Thread: Sr20 vs qr25

Do you know how much more a vq35de weighs then a qr? What about after swapped and the battery is relocated to the trunk? (If you'd like to argue in terms of weight distribution.)
And saying "and i got vvl" Is just like a honda fanboy saying "I GOT VTEC SO I HAVE ADVANTAGE"
Oh shit? You have vvl?!
Aww. Qr has cvtc.


The only REAL reason that I personally think qr's blow at 300whp is because of improper tuning. Tuning usually done by ONLY safc2 (or another piggyback). Ive seen my share, if not more, of blown sr's from the same cause. Osiris has emerged as a reliable, easy, and efficient tuning solution. And there are people that make much more then 300 whp, daily the car, and it stands the test of time. Local guy ran a GT3071R on 16 psi and made 4xx whp, STOCK internals. Railed it like that for 3 months before he blew a STOCK 90k mile head gasket. He put a head gasket in it, sold the kit, and sold his car.

I personally have owned 2 b15's, the first was a qr, stock, then bolted, then turboed (fucking awesome). Never had a problem with the qr. Drove it from 27,000 to 90,000 (maybe the last 10k turboed), maintenanced myself.
I then got a new b15 shell, and started building a sr for it and will be completed shortly, mated to a spec-v 6 speed.

From a qr and several sr owner: The Qr is a great engine with a TON of potential (as seen from sqr's and other recent bolt on developments), but is still emerging as a "tuners" engine, and doesn't have the aftermarket support that an almost 20 year old engine like the sr has. I went to a sr because I am very familiar with them from 240's ive owned, and friends have had.

No the only real reason QR's blow at 300whp isnt just because of the tune. Its pure physics that those pencil rods can only take soo much before your asking for trouble.

Seen SR's blow at 300whp. Unlikely unless they developed rod knock and starved themselves of oil consequently launching the rod out the block. Proven facts are, that your more than likely to melt a piston from a bad tune then launch a rod out the block at 300whp even with a bad tune. lol. You get any slight detonation on a QR at that hp level, bye bye rod. No questions about it. It better be soo well tuned to keep that from happening because literally one ignition even slightly too soon is more than likely gonna bend and break the rod and send it flying. Seen it way too many times. Whereas on and SR, slight detonation, pff ok, heavy detonation, you might break a plug ground strap and at worse case crack a ring land and at ultimate case melt a hole in the side of the piston well well before you send the rod out the block. Then that can only be blamed on a bad tune or pushing a turbo beyond its limits.

This arguement can go on for days but your points of it blew the headgasket and he sold the setup and car are not helping the fact that it states it wasnt worth keeping it to try to make good power on. lol

And dont get me wrong, im all for seeing developement on nissans no matter the motor and I gave 2J the props they deserve for it.

Id like to see someone sleeve a QR, put an SR 86mm crank, make it a 2.2L and see what it can really do. The variable cam timing can make for some great power and with the SR crank and proper valvetrain you should have no issues reving to 9k and should be able to make some good power.

One of the key things I like about the QR is the bottom girdle/belly pan. Its a solid design, It just needs everything else beefy to go along with it. Dont know why they went soo solid on the girdle and mains but left the rest of the bottom end soo weak and fragile. It has potential though if someone would put some good money into one. Same potential as an SR20VE-T with the same money dumped into it? Unlikely. As the only stronger point of the QR block is that girdle/belly pan but dont know many SR's that have launched a crank out the block or had main bearing/journal issues. Ive yet to see one except for one that was ran out of oil. lol

True that the only problems I had with my sr is breaking the ring lands. Just lost compression on couple cylinders but the engine kept on going. Took it apart after tons of abuse the rod bearings were Perfect just normal wear. The only reason the rings lands Broke was cuz I didn't know I had a 10:1 motor. Motor didn't like 18psi on a 71R. SR'S are really good reliable motors. I got 265k miles on one my b13's and running strong!!

A more reasonable comparison 13 years between the first JDM SR20DE and first JDM QR20DE.

SR20DE 150 HP and 138 Lb ft Torque ( 86 x 86 ) 10 to 1 compression.

QR20DE 147 HP and 148 Lb Ft Torque ( 89 x 80.3 ) 9.9 to 1 compression.

QR20DD 150 HP diret injection

The QR20DE was replaced by the MR20DE and I figure the QR25DE is going to be on its way out soon. Thank god.


13 years of improvement. What a joke.

the QR is getting a superchaarger, at the very least, in the Altima hybrid.

It's not going anywhere.

2014 Nissan Altima Hybrid Tech Preview - Popular Mechanics

I'm over 100k, 70k under boost, all around 315whp and 300ft/lbs. Most of the motors that have blown were because of bad tuning and subsequent ring land failures.

The pistons will go before the rods go.

I read about seomthing like that a while back but was hoping it would not happen.

I would have been more accepting of a QR25DET with 270-300 HP. Turbos as we all know, are more tuner friendly as far as making HP and turbos also get better fuel economy.

Hopefully for the B16 guys they keep the sensors the same so it is an easy swap into the B16.

Nissan comes out with a better QR25DE with 200HP and it is a pain in the ass to put it in the B15 car. Nissan should have used their heads with that. Could have gotten some cars guys going to bring more suport to the QR.

Still hate the motor.

...

MR16DDT is to small

Need MR20DDT