Jump to content
SAU Community

Rev Limit On Rb25det?

dan22

By dan22,
in Engines & Forced Induction

 Share

Recommended Posts

hijaked Collaborator

hijaked

Posted
Posted

This moring driving to skool.

i wanted to test mine out. got her up to 8100rpm in seccond and then it cut out completely.

mind you this is with stock everything, except filter, cooler n xhaust.

however my cars been messed with, ive had it up to 220+kmph.

however i drive my other mates car (r33) and i had got confussed because i didnt know why the power cut out at 7ish, wel now i know!

cheers

Munna Rising Star

Munna

Posted
Posted
You havent lived till youve heard a '25 @ 9000+ RPM :)

Id love to hear that @ 7000rpm the engine doesnt sound stressed at all it feels like it could rev to 9000rpm without a problem although im sure it wouldnt last long if you did. The RB25 is Such a smooth engine especially when your previous car was a V6 VN commodore.

GKTECH Mentor

GKTECH

Posted
Posted
Id love to hear that @ 7000rpm the engine doesnt sound stressed at all it feels like it could rev to 9000rpm without a problem although im sure it wouldnt last long if you did. The RB25 is Such a smooth engine especially when your previous car was a V6 VN commodore.

Yeah the sound on the RB25 is unbelievable!! Sounds great at 7,000rpm's with a screamer pipe and no cat.. lol

I could not believe how smooth it is for a 2.5ltr. Very smooth when your previous car was a 60kw 1.6ltr nissan exa.. lol

Greg

R31Nismoid Grand Master

R31Nismoid

Posted
Posted
also saying that if u shif up you will end up going faster isnt as ture as it sounds. the fact of the matter if u shift at the limiter would will be futher along in the next gear.

not correct, if you shift @ the end of the power band rather than keep going another... 500-800rpm then the car will be faster.

changing from 2-3rd say, you aint going to loose 4000rpm.

The car shifting @ the end of thier power band will be faster.

EG. Car stops making power @ 6500rpm, and you rev to 7000rpm where the last 500 is a struggle for the car and the turbo and 6500 shifted car will be faster.

look in the drag section on the forums. Been covered before

yeah blocked da plum back tube....n tried adjustin da bov as well....at 3000 to 4000 rev if i shift from 1st 2 2nd....da rev jus drops below 1000rev and engine cuts of....it seems like fuel is cut out....i wuz wonderin whether its cus da hks bov is exactly where the stock bov used ta be...

Put the stock on back on. Problem solved

Its a common problem. Look in the sticky @ the top of this section.

It contains the answers if you dont wanna search

siksII Grand Master

siksII

Posted
Posted
My r33 s1 rb25det, has a rev limiter of 7100rpm. secondly i dont see how if tacho read 7000/7100 is only reving to 6700-6800  :angry:  :)

also saying that if u shif up you will end up going faster isnt as ture as it sounds. the fact of the matter if u shift at the limiter would will be futher along in the next gear. i have drag many mid mod r33, (exhuast,fmic,airfilter the normal) and i have a Rb20 turbo on my car making farless as quick as a normal r33 would be with my mods and i can beat, keep up with them due to them shortshifting and me pushing all the way to the limiter (when i say shortshifting i mean they shift around 5500,6000rpm)

just my 2cents

What r31nismoid said, if you shift at the end of your powerband(which i cant ell u wont be the redline if u have the stock turbo) u will be faster. also im assuming all your races have been on the street, and therefore mean nothing, go to the dragstrip and try it out, i have ;)

Also i should have explained about the revving thing. the tacho is not correct. true engine revs can be seen on the powerfc handcontroller, if you have one, and this is what i am talking about.

the faster the car is revving up the more incorrect it seems, ie in lower gears the tacho does not keep up with the revs up the top, which is why when is shows 7000 it is in reality lower, which is why u can rev it into the red zone and it looks like u are revving at like 7300 or something.

ctjet Grand Master

ctjet

Posted
Posted

on my 33 it came from japan without a rev limiter....i discovered this after buying it and driving off down the road, took a corner sideways and looked at the tacho and saying 'shit it's at 8!'

I used to take it to 8k rpm quite frequently, and on flat shifts sometimes it would tap 9k rpm for a split second.

With all this in mind i wouldnt' recommend taking stock rb25det over 7k rpm! its not a rotor!!!

Col-GTSX Grand Master

Col-GTSX

Posted
Posted (edited)

My d spec pfc came out of the box set to 6900rpm.... So i left it alone....

Once the gt30 goes on i will lift it to 7500rpm... but my motor has only done 4000kms so im going easy to start with....

Edited by Col-GTSX
R31Nismoid Grand Master

R31Nismoid

Posted
Posted
on my 33 it came from japan without a rev limiter....i discovered this after buying it and driving off down the road, took a corner sideways and looked at the tacho and saying 'shit it's at 8!'

