn’t have an intake upgrade. Why? These are cheap, simple mods that offer fair results for the price.
You may also hear intakes referred to as filters, cold air intakes, performance intakes, or intake systems. The last three are often used interchangeably. There is a difference when discussing just intake filters, though. We’ll discuss that in a few moments. For now, let’s discuss the benefits of Nissan Altima performance intake mods:
- 3-10 horsepower gains
- Similar torque gains
- Better throttle response
- Improved sounds
A modified Nissan Altima intake can offer gains of about 3-10 horsepower. Without other mods expect results on the lower end. You’ll also pick up pretty similar torque gains. The power/torque gains are also throughout most of the rev range, so it adds a decent bit to the overall power band.
Many notice better throttle response with Altima intake mods. This is especially true if you opt for an intake with straighter piping. Stock Nissan Altima intakes bend quite, which can slow the flow of air into the engine. It’s also a large reason the intake upgrades offer solid power gains. You probably won’t notice a huge change in sound, but intakes can help wake things up a little bit.
Air Filter Upgrades vs Intake Systems
The term drop-in filter refers to an air-filter designed to simply fit the stock air-box. You’ll find plenty of options like this for the Nissan Altima. They’re a lot cheaper since it’s a basic filter rather than a complete air-box, filter, and piping. However, power gains with a filter upgrade alone will be minimal to none.
Again, the Nissan Altima intake piping isn’t the greatest design from the factory. That’s why full intake upgrades offer as much power as they do. You essentially want to find something with straight, smooth piping.
Best Altima Intake Mods
Our preference is sticking with high-quality air filters from companies like K&N or S&B. There’s other quality stuff out there but be cautious with cheaper, low-end filters. When it comes to the full kit you want straight and smooth pipes to the throttle body. Outside of that most intake kits are going to offer similar power and performance.
You can go budget but we would advise upgrading to a quality filter. Here’s a great example for the 2003-2006 Nissan Altima 3.5. Reviews are mixed as you would expect from a $50 intake system. However, if it fits well it’s not a bad option. You could then simply find a cone filter from S&B for probably $20-40, for example.
On the contrary, there are some good options sold as complete Nissan Altima performance intake systems from K&N. They’re a bit pricier due to brand name, but surely quality kits.
3) Nissan Altima Exhaust Mods
Next up on the list of best Altima mods is an exhaust system. As with the intake the 2.5 & 3.5 exhaust doesn’t flow very well. A lot is also due to bends. It doesn’t allow for a straight, efficient path for exhaust gas flow. There are tons of different options with Altima exhaust upgrades and we don’t have time to cover it all.
Options include cat-backs, axle-backs, y-pipes, full exhaust systems, etc. The more exhaust you replace the better power gains you’ll see. Going with catless systems also offer the best performance and bang for your buck. However, they’re intended for off-road use only. Benefits of Nissan Altima 2.5L and 3.5L exhaust upgrades include:
- 5-10 horsepower
- Similar torque
- Engine/exhaust sounds
For basic mods alone a 5whp gain may be an aggressive number. However, a good free flowing exhaust can offer solid power gains with additional mods like tuning, intake, headers, and more.
Ultimately, an exhaust can be a great mod for the Altima. It wouldn’t really be at the top of our list since you can get better power gains relative to the price point. Many exhaust systems are going to run about $500-1,000. We think exhaust upgrades are best for those who want sound and some power on the side. If your only goal is power then the money is better spent on other mods.
Altima Exhaust Sounds – Too Loud? Too Raspy?
Alright. Exhaust and engine sounds gets its own quick section here. It’s nearly impossible to describe sounds with words (often, videos don’t even do it full justice). Although, we can say certain exhaust setups may be too loud or raspy for some. That’s a big reason we believe Altima exhaust systems are best for those looking for a different or louder exhaust note.
The best exhaust power mod is a set of headers, which we’re discussing next. If power is your end goal the headers are going to be the best option. Be careful combining a full exhaust with headers since things can get loud and drone can become more of a concern.
4) Modded Altima Exhaust Headers
Are you looking for the absolute best bang for your buck Nissan Altima mods? If so, headers are the near the top of the list. Headers are also commonly known as the exhaust manifold. Headers bolt directly to the cylinders exhaust ports. It’s the most important part of the Altima’s exhaust system due to its location.
The idea of exhaust mods is to reduce back-pressure. The closer to the engine the back-pressure is reduced the bigger the power gains. Benefits of Altima header mods include:
- 8-15 horsepower
- Similar torque
- Lower EGT / Healthy for engine
Considering most headers run around $100-300 it’s hard to beat these power gains. However, DIY’ing exhaust manifolds are more challenging than most of the other Nissan Altima mods on this list. You really just won’t find another mod that offers this much power for the price point, though.
Sounds are another benefit, and most headers aren’t obnoxiously loud if the rest of the exhaust is stock. Reducing back-pressure also helps lower temperatures, and is healthy for the engine overall.
Altima Catless vs High-Flow Catted Headers
Several types of aftermarket headers are available for both the Altima 2.5 and Altima 3.5 engines. The major differentiations are:
- Long-tube vs Short-tube (shorty)
- Catless vs High-Flow
Short-tube headers refer to the actual exhaust manifold itself. Long-tube headers include the y-pipe that the manifold bolts onto (the y-pipe is only for 3.5L engines since there are two separate banks). If power gains are the end goal then you should consider the full long-tube manifold upgrade. However, the gains from the y-pipe aren’t as impressive as just the manifold by itself. A Nissan Altima modded with short-tube headers will still offer good gains, but go for the long-tube if you want the few extra horsepower.
