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Efi Vitesse


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Hi all

 

I am getting the Vitesse back together slowly and thinking of putting the Stromberg carbs and manifold back on just to get the car back on the road next year, but i do intend to EFI the car and was wondering wether to do it now at this stage. I have a couple of sets of early PI throttle bodies and want to use the individual throttles as apposed to going for a single throttle on a plenum. I know there is lots of DIY info but was wondering if there are any firms or individuals who will supply the fuel rail pre drilled and someone who is able to drill out the bodies for the electronic injectors. I would also like to have roller bearings fitted in the bodies. 

 

Thanks

 

Mark

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I would say better to go EFI now as I'm sure you will have to spend cash on the carbs and dizzyetc. to get it running correctly.

 

What state of tune is the engine?? I wouldn't go PI throttles but instead speak to Nick about a manifold with single throttle body. Pi throttles are too large for most setups and smaller throttles will give a more driveable car. Nicks style EFI is idea for 90% of applications and everyday cars and will perform much better then the carbs any day of the week and I'm sure he can make a kit for the correct price which will be much less than the Pi throttles which need the bearings and special linkages not to mention drilling for the injectors. Speak to Nick, thats where my money would be if my car didn't do Hill climbs.

 

Chris.

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I have the six butterflies and my own linkage and the ROSS fuel rail in use and would not

build up anything else than that, although with the 123HP cam it is not necessary.

 

Anyway it does no harm and removing the butterflies and set a big one at the end of the plenum

does not make the things better.

In this case it seems to be more or less resignation at the problems.

The manifolds with the size and opening for injectors are in both cases the same.

 

The drilling of the fuel rail and the manifold refurbish is only a small part of the build up.

You should be aware that there will be lot of other things to build as ther eis the pump in the trunk

or the two fuel lines to/from the engine,

 

Also the setup of the injection is something that should be done with knowledge and time.

The result is worth that effort and is fun to do when understood how to do.

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Hmm, toying with the idea of something similar, possibly using BMW K75  / K100 Throttle bodies (don't have injectors in them but are compact).

 

Not sure how you miss the bulkhead as my plenum is damn close even though the runners are offset forwards.........  Think my engine must be further back than yours.

 

Single throttle body works really well with a mildish cam,  The 300º cam is giving some driveability issues, which would be minor but for the fact that they manifest when trickling along in traffic queues......

 

Nick

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It looks great and the main advantage I see from my refurbishment

of my PI systems is that you have here nice modern throttle bodies

that will sync properly and keep that sync for a longer period.

 

Anyway with six butterflies on a 2.7 litre the 300 degree Bastuck cam

still is a nice idling item than can be used in daily traffic.

 

Nice inlet!

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There is a 3rd way ;)

 

DSC_1021_zpspvnj5cwk.jpg

Yes looks like a really good set up. I may have restricted my options now I have moved my engine right back unless I modify the bulk head. The Triumph Pi bodies fit as is so I may still pursue that route. I ran my last Vitesse on tweeked HS4 su's and it went really well so may revert to that to get it running whilst I work on the triumph throttle bodies.   

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  • 2 months later...

My thoughts on applying bike bits to cars is that you should go on bhp rather than capacity.  This assumes that bhp and gas flow are very closely linked.  It may only be 675cc, but it will be reving at around 13,000 rpm and producing a lot of power.  A quick google tells me a 675 is 90bhp, so 2 should in theory be able to fuel for 180bhp without any issue.

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That is exactely how i approach to the problem.

In practice the throttle plates are often a bit on the large side.

That may have its reasons in the choice which way to go:

 

Stock engines with less power use cams with small overlap.

They respond properly on one single throttle plate for all cylinders.

They keep proper sync and are cheap.

 

The swap to individual butterflies already means we are on the way on

serious tuning and from that all manifolds are designed really big.

 

 

Smaller manifolds do not cut that much from top power.

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I applied the same logic (?) to sizing these as you would to bike carbs. ie, approximately doubling the capacity they'll handle on a car engine as opposed to a bike engine, as they're doing less than half the revs, so less than half the air volume. So for a 2ltr car engine you'd select bike carbs off a 900-1000cc. For a 1.6ltr you'd go 650-750cc etc etc.

 

I also did a little investigation on a couple of bike forums, which led to the general consensus that standard 675 throttle bodies and injectors are good for approx 140-150 bhp on the Triumph Speed Triple.  As I was 'only' aiming for 150 bhp on my Vitesse engine, I figured they'd be well within parameters.

 

Turns out, I was correct! The standard injectors are more than up to the job. In fact, if anything, it's over fuelling,

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  • 6 months later...

Hi all

 

Working away on the Vitesse and have gone for Sprint carbs for now but as i am just refubishing the fuel tank i want to fit a fuel return ready for when i go EFI. I was going to weld in a pipe close to the top rear of the tank in the area of the reserve lever. Is this a good place? It just occurred to me is it going to sound like a toilet re-filling after the chain is pulled as the fuel tank won't be full all the time. If I position the return lower will there be enough fuel pressure to empty back into the tank? Any pics advice appreciated.

 

Mark

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Position of return pipe is not critical.

Proper tank venting should be focussed instead.

 

I see the advantage of the higher positioned return line entrance

that nothing drops out when the hose is pulled off.

 

The noise will not be heard when engine is running.

Same with the fuel pump(s) that make some noise

when running without engine running.

 

We are no longer used to that noise on EFI and modern cars

because the pumps just start before the engine and shut

off immedeately if crank is not turning.

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  • 3 months later...

There is a 3rd way ;)

 

DSC_1021_zpspvnj5cwk.jpg

 

Hi all

 

Bit of a thread revival 

 

Hi Mr Speedy, do the throttle bodies you use have an idle speed assembly, I've seen some with and some without, just trying to understand how the idle is controlled by the ECU on tick over and cold days etc.

 

thanks 

 

Mark

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Thanks Chris.

 

That makes it a lot clearer.

 

Lots to learn, but getting there.  Been spending a couple of days reading up on the diyautotune site 

 

I realise now the black box and plunger on a lot of motorcycle throttle bodies is an idle air control (IAC). 

 

Going to try and follow Mr Speedy's lead and eventually fit motorcycle bodies to the Vitesse. I have Triumph PI Bodies I was going to use but its going to work out a lot cheaper and probably more efficient using bike ones than converting the PI bodies to EFI. 

 

Hopefully design the inlets so that the throttle bodies mis the bulkhead.

 

Mark

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