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efi throttle bodies size


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I extended inlet length a bit and still use the 45mm throttle plates.

 

attachicon.gifPI manifold01.jpg

 

Hi Andreas,

 

What did you experience, after the elongation of the inlet length? Is it noticeable, as your engine is supposed to have already a lot of torque at low rpms?

 

The increase of the plenum diameter might also be an interesting improvement. Unfortunately on can only do on at the same time, as the fender come int the way.

https://mytriumphblog.files.wordpress.com/2014/05/modified-enlarged-plenum_2.jpg

 

 

Cheers,

Patrick

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Hi Patrick,

I personally had the feeling things went better with the extensions

but to be honest it was not necessary to make corrections in the fuel table.

That gives indication that advantage must be limited but my personal opinion anyway

is that power progress on the TR6 engine is done in small steps and this is one of them.

 

The plenum diametre increase was reported to be a good idea by a clubmate

but up to now I did not do so. One reason is the limited space as you told with

my. manifold extensions, the other is that I am not fully convinced.

I used 150mm open trumpets instead of the plenum for a test and had similar results

although the take away from the air filter was noticed to be better.

 

On the web some time ago I watched a nice solution where the six manifolds are

turned like sausages around the plenum with increased diametere. Also the length

could be changed by opening a shortcut at the beginning, where the manifolds reaches

the plenum. Very nice idea but looks very different to stock solution and difficult to build.

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Interesting discussion.

 

I have a CF carb car that I will be fitting a Megasquirt/EDIS set-up to based on re-using the standard PI throttle bodies and the associated air inlet manifold.

 

I had a lot of success with Megasquirt/EDIS on a Rover V8 engine that I am sure will also work well on the Triumph six cylinder.

 

For our engines I think a throttle body and injector per cylinder is definitely the way to go for power and flexibility over the single TBI option. Clearly space restrictions mean it is difficult to do much more with inlet length and air inlet manifold diameter, hence my plan to use the standard parts as a base.

 

One thing mentioned in this discussion that I question is throttle body diameter. It seems logical to propose the use of the original PI parts (as I am of course) or DCOE manifolds with commercially available injection throttle bodies to match, but I think that for this engine the throat diameter of these throttle bodies will be too great for the amount of air flow required, leading to (relatively) poor throttle response and inefficiency. There's a good discussion of this (and other related issues) on the Jenvey website: http://www.jenvey.co.uk/jenvey/throttle-body-selection-with-jenvey-dynamics For our engines, something much closer to 30mm rather than 40mm (or even 45mm) is optimum. Anyway, it's a moot point, as doing anything else is probably not practical, unless someone knows of suitable parts that can be modified for our purposes?

 

I'd also be interested in details of what people are using for throttle linkages on this sort of set-up.

 

 

Andrew

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What I can say is that the 6 butterflies give a better response than the single body

but to be honest you notice that when hammering on the pedal when standing

but when the car is running the milliseconds delay is there but not noticed.

 

Before I buy expensive bodies I would take the PI system, it looks nice,

is widely availiable and can be made to work perfect.

No need to spend work on other systems.

I made three of them, they all work pretty.

MegaSquirt is the right choice because its reliable, not expensive and

provides a lot of tools to find good setup.

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I agree that Megasquirt is the way to go but I can understand why some people would be afraid of all the input needed to optimize it.

 

I strongly recommend the Ford EDIS ignition system to go with the Megasquirt, since Megasquirt is optimized to use it, parts (including aftermarket high power coil modules) are easily available and it's practically bomb proof, with a limp home feature if you lose the ignition control.

 

 

Andrew

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  • 3 years later...

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