B15 Sentra Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
2,871 Posts
Discussion Starter #1
1)The QR25DE valve springs are not up to the task to revving high.
2) the QR20DE revs high...
3)....
4) Profit!!

I mean...would the QR20 valve springs work in the QR25? They would prolly be cheaper than JWT valve springs, yes?
 

·
Boost Addict
Joined
·
3,414 Posts
pio!pio! said:
1)The QR25DE valve springs are not up to the task to revving high.
2) the QR20DE revs high...
3)....
4) Profit!!

I mean...would the QR20 valve springs work in the QR25? They would prolly be cheaper than JWT valve springs, yes?
its going to take more than valve springs to make the qr rev higher and still be safe.
 

·
Registered
Joined
·
1,404 Posts
david said:
yep keep searching grasshopper. here's a hint. Piston speed....
Seems like the limit would be 6900 with just valve springs and not doing anything else to the motor. (I searched!) I think the QR really only needs a slightly higher rev limit, not 7500 or something.
 

·
Registered
Joined
·
2,871 Posts
Discussion Starter #6
yeah i understand it's not the only thing to safely increase revs..i'm asking if they would be a cheaper alternative to the JWT valve springs in conjunction w/ the JWT cams
 

·
SER Mod Father
Joined
·
3,419 Posts
7000rpms is the max piston speed. 6900 leaves a little safety cushion. The piston rod combo JWT developed has a little shorter rod with higher wrist pin, which CHILLIN2 has, but we're looking at 6900 still in the interest of safety. The key to this is engine management. Stand alone is the option for now.
 

·
Registered
Joined
·
122 Posts
New rods and pistons, camshafts, springs, ecu. Then you can run up to 6900 no problem. The question is are you still going to see gains pass that rpm...
 

·
Boost Addict
Joined
·
3,414 Posts
craigsward said:
New rods and pistons, camshafts, springs, ecu. Then you can run up to 6900 no problem. The question is are you still going to see gains pass that rpm...
correct 6900 rpm would require new internals. I think 6500 rpm might be asking too much of the stock internals.
 

·
Casual Lurker
Joined
·
2,135 Posts
chickracer said:

Hello Miss Racer, why so much talk about Overhead Projectors in your sig. Get a DLP projector and be done ....lol...
 

·
Registered
Joined
·
773 Posts
^ haha good question... i think there might be gains in the upper rpms like to say 7,000- 7,500. only if cams are used because most cams dont add power, they shift the curve to make more top end. Or i could be high....?
 

·
Canyon junkie! ( ^o^) <3
Joined
·
4,332 Posts

·
///N Power
Joined
·
577 Posts
i dont understand this higher revving revolution.... I mean, why on earth would you want to rev higher when you really just want to get more power in the rpm band we already work with? isnt it all relative?

I wouldnt rev any higher or do any f/i on this engine after having seen the spindly stock rods. thats really small. they look like the CA20E rods in my 200sx. I am wondering why they would put rods like these in a 180lb/ft rating car. its almost like they want it to break... I guess you get what you pay for. those things must get weak over the years.


-jw
-------------------------------------------
Torque breaks stuff.
 
1 - 20 of 20 Posts
Top