Possible Upgrades?

[Ralph Wiggum]

All you need to do that is a vacum gauge tapped into the manifold. That will tell you how much vacum your pulling at WOT

[NA-06-XR]

Hey I had a brainstorm on the drive to work today... on several things...

Your old thread on FF discussed your engine cut and high idle issues... I have the same thing happen on the odd occasion when there's too much load on my engine... The CAMS cause a lot of choking and flooding... to have my car idle, I usually have to tap the accelerator, manipulate revs until it sits at the rev range its supposed to idle at... alls good after that

if it sits idling too long though, it attempts to drop the idle to conserve fuel (I don't have evidence to back that up but I've noticed it do it heaps of times...) and then it goes all over the place again and usually either stalls or sits at its engine test revs of 3000rpm...

anyways that's what I had to contribute to your stalling issues you previously mentioned... as for dual throttle body, I thought of a setup that is staggered... by that I mean that the second throttle body only activates if you exceed 50% throttle and opens respectively progressively.... its like having stage1,2,3 of throttle....

The way I can think to make it work is by cable and a series of levers and springs... this design used a smaller throttle body as the second as well... that way it doesn't over indulge the engine in flow...

I'll work out some designs and PM them to Greg and Ruger... you can tell me what you think, and if all is thumbs up... we'll find someone to make it...

anyways... catchya

- Daniel

[Gavin.K]

I dont think it would work due to the placement of the bodys. you will need them to be in an central place on the manifold or you will have ballance problems that will be hard to get over.

I could be wrong.

[NA-06-XR]

my aproach adds one to the side of the Nizpro Plenum...

A smaller one which opens at more than full throttle should increase flow enough and at such a point on the flow path that it improves suction

...

I don't know if it'll work, but that's my idea...

[Ruger]

I dont think it would work due to the placement of the bodys. you will need them to be in an central place on the manifold or you will have ballance problems that will be hard to get over.

I could be wrong.

←

That makes sense

With my manifold in particular if you looked at it in detail each throttle body is positions perfectly above each bank of 3 cylinders. That I dont see as a problem.

If you implement the staged throttle body (similar to the vac secondarys on a carb) then there will definately be phasing issues.

the only way to do a secondary would be for it to be fed in the middle of the manifold.

I did go through alot with it ill post up in more detail after some rest, im screwed.

[NA-06-XR]

here's my mock up design (in the basic sense)... (see below)

the secondary being about a 40-45mm throttle body which works as such

primary = 1.0 > secondary = 1.0

Primary = 0.25 > secondary = 0.0

Primary = 0.75 > Secondary = 0.5

Primary = 0.625 > Secondary = 0.25

etc etc

you get the idea...

do you think its possible? I look at the way its supposed to work as like the extra cam in a VTEC.... ( I hope I have that analogy right... )

...

Edited 01/02/07 01:22 PM by NA-06-XR

[Ruger]

I know exactly what you mean but problem being it will most likely have to be electoronically driven.

To get the twins to work on mechanical linkage youll need the tps to be on one tb and the driven motor on the other one so you have 1 of the sides of each tb free so you can do your linkage there.

Problem being with a staggered setup the TPS will have to be on the main throttle body and the also the motor on the main one has to be the driven one. This leaves you no room to setup a mechanical linkage (like you said with springs and stuff) because you have nothing to run it off. Pain in the but? Yep I know :(

Driving the second one with a high torque servo and appropriate controller with the right programming might do the trick though.

As for my rough idle you wanna know what it was like? unplug the motor on your throttle body and the idle will go skitzo very very very rough, not the occasional caugh, splutter, or misfire. sounds like its running on 2 cylinders.

The stalling that was probably just the computer freaking out, tune would prob fix it.

The idle when it was working sat on 900rpm it wasnt possible for it to go any lower because the each tb was letting too much air through and the butterfly was already set as far back as possible.

also when you start the engine usually in an ideal setup itll rev to 1100-1300 or so then settle. with the twins it would rev to about 2k (wouldnt be good on a cold morning!). ecu tinkering could fix that though.

Its possible to get it going definately not out of reach just gotta keep working at it.

[NA-06-XR]

I don't know if your interested but in the latest Street machine fords (or was it street fords??) anyway, there's an article about a dual throttle bodied XR8 using the standard electronically controlled throttle bodies.... its working on a supercharged system.. good article too...May be someone we have a chat too?

[Ruger]

I don't know if your interested but in the latest Street machine fords (or was it street fords??) anyway, there's an article about a dual throttle bodied XR8 using the standard electronically controlled throttle bodies.... its working on a supercharged system.. good article too...May be someone we have a chat too?

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I read it, Re read it, Re read it again, squinted at the photos for a good hour then said to myself how the **** did he get that working! he mentioned someone in perth if I get another twin system going ill be giving him a call alright!