Shaftless throttles for RB26DETT

[Chris Wilson]

That sounds more like it For sure, used throttle bodies build up a deposit around the area the butterflies close, and it can be stubborn and rubber like to remove. Once removed the air flow will differ, hence idle may change if the AAC can't bring the air flow down low enough. The Nissan RB manual goes into depth about how to set up the TB's.

[goddard]

Thanks to all those that have been PM'ing away.

To answer a few questions;

1. Price - I'm not sure yet as no one has looked at them in detail at AT. I have given a rough indication above of where they may fall.

2. Delivery - Again as no one has looked at them at the moment I can't give a definate answer. I have been designing a set for a Formula 3 team today, but may get a chance to look at them tomorrow and have a chat with the bosses about their priority. Fingers crossed that, because of their simplicity, it shouldn't be ages. Maybe a few weeks for a first off to test?

3. AT Power will always try to test their throttles against competitors and get flow results. They have nothing to hide in that regard, this isn't magic, everyone can see the difference in the pictures.

Stay tuned and I hope to have some more information asap

[tarmac terror]

Post DIY help!! Mapping problem??
GTR High Idle... Help

A couple of links which explain what I'm on about.

TT

[icydude]

get these bad boys built
I will buy a set

[Piggaz]

Is fitting inlcuded in the price? Taking the plenum off is the worst job EVER!!!!!!!!!!!

[rb26r32]

very intrested, would be great if these got going before i started the rebuild of the engine

[Piggaz]

Any progress with these?

[rbmrhd]

Not an engineer, but this looks like a pretty obvious modification. The only question is why hasn't anyone thought of this before?

[goddard]

Hi Guys,

Thanks for the poke. Been meaning to update this thread.

OK. I managed to do an initial design, which should fit and packadge onto the standard manifold and plenum. The idea is that the AT throttles use their own linkage, but is then linked to the GTR linkage via one of the tie rods. The other two tie rods would be reduntant, and would be removed.

Here are some renders,







The second part of the update is that AT are going to get an independant engine builder to run some flow tests on the throttles and manifold, using a 45mm DCOE made to fit onto the manifold. I calculated there is a massive 30% gain in cross sectional area from the AT throttles.

I also drew the GTR inlet port and measured the area on the computer. It comes out as 1552mm^2. Now the area of the std GTR throttles with spindle is just 1140mm^2. The 45mm AT throttle on the other hand will come out at 1500mm^2. So is nearly a perfect match area for area for the inlet port. Hopefully the flow tests will show a good improvement, looking at those numbers they should do!

Guys. I could also do with a list of people who are interested to get some numbers together. I was thinking along the lines of

Name / Car / Horsepower / What car is used for (track, drag, road etc)

If you have more than one car and would want more than one set please list them both.

Much regards!!

John.

[goddard]

Originally Posted by tarmac terror

A couple of links which explain what I'm on about.

TT

TT,

I can't comment on the mechanical ability of those people setting up their throttle bodies. One thing non of them mentioned is that there is an idle adjustment screw on each throttle body. If that is set too high then no ammount of tinkering with the linkages will get the butterflies to close. It read to me like it was more a case of "finger trouble" than there being a problem with the throttles themselves.

On AT throttles, the tight machining means there is no need for any seals, or coating.

Hope that helps,

John.

[rb26r32]

Name: norm
Car: R32 GTR
Power: 180awkw current going to 300-320awkw
Use: 90% street 10% drag

[GT-R Glenn]

I calculated there is a massive 30% gain in cross sectional area from the AT throttles.

Eh ?
From a 10mm spindle , to no spindle ?

[goddard]

Sounds alot yes.

45mm dia = 1590mm^2
10mm spindle 45mm long = 450mm^2
2mm blade 45mm long = 90mm^2

GTR 1590 - 450 = 1140mm^2
AT 1590 - 90 = 1500mm^2

1500 / 1140 = 1.316 (or in other words 131.6% which is a 31.6% increase)

[DarkChild]

I'm interested but will only make a decision after more data and results are available.

Name: Leo
Car: BNR34
Power: (Unknown) Currently having some parts fitted and mapped.
Use: Mostly Street.

[Piggaz]

Name: Paul
Car: BCNR 33
Power: 400 KW at wheels
Use: Mostly street