Jump to content
SAU Community

Single Throttle Body Vs 6 Itbs On Rb26Dett

Goved5

By Goved5,
in Engines & Forced Induction

 Share

Recommended Posts

Goved5 Apprentice

Goved5

Posted
Posted

A tuner wants to install a spitronics ecu, he suggested to install a single large throttle body on MY RB26DETT which currently has 6 ITBs, he also will do away with the MAFs,He is going to upgrade my turbos with steel shafts, he promised me between 350-400kw after he his complete. Will my throttle response be affected by going single Throttle body? Is this recommended?

GTSBoy Grand Master

GTSBoy

Posted
Posted

Yes throttle response will be (negatively) affected by doing that. It is hard to get any better throttle response than what you get from 6x ITB.

I wouldn't do it. If he needs a vacuum signal to run a MAP sensor, he could use the existing tapping points on the runners to get it.

KiwiRS4T Grand Master

KiwiRS4T

Posted
Posted

supposedly it's easier to tune with a single throttle body rather than the ITBs. RIPS here in nz uses a single for almost all of builds.

But they're mostly massive power engines destined for the drag strip rather than street or track.

GTSBoy Grand Master

GTSBoy

Posted
Posted

Laziness. The myth of easier tuning goes back to the 90s in Japan tuning with shitty add on HKS modules and not being able to deal with AFMs. They'd convert to MAP, and single throttle to achieve it.

This is no longer true. People know how to swap to bigger AFMs, how to tune with them, etc etc. No point in removing ITBs.

zac the muss Explorer

zac the muss

Posted
Posted
Laziness. The myth of easier tuning goes back to the 90s in Japan tuning with shitty add on HKS modules and not being able to deal with AFMs. They'd convert to MAP, and single throttle to achieve it.

This is no longer true. People know how to swap to bigger AFMs, how to tune with them, etc etc. No point in removing ITBs.

so are you saying afms are

in some way better than running a map sensor?

scotty nm35 Grand Master

scotty nm35

Posted
Posted

In some ways, yes, in others, no.

I run a map sensor just in case a cooler pipe pops off, my car will keep driving. This becomes more of an issue the higher boost you go.

AFM's are better at metering small changes in air velocity, and can be easier to tune for some. They will let you know if there is an intake leak by ruining the tune and running rich.

Why not run both? I do. :P

post-63525-0-39629700-1390185725_thumb.jpeg

scotty nm35 Grand Master

scotty nm35

Posted
Posted

which one does your ecu follow as the master sensor?

Map atm, but I have tuned with both before, AFM to 2psi them Map. It worked very well.

The auto gearbox needs the afm signal for line pressure adjustment...

ido09s Mentor

ido09s

Posted
Posted

I wouldnt even take the car back .If the guy cant tune an ECU with multiple throttle bodies, or is in any way scared of them, then hes not up to the task.

As has already been said its an old school thing that has no bearing on todays products.

I would use a MAP sensor only because, in my experience, they are less likely to fail. For some reason i have seen quite a few dud AFM's

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

    • GTSBoy
      New kid on the block

      By GTSBoy · Posted

      The wiring diagram for the R33 RB25 is freely available, and is essentially the same same as most other RBs (just with differences as to which pin # does which job). To get the ECU to power up, you just need to provide power to the ECCS relay, and have the other power feeds that come in from the top left of the wiring diagram (wrt the ECU) that give perma power to the fuel pump relay, the ECU itself, etc etc, all connected. When you put power on all these it will just come to life. It's pretty clear from the diagram what needs to happen. Just follow the lines from the 12V + supply stuff in the top left over towards the ECU. I've even posted snips of such diagrams (not for vanilla 25, I think for Neo and 26) to various threads here in the last few months, talking about what it takes to get the fuel pump and FPCM up and going. Search these up and they will help get you started on doing the same with the vanilla 25 diagram. Hell, for all I know, I've done the same with that one in years past and have forgotten.
    • Duncan
      New kid on the block

      By Duncan · Posted

      Yep...so unless someone posts up the answer you will need to probe from the ECU connector to the dash plug with a multi meter in continuity mode to trace the wires.  Note the ECU has multiple - and + (and across different key settings - Battery, IGN and Start) and most likely the power is fed from the connector(s) that is normally near the left hand headlight.
    • Songo
      New kid on the block

      By Songo · Posted

      Thanks Duncan, I am actually just trying to get the Rb turning and running with the RB25DET S2 original loom itself  I am just trying to get it going outside the body and not thinking about the S15 or trying to match anything to the S15 loom at all I am only trying to see if anyone has done this and what pin they found to be the ignition trigger and ECU+/- on the dash connector, that's about it. Thanks  
    • iain_ST44GA
      M35 VQ25DET starter motor

      By iain_ST44GA · Posted

      Hi Guys, Does anyone know any aftermarket part numbers for a starter motor to suit the VQ25DET? I can find lots of alternative part number for the VQ35DE, which I assume would fit, but there is a lot of conflicting information out there. Thanks..
    • Murray_Calavera
      R33 GTR running -9 with no tune

      By Murray_Calavera · Posted

      I don't understand how this hasn't boiled down to - Upgrade the turbo when you have everything required. ECU, injectors, fuel pump, turbo, etc. Do it all at once.  If you don't have everything required, just enjoy the car as it is and keep saving up your pennies. 
×
×
  • Create New...