2004 Nissan Sentra V6 swap

that is lighter and much more powerful than my rx8 - that thing must be a rocket!

So I was junkyard hunting a couple weeks ago and came across this:

2004 Maxima with a 6 speed manual. Unfortunately someone had already scored the ECU ($35 at the yard) but I did take an afternoon off work to grab all this:

That's the entire engine harness, with all 4 wideband/o2 sensors, the BCM, the IPDM (smart fuse box), MAF and tube, crank sensor, gas pedal, immobilizer transponder, and some other wiring pigtails. Cost me $40 CAD. An ECU is $50 USD plus shipping from car-part.com and once installed is worth 20hp over my current one (03 Altima was rated at 245hp, the Maxima at 265hp - no mechanical differences in the longblock).

The newer harness is a bit more difficult to integrate nicely as it relies on the CAN system a lot more, and I didn't grab the cluster, ABS system, or auto a/c meter amp that it will want to see. Fairly confident it should work without, just might set U1000 codes. Worst case I need to buy an Osirus UpRev tune. That should put the car around the 265whp mark.

While researching this I also found it's possible to swap what is reffered to the "FWD HR" engine, which is all 07+ Altima V6, 09+ Maxima, 09+ Murano, and 10+ Quest. There's a company that makes a cam sensor inverter which allows this engine to be run on the older ECUs once some minor modifications are done. The 09+ Maxima engines add the ability for exhaust side variable valve timing, but the older ECUs don't support this. I think the proper year 350Z ECU with a UpRev tune can get this system running. Even without, I'm seeing dynos in the 285whp mark for this engine. The best part is that they're cheap - car-part.com has a few listed at $350 USD.

Not saying I'm going for it, but some interesting info I wanted to share.

Dirty car glamour shot:

18 month update!

So I stopped driving the car around the time of the last update. I was driving the '98 K1500 daily instead as I figured out the cost of fuel + insurance on the truck was less than fuel + insurance on the Sentra with the amount of driving I did and the cost of 91 octane used in the Sentra vs 87 in the truck.

The Sentra sat and sat until a few weeks ago when I decided I should probably sell it, and I wanted to take the truck off the road to do some bodywork before winter.

Since the car sat, it developed an ABS light as well as an exhaust leak. The ABS turned out to be a bad right rear wheel speed sensor, taken care of from Rock Auto for about $50.

For the exhaust leak, the flexpipe on the eBay headers was leaking. I bought a Vibrant 4" long 2.25" diameter flexpipe for $40 off Amazon and hacked off the leaky flexpipe.

Here's what I found:

The collector was horrible.

I used a torch, my welder, and some carbide bits to clean that up

And some scrap 2.5" piping I had to work to make fit. Ugly but doesn't leak.

I was cleaning out the basement and found a nitrous kit I had been sitting on for probably 8 years now. I think I paid $300 for the kit, and purchased the heater separately on ebay for an amount I don't remember.

I had to either use it or sell it, and had one week until the last Test&Tune at the local dragstrip so this happened:

I bought the blowdown kit on Amazon for $38

A $10 bag of microswitches from Amazon, some cotter pins, used wire from an old alarm system I took out, and 5-minute epoxy got me a WOT switch

A toggle switch, relay, momentary button, and chunk of power steering line finished out my control side. The interior is filthy, excuse me.

A $30 fuel injection test port (tool #J-44321-4) I grabbed from work (bought a new one to replace it) got drilled out for a bit more flow to supply the fuel.

A pair of longer bolts and cut up bits of dipstick tube from a blown engine completed the fuel supply adapter. I cut the dipstick tube with a cut off wheel and chucked them into a 1/2" drill held against a grinding wheel to get a nice flat edge on the tube.

Solenoids got placed on some un-used threaded holes on the firewall, and the fogger nozzle about 12" from the throttle body.

I knew traction was going to be an issue, so I saved some 245/40/17 Bridgestone RE71 tires off a buddy's S2000 destined for scrap and pinched them onto the stock 7" wheels.

I had to buy a nitrous gauge, fittings, and all the small jets they had in stock from a local speed shop. They also filled my bottle for $100 CAD. I didn't get time to wire up a high amperage power wire for the bottle blanket so I just used jumper cables up to the battery in grid and kept an eye on the bottle gauge.

First time using nitrous, I was nervous and excited! I was worried about the stock fuel pump and clutch. With the limited choice of jets I had I settled on two combos, a .032 N2O and .016 fuel (good for about 40hp) and a .045 N2O and .026 fuel (good for about 90hp). The factory returnless fuel system is supposed to run at 51psi.

Here I am waiting in line. The tech guy didn't ask any questions, and didn't pop the hood or trunk. Probably thought the car was stock.

