Nissan Forum banner
1 - 7 of 7 Posts
G

·
Discussion Starter · #1 ·
Does the new Spec V engine kick like vtec because it does have variable valve timing right? I heard it doesnt from someone else.
Does the engine adapt good to turboes, supercahrger or nitrous?
Im trying to get all the info from a tuners point to see if i really want one.
peace
 
G

·
Discussion Starter · #2 ·
The QR25DE in the Spec V has variable valve timing, but NOT variable cam profiles like Honda's VTEC or Nissan's NEO-VVL.

So no, it does NOT behave at all like VTEC. Instead the QR25DE behaves like much of its Nissan brethen, a nice fat midrange with power falling by as much as 30% from the power peak at redline.
 

·
Registered
Joined
·
172 Posts
milla

what the Qr25 does is it advances or retards the cam itself constantly, through the entire rpm range. thus it is able to make alot more low end torque and top end hp. so there isnt a switch over point like the vtechs. honestly nissans variable cam timming is a better way to go, expensive to fix if it breaks but still better.

add this with the variable intake runner system with a really large engine and WOW impressive. so no it does not kick like a vtech motor does. its changes are less subtle but more efective for the simple face they are based on rpm, car speed, and throttle position. as where vtech is based on just rpm, thus why they have a controller to adjust the point of switch-over. the qr25 will not need a device like this but instead changes can be made in the ecu mapping to make better use of the qr25's cam timming advantage over the vtechs...

also the top end power doesnt fall off much at all it makes its peak hp at 6000 and torque at 4400. this is duew to the two main systems at work on this motor. the variable cam timing and variable intake system to smooth out the power band so the car pulls hard through the entire rpm range.

there are some rumors of a couple people putting turbos on this motor but no one on here that i know of. area 51 has a supercharger in testing for it, when it will be available is anyones guess. there is a company or guy (cant remember) who has a turbo kit out for the qr25 but i dont know how reliable it is and it runs 5K. it will handle nos but from what i understand no more than a 50 shot though.

nismo has been testing turbos on these engines, so far they keep blowing the piss out of them. so who knows when or if nosmo will put out a kit.

hope this helps
 

·
Registered
Joined
·
25 Posts
yes there is a noticeable point (5100 rpm) when the second intake kicks in. Most mistake this for vtec, which it is not. Get a cai and the noise will let everyone within a mile know your out there:)

Been just one year w/ the qr25. there is no reason for companies to develop for the qr compared to a rsx type s. Be lucky for what we do have.

Jeff
That's the price we pay for being nissandriven:D
 
G

·
Discussion Starter · #5 ·
red SE-R said:
milla

what the Qr25 does is it advances or retards the cam itself constantly, through the entire rpm range. thus it is able to make alot more low end torque and top end hp. so there isnt a switch over point like the vtechs. honestly nissans variable cam timming is a better way to go, expensive to fix if it breaks but still better.

add this with the variable intake runner system with a really large engine and WOW impressive. so no it does not kick like a vtech motor does. its changes are less subtle but more efective for the simple face they are based on rpm, car speed, and throttle position. as where vtech is based on just rpm, thus why they have a controller to adjust the point of switch-over. the qr25 will not need a device like this but instead changes can be made in the ecu mapping to make better use of the qr25's cam timming advantage over the vtechs...

also the top end power doesnt fall off much at all it makes its peak hp at 6000 and torque at 4400. this is duew to the two main systems at work on this motor. the variable cam timing and variable intake system to smooth out the power band so the car pulls hard through the entire rpm range.

there are some rumors of a couple people putting turbos on this motor but no one on here that i know of. area 51 has a supercharger in testing for it, when it will be available is anyones guess. there is a company or guy (cant remember) who has a turbo kit out for the qr25 but i dont know how reliable it is and it runs 5K. it will handle nos but from what i understand no more than a 50 shot though.

nismo has been testing turbos on these engines, so far they keep blowing the piss out of them. so who knows when or if nosmo will put out a kit.

hope this helps
I've been running a NX 75 shot for a few weeks now and haven't had any problems yet *crosses fingers*. I hope to break into the 12's as soon as my new tires come in.
 
G

·
Discussion Starter · #7 ·
Not Really

They aren't blowing the piss out of them. They are blowing out the main bearings. The engine still runs, it just makes a lot of noise. They don't sieze or anything.
 
1 - 7 of 7 Posts
Top