Jump to content
SAU Community

Skyline vs LS1 vs Soarer dyno day 17th May

Martin Donnon

By Martin Donnon,
in South Australia

 Share

Recommended Posts

  • Replies 130
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

Martin Donnon Mentor

Martin Donnon

Posted
  • Author
Posted
Originally posted by whatsisname

I don't know the full details yet. I'll let you know when I do.

Reason I say this Matt is because AFAIK the Microtech doesnt have individual cylinder fuel trim control, hence 6 would be running the same pulsewidth as 5 and as 4 etc. etc. As for air distribution in an RB manifold? Generally 6 will receive LESS air than cyls 2 and 3, making it inherently richer. You will more than likely find that 6 has been running physically hotter than the other cylinders, due to the Skyline cooling system design, which has pushed it over the detonation threshold. Ie. it detonated to death, rather than 'leaned out'. I may well be wrong though.

whatsisname Grand Master

whatsisname

Posted
Posted

Yep your right mate, the LT12 doesn't have individual cyl control. What you've explained, re 6 running hotter & leading to failure, sounds quite feasible. I'll post up the exact findings when the motor is apart.

Freebaggin Proficient

Freebaggin

Posted
Posted

Could the cause be a high pressure drop across the factory fuel rail and therefore no. 6 injector gets less fuel pressure and may have pushed it over the safe AFR edge? I would say the harder you push the fuel pressure, the greater the pressure drop.

Martin, what ECUs has individual injector control? Have you seen high pressure drops across RB25 fuel rails?

I've seen on a number of tune shop designed items, the fuel feed line is in the centre of the rail, thus ensuring more even fuel delivery for each injector.

I will be thinking serously about a better fuel system when I bolt a bigger turbo on I think (as per Martin's HPI story some time back re RB25 injectors). Either straight fit SARD or new/better rail with whatever injector we come up with.

Sorry for hijacking thread, should be in Matt's rebuild thread!

Freebaggin Proficient

Freebaggin

Posted
Posted

Hang on guys, the problem with Whatsisname's motor was nothing to do with the Microtech.

I just asked, what other ECUs have individual injector control?

What if it did, how would you measure AFRs for each cylinder anyway?

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

    • Dose Pipe Sutututu
      NC MX5

      By Dose Pipe Sutututu · Posted

      Lamb roast on Saturday will be different 🥲
    • TurboTapin
      RB25DET with solid lifters - which cams ?

      By TurboTapin · Posted

      They are under bucket shims. Tomei provides a test shim kit and then any measurement of shim required. 
    • GTSBoy
      RB25DET with solid lifters - which cams ?

      By GTSBoy · Posted

      I always wondered how you were supposed to buy a set of 24 buckets and somehow magically have every single one of them yield exactly the desired clearance. I would have thought you'd need to assemble a cam with either 12 "sample" or "example" buckets of known top thickness (or a single such sample/example 12 times over!!) measure clearances at every valve, and then do the usual math to work out what the actual "shimness" of each bucket needed to be, before buying the required buckets to make up he thicknesses that you didn't have on hand.
    • TurboTapin
      RB25DET with solid lifters - which cams ?

      By TurboTapin · Posted

      I now seem to be limited in power due to my rev limit/hydraulic lifters in my built RB25. I'm looking into converting over to Tomei solid lifters. Question for anyone that has done the conversion. I was always under the impression that when using the Tomei solid lifter conversion, you would also require new valves (Longer or shorter stems, I can't remember which).  I don't know where I got this idea, as so far I see no mention of this in any of the Tomei documentation. It just states I need the Tomei solid buckets, solid lifter cams and upgraded springs. As my head is already built, all I would need is another set of 1000$ Kelford cams, 500$ buckets and about 4H hours of my time installing and I'm off to the races!?!? There's no way it's that simple, I must be missing something? 
    • TurboTapin
      Why am I hitting a power wall with my stroked RB25?

      By TurboTapin · Posted

      I couldn't agree more. I should have started from the get-go with a NEO or solid bucket conversion. I started looking into converting over to solid lifters yesterday. Now for some reason I was always under the impression that when using the Tomei solid lifter conversion, you would also require new valves (Longer or shorter stems, I can't remember which).  But I see no mention of this on any of the Tomei documentation. It just states that I need the Tomei solid buckets, solid lifter cams and upgraded springs. As my head is already built, all I would need is another set of 1000$ Kelford cams, 500$ buckets and about 4H hours of my time installing and I'm off to the races!?!? There's no way it's that simple, I must be missing something? 
×
×
  • Create New...