I used to take it to 8k rpm quite frequently, and on flat shifts sometimes it would tap 9k rpm for a split second.

With all this in mind i wouldnt' recommend taking stock rb25det over 7k rpm! its not a rotor!!!

but that only means the ECU wasnt stock

TTT Grand Master

TTT

Posted
Posted

I would have thought that if you look at a dyno graph that shows torque curve, and found the spot where the peak torque hits, then you would want to be at that rev in the next gear you select.

so lets say redline is 7K.

dyno shows that max torque is at 4500rpm.

and lets say you the revs drop 1500rpm between 2nd and 3rd gear.

in this (obviously incorrect) example, you would want to change from 2nd to 3rd at 6000rpm.

does that make sense to anyone else?

33SOM Experienced

33SOM

Posted
Posted
The default Power FC rev limit for an RB25DET is 7,500 rpm, that's real RPM as measured by the ECU.  Not necessarily the RPM displayed on the tacho.

:) cheers :)

My power fcs factory setting is 6900???

Craved Grand Master

Craved

Posted
Posted

At what rev range do the hydrolic lifters start pumping up though? this would be the main issue regarding revving high before the rods etc start bending.

ive got a set of GTR rods at home , thinking about whether solid lifters are required to have the 25 revving to 8000rpm as limit with the bigger 3040 turbo and cams!

  • 1 month later...
PHaT MR30 Grand Master

PHaT MR30

Posted
Posted

can someone confirm if the rev limiter on RB25's is a fuel cut or ign cut???

Ive just sent my ecu away to have a few things modified on it and asked for it to be changed to an ign cut!

i want it to be able to sit on the limiter not just die in the arse (not sure which one does which), please let me know so i can call up and cancel it if necessary!!!

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • TurboTapin
      boost source Size Garrett gt28 gen2

      By TurboTapin · Posted

      You just need to remove the compressor housing, not the entire turbo. I would not be drilling and tapping anything with the housing still on anyways. 
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      So, I put my boat on a boat. First of all, I'm going to come out and say it. Why is Tasmania not considered a holy goal, an apex that all road-legal modified cars go to, to experience? This place is an absolute wonderland of titanic proportions. If people are already getting club runs for once in a lifetime 30 person cruises to Tassy then I've never seemed to see it. It is like someone replaced the entire place with an idyllic wonderland for cars, and all of the people living there with paid actors who are kind, humble, and friendly. Dear god. After doing a lap of almost all of the place I've found that it's a great way to find out all of the little things that the car isn't doing quite right and a great way to figure it all out. All in all, I drove for 4 hours a day for a week and nothing broke. I didn't even need to open the engine bay. This is by all means a great success, but it has left me with a list of things to potentially address. I also now have a 3D printed wheel fitment tool which annoyingly hasn't got any threads in it to actually assemble it. I might be able to tape it together to check the sizing I actually want to use, but it'll likely involving pulling the shocks out to properly measure travel at least at the front, and probably raise the car while I'm at it, at least in the rear. I scraped on quite a few things and I'm not sure how else to go about it. I was taking anything with a bump at what felt like 89 degree angles. And address those 10 other tasks. And wash the car. God damn it is dirty. And somehow, the weather was perfect the entire time - And because I was on the top of Mt Wellington it turns out it was very much about to freeze up there. I did something I typically never do and took some photos up there in what must have been -10 and the foggy felt like suspended ice, rather than mere fog. If you own a car in Australia, you owe it to yourself to do it.
    • QB6SAGR
      Battle of the broken skylines

      By QB6SAGR · Posted

      Damn that was hilarious, and a bit embarrassing for skylines in general 😂 vintage car life ey. That R33 really stomped. Pretty entertaining stuff
    • cosline
      R32 gtr transmission strength, billet plate

      By cosline · Posted

      Hi, I have a r32 gtr transmission. Does any of you guys have an idea how much power it will hold with the billet center plate and stock gearset? At what power level and use did yours brake with or without billet plate? Thanks, Oystein Lovik
    • Rezz
      Spotted on the street....

      By Rezz · Posted

      Saw this replica police car based on a Mitsubishi Starion XX parked next to a 'police box' (it's literally a box) in Hirohata, Himeji City in Hyogo prefecture the other day. It's owned by Morii-san who is a local Mitsubishi Starion enthusiast. According to a local radio station blog post, he always wanted to make a police car himself based on ones he saw in his favourite Manga comics.  As it's illegal to modify a car to look like a police car and drive on the road, Morii-san tried many times to get permission from Aboshi police station headquarters nearby. They refused initially by after they got tired of that they granted him permission. However, the car can only be displayed on private property and obviously can't be registered as long as the police livery is present. The car was completed at a cost of 1.5 million yen (US$ 10,000) in addition to the car cost. A location was chosen outside Hirohata Police box where the car can easily been seen from the street. Morii-san has two other Starion road cars, both widebody GSR-VRs.
×
×
  • Create New...