Jump to content

Build up your VG30E to get 160-170hp and have 20mpg!


Tungsten
 Share

Recommended Posts

Using these simple guidelines, you can have your Pathfinder keep up on the highway, be efficient, and be reliable for daily driving:

 

 

1. TUNE UP YOUR TRUCK

 

A proper tune up is the best way to ensure good engine performance and efficiency. If you haven't done it yet, change the plugs, cap, rotor, wires, filters, etc.

You will already notice a boost if it has been a while since the truck was tuned up.

 

For spark plugs, use either the OEM NGK V-power plugs, NGK G-power plugs, or the NGK Iridium plugs. They should be in the NORMAL heat range, which is 6. Using these NGK plugs will grant you the most power and fuel economy since the VG motor was designed to run these plugs. I have had success with the V-power plugs but people have also reported good results with G-power and the Iridium plugs. The ignition timing is set by the ECU but it should start at 15 deg BTDC, as indicated by the inside hood sticker. Hint: If the crank pulley has been put on with the marks in the wrong place, make new marks at the engine in TDC or rotate the pulley back into its proper position.

 

For everything else, I suggest you go to the dealer. These are maintenance items so they will not be overpriced at your local dealer. If you want aftermarket, make sure it's a proven and trusted brand like MSD ignition.

 

Also, make sure there are no codes stored in the ECU and that there are no sensor malfunctions.

 

 

2. TIMING BELT

 

Replacing your timing belt during the recommended replacement intervals will ensure your engine will not fail from smashing its valves. This should be fairly obvious to anyone that has dealt with interference engines. Don't forget the water pump! Also, setting the timing belt incorrectly will damage the engine or even have the engine throw a rod.

 

 

3. THERMOSTAT rated for 180F

 

The VG engine loves to run very HOT for peak efficiency. Close to the boiling point of water! If you will be replacing your thermostat, either a part of the timing belt job or just by itself, get a 180F thermostat unless you live in a hot climate that would require using a 170F or a 175F thermostat. If you see your temperature needle a pinch under half in the winter and a pinch over half in the summer, this is how it should be. The closer the VG engine gets to 205F, the more efficient/powerful it becomes. If your temp gauge needle goes way over half and you tested that it isn't just the gauge, it's time to upgrade the radiator (possibly to a single core aluminum radiator). It is also recommended to perform a coolant change every other year just to keep the cores from clogging. Although generally good quality coolant will last a while. As an alternative, the thermostat sold at the dealer, which is a 170F, will also keep the engine on the right spot. It works much better than an aftermarket 170F thermostat.

 

 

4. TRANSMISSION COOLER

 

The transmission cooler is a very important item if you want to run the VG engine in the temp range it should be ran in. You want to keep the transmission slightly cooler than the engine for peak efficiency and durability. Ideally, to avoid transmission overheat issues, you should get one as big as you can fit it, a size of about 16,000 GVW is the minimum recommendation. However, one thing you have to watch for is running the transmission too cold in cold weather. If you have a new radiator, or one that isn't clogged, you can run the transmission cooler inline with the radiator so the transmission can warm up faster in the winter. If you bypass the radiator and run the cooler by itself, make sure you have a way of making sure the transmission gets in the correct temperature range before driving off.

 

 

5. FLUID CHANGES

 

Make sure you are on top of all your fluids, don't forget the transfer case and differentials. Visually inspect or replace the transmission fluid after 30,000 mile intervals, especially if you don't have a transmission cooler. Be sure to use the correct compatible fluid or Nissanmatic D. You may be able to get away without installing a transmission cooler as long as you always inspect the transmission fluid. Also, using synthetic fluids in everything improves your MPG rating.

 

 

6. ENGINE OIL

 

Use fully synthetic oil in this engine for peak efficiency and performance. If your seals fail from using synthetic oil, replace them with new seals. Dust shouldn't be holding oil in place anyway! Change the oil in between 3000 and 5000 mile intervals and don't forget the filter.

 

 

7. PERFORMANCE EXHAUST

 

Nissan's factory exhaust system can become problematic over time. The factory crossover Y-pipe will eventually rust in half and will spit hot exhaust gas on your floor pan, which if rusted, will cause your carpet to go up in smoke and your MPG rating to severely drop. The exhaust manifolds can also pop off the studs since the original studs are too weak. The general consensus is to get Doug Thorley short tube headers and put them on 300ZX turbo studs. The headers will have a superior heavy duty Y-pipe which should not break as easily. You can get creative with the muffler and catalytic coverter. Magnaflow catalytic converters are generally recommended for their efficient designs. As for mufflers, you will hear people either suggest Magnaflow or Flowmaster as they are better than the crap in the can mufflers. This way, your engine will be more efficient and put out more power.

 

 

8. AIR FILTER/INTAKE SYSTEM

 

The factory air intake system is already quite good with a short path between the air box and the intake plenum. You can ensure peak efficiency and performance by making sure there is no obstruction between the air filter and the plenum. If you have a dirty throttle body that likes to whine, spray it with some carb cleaner and use a toothbrush. At the very least, you should have either a very fresh standard air filter from a name brand like Wix or Nissan or a performance air filter from a trusted brand, for example, either K&N or HKS (3 layer super hybrid filter). Cold air intake systems have been proven to be effective but with marginal differences and do put you at a higher risk of getting crap into the engine. A clean decent flowing filter will increase your MPG rating.

 

9. BELTS AND PULLEYS

 

Check the belts for correct tension and make sure pulleys aren't noisy and can spin freely. These should be in tip top shape so that the engine can work nicely with its accessories. Use Gates brand (or NAPA Premium) V-belts for the best results.

