[GreySinclaire]

I'm new to this platform and have only owned my 2006 XE King Cab for a little over a month, so forgive me if there is some hidden knowledge with these engines that I'm unaware of. But it seems to me that nobody has really tuned these engines up much aside from old YouTube videos of Altimas and Sentras racing these things at barely over 200hp, besides that ridiculous fully built track monster running 9's on a 1/4 mile.

1. Does anyone really know the limits of a fully stock QR25?
2. Any weak points within tuning these engines? Boosted or N/A
3. Any tuning platforms out there besides UpRev without going standalone?

I'm asking because I want to see what I can do for this truck as a prerunner build. There's heaps of aftermarket stuff out there for the frontier model but it's hard to believe that it's all only for the v6 platform. I'm sure I'll have to build an engine at some point but I don't want to v6 or v8 swap my frontier. I want to keep things light for the build but also be pushing around 400hp comfortably and reliably. Any information would be highly appreciated.

 

[bajasam]

It's already maxed out at 170hp which moves it around fine if your not in a hurry, 400hp is high school fantasy dreaming.

 

[sirnixalot]

If you really want to check out what they do to the Sentra QR25. Balance shaft delete, build the bottom end, cams/springs/retainers and boost. That being said the QR engine is pretty horrible to extract any meaningful power from, the open deck block, long *** stroke.

By the time you add the power adder stuff you'll be in VQ40 weight territory anyway.

 

[shift_RUSH]

If you really want to check out what they do to the Sentra QR25. Balance shaft delete, build the bottom end, cams/springs/retainers and boost. That being said the QR engine is pretty horrible to extract any meaningful power from, the open deck block, long *** stroke.

By the time you add the power adder stuff you'll be in VQ40 weight territory anyway.

Then might as well VK56 swap, eh?!?

 

[sirnixalot]

Then might as well VK56 swap, eh?!?

I am a broken record on the subject, yes

 

[Paulgray]

I'm new to this platform and have only owned my 2006 XE King Cab for a little over a month, so forgive me if there is some hidden knowledge with these engines that I'm unaware of. But it seems to me that nobody has really tuned these engines up much aside from old YouTube videos of Altimas and Sentras racing these things at barely over 200hp, besides that ridiculous fully built track monster running 9's on a 1/4 mile.

1. Does anyone really know the limits of a fully stock QR25?
2. Any weak points within tuning these engines? Boosted or N/A
3. Any tuning platforms out there besides UpRev without going standalone?

I'm asking because I want to see what I can do for this truck as a prerunner build. There's heaps of aftermarket stuff out there for the frontier model but it's hard to believe that it's all only for the v6 platform. I'm sure I'll have to build an engine at some point but I don't want to v6 or v8 swap my frontier. I want to keep things light for the build but also be pushing around 400hp comfortably and reliably. Any information would be highly appreciated.

I dont know much about the i4 motor but z1 offroad has a bunch of engine internals for it, valve springs, new piston rods. I think I saw somewhere that it's also the same as the one in altimas and I believe turbo kits are available for those so some modifications would need to be done to that kit but should work. Personally I like the idea of keeping and moding the crap out of factory motors even if it's costs as much if not more than a motor swap. Personally I'm trying to see what will break my vq but good on your for moding that 4 banger.

 

[chickdr]

From what I have seen there isn't a whole lot to do for the 2.5. It is a base motor and not really designed for big power upgrades - thus the V6 option. As someone else said- by the time you did a bunch of mods to the 2.5, it will likely weigh what a V6 does. Then you have everything else that will need to be upgraded to handle the increased power- brakes, transmission, etc. By the time you do all this why not just get the V6 instead? Really a V8 swap would be so much more effective, no?

 

[GreySinclaire]

Thanks to everyone who replied! After speaking to one of the techs over at 2JR for over an hour on his own time, I was able to find out that these engines are actually very much worth keeping to modify. I'm surprised that nobody has every really torn into these engine platforms besides the Sentra community being that they are the same engines.
Below is what I've been able to gather from a 2-day binge of comments, phone calls, and research.

