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thinking of fitting efi to my car this winter.using one throttle body on the inlet.

already converted the ignition to megajolt.and that is A1

i have su on my car ,and so have no throttle bodies to modify.so intend to make some inlets

question is how long are std pi inlets between head and plenum

would longer inlets be better, ie more torque

would a tapered inlet be better.

richard

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Hiya Richard,

 

The easiest way is to obtain a set of PI inlet manifolds. It doesn't matter if the butterfly spindles are stuffed as they are removed and the holes blocked off. The two pipes linking them are also removed and blocked off. You will have to machine out the injector holes to fit modern EFI injectors. You can then use a standard PI plenum and fit a 50 -55mm single throttle body (with throttle position sensor fitted). This appears to be the favourite setup by others too.

 

There are a few recent post's regarding EFI which you may find useful too.

 

http://www.tr-regist...pic=31786&st=20

 

With regard to the inlet lengths, you will increase the torque by having longer inlets but you are limited by the amount of room between the engine and the inner wing.

 

Cheers

 

Tony

Edited by Tony Millward
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Hiya Richard,

 

The easiest way is to obtain a set of PI inlet manifolds. It doesn't matter if the butterfly spindles are stuffed as they are removed and the holes blocked off. The two pipes linking them are also removed and blocked off. You will have to machine out the injector holes to fit modern EFI injectors. You can then use a standard PI plenum and fit a 50 -55mm single throttle body (with throttle position sensor fitted). This appears to be the favourite setup by others too.

 

There are a few recent post's regarding EFI which you may find useful too.

 

http://www.tr-regist...pic=31786&st=20

 

With regard to the inlet lengths, you will increase the torque by having longer inlets but you are limited by the amount of room between the engine and the inner wing.

 

Cheers

 

Tony

 

pi inlets and other stuff goes for silly money on ebay knackered or not.

i dont mind buying junk ones so long as they sell for junk prices,but junk ones are never for sale.

i dont mind making some.

what lenght are your pi bodies..

the reason for making them longer,is to copy the SU manifold.

i think the reason the humble SUs work so well is due to the longer intake manifold.

i had though of making them as long as possible [room for plenum] and taperering from say 50mm down to the ports.

also which version mega squirt do you have.

cheers richard

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pi inlets and other stuff goes for silly money on ebay knackered or not.

i dont mind buying junk ones so long as they sell for junk prices,but junk ones are never for sale.

 

As far as PI throttle bodies go there is no such thing a junk these days as bare bodies are used on EFI conversions.

But you knew that.

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Hi Richard,

 

The manifold length is approx. 6". and Kas Kastner found benefits in moving the injectors further away from the cylinder head ie. Torque.

 

As far as I'm aware, the megajolt only controls ignition system and not the fuel injection. The Megasquirt MSII handles all this.

 

Cheers

 

Tony

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pi inlets and other stuff goes for silly money on ebay knackered or not.

i dont mind buying junk ones so long as they sell for junk prices,but junk ones are never for sale.

i dont mind making some.

what lenght are your pi bodies..

the reason for making them longer,is to copy the SU manifold.

i think the reason the humble SUs work so well is due to the longer intake manifold.

i had though of making them as long as possible [room for plenum] and taperering from say 50mm down to the ports.

also which version mega squirt do you have.

cheers richard

 

 

Here are some - why not purchase the whole lot and then sell on the bits you don't need - surely manifolds won't cost more than about 100-150 quid that way - hardly mega bucks

 

 

http://www.ebay.co.uk/itm/Tr5-Tr6-2500-Pi-Fuel-Injection-System-/120797871629?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item1c201d3e0d

 

Using Triumph manifolds makes it so easy....

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pi inlets and other stuff goes for silly money on ebay knackered or not.

i dont mind buying junk ones so long as they sell for junk prices,but junk ones are never for sale.

i dont mind making some.

what lenght are your pi bodies..

the reason for making them longer,is to copy the SU manifold.

i think the reason the humble SUs work so well is due to the longer intake manifold.

i had though of making them as long as possible [room for plenum] and taperering from say 50mm down to the ports.

also which version mega squirt do you have.

cheers richard

 

 

I have a set of the Rick Patton SU adaptors and a TPS sensor - used them for about two years http://triumphwestoz.blogspot.com/2008/01/feature-car-of-month-triumph-2500-tbi_22.html - no longer required as I went for multi point injection with Megasquirt - no reason that they wouldn't work well with Megasquirt. pm me if you are interested - they are gathering dust under my bench and will be cheap.

