Fuel Injecting the Sprint

[sprint95m]

There was a blog on the Club Triumph website from Mike Weaver (I believe)
that detailed his EFI conversion.
Unfortunately this seems to have disappeared, which is a pity because it was informative.


I did do some research on EFI conversions (in general)
and concluded that a single throttle body/plenum arrangement is not necessarily easier
because it is important to get both the shape and volume correct for the best result.
(Back in the days of the DSR I remember someone used an Escort XR3i setup adapted to
his Sprint and I don't know if he ever got the plenum right. Obviously things have moved on since
the days of an XR3.)

For low down torque it is important to have as long an intake as possible, preferably straight as well.
The ITB set up on Keith's car should be okay in this respect due to the long trumpets he has employed.
As you said it is a cracking car with a lot of interesting features.


Ian.

[JPSPRINT]

Superb links Ian (and great car