1. The stock QR25DE Gen1 (2000-2006) engine is really only capable of around 250-275WHP safely with a turbo kit. 2JR even sell a QR25DE turbo kit that can push up to 350WHP but they do recommend a built motor for those numbers along with their kit.
2. The stock QR25DE Gen2 (2007+) engine however can safely hold around an extra 85+WHP compared to Gen1 QR25DE's. There are YouTube videos of Gen2 engines pushing safely into 320+WHP on stock internals. This is due to 2 things that Nissan started using in the Gen2 Engines.
   • Revised Piston Crowns. Gen2 Engines came with a revised piston crown design that allowed higher compression ratios compared to Gen1 engines.
   • Reinforced Connecting Rods. Along with the revised pistons, the Sentra SE-R Spec-V Gen2 engine had stronger connecting rods. These rods were not on all Gen2 engines.
3. Tuning the QR25DE engine is actually pretty extensive with the UpRev program. There are cars that have seen over 480+WHP utilizing the UpRev program and a built engine.
4. Building the QR25DE is pretty straight forward, the more you build the more expensive. But that's not to say you need a fully built and sleeved 2JR block just because it's capable of making 800WHP. Below are the basics you would need (with prices) to safely build a QR25DE engine for 450+WHP.
   1. ARP Main Studs - $129.99
   2. MaxSpeedingRods 4340 Forged H-Beam Connecting Rods - $399.99
   3. Wiseco 89mm Bore QR25DE Forged Pistons - $189 EACH ($756 Total)
   4. Darton MID Block Sleeve Kit - $768
      • Total Parts Cost - $2,054
        • I purposely left out Injectors, Intake, Fuels Pump, and Spark Plugs because those are subjective from build to build and are FAR less expensive than the items listed.
5. For Forced Induction (Turbo), STAY AWAY FROM PREFABRICATED KITS! Prefabricated kits are 100% of the time always far more expensive than if you were to source your own turbo, turbo manifold, front-mount intercooler (FMIC), blow-off valves (BOV), wastegates and piping. Yes, 50% of the time you will need to do some fabrication to mount everything, but normally it's no more than $100-$200 for the mounting materials. The same is said for ordering AN fittings & hoses, boost controllers, tubing, pipe cuffs, and boost gauge(check Amazon, Summit, or Google). A prefabricated kit from 2JR costs $3,799.99!! With parts and materials, you can have your own kit bult for around $1,700 (TURBO INCLUDED). That's less than half price of a prefab kit.
   • PRO TIP: Stay away from big name-brand turbos all these YouTube stars and professional drivers use. Smaller companies build within the same specifications and materials as the big companies but for half the price with honest reviews to back up their quality.

Thank you once again for anyone who has replied. At the end of the day, we aren't driving a Ford. We are on one of thee most reliable platforms out there and you have to understand just why this brand (Nissan) is so highly praised for their tuning capabilities. Just as Toyota, they don't just build 2 or 3 great engines and drop the ball on every consecutive engine after another. Good rule of thumb, a 500k mile motor isn't on the road just because of oil changes.

Now before everyone goes out and talks about "Well my VQ this and her SR that and his VK there", it's not yours if you copy someone. Part of building something of your own is to HAVE SOMETHING OF YOUR OWN. Unique builds are remembered, similar builds are reposted.

 

[chickdr]

I will certainly be interested to see your 400hp build.

 

[GreySinclaire]

I dont know much about the i4 motor but z1 offroad has a bunch of engine internals for it, valve springs, new piston rods. I think I saw somewhere that it's also the same as the one in altimas and I believe turbo kits are available for those so some modifications would need to be done to that kit but should work. Personally I like the idea of keeping and moding the crap out of factory motors even if it's costs as much if not more than a motor swap. Personally I'm trying to see what will break my vq but good on your for moding that 4 banger.

I really appreciate the kind words!
Like yourself, I like to see what's possible with what I have. I get engine swaps are cool and can definitely be unique, but especially if a platform I have has never been explored, curiosity gets the best of me. Who knows, you might just stumble onto something new others haven't found yet and then you feel some pride for the hard work paying off. Even if it is a copy and paste build that others have done, once you're finished building or swapping a motor, that joy of starting it up for the first time and trying it out is one of the best feelings.

 

[GreySinclaire]

I will certainly be interested to see your 400hp build.

I will definitely document my build process either through video and/or pictures. Thankfully 400+WHP has been achieved before but there's just not much info on those builds.

 

[sirnixalot]

Take a fools advice and be prepared for setbacks. I am not trying to discourage you but be forewarned, It SUCKS to be the first to do something. Secondly if this is your only vehicle look into a daily before you start the heavy mods.

 

[GreySinclaire]

Take a fools advice and be prepared for setbacks. I am not trying to discourage you but be forewarned, It SUCKS to be the first to do something. Secondly if this is your only vehicle look into a daily before you start the heavy mods.

I appreciate the heads up, much more appreciated than to see someone discourage.
It's currently my daily but I do have 2 other cars and a motorcycle to ride so I won't be stranded while working on this. However, I'm actually going to buy a used block in good condition then send it off to get cleaned and resurfaced. That way I can just work on it in my garage/shop without having to have the truck just sitting without an engine. It's far easier to do that and then sell my current engine when it's time for the swap.
Also, I do feel a hell of a lot more comfortable knowing there's people who have built these engines before far more than what I would ever need.

 

[sirnixalot]

That is definitely the best plan and good to see you have extra vehicles just in case.

BTW when you dis-assemble a stock block, the pistons/rods look like oranges on a tooth pick 🤣

 

[UntilWheelsFallOff]

Thanks to everyone who replied! After speaking to one of the techs over at 2JR for over an hour on his own time, I was able to find out that these engines are actually very much worth keeping to modify. I'm surprised that nobody has every really torn into these engine platforms besides the Sentra community being that they are the same engines.
Below is what I've been able to gather from a 2-day binge of comments, phone calls, and research.

