I am looking into buying a 2004 Sentra SE R Spec-v but I have heard there was a problem with the computer on them and they cost a lot to replace is this true and if not is it worth my buying.

not the 04, the 02-03 had ECU problems but it was fixed in the 04 redesign, only thing you need to worry about in the 04 version is a bad precat (get aftermarket header) and the butterfly screws in the intake manifold, neither of these is a big deal and it is definitely worth the buy, pm me for any more details

you could always swap engines, then you wouldnt have to worry about teh shitty qr25 and its ecu.....lol

you could always swap engines, then you wouldnt have to worry about teh shitty qr25 and its ecu.....lol

I like the qr25. I think it's a pretty solid engine and it's pretty beefy for a 4 cylinder. I'd take it over a 1.8 any day. We don't all have the money to do the 3.5 swap. And you have to look at the fact that the stock spec is the quickest non forced induction 4 cylinder compact besides rsx... I think? lol. After all, the engine on my spec is the only thing that hasn't fallen apart.

the qr25 puts out plenty of power, but its not known for reliability as just about everyone in the b15 community knows, i love the engine, but the potential for problems has got me a little worried, kinda wish i had the cash for the vq swap.....lol

the qr25 puts out plenty of power, but its not known for reliability as just about everyone in the b15 community knows, i love the engine, but the potential for problems has got me a little worried, kinda wish i had the cash for the vq swap.....lol

What kind of problems does it have? How concerned should I be to go WOT at 65k miles?

How concerned should I be to go WOT at 65k miles?


If you havent loctited your butterfly screws by now id be pretty scared to go WOT :grinno:

If you havent loctited your butterfly screws by now id be pretty scared to go WOT :grinno:

Where are they? Easy to get to?

in between the intake manifold and block, pretty easy fix

in between the intake manifold and block, pretty easy fix
I hate to bother you but is there anyway you could elaborate a little for someone who doesn't know shit about cars?

hahaha no bother, you have to disconnect the battery, unplug all of your sensors that attach to the intake manifold, i think there are six bolts that hold it on, im not too positive, then you unscrew the butterfly screws that are on the secondary intake runner butterfly valves, you'll see what i mean if you pull it off, apply loctite to them and re-install the screws and torque to spec....doesnt rank too high on the difficulty meter

if you have any questions feel free to ask, also you may want to search b15sentra.net for "butterfly screw fix" and you should get a few full length writeups on it

you could always swap engines, then you wouldnt have to worry about teh shitty qr25 and its ecu.....lol

lol...you know the vq also has a similar butterfly valve that opens up the secondaries right? which means the problems with the qr could easily become your new engines problems...though I haven't heard much about 350z/g35 owners complaining about butterfly screws yet.

for the price of a vq swap...why not go awd...there's probly enough clearence where the exhaust is mounted for a driveshaft...

I owned a 04 spec v and i used to post on the V-board.i've never heard anything about faulty butterfly screws or ecu's. i had no problems with my car the entire time i owned it. as far as reliabilty that has to do with what things you are doing to that motor. i was sporting full bolt ons and consistantly running 14.5 before my cams and pulley. I think it's a reliable motor, but just like every motor it has it's limits. Most of this talk of it being unreliable comes from kids basically learning from there mistakes with novice turbo setups. Almost all of the stories i've heard of motors blowing wre motors that were under boost(turbo kit or nitrous) and the kid either boosted way to much or was using too high a jet. You can't label a motor unreliable cause you deside to make a stupid move and boost far more then even a built motor could handle. Remember this nissan uses block gaurds in there motors and the QR has fairly low compression. i would trust a qr over a hi strung non reinforced high compression honda engine. thats just my opinion. Do the research and make your own choice on if its relable to you or not.

Also, why would someone buy a new car just to swap the engine. if that were the case i would buy the crappy base level sentra. the spec v is what it is because of that qr25, it's handling, and its performance. I've disagreed before in other threads over the VG swap because to me it seems unpractical due to cost and effectiveness. many will argue yea my swaped sentra makes 250whp this and that but the painful truth is that only new VG's make numbers as high as 212whp. all the older engines that would be used in a swap, unless you wanna buy a new one for 5k, make 200whp and even less. you can easily make 180whp in a qr25 with just bolt ons. don't get me wrong i like the V6 aqnd its a great engine it just doesn't seem practical.

the vq doesnt fit in the base model......

how can it not fit? same car or is there something different because of the 1.8 engine? i don't see how it couldn't be put in there.

different cross member makes the mounts impossible, also differetnt axle lengths as well on the base model chassis, the body is the only thing the two share all of the rest of the stuff is diffferent

someone should come out with a swap kit to make the engine fit. to me that would be the best way to go. cheap base model with the VG. i bet the base model is lighter then a spec v cause you don't have all the electric stuff. i dunno why but i would hate to take the engine out of any new car.

a kit is offered by forced induction racing, mounts, custom passenger axle, wiring instructions, all that good stuff

That's cool, Cause a base model weighs over 200lbs less than the Spec.

take my 250 pound ass out of the spec and youre even! hahahahah

Haha, well my 130lb ass must be why I have such a damn good street racing record.

not only do you easily shave off two tenths at the track you also save a bundle of cash on the base model. i just realized that for the price of a spec v you can have a base sentra with a 3.5. that would sure give a lot of civic swaps a kick in the ass. best motor you can swap into a newer civic is the 200 hp k20.

Yup, you could get a 2000 Sentra XE for like 5g's. Hahah, what a hilarious car to go street racing in! You'd have to invest in a video camera to capture all of those "wtf" faces.

i have that same face when i see cars running 18second times at my track lol theres a group of ppl that are just dirt slow. theres a civic with a huge wing that runs 18's and theres a bunch of trucks and crap. although one time i almost got beat by a z71 in my old z24 cavy. it's kinda funny how many cars i've owned that i raced at that track.

2000 z24: AEM short ram,RSM inatke manifold and 62mm TB, AEM alternator pulley, Magna flow exhaust. 15.3@91mph

1999 Mustang Cobra: BBK under drive pulley, Flowmaster catback,4:10 gears. 13.3@105mph

2004 Spec V: Hotshotheader, removed balance shaft, AEM cold air. 14.59@95mph

1991 Firebird Formula: completely stock with 110k miles. throwing codes and running on 7 cylinders. 15.1@95mph

that k20 can be built to rev to 10k rpm and produce 280 hp NA for cheap though......read this write up in one of these mags at the tire dealer, shit was hardcore

yea i'm familiar with it. i know a kid that has one with full bolt ons including cams and a tune. i dunno about cheap though. cheap can meen different things to different ppl though. i bet you can get the 3.5 cheaper then the k20a and the 3.5 has way more torque and more horsepower. this would make for a great magazine camparison base sentra vs. base civic both swapped. i bet the civic would handle better but i bet the sentra would run the quarter faster. now we just need someone to build these cars lol

the writeup i saw was for custom pistons and rods, new crank milled for the h22 crank bearing, port and polished heads, new cams, and a sleeved block, the ECU was reflashed by hondata to take advantage of everything, the thing was bad, had a 10k redline......i think the 3.5 would prolly still get it in a drag but its impressive nonetheless

Haha, I don't think the 3.5 could take a motor like that unless it was also seriously modified. Nismo seems to easily make the VQ35 rev to 8000rpm tho, which is impressive for a motor with such an even bore/stroke ratio.

Plus, I'll bet the Spec could give any civic a run for it's money in the handling department. Probably not the base, tho.

redline really has nothing to do with it. plus from what your saying they had to do to get that 280 that motor is prety much maxed out and reached its NA limit. the 3.5 is a much bigger engine with much bigger displacment. na for na the 3.5 will make way more power. on a road coarse and drag race the 3.5 will be better because in both you need low torque to get out of the whole. if your comming out of a tight slow corner you can't wait around for v-tec to kick in half way through the rpm range to start making power. a spec v would most deffinatly hand a civic its ass in the handling department. it's too bad the new 06 civic is so heavy. it weighs as much as an rsx which is why its just as fast. i was hoping it would be lighter and out perform the rsx s.

i know the 3.5 would take it.....im just saying there are some amazing things that can be done to that engine.......if the low comp pistons were used and a turbo was added you would have a beast after first gear was out

LESS torque would be an advantage to FWD cars when track racing. Torque would overpower the wheels when exiting a corner. HP would not. Plus, any driver who knows what their doing wouldn't have to "wait for vtec to kick in". You keep the engine in the higher rpms the whole time you race. The engine should never be out of the VTEC range.

Also, the redline has more to do with it than you think. If one motor revs to 6700rpm and exits 1st at 35mph, and the other to 10,000rpm, you can put a MUCH smaller final drive in the car with the higher redline to match the 35mph 1st gear. This will make the car feel hundreds of pounds lighter to the engine. I'd have to say, the K20 is a work of art and easily the best motor Honda has ever made. But I'd still rather rock a Spec with the VQ. Torque is more fun on the street.

your right too much torque isn't great. but in some tight coarses where in some turns you need to come to almost a complete stop to handle you can't really keep a motor in v-tec. theres gonna be a track out there where your not gonna be able to make up for the lack of torque just with good driving.

Maybe, but I've never seen a turn on a race track that you have to take at less than 20mph.

20mph in 1st gear = VTEC!! yeeah!

autocross........but then again turbo motors and vtec style motors get pwned at it anyways.....it takes a hell of a driver to keep the turbo spooled up in a vw golf, and civics get crushed all day.....the spec is one of the best in its class along with the miata there are some races where you cant help but fall out of the power band.....it takes a good driver to do well in that type of enironment

True, I've seen an N/A sr20de 200sx stomp a turbo GS-R in autocross. Tein coilovers help too!

torque for teh win!!!!!

thats why i gotta race my 240 this spring :p
actually im thinking of selling it and i have my eye on a FC3s rx7.

ka powered? then you got you some torque

not to say hondas suck, but they normally do well on circuit tracks. in fact almost every japanese race video you'll see is on a big track will wide turns. thinking about it now the technology in some aspects really isn't for racing. just like nissan, honda has the intake technology to even out power with the butterflys, but cam timing and ignition timing changes are for economy. in a race car you wanna eliminate that stuff and go for all out power with max ignition and cam timing.

yeah vtec and cvtc are designed for street vehicles for an added measure of performance..... teh qr would be pretty bad with a new set of internals and a 10k redline too........

10k redline is like impossible with that motor. shoot its hard in most motors. the stroke is too great. in the moded race sentra the use a beefed up QR and that thing redlines at 7500rpm. and think of it its a rcae car they rebuild motors every race lol

Yeah, the QRs stroke speed and distance is already far too great to rev much higher than 7000rpm.

Also, having vtec "off" actually INCREASES low-end power and torque. I forgot why. If it was better to have it on all the time, Hondata and all those ECU modding programs would have vtec engage at 0 rpm. And if you look at any real Honda tuner's car, they never have vtec engaged throughout the whole powerband.

destroke teh qr to 2.3 litres and 10k isnt too far off......need a custom exhaust/ intake manifold designed for higher flow rates and custom rod piston cam and valve spring combo and some P&P and youre set.....hard but not impossible

oh and you have to underdrive teh water pump