Jump to content
SAU Community

Recommended Posts

This is still in the thought process. The only thing set in stone is the material used.

The main reasons im doing this is to reduce some of the heat soak from the engine and to make a slight alteration to the intake runner length.

Looking for better low to Mid range without effecting top end

Here are the links to wiki

http://en.wikipedia.org/wiki/Bakelite

http://en.wikipedia....maldehyde_resin

The RB26 and its ITB's make it a little different from most cars where they run a plenum- runner- throttle- runner again

and most cars run a throttle- plenum- runners so adding spacers between the head and intake manifold also effect

runner length and crosses over to plenum volume slightly.

So we know a few things.

Longer Runner length can aid in low/mid power but this isnt necessarily at partial throttle since that is more effected by velocity at low flow

Increasing plenum volume can give more mid to top end power

Actual heat reduction of the intake manifold etc will only help when in heavy traffic in low flow situations. I.e under 2k rpm. There are guys

who have had heat soak issues on the dyno and once an ice bag was left on it for a while power returned.

Pic's borrowed from google

Stock intake set up fitted to an engine

rb26-stock-intake1.jpg

Plenum and throttle bodies. Increasing the plenum and the first part of the runner volume will need to be between the plenum and throttle bodies

however this will require adjustment of the linkages and throttle cable. TPS voltage would need to be checked and could even be used to adjust throttle position

back to whereI had it before. Initially I was thinking of a 6mm spacer here, but I think 3mm will work out better. More later

rb26-stock-intake5.jpg

This is the manifold showing where the ITB's bolt to. It has the radiator neck incorperated into it so I will want to run a 3mm spacer here. Looks like

the studs will be just long enough. Was going to just run 6mm spacer here and forget the 3mm spacer above. I have a feeling that 3mm spacers

on either side will work better then just a 6mm spacer after the ITB's for partial throttle responce. (unsure as I have a cold and head hurts)

rb26-stock-intake3.jpg

I'm not sure if I will bother running a spacer here. It looks like a pain to cut and is heated by coolant anyways. The only reason why I can think of running one is

for additional runner length. Running a 3mm spacer here as well will give a total of 9mm which might put the intake pipe out of alignment

rb26-tidy1.jpg

i had a customer come in and this was all he had done to his motor (holden v6) and he said he had made gains on the dyno.

i would just do the 3mm either side of the ITBs and leave it at that

  • 2 weeks later...

gizzmo do make these already - I have one on my RB26 and have found it has reduced intake temps when heat soak was an issue (when it was driven on the road). As far as making more hp, it can only help, I do not have back to back figures but the intake temps are down by around 5 degrees over what they used to be.

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

    • Yep, pretty much what you said is a good summary. The aftermarket thing just attached to the rim, then has two lines out to valve stems, one to inner wheel, one to outer wheel. Some of the systems even start to air up as you head towards highway speed. IE, you're in the logging tracks, then as speeds increase it knows you're on tarmac and airs up so the driver doesn't even have to remember. I bet the ones that need driver intervention to air up end up seeing a lot more tyre wear from "forest pressures" in use on the highway!
    • Yes, but you need to do these type certifications for tuning parts. That is the absurd part here. Meaning tuning parts are very costly (generally speaking) as well as the technical test documentation for say a turbo swap with more power. It just makes modifying everything crazy expensive and complicated. That bracket has been lost in translation many years ago I assume, it was not there.
    • Hahaha, yeah.... not what you'd call a tamper-proof design.... but yes, with the truck setup, the lines are always connected, but typically they sit just inside the plane of the rear metal mudguards, so if you clear the guards you clear the lines as well. Not rogue 4WD tracks with tree branches and bushes everywhere, ready to hook-up an air hose. You can do it externally like a mod, but dedicated setups air-pressurize the undriven hubs, and on driven axles you can do the same thing, or pressurize the axles (lots of designs out there for this idea)... https://www.trtaustralia.com.au/traction-air-cti-system/  for example.... ..the trouble I've got here... wrt the bimmer ad... is the last bit...they don't want to show it spinning, do they.... give all the illusion that things are moving...but no...and what the hell tyre profile is that?...25??? ...far kernel, rims would be dead inside 10klms on most roads around here.... 😃
    • You're just describing how type certification works. Personally I would be shocked to discover that catalytic converter is not in the stock mounting position. Is there a bracket on the transfer case holding the catalytic converter and front pipe together? If so, it should be in stock position. 
    • You talking about the ones in the photo above? I guess that could make sense. Fixed (but flexible) line from the point up above down to the hubcap thingo, with a rotating air seal thingo. Then fixed (but also still likely flexible) line from the "other side" of the transfer in the hub cap thingo up to the valve stem on the rim. A horrible cludge, but something that could be done. I'd bet on the Unimog version being fed through from the back, as part of the axle assembly, without the need for the vulnerable lines out to the sides. It's amazing what you can do when you have an idea that is not quite impossible. Nearly impossible, but not quite.
×
×
  • Create New...