1. The stock QR25DE Gen1 (2000-2006) engine is really only capable of around 250-275WHP safely with a turbo kit. 2JR even sell a QR25DE turbo kit that can push up to 350WHP but they do recommend a built motor for those numbers along with their kit.
2. The stock QR25DE Gen2 (2007+) engine however can safely hold around an extra 85+WHP compared to Gen1 QR25DE's. There are YouTube videos of Gen2 engines pushing safely into 320+WHP on stock internals. This is due to 2 thingsthat Nissan started using in the Gen2 Engines.
   • Revised Piston Crowns. Gen2 Engines came with a revised piston crown design that allowed higher compression ratios compared to Gen1 engines.
   • Reinforced Connecting Rods. Along with the revised pistons, the Sentra SE-R Spec-V Gen2 engine had stronger connecting rods. These rods were not on all Gen2 engines.
3. Tuning the QR25DE engine is actually pretty extensive with the UpRev program. There are cars that have seen over 480+WHP utilizing the UpRev program and a built engine.
4. Building the QR25DE is pretty straight forward, the more you build the more expensive. But that's not to say you need a fully built and sleeved 2JR block just because it's capable of making 800WHP. Below are the basics you would need (with prices) to safely build a QR25DE engine for 450+WHP.
   1. ARP Main Studs - $129.99
   2. MaxSpeedingRods 4340 Forged H-Beam Connecting Rods - $399.99
   3. Wiseco 89mm Bore QR25DE Forged Pistons - $189 EACH ($756 Total)
   4. Darton MID Block Sleeve Kit - $768
      • Total Parts Cost - $2,054
        • I purposely left out Injectors, Intake, Fuels Pump, and Spark Plugs because those are subjective from build to build and are FAR less expensive than the items listed.
5. For Forced Induction (Turbo), STAY AWAY FROM PREFABRICATED KITS! Prefabricated kits are 100% of the time always far more expensive than if you were to source your own turbo, turbo manifold, front-mount intercooler (FMIC), blow-off valves (BOV), wastegates and piping. Yes, 50% of the time you will need to do some fabrication to mount everything, but normally it's no more than $100-$200 for the mounting materials. The same is said for ordering AN fittings & hoses, boost controllers, tubing, pipe cuffs, and boost gauge(check Amazon, Summit, or Google). A prefabricated kit from 2JR costs $3,799.99!! With parts and materials, you can have your own kit bult for around $1,700 (TURBO INCLUDED). That's less than half price of a prefab kit.
   • PRO TIP: Stay away from big name-brand turbos all these YouTube stars and professional drivers use. Smaller companies build within the same specifications and materials as the big companies but for half the price with honest reviews to back up their quality.

Thank you once again for anyone who has replied. At the end of the day, we aren't driving a Ford. We are on one of thee most reliable platforms out there and you have to understand just why this brand (Nissan) is so highly praised for their tuning capabilities. Just as Toyota, they don't just build 2 or 3 great engines and drop the ball on every consecutive engine after another. Good rule of thumb, a 500k mile motor isn't on the road just because of oil changes.

Now before everyone goes out and talks about "Well my VQ this and her SR that and his VK there", it's not yours if you copy someone. Part of building something of your own is to HAVE SOMETHING OF YOUR OWN. Unique builds are remembered, similar builds are reposted.

There was also a supercharged variety of qr25de engine used in the hybrid Infiniti QX60, Murano and Pathfinder: QR25DER. I found this thread looking for some performance upgrades for my Rogue but it's got the CVT so it's not realistic for me to consider any more power without a different transmission (X-trail 6 speed)

 

[chickdr]

There was also a supercharged variety of qr25de engine used in the hybrid Infiniti QX60, Murano and Pathfinder: QR25DER. I found this thread looking for some performance upgrades for my Rogue but it's got the CVT so it's not realistic for me to consider any more power without a different transmission (X-trail 6 speed)

Wow- something learned today. Never knew they made a factory S/C 2.5l. Interesting! Too bad it wasn't used in some other cars with the 2.5. Would have made a fun Sentra or Rogue for sure.

 

[rone465]

Just a heads up to everyone interested I decided to go ahead and turbo mine. I have everything already just need to do the rom dump and wait on tuning. 2J-Racing is taking care of the tune so in 4-8 weeks I will let you all know how it turns out. 2J-Racing told me that for my 2013 frontier 300-320hp will be reliable as long as it’s a healthy engine that’s not burning oil. We shall see! Extremely excited.

 

[RyanD1966]

Then might as well VK56 swap, eh?!?

My thought as well. 2x4 = v8, yes?

 

[Ted722]

Look forward to hearing / seeing the updates. Can't imagine 300+ HP I4 power delivery mated to my current 2.5's manual transmission / 4.36 differential gear ratio. Already shifting fairly quickly thru the first 3 gears.

Definitely going to be a thrill ride!

 

[rone465]

just mocking it up.. so far so good. And anyone wondering about my fenders… I’m in the process of a xterra body swap currently fabricating the rear bedsides. I just like the body style a little better.