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Turbo Charging A 2005 V35 250Gt Vq25Dd

Hunter_in_a_V35_250GT
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fatboyslim27 Rookie

fatboyslim27

Posted
Posted

If you're looking for mods to do to a 250GT, try first with just really a really good service. Every think clean and new, and brand new fluids. Following this, go for a Z-Tube. In terms of performance gains its really quite negligible (Tiny TINY feeling in power), but it does make for some nice intake sounds.
A grounding kit is also a recommendation. If you look at the grounding cable coming from you're battery you can see how it really is quite shit. A decent grounding kit can just help with the overall running of the car, esp with automatic. Personally I noticed a much better charge to the battery when the engine was running. 14.1v vs 14.5v with the kit.
I've asked around with the plenum spacer but no one really seems to know. I also really want to know whether or not the plenum spacer from the VQ35DE will work on this because some people are reporting dyno figures of around +8-13hp with it on. So if anyone does know please also respond to this.
Apart from that, that's pretty much it. This is one of the highest HP naturally aspirated 2.5l nissan has made, so the ECU is very temperamental for any changes and it self learns as well. Piggy back systems are possible, but they are quite expensive.

Also i'm all the way in NZ and currently theres a VQ25DET engine on trademe here going for $1900 with only 130,000km done on it. SO tempting, but wouldn't know where to start to get the engine fitted into my 250GT

Howaitonaito Mentor

Howaitonaito

Posted
Posted

Plenum spacers on DD can work but modification to the EGR os required. Have your plenum cleaned, plug changed and oil changed will improve it.

Z tube all it does is make a noise and does sweet fark all. May aswell put a pod filter on for the full sick induction noise.

VQ25DD were not designed for power they where designed for economy. Really should have done your research with modifications in mind before buying a 250

Hunter_in_a_V35_250GT Contributor

Hunter_in_a_V35_250GT

Posted
  • Author
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Plenum spacers on DD can work but modification to the EGR os required. Have your plenum cleaned, plug changed and oil changed will improve it.

Z tube all it does is make a noise and does sweet fark all. May aswell put a pod filter on for the full sick induction noise.

VQ25DD were not designed for power they where designed for economy. Really should have done your research with modifications in mind before buying a 250

When you say the plenum will work with modification, is this process expensive/time consuming, or is it not worth the 8 - 10 HP from the plenum spacer? Considering if these gains will even be similar or not to a DET engine compared to DD I upgraded the air box with a greedy complete box conversion, noise isn’t really louder and power gain is only slight, I’ve been told that changing the headers will give some decent increases in power, but the only performance headers I can find are for the VQ30DET and VQ35DET, the engines look the same as my VQ25DD, but I’m sure there is some minute differences which makes these parts incompatible for me, although I’d love to be mistaken and have these headers fit with the VQ25DD.

Howaitonaito Mentor

Howaitonaito

Posted
Posted

When you say the plenum will work with modification, is this process expensive/time consuming, or is it not worth the 8 - 10 HP from the plenum spacer? Considering if these gains will even be similar or not to a DET engine compared to DD I upgraded the air box with a greedy complete box conversion, noise isnt really louder and power gain is only slight, Ive been told that changing the headers will give some decent increases in power, but the only performance headers I can find are for the VQ30DET and VQ35DET, the engines look the same as my VQ25DD, but Im sure there is some minute differences which makes these parts incompatible for me, although Id love to be mistaken and have these headers fit with the VQ25DD.

8-10hp? 10hp is just over 7kw. Do you know how much of that 7+kw will get the rear wheels and make a difference. Sweet fark all.

The factory air intake isnt that bad just take that stupid lid/cover off the front and change the filter.

As for headers and shit ask scotty. From what i can remember the 30DD takes some of the 35DE stuff but not much if not none will work on the 25DD.

VQ25DD to V35s are what CA18DE are for silvia. The VQ25DD is actually out of a FWD nissan cefiro (maxima here) and it barely moved that.

sonicii Veteran

sonicii

Posted
Posted

The VQ25DD is actually out of a FWD nissan cefiro (maxima here) and it barely moved that.

Sort of, it was released in the Nissan Cedric at the same time as the A33 Cefiro, and the Cedric is a RWD.

Also, the VQ30DE in the Australian A33 maxima got along ok, and the VQ25DD was only a few KW down and about 18Nm down on the VQ30, so it shouldn't have been too bad.. I have never driven a JDM A33 Cefiro though.

Still, there probably isn't too many performance options for the VQ25DD, as most would go for the VQ35 or a stock DET engine if they want performance.

Hunter_in_a_V35_250GT Contributor

Hunter_in_a_V35_250GT

Posted
  • Author
Posted

While we are talking about upgrades, anyone have any experience with the Apexi SAFCII with a VQ25DD or any automatic car for that matter? is there much room for any real gains or is this going to add a mere 3-7 Kw, saying that would combining multiple minor mods equal a decent gain? have seen some pro shops around Sydney that custom build turbo’s, I got a quote for a full kit and installation designed for DD engine, would be around 4-8 K but he said he would have to take a look at my engine, so there may be some hope, hope for future Vince who has money, who will most likely just buy a new faster car.

junkie Mentor

junkie

Posted
Posted

The 250 is a nice unique daily but not a performance car. I suggest saving for something later down the track and just enjoy what you have now... I bought mine without any performance expectations and not going to mod it, just stick to general maintenance and replacing stuff as it wears our or breaks

scotty nm35 Grand Master

scotty nm35

Posted
Posted

While we are talking about upgrades, anyone have any experience with the Apexi SAFCII with a VQ25DD or any automatic car for that matter? is there much room for any real gains or is this going to add a mere 3-7 Kw, saying that would combining multiple minor mods equal a decent gain? have seen some pro shops around Sydney that custom build turbo’s, I got a quote for a full kit and installation designed for DD engine, would be around 4-8 K but he said he would have to take a look at my engine, so there may be some hope, hope for future Vince who has money, who will most likely just buy a new faster car.

The more you post the less I want to help, mainly as you don't listen well. I have already mentioned a few easy power gain mods you DD guys can do, but none have run with it.

You engine is very high compression, there is no way a turbo can help you. Anyone saying they have designed a turbo kit for the DD is talking out their ass. You can swap in a det engine if you want to go that path, but it has never been done before as far as I know, so you are on your own which costs big dollars.

The SAFC will most likely destroy your engine. At least get something with separate timing and fuel control such as the Emanage Ultimate, although I am still unsure if it will control the direct injection circuit.

Go and see your Pro shop that have never seen a VQ25, let alone a direct injection model. They would love to spend your hard earned...

Hunter_in_a_V35_250GT Contributor

Hunter_in_a_V35_250GT

Posted
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Hi Scott, no disrespect was intended, I will be giving all the options that you have given me in the past to get some extra gains, just getting a lot of info from other sources which I don’t fully understand/believe is true, hence why I come here to speak with those with the experience, I also agree that turbo is a no go with Direct Injection, I’m not a mechanic and I don't have a great amount of knowledge on cars, so any information I do have is purely from the internet and from others around me. But again I do appreciate all the help/suggestions everyone has given me, and will be running with them :)

Thanks Again,

Vince

sonicii Veteran

sonicii

Posted
Posted

I also agree that turbo is a no go with Direct Injection.

The problem isn't direct injection, the high static CR of this engine prevents forced induction on regular petrol without major engine modification.

scotty nm35 Grand Master

scotty nm35

Posted
Posted

Actually, it is also the direct injection, as there are no highflow direct injectors available anywhere. You would need to make a new plenum with larger standard 14mm injectors and try to work around the ecu issues.

Some things just aren't meant to be, financially at least. Sell the car and buy a 3.5, there is a huge market for performance parts, as opposed to no market for the VQ25.

sonicii Veteran

sonicii

Posted
Posted

Interesting.. wasn't aware of that.. what about the VQ30DD injectors? .. I thought someone would have made larger Di injectors.

Either way, it is kind of a moot point I guess.

KiwiRS4T Grand Master

KiwiRS4T

Posted
Posted

Also i'm all the way in NZ and currently theres a VQ25DET engine on trademe here going for $1900 with only 130,000km done on it. SO tempting, but wouldn't know where to start to get the engine fitted into my 250GT

What town are you in? I could suggest two or three shops that could do the work for you as well as one that may be able to tune your stock ecu.

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