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At the latest International I noticed quite some PI throttle bodies lying around and traders did not ask the price of gold, did prices change that quickly <_<

Unfortunately many traders and braker yards with buckets of valuable Triumph parts are not handy on the Internet, so it's sometimes very hard to put your hands on this parts.

A few years ago a friend of mine bought a few hundred Triumph o/d boxes from a trader who had around 800 in stock. :blink:

At the time it allowed me to fit reconditioned A type o/d boxes into both my TR's. :rolleyes:

Yes it's sometimes important to know the right people

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  • 3 years later...

Hi Tony,

I´m in the final stages of replacing the original PI system on my 73 TR6 CR.

I got a set of 2500PI bodies which I use to carry the injectors and a single throttle buy from a BMW 525i on the airbox.

My concern are the original rubber hoses between airbox and throttle bodies. Mine are old but still strong.

Did you experience any problem with collapsing?

Regards

 

Heinrich, South Africa

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Hi Tony,

I´m in the final stages of replacing the original PI system on my 73 TR6 CR.

I got a set of 2500PI bodies which I use to carry the injectors and a single throttle buy from a BMW 525i on the airbox.

My concern are the original rubber hoses between airbox and throttle bodies. Mine are old but still strong.

Did you experience any problem with collapsing?

Regards

 

Heinrich, South Africa

 

Heinrich,

That is indeed an area that needs careful design.

If the throttle body comes away from the manifold as as result of those rubber joints failing the engine will rev uncontrollably. If the only way of turning the ignition off is the ignition switch, and locking the steering......... nasty.

A backfire in the inlet manifold could blow the plenum chamber off unless it is really securely anchored- by nuts and bolts not jubilee clips.

Peter

Edited by Peter Cobbold
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I heard of this backfire in the PI system with one throttle body several times.

The plenum popps off and you are happy if the engine stalls or

minimum you have a rev limiter fitted.

 

Recently I drove a PI with single throttle body against my PI with hotter cam and 6 butterflies.

I would wish anybody to think about that conversion could get the same impression.

 

Anyway the conversion to Megasquirt EFI is such a big improvement over twin carbs

that there is definitely no need to thing about more modification.

It will be a very nice engine when setup is done carefully.......

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

 

As far as I know Tony is happy with his single throttle, I am with six butterflies.

More relevant is to do the work good!

 

I would recommend three ways to swap manifolds:

 

Buy a PI system and use one throttle body from modern car

 

buy a PI system and restore it to keep the six butterflies

 

buy WEBER manifolds and use EFI throttle bodies shape like Weber DCOE

with all the equipment like injectors, holders fuel ines just out of the box.

 

http://www.dbilas-shop.com/Produkte/Drosselklappenteile-Zubehoer/45mm/Drosselklappenteil-%D8-45-mm-L-110-mm-mit-Flansch-mit-Bohrungen::1731.html

Edited by TriumphV8
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Thanks Peter,

this is also of some concern and I must discuss it with the company who's electronics I use if there is some sort of fail safety.

I use extra mounting points which connect the airbox to the front and rear throttle bodies.

Tried to upload a picture already when I posted my question earlier and failed, but will try again.

 

Heinrich

 

post-12024-0-46087100-1422972787_thumb.jpg

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Thanks Peter,

this is also of some concern and I must discuss it with the company who's electronics I use if there is some sort of fail safety.

I use extra mounting points which connect the airbox to the front and rear throttle bodies.

Tried to upload a picture already when I posted my question earlier and failed, but will try again.

 

Heinrich

 

attachicon.gifTR6_EFI.JPG

Heinrich,

Apologies, you had thought of the problem and devised the solution. Neat.

If I had more faith in an injector never - ever- failing than I'd be tempted myself to go for eFI,

and intercooling.

Peter

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Peter,

no need to apologize. I´m grateful for any meaningful input and your's is such one.

I did not like the idea of the airbox being only connected by rubber hoses and I cannot use the original below the airbox support bracket since one previous owner replaced the cast iron exhaust manifold by a performance type tubular one.