 

 

10. E-FAN/FAN CLUTCH UPGRADE

 

If you have a seized fan clutch, your MPG rating will drop significantly. Replace the fan clutch with either an electrical fan or a good working fan clutch. For the fan clutch I recommend using either a OEM Nissan fan clutch or one from NAPA by NAPA Temp Products.

 

 

11. GOOD BATTERY

 

A good battery will ensure your electrical system is at peak efficiency. I highly recommend using an AGM (absorbed glass mat) battery, for example, a DieHard Platinum. An AGM battery will always start your truck and will not ever corrode/eat the terminals.

 

 

12. SMOOTH DRIVETRAIN

 

A properly functioning drivetrain and suspension will reduce drag on the engine. Inspect all joints, tension rod bushings, and get an alignment if you haven't done so already. Jack up the truck and spin the tires to make sure nothing is seized or dragging.

 

 

13. FUEL RECOMMENDATION

 

The factory user manual specifies to use at least 87 octane fuel. If you use regular gas and it's from a crappy station, don't forget to use the occasional fuel treatment to keep those injectors running well. However, if you do have spark knock or pinging or if you have any engine mods that cause too much spark knock or pinging on 87 octane fuel, then switch to midgrade 89 octane fuel which will lower the risk of detonation or spark knock at higher rpms. Switching to more refined fuel will also make those fuel injectors last much longer as the fuel will have an injector cleaning solution in it. Most people do recommend running 87 octane gasoline so it's safe to stick with that.

 

 

14. TIRES

 

Tire size, tread pattern, and pressure are very important in saving fuel. Pick the right tires for what you are doing. Don't use aggressive off-road tires if you don't go off-road. Try to keep the factory issued size tires for best performance and fuel savings.

 

 

As always, if you want any in-depth information, :search: or browse NPORA. Good luck with your Pathfinder! If anyone disagrees to any of the above points, please reply and state your reasoning.

Edited by Tungsten
  • Like 3
Link to comment
Share on other sites

MPFI Pathfinders adjust the timing curve via the ECU off-idle. TBI Pathfinders do not. What you set it at is what it will remain at throughout the RPM range, and they also run a base timing of 12 degrees BTDC. You can advance the TBI timing to 15 degrees BTDC for some extra oomph and fuel mileage.

 

Timing belt interval for '98-'93 Pathfinders is 60,000 miles and 105,000 miles for '94-'95 Pathfinders. Do the cam seals while you're in there.

 

VG33 exhaust manifolds are also 10MM just like the Z31T studs.

Edited by Kingman
  • Like 1
Link to comment
Share on other sites

MPFI Pathfinders adjust the timing curve via the ECU off-idle. TBI Pathfinders do not. What you set it at is what it will remain at throughout the RPM range, and they also run a base timing of 12 degrees BTDC. You can advance the TBI timing to 15 degrees BTDC for some extra oomph and fuel mileage.

 

Timing belt interval for '93 and older Pathfinders is 60,000 miles and 105,000 miles for '94-'95 Pathfinders. Do the cam seals while you're in there.

 

VG33 exhaust manifolds are also 10MM just like the Z31T studs.

 

Fixed it for you! :D

 

The TBI Pathfinders are VG30i, not VG30E but yes, that's how it is.

Link to comment
Share on other sites

i find it hard to believe that a 19 year old engine can get 17 more horse power by those small things, maybe some from the msd but not even 17. one thing that can help gas mileage is put mud flaps in front of your tire (just look at hybrids), and for horse power eneos oil

Link to comment
Share on other sites

i find it hard to believe that a 19 year old engine can get 17 more horse power by those small things, maybe some from the msd but not even 17. one thing that can help gas mileage is put mud flaps in front of your tire (just look at hybrids), and for horse power eneos oil

 

You better believe it. Everything he said is true. And the MSD will only get you maybe 1/2 hp over a properly functioning, stock ignition system.

 

Mud flaps in front of a tire? What are you talking about?

Link to comment
Share on other sites

besides the electric fan most of that is basic maintenance. i still doubt 20 mpg unless it was the best conditions with down grade or back wind actual mpg

I get way better than that easily. I have 6" of lift and I can still get 20 mpg on the highway and 16 in the city it's all in how you drive it. And my exhaust is stock fyi.

Link to comment
Share on other sites

I can see at most 170HP at the crank, definitely not at the wheels. NA VGs are, well, dogs...

 

I've gotten 23MPG in my TBI Pathfinder before doing 75. No big deal. You would have to have a pretty light foot to get good mileage consistently.

Link to comment
Share on other sites

Sorry, why would you put 2 stroke oil in?

Dont want to thread jack or anything but E10 and e15 fuels are 10 and 15 percent ethonol which doesnt have the lub propertys of regular gas, so theres claims of more wear in the cylinder heads and injectors then running regular gas. Adding 2 stroke oil to it adds that lube back into(marine sta-bil does the same thing but it costs more) it. The engine does seem smoother and mpg will raise on some engines.

 

Bobistheoilguy has some very good info on this and I did a random write up on it a while ago.

Link to comment
Share on other sites

File fitting rings and back cuting the valve would also help the power in a milage build.

 

 

As far as milage for me I got 13-14 winter and 17-19 summer with as high as 23 on long free way trips.

 

Also, a deep oil pan will see better hp numbers, because it keeps the oil away from the crank(read that these arent splash lube engines, they have pumps)

Link to comment
Share on other sites

I get 20-24 on the highway in the summer. 22 at the most if the ac is on. And I have stock exhaust intake and ignition.

 

On my 15k road trip this summer, I averaged 23 mpg most of the way. Even in the mountains it was around 19-21. I kept every gas receipt and wrote down the mileage whenever I filled so this is not bull@!*%.

 

I had the air on a lot and a roof basket on. Set the cruise at 65-80 mph depending on area and I was good.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...