Jump to content
SAU Community

Recommended Posts

Is it safe to take the redline up to 7500rpm or so? With stock internals, and a PowerFC. I've got an adjustable exhaust cam gear so that should help with any breathing problems, but I'm also worried about affecting the longevity of the engine.

Link to comment
https://www.sau.com.au/forums/topic/49107-increasing-redline-on-rb25/
Share on other sites

  • Replies 156
  • Created
  • Last Reply

Top Posters In This Topic

Long term = completes a track session

Standard internals = un-opened motor

:D

:cheers: always the realist ;)

I took mine to 7500rpm no drams for over 12 months.

Motor died - but that wasnt due to revs, just a few too many psi snuck in one night and caused it to ping.

So 7500 all the way.

Although, i found with stock cams, the car didnt have any go after about 7300 at that was still pushing it.

Also due to many other factors aswell im sure, like ECU and all sorts of other things

There is no point at all to increasing the redline, You will lose so much power after 6500RPM that its not even worth it. It may seem like its still pulling but on the dyno it shows that the HP drops like hell.

Although, i found with stock cams, the car didnt have any go after about 7300 at that was still pushing it.  

Also due to many other factors aswell im sure, like ECU and all sorts of other things

I'm only considering it because I've got an exhaust cam wheel, and will be running 15 psi after the tune. I used to run 15psi with the factory ECU, but the PowerFC at the same boost maxes out my injectors and AFM. So I'm running at 11psi until I get it tuned.

Anyway I'll see what the mechanic has to say when I take the car in. At least now I know I have some room to experiment.

I've run my Skyline up to 7500 for over 9 months now, I have had no drama's with this setting, however yes in Dyno runs I have found that there is no real power increase around the 6500 mark. I am running a Haltech E6K I think with a Stock engine and turbo along with ARE intercooler. I pulled about 187kw out of the rear wells and about 1350nm of Torque which I thought was quite high but this has been verified by two different dyno stations.. Also running the stock turbo at 14psi with a 3" Dump running into a Apexi 3.75 cat back exhaust.. (yes it scraps everywhere). I did a recent check and found compression to be around 135-150 over all 6 cylinders.. I have been told this is about right for a skyline, I dunno? shrug :P I think that a GT2540 would be great to upgrade to with new 700+cc injectors with fuel rail and pump to be upgraded as well. What ya think? do you think a new Cam gears would be wise too?

Aridyne

The exhaust camwheel retarded 3 or 4 degrees is good for enhanced torque low and midrange. In all our dyno runs stock and modified power tended to drop off fairly sharply over 7000. In the early days we hit 8200 on a regular basis.....but not anymore. After 3 years of street/drag/track the engine still doesn't use any oil between 5K changes so I guess the revs didn't hurt it any. When you get it tuned and see your power curve then you can decide on your rev limit

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Had I known the diff between R32 and R33 suspension I would have R33 suspension. That ship has sailed so I'm doing my best to replicate a drop spindle without spending $4k on a Billet one.
    • OEM suspension starts to bind as soon as the car gets away from stock height. I locked in the caster and camber before cutting off the kingpin. I then let the upright down in a natural (unbound) state before re-attaching it. Now it moves freely in bump and droop relative to the new ride height. My plan is to add GKTech arms before the car is finished so I can dial camber and caster further. It will be fine. This isn't rocket science. Caster looks good, camber is good, upper arm doesn't cause crazy gain and it is now closer to the stock angle and bump steer checks out. Send it.
    • Pay careful attention to the kinematics of that upper arm. The bloody things don't work properly even on a normal stock height R32. Nissan really screwed the pooch on that one. The fixes have included changing the hole locations on the bracket to change the angle of the inner pivot (which was fairly successful but usually makes it impossible to install or remove the arm without unbolting the bracket from the tower, which sucks) and various swivelling upper arm designs. ALL the swivelling upper arm designs that look like a capital I (with serifs) suck. All of them. Some of them are in fact terribly unsafe. Even the best one of them (the old UAS design) shat itself in short order on my car. The only upper arm that works as advertised and is pretty safe is the GKTech one. But it is high maintenance on a street car. I'm guessing that a 600HP car as (stupidly, IMO) low as you are going is not going to be a regular driver. So the maintenance issues on suspension parts are probably not going to be a problem. But you really must make sure that however your fairly drastically modded suspension ends up, that the upper arms swing through an arc that wants to keep the inner and outer bolts parallel. If the outer end travels through an arc that makes that end's bolt want to skew away from parallel with the inner bolt, you will build up enormous binding and compressing forces in the bushes, chew them out and hate life. The suspension compliance can actually be dominated by the bush binding, not the spring rate! It may be the case that even something like the GKTech arm won't work if your suspension kinematics become too weird, courtesy of all the cut and shut going on. Although you at least say there's no binding now, so maybe you're OK. Seeing as you're in the build phase, you could consider using R33/4 type upper arms (either that actual arm, OEM or aftermarket) or any similar wishbone designed to suit your available space, so alleviate the silliness of the R32 design. Then you can locate your inner pivots to provide the correct kinematics (camber gain on compression, etc).
    • The frontend wouldn't go low enough because the coilover was max low and the upper control arm would collapse into itself and potentially bottom out in the strut tower. I made a brace and cut off the kingpin and then moved the upright down 1.25" and welded. i still have to finish but this gives an idea. Now I can have a normal 3.25" of shock travel and things aren't binding. I'm also dropping the lower arm and tie rod 1.25".
    • Motor and body mockup. Wheel fitment and ride height not set. Last pic shows front ride height after modifying the front uprights to make a 1.25" drop spindle.
×
×
  • Create New...