Honestly, I have no idea of the forces unleashed in case something goes badly wrong and I´m not sure if my solution - two long shank bolts, screwing into the throttle bodies - can hold out. But I´m sure the airbox cannot just fly off. I did some research beforehand and there are a number of cars around using the same setup, it´s just a question of getting feedback on it.

 

Cheers

Heinrich

 

post-12024-0-71479900-1422985717_thumb.jpg

 

You might observe that the break booster looks odd. Correct, it's from a mid 90's Toyota Corolla. The size is about 30% bigger then the standard TR6 one and just fits the space. Very little adjustments have to be done to fit it and it works with the original TR master brake cylinder. A member from the Cape Town TR center developed the conversion to good success.

Edited by w147ik
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Peter,

no need to apologize. I´m grateful for any meaningful input and your's is such one.

I did not like the idea of the airbox being only connected by rubber hoses and I cannot use the original below the airbox support bracket since one previous owner replaced the cast iron exhaust manifold by a performance type tubular one.

Honestly, I have no idea of the forces unleashed in case something goes badly wrong and I´m not sure if my solution - two long shank bolts, screwing into the throttle bodies - can hold out. But I´m sure the airbox cannot just fly off. I did some research beforehand and there are a number of cars around using the same setup, it´s just a question of getting feedback on it.

 

Cheers

Heinrich

 

attachicon.gifTR6_EFI2.JPG

 

You might observe that the break booster looks odd. Correct, it's from a mid 90's Toyota Corolla. The size is about 30% bigger then the standard TR6 one and just fits the space. Very little adjustments have to be done to fit it and it works with the original TR master brake cylinder. A member from the Cape Town TR center developed the conversion to good success.

Nice looking engine bay anymore pictures?

 

Cheers

 

Mike

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Single throttle body from a BMW 525i, custom made accelerator cable, fuel rail made from copper installation pipes and then nickel plated.

 

post-12024-0-15318400-1423005840_thumb.jpg

 

Stainless Steel mesh to protect the oil cooler, relays for low and high beam nicely tucked away, anti roll bar inside the radiator protection shield!

 

post-12024-0-37131700-1423006126_thumb.jpg

Edited by w147ik
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Hi Heinrich,

 

That is a very neat installation. Did you make your own fuel rail.

 

Regarding the brake booster, do you have more specific part numbers for the Toyota bits. You are probably aware that there is also a Toyota 4 pot caliper conversion that can be done but this results in long pedal travel. I wonder if the Toyota M/C would be a solution.

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Hi Tony,

I´m in the final stages of replacing the original PI system on my 73 TR6 CR.

I got a set of 2500PI bodies which I use to carry the injectors and a single throttle buy from a BMW 525i on the airbox.

My concern are the original rubber hoses between airbox and throttle bodies. Mine are old but still strong.

Did you experience any problem with collapsing?

Regards

 

Heinrich, South Africa

 

 

Hi Heinrich/Graeme,

 

I am now using 6 butterflies. I was concerned about the rubber connectors but your method certainly looks efficient. I changed back to 6 individual butterflies for better running. I now have instant acceleration and the engine is definitely more brisk. Interestingly, I had to re-tune my VE (Volumetric Efficiency) table as more air was allowed in... this is obviously more efficient than using a single butterfly with the plenum. I also fitted K&N filters to each throttle body and love the sound these make, very much like Weber carbs.

 

I also made an overhead throttle linkage which makes it easier to tune my butterflies.

 

Cheers

 

Tony

Edited by Tony Millward
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Hi Tony,

Thanks for the input.

Please let us have some pictures of your setup, in particular the linkage. The ones I have seen so far don't look neat to me.

 

Heinrich

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Hi Ragtag,

the booster is from a 87 Corolla/Tazz which I bought from a scrapyard for about 15£.

In the picture attached you can see a number on it, which might be the part number.

 

You have to elongate the 4 holes in the firewall and pedal box towards the center as the PCD is slightly smaller. The aluminum spacer needs to machined back about 3 to 5mm, the bolts on the booster are just a bit shorter then the ones on the original booster and you want to make sure you have enough threads engaged.

The fork on the booster needs to be shortened to the absolute possible minimum or the break pedal will stand up too high and you would touch it with the cranked shaft of the accelerator at about half throttle.

 

There is a long quite scientific article about the use of Toyota 4 pot calipers on the internet which proofs that the brake increase is minimal.