Then there are catless options that completely remove the catalytic converter. Doing so results in the biggest drop in back-pressure, and the best performance gains. High-flow cats still offer good gains, but expect about 3-5 less horsepower than catless. The real upside to cat headers is that they may still keep the car emissions & road legal.
Best Exhaust Manifold Upgrades
There isn’t a perfect answer to the best exhaust manifold mods for the 2002-2018 Nissan Altima. If you’re going catless then there isn’t much to worry about quality wise. Stainless steel or other designs that strongly resist rust are a good idea for long-term use. Aluminized can be cheaper, but it’s prone to rusting.
Otherwise, as long as the fitment is good and the welds hold up that’s all that really matters. Going high-quality isn’t necessary to get a reliable and long-lasting header upgrade. A few good options include:
5) Altima Mods – Pulley Upgrades
We’ll be a little quicker moving through these next sections. The drive belt connects to a pulley, which weighs in around 4-5 lbs on the stock Altima 2.5 and 3.5 engines. Changing this pulley to a light-weight option can help reduce rotational mass. In essence, it makes it easier for the engine to drive the belt and pulley.
Power gains with Nissan Altima pulley mods aren’t huge, but it’s a pretty inexpensive upgrade. Expect the following hp and tq gains with a pulley upgrade:
- 3-7 horsepower
- 3-7 torque
It might not be too appealing. However, horsepower gains aren’t always easy to come by on NA engines. Check out 2J-Racing as they have some popular options for the QR25 Altima 2.5 engine. Stillen also has some options for the 2.5 and 3.5 engines.
6) Nissan Altima Mods – Turbo Kit
Turbo kits aren’t a topic we’re going to cover in-depth in this article. It’s a long topic that would need a lengthy article just to scratch the surface. The main reason we’re adding a turbo kit here is to discuss bigger power mods.
Naturally aspirated (NA) engines like the 2.5L and 3.5L Altima engines don’t have tons of modding capability. Once you reach the limits with NA mods it’s time to consider turbo or supercharger kits and other more serious, expensive mods.
It also brings about higher risk of engine damage and problems while running boost. Adding forced induction isn’t for the faint of heart. However, the QR25 and VQ35 hold up pretty well on moderate boost. It’s a good option if you’re looking to pick up more than 50whp.
By the time it’s all said and done you could easily spend $5,000+ just for engine mods. Then you need to consider suspension, wheels & tires, and other mods to handle the newfound power. Point is – the gains from turbo kits or the like might be appealing, but costs can spiral out of control.
Altima Engine Upgrade Power Gains
When combining certain Nissan Altima mods how much power can you expect? How much power can a fully modified Altima make? There isn’t a perfect answer since results can vary a lot from car to car. However, let’s jump into some general numbers and the best Altima mods to hit specific goals.
Altima Mods For 10-20whp Gains (~$1,000)
The below mods are a good starting point to pick up roughly 10-20 wheel horsepower for less than $1,000:
These mods can be done for around $1,000 if not a bit less. An Altima with an intake, pulley, and tune should pick up at least 10whp. Gains may even be a bit higher, especially on the 3.5L VQ35DE Altima engine. You can also substitute certain mods here, such as opting for an exhaust instead of a tune.
If you plan to do headers or other more serious mods in the future then holding off on the tune is a good idea. To maximize output you’ll end up re-tuning the car after headers, which can add an unnecessary expense. However, a tune is a good option here if you’re planning on stopping after a couple basic mods.
Upgrades For 20-30whp Gains (~$1,500)
Those looking for more power should consider the following Nissan Altima mods:
Modded Altimas with the above upgrades should see total gains of around 20-30whp. It may be a little lower on the QR25 engine or maybe a bit more power on the Altima 3.5 V6. Anyways, it’s pretty much the same list as above with the addition of headers. These alone can help pick up the extra 10-15+whp.
None of this is a perfect science, so you can add or remove mods from the list as you see fit. However, a tune is definitely a good mod to have once headers are installed. Still wanting more power? Time to add a couple more mods.
30-40+whp Gains ($2,000+)
We’re getting pretty close to the power gains limits on the Altima 2.5 & 3.5 engines without adding more expensive mods. The smaller 2.5L QR engine might even struggle to see these gains without forced induction. It should be a bit easier with the larger V6 Altima engine. Anyways, expect to need the following mods to hit 30-40+whp gains:
- Throttle body
- Cams (optional for more power)
- Forced induction (optional for more power)
The first 6 mods on this list is pretty close to all of the basic bolt-on mods for the Nissan Altima. With all of these mods you might see gains close to 30-40whp. Again, it might be a stretch for the smaller 2.5L inline-4 engine. Going much further on either engine is starting to get into expensive territory. You’ll be looking at more serious mods like cams, turbo or supercharger kits, etc.
Best Nissan Altima Mods Summary
When it comes to mods and upgrades the Nissan Altima isn’t the first car that comes to most peoples minds. However, they can be great cars that are fun and easy to modify. The Altima 3.5 even uses the VQ35DE engine found in Nissan 350Z models. It’s the best 2002-2018 Altima engine when it comes to performance potential. That’s not to say the 2.5 is a complete slouch, though.
A couple basic bolt-on Nissan Altima mods can help unleash about 10-30whp depending on how far you go. A tune, intake, exhaust, headers, and pulleys are all good starting points. Those looking for more should consider more serious mods like forced induction, camshafts, and other options.
Anyways, the Nissan Altima is pretty easy to modify and they remain reliable engines with basic mods. Choose the mods that best meet your goals and budget. Otherwise, just have some fun with it and enjoy your newly modded Altima.
What’s your experience with Nissan Altima mods? Are you considering any?
Leave a comment and let us know!