Jump to content
SAU Community

Rb25 Slow From 5000rpm Onwards

islade

By islade,
in Engines & Forced Induction

 Share

Recommended Posts

islade Rising Star

islade

Posted
Posted

Hey guys, I have a 1993 R33 Skyline.

I recently had it converted to manual, at the same time, i had a full service (inc spark plugs), new timing belt and water pump (by NisPro).

The car has 3" catback exhaust, turbotech manual boost controller set at 10psi, VeePort BOV and a HKS mushroom air filter, stock ecu and smic.

When flooring it, the car seems to pick up nicely around 3-4000rpm, but once it gets around 5, the boost guage still reads 10psi, but the car seems to take noticeably longer to get to 7rpm than from 3 to 5rpm. I had a friend with a 32 drive it, and he confirmed, from 5000rpm i've got nothing!

The car isn't hesitating/stuttering/making funny noises, it just seems like it's n/a from 5000rpm onwards.

I'm wanting to work out what's wrong. Jez suggested it could be my coil packs. After reading a few threads on SAU about them, I think i'm going to try and find a working pair to test that theory, what else can i look at?

Thanks guys :laugh:

Isaac

Link to comment
https://www.sau.com.au/forums/topic/246451-rb25-slow-from-5000rpm-onwards/
Share on other sites
RB JET Apprentice

RB JET

Posted
Posted (edited)

I had the same problem in my 33. My ecu was richening a/f mixtures and retarding timing. Power FC and a good tune fixed me up, but if i were you id get it on the dyno and get the problem diagnosed that way. Itll save you a lot of money in the long run.

Edited by RB JET
nuclear_skyline Mentor

nuclear_skyline

Posted
Posted

very well could be the bad rich and retard thing... too much air coming in so the stock ecu craps itself - dumps heaps of fuel in and pulls all the timing...

Pal Veteran

Pal

Posted
Posted

i done a manual conversion 3 years ago and have only just changed my ecu to a manual one(had SAFC2 fitted). it done nothing to the power when flooring it, only cleaned up idling and cruising. you need to get yourself at minimum a SAFC2 and get it tuned.

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

    • MBS206
      Shoota's R33 GT-R RB30/26

      By MBS206 · Posted

      It only looks tidy, as most of the stuff that was on the whole back wall, is now in the trailer to go to the tip, or has been shoved in my 2.2x2.4m "Spare parts room", and now I can't get to anything in there Ha ha ha I could definitely do with a bit more space, but I'd just end up with your problems I'm going to enclose the car port beside the garage, and move a lot of stuff into it I think. OR... It will be setup as a fabrication area, and the main garage will have parts storage in it. I'm not sure yet... Need some pictures of that big shed you've got with the bikes and Skyline in
    • PranK
      My BMW 335i

      By PranK · Posted

      No. I think it's gone. 😭 I think you can get body coloured ones on eBay so I think I'll get one of those... Or just hang a red ribbon from the hole and whack a TOW sticker next to it.
    • Milkmun
      Cleaning my wheels 😍

      By Milkmun · Posted

      Can't say I've had a bad experience with one on my car, then again it only gets washed once or twice a year... The wheels on the other hand, get a good spray often due to my shitty dusty pads.
    • Shoota_77
      Shoota's R33 GT-R RB30/26

      By Shoota_77 · Posted

      @MBS206 thats pretty neat and tidy to me!  I'll get a photo of mine when I'm out there next. It might require multiple photos to understand the scale of the atrocities though... In total I have 4 sheds of varying sizes and layouts. Main shed is 14x8, second shed is 3x8, third shed is 11x2.5, fourth shed is around 6x4.  All are pretty much full.   The main goal of my cleaning tsunami is to make the main shed predominantly car and motorbikes only. Second shed is my metal fab room (2 x bench grinders, drill press, bench belt sander, metal band saw, scrap metal storage and some of my garden tools.  3rd shed is more bigger garden stuff, storage for engine crane, jack stands, concrete grinder, concrete mixer, air compressor lives there, and it now has two 2mx2m pallet racking shelves with itemised boxes holding building stuff, electrical stuff, plumbing stuff, etc, etc.  The 4th shed is Ryobi electric ride on mower, mini boom sprayer, ancient Kubota tractor, more garden stuff!  I have got a lot of shit....  Then there's the pool house (8mx4m) and the pool pump shed (4mx4m).  I built all of the sheds over the 11 years we've been here.  The main shed was a Ranbuild kit, the rest are all custom made to fit the areas available. Building the main shed taught me a LOT as I had no idea about building anything prior to that!  I've still got one more in me. It will be my man cave which I poured the extra concrete for way back when I poured the concrete for the main shed. The idea is the Skyline will be a centre piece of the main cave once (if...) it's finished.  I told my now 14 year old son yesterday that I will 100% drive him to his year 10 formal in 2 years. Still a long way off but at least I now have a date to work towards! 🤣
    • niZmO_Man
      Duncan's V37.......race car?

      By niZmO_Man · Posted

      Modern oils are amazing. Add tyres to that as well.
×
×
  • Create New...