# modifying my 86 maxima



## christopherb (Feb 1, 2014)

I am thinking about installing a cold air intake and bigger exhaust on my 1986 maxima. it is a good running little car with low miles. what do you guys think? Any suggestions?


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## smj999smj (Jan 1, 2006)

Personally, unless you are making other modifications to the engine, I think you're wasting your money as you'll see little, if any, gain in performance. Avoid filters that use an oil coating, such as K&N, because the oil can contaminate the mass air sensor hotwire and cause inaccurate readings. Make sure you replace the timing belt every 60000 miles or 5 years, as you will bend valves in this engine if it breaks.


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## christopherb (Feb 1, 2014)

what other modifications would you recommend? 
I am new to the Nissan scene, I have built a few chevy engines and I really like the quality of a Nissan car but I don't know much about them


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## smj999smj (Jan 1, 2006)

The U11 Maxima was a sharp looking car in their time. Back then, they were in the $16000-$17000 range, which was in the same ballpark as the 300ZX. 85 was first year of the U11 Maxima and the first year it had a V6, rated at 157 horsepower; the VG30E engine had been introduced a year earlier in the 84 300ZX and the VG-series engines were used in the US all the way up through 2004 in the Frontier truck. Stock, it wasn't much on power, but was very reliable and not hard to work on (although they were a bit cramped in the U11's). I'm glad you were able to find a low mileage example as it's getting harder to find good examples of these cars, anymore. When you do find them, it's not uncommon to find them with over 200,000 miles on them. As far as modifications, I can't say as I don't know what your intentions are. The U11 isn't a very popular platform on the aftermarket, so you're going to have to do your research. If you have the deep pockets, there are some things you can do to increase power of the VG30E. Camshafts are available from a few sources. For ECU remapping, I would get in touch with Jim Wolf Technology as they were among the first to work on Nissan ECU/ECM's. They also have cams, valve springs, etc. You might be able to find some forums dedicated to the U11 Maxima (in Japan, it's the "Bluebird") or VG-series engines. Not sure if Stillen Motorsports has much, but you could check their site. Nico clubs forums may have some useful info for you, as well. Good luck!


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## christopherb (Feb 1, 2014)

*thank you for the info*

this is a good running little car with only 33,000 miles. I plan on doing an ecu upgrade but I'm not sure about the cams. definitely something to think about though


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## b13er (Apr 7, 2010)

I would add an intake an exhaust, you will get about 10 horsepower and better fuel economy.

SMJ, 

That K&N oil filter ruining your MAF is just hearsay. K&N personally soaked MAF's in K&N oil for 12 hours, and they still ran perfect. They also sent the MAF to a lab to be tested and they didn't find any K&N oil residue on the hotwire whatsoever.

Also K&N said they have had 100's of complaints from people who said "my mechanic said my K&N oiled filter ruined my MAF", so K&N has that person send the MAF to them which is sent out to a lab. Out of the 100's they received, not one had any oil on the hotwire. I think the percentages went like this: 50% were just broken, and 50% had dirt on the hotwire. There is a video all about this on youtube, here is part 1 of 4:


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## christopherb (Feb 1, 2014)

What about suspension mods? It handles well but I think it could be better.


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## ziggatron (Feb 6, 2014)

Suspension is always a good place to start. It will help handling and stopping. Also acceleration if setup right. The k&n and other oil filters only messed up mafs after people cleaned them and didn't let the oil dry properly. Port and polish with gasket matching can yield up to 5hp and you can do it yourself. Cheap but time consuming. Weight reduction always works.


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## b13er (Apr 7, 2010)

ziggatron said:


> The k&n and other oil filters only messed up mafs after people cleaned them and didn't let the oil dry properly.


Considering K&N has soaked MAFs in their oil for 12 hours and it never messed up the hotwire, I still find it hard to believe. I guess the oil could short out the circuitry; I have read about MAFs where the glue failed which allows the circuitry to get messed up. Well if not letting the oil dry was the case, then that's what they get for being too stupid to follow the simple directions, and those people broke their MAFs themselves, not the filter companies.

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As for suspension, be aware that adding new high performance springs without adding high performance shocks, can mess up your stock shocks. My KYB AGX shocks and Eibach Pro springs setup I'm using will set you back about $700, but boy is it awesome. It's not that great at lowering your car(1 - 1.5 inches), but my bodykit took care of that.


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## christopherb (Feb 1, 2014)

I have some other questions. For one, there is a small electric fan mounted on the fender well on the passenger side with plastic ductwork that blows on the intake manifold under the plenum. What is that for? Also there are three vacuum operated devices on the plenum, one on the front and two on the rear. I'm sure that they are emissions related but I would like to know exactly what they are.


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## warzaz (Feb 21, 2014)

*We did a 300zx turbo swap on my 86 maxima*

Hello,
My buddy Ed and I replaced my shot stock engine (bent valves) with an 84 VGET from an 84 300zx. I had to put the matching ECU, but before that engineer new engine mounts and a whole bunch of little things. No room for original turbo location, so it is placed in the front bottom of the engine. Also, we added a transmission coolant radiator but no oil coolant yet, which may be more relevant. Car is fun to drive, but I still have to deal with vacuum issues at idle. Overall, it's a big job, but if your engine is healthy you might just want to add a turbo to your stock engine (don't know how hard this would be tho).
Check online for "maxima second generation turbo" and you should find a few threads about either mods. Good luck,


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## smj999smj (Jan 1, 2006)

The electric fan blows air onto the fuel injectors to help keep them cool. They deleted this fan system on later models.

As far as the K&N, everyone has their opinions. All I know is that Nissan released a TSB stating that MAS failure could occur due to oil-coated, cloth aftermarket air filters and they should be replaced with a genuine Nissan filter if such failures occurs. Also, The Spicer air filter tests show that K&N filters let in considerably more dirt than conventional paper air filters. For that report:

ISO 5011 Duramax Air Filter Test Report


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