So I made about 18 passes. Fair warning, I'm not a drag racer and suck at driving.

I made 8 passes without nitrous first, the best which was a 14.1 at 102mph with a 2.36 sixty foot. To refresh for those that don't remember, the car makes about 235whp/235tq and weights a little under 2900lbs. I had trouble launching the car, it either dead hooked and bogged or spun and wheel hopped. I was right close to the limiter in 4th across the finish, I knew that would be an issue when I turned on the nitrous. The factory ECU seems to take a half second to allow full power after going wide open throttle in the lower gears too which made things difficult. You'd be at part throttle to keep it from spinning then once it hooked and fed more throttle in you wouldn't get it right away. You can feel this on the street when rolling on the throttle in all gears. Whack the throttle and you get about 80% instantaneously, then half a second later the rest of the torque swells in.

Next I put in the 40hp jets and tried it out. Nitrous is fun!  I made 4 passes with this setup and had a best time of 13.6 at 107mph with a 2.27 sixty foot. I was on the limiter in 4th here, and found the car seems to have both a soft limiter and a hard limiter. Sometimes it would bounce, sometimes it just felt like the car hit jello and the rpm would drop slowly. It seemed like if I hit the rev limiter in 3rd, I was more likely to get the soft limiter in 4th so I tried to get my 3-4 timed right.

Finally I put in the 90hp jets and made 6 more passes. I managed to figure it out on my 4th pass with these jets and got the car down to a 2.16 sixty foot, but tried for 5th gear at the finish and missed. I coasted to a 13.0 at 105mph! I was stoked and had to try again for a 12 second pass. This was near the end of the day and I think the bottle was getting low as I only managed a 13.5 at 107 despite hitting another 2.16 sixty foot. The trick I found is a lot of slipping the clutch...makes me cringe but it's the only way to keep the engine in the power band and the tires right at the limit of traction without getting into wheel hop. I hot lapped the car on the last two passes as it was right at the end of the day and got a little whiff of clutch after the last pass.  The tires could actually take the 90 shot in second gear once they had settled after the 1-2 shift.

Here are the time slips, left is on motor, center 40 shot, and right the 90 shot.

So doing a little bench racing, I think I could easily get the car into the 13s on motor alone (the 60ft alone between the best pass on motor and the last pass should do it) and with a cool clutch and full bottle hit that 12.9 on nitrous just riding the limiter through the traps.

I brought my knock-off gopro along, but unfortunately filled up the SD card by the time I ran the 13.0.

Here's my second pass on the 90 shot, reeling in a JDM Toyota Aristo (2JZ-GTE Lexus GS300 basically). This run was 13.4 at 106mph. You can see I got a bit of wheel hop at the 1-2 shift and the nitrous hit at about the 0:09 second mark in second gear. Also where I hit the rev limiter in 4th before the traps.

I'd love to upgrade the clutch, fuel pump, and swap a taller tire or the 3.8:1 final drive into it and try again. Getting a 04+ ECU in the car with UpRev would also be killer for bumping the rev limiter a bit and smoothing out the drive by wire response.

This is all mighty awesome, sir!

Awesome write-up on the nitrous adventure! I am having a similar experience (and very similar times!)  with my own VQ swapped machine. Traction is our mutual enemy, even though I'm RWD. I also notice the slow throttle/torque response since mine is an 03 with the older style ECU. I would love to upgrade to a newer one, but I've heard the harness plugs are different. With the right harness and ECU, that opens the door to tuning like you mentioned. Mine is a Challenge car, so budget is keeping me from doing that. But it may happen post-Challenge. Keep us updated! 

yeah FWDs generally respond best to a soul-crushing clutch slip off the line

with my first turbo tercel i found a 5k "half dump" while simultaneously flooring the throttle (not just jamming it thru the floor) worked best.  Turbo was already lit just had to find that happy spot.  Im sure I could of gone harder but I like to keep my record of driving home from tracks still 100% intact 

I later confirmed nearly the same exact launch in my Yaris worked just as well

FF to around 4:30 https://www.youtube.com/watch?v=pgDCNfNJkMg&t=56s

That car should run a ~13.5 on slicks without the nitrous. Slicks are just another expense but if they save you any CV axle replacements due to wheelhop then they partially pay for themselves.   

3.5 HRs are interesting to me because even though i don't like nissan's CVTs much, the thought of it sitting at 6000+ rpm and just making ~300whp continuously  makes a late model CVT Maxima (which i already like the looks of)  with bolt-ons a fairly enticing thought for a highway bomber. I raced a current-gen Maxima in my old GS450h a few years ago and it wasn't losing by much. A few bolt-ons would probably have turned the tables, and i was already super-pleased with how fast the GS450h was.