I recommend investing in a set of EBC Green Stuff pads and you will have an instant improvement when they are bedded in properly.

But thats another topic.

 

Cheers

Heinrich

post-12024-0-40366300-1423031503_thumb.jpg

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Hello

 

 

No religion !

Proven track record has become the single throttle

Maintenance-free , better flow, more torque.

Driven over 150,000 km away.

In camshafts over 280 Duration not recommended

But who needs that .

Performance is made in the head.

 

Regards

 

Ralf Schnitker

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In camshafts over 280 Duration not recommended

But who needs that .

Performance is made in the head.

 

To be honest, already the 280 degree cam in the above configuration was a pain

what forced the owner of such an engine to let swap back to 260 degree Newman PH1.

He was not the only one from whom I know that personally!

 

That engine was fully prepared and head expensivly built up and with that we

started a comparison with two witnesses on board this autumn to see clearly

what is the difference between "Single Body" and "6 Butterflies":

 

Cars have been my TR6 and a TR5 from a clubmate.

 

We noticed first the less stable idle of the 260 although the engine was fresh from maintenance.

With the 290 degree cam the idle was stable at 900, the single throttle was swapping between 800

when started and later up to 1100.

 

The single throttle solution missed completely the cold start equipment

and instead increased ingnition advance by 10 degrees when cold.

My CP solution simply provides the choke built in!

 

What was real astonishing was the lack of torque what forced me nearly to stall the engine at my first drive,

reported also by the owner who already has thrown away the progressive linkage to get things better.

Another engine, similar built but a 2.7 litre, is reported to have the same problem.

So that seems to be related to this Single-Body-Solution.

 

Later when driving the engine with 290 degrees pulled same way at lower revs like the one with 260 and single body.

 

We went down up to 1200rpm where the 260 under full load felt better. Both engines work properly , pulled same

(other than WEBER DCOE that simply do not accept full throttle under a decent rpm)

but mine started more humming due to very light flywheel and the cam indicating that there is a limit.

 

The things turned progressively from 3000 rpm on where the 290 engine was more crispy

and reved that freely that one of the whitnesses accompaning in my car had to encourage

the driver to let go. I think he was really impressed about the way this engine performed.

 

I set the rpm limiter to 6500 and the engines likes to fire into the limiter when driven hard.

The Newman cam equipped engine feels tired from 4500 on and could be forced up to 5500.

 

I was happy to find out that all this stories about low end torque is absolutely not the truth

and with the six individual butterflies you have simply the option to drive the engine

like a stock PI at low revs with pretty torque and have a real sporty engine at higher revs.

If I would have stayed with the 260 degree solution during years I would have lost the fun and have sold it!

 

What I had to admit was the smooth engine running of the single throttle.

Runs like a modern car close to an BMW.

 

So if the sync is a problem, 4500rpm is enough and a pretty smooth running

is one of the main topics the single throttle body is a good solution if a cold start

equipment is provided but hands off from 280 degrees KENT or BASTUCK cam,

what was the close to CP engine!

Although some people got it run in single-body it was such a pain for two owners who like power

that they turned back to the Newman PH1.

 

Hope this helps to make a decision because not many could drive a direct comparison

between these two types. I had to beg and wait one year till a single body owner agreed........

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Hi to all addressing my concerns about he rubber hoses between the airbox and the original throttle bodies.

 

I use a locally produced EFI system, called Spitronics and the integrated rev limiter shuts down either spark or the whole ignition, in case something goes wrong with the air intake . The system also shuts down the fuel pump in case of a crash!

Pretty reassuring.

Not far from us in Knysna is a company manufacturing the Cooper Healey, a Austin Healey 3000 replica based on a modern chassis and suspension and BMW 320i, 325i engines and BMW drivetrain. The guys using exactly the same system and setup. Simple to control via your laptop.

 

During the engine rebuild we shaved about 4kg off the stock flywheel, pistons conrods and gudgeon pins were matched and balanced in itself and the sets against each other. 5 of the 6 weigh 695 g on is 695,5 g.

Crankshaft, flywheel, crankpulley and clutchplate have been dynamically balanced.

The tired CR cam was replaced by a new stock CP one.

All in all I hope for a very smooth engine, I'm not looking for a race car but a sporty tourer which can surprise some modern cars.

Edited by w147ik
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