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Living up Boost
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I just read an interesting article about the qr25de on scc's website...here is the link:

http://www.sportcompactcarweb.com/archives/tech/tech02_0401.shtml

The article talks about the positive and negative aspects of this motor compared to the sr20 and ka24. Anyway, all in all it seems that this motor is not as strong as the sr20 and will not handle vast amounts of power compred to the sr20 mainly because it is an open deck design along with other reasons...good read.

-saaby

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Red 99 SE with: CAI, KYB AGX/Ground Control 350 in/lb front 300 in/lb rear, Stillen Front STB, Redline MT90, ES Motor Mounts (4-set), Timing changed to 15 degrees
 

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Stuck on an island
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thats a bummer

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92 NX2000, kyb agx, intrax springs, jwt pop,
3a Racing muffler with bonzi tip,
17 " mille miglia mm 112, Yokohama avid h4
ACT clutch on order
 

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this was taken from an article i read:
The standard SE-R is an import tuner’s dream,” said Kirrane. “We’ve given them the best possible combination of parts and performance, ready for their enhancements.”
“The Sentra SE-R Spec V is the extreme model – almost track-ready right from the dealership floor,” says Kirrane. “Both SE-Rs indicate the future direction of Nissan’s sedans. It’s a spirited one, to say the least.”
nissan is fully aware of the following it has with the SE-R. i doubt that they would deny the owners an opportunity to continue this legacy. the SCC article even stated that there's approx. 20hp tied in the exhaust. how many sentras do you know of that have ONLY an aftermarket exhaust and almost 200hp? how much money would be spent getting a N/A SR20DE to those specs?
 
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Well, I don't really like the design of the QR25DE from the tuners stand point. The ignition isn't adjustable, returnless fuel rail, so no fuel pressure regulator. The displacement is already maxed out for a 4-cyl. at 2.5. The open deck design is a bad. Never liked the idea of direct-acting valvetrain. The whole drive-by-wire throttle SCARES me, can you say possible maintenance nightmare in the future. On top of all that, the design is weaker than the SR20. I'd rather have the 2.0 VE or VE-T than a 2.5.
 

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You like that, dontchya?
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I just wished they would have thrown in the SR20VE. Too bad that engine is like $5 G's or else I would think about dropping that into my SE-R.

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Antonio Garcia
91 SE-R w/ lots of stuff
Bay Area, CA
 
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*Shrug*

Name me any one of the next generation motors which will be easy to tune. Times are a' changing, and all the automakers are changing with the times. Each designing their new motors to meet ever increasing emissions regulations and therefore becoming less tuner friendly.

Remember when fuel-injection systems first started showing up? Remember how everyone cried that it would be the end of being able to tune cars? You can relate the situation of that preiod in time to what's going on today. For the past 20 years we've been perfecting fuel-injection, now we're starting on the road to perfecting efficiency and lessening polutants produced.

Personaly I'm optmistic about the QR25DE. The aftermarket support will no doubt be just as large as the SR20DE when you realize this motor will be the same one found in 80% of the new sporty Altimas. It produces excellent torquey power right out of the box and will offer two and a half liters to play with. Here's some comments that were posted by Alex over at club Si regarding the motor:

<font face="Verdana, Arial" size="2">Bad points:

1) To get hydrocarbon emissions down, the QR has very little crevace volume. this means thin ring lands. This means cracked ring lands under the influence of a lot of boost.

2) The QR25 has a poor rod-length to stroke ratio (somewhere in the low 1.5 range, I think, according to the information I saw, which conflicts with SCC's info, but which I have more faith in, since it came direct from Nissan).

3) Bucket-type valve train. This will put a limit on how radical you can get with cams. Since the SR likes big cams so much (+35 whp, anyone??), this hurts a bit.

4) ~6500 (maybe less!) stock rev limiter.

5) New ECU logic with Drive By Wire throttle that will take a while to figure out.

Pros:

1) The stock motor is designed to rev to 7500 RPM with no problems (I know, weak by Honda standards, but still not bad).

2) Intake and exhaust ports are pretty well done (maybe not as good as the SR, but pretty good).

3) Stock valve springs are very soft, and stock cams are small. A lot of performance potential was left on the table here.

4) Displacement displacement displacement.

5) Split-case block should prove to be *extremely* strong structurally once a few of the weaknesses are fixed (aftermarket pistons, rods, and a 'block guard')

6) Forged crank. You know Nissan loves ya!


The motor will be different to mod, and maybe a little more expensive. But I'm not sure it will prove to be any worse. Everyone's thinking "turbo", but I think the QR will have a lot of all-motor potential.

I've heard 4G63's get as much as 15 hp by removing the balance shafts. The balance shafts in the QR look very easy to get out (a certain well-known Nissan tuner has a JDM service manual for the QR25 that I've had a chance to look through). Hey, open exhaust, remove the balance shafts, CAI, some cams, springs, and ECU, you're starting to talk some pretty serious all motor power.</font>
*Shrug*

EDIT: to give Alex credit.

[This message has been edited by Classic SE-R (edited 08-01-2001).]
 

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El Chingon
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WhiteSER is Alex (which needs to e-mail me, btw.. Alex.. where are you..). Rob is ClassicSE-R on here and over there.

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David
'98 Super Black SE w/stuff
 
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I feel that the new SE-R will be just what the older SE-Rs are now. They're not the fastest but they damn sure are fun to drive.
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Just like some of you, I do not understand why Nissan did not bring the SR20VE. It costs less than developing a new engine line. It can pass smog due to the lower cam lobes being less aggressive. Hell Honda gets its VTEC engines to pass smog, why can't Nissan. They can use the SR20VE in the G20 (keep it as an entry luxury vehicle along the G35), in the entry Altima (along the SE) and in the SE-R.

I think Nissan wanted the QR engine to use it in trucks as well as cars. I will not be surprised if the engine does not make it to the entry Frontier truck.

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Naji Dahi, aka Red Mist
Fast 1998 SE-R Last of the SE-Rs
Slow 1996 G20 (AGXs/G20t springs, K&N drop in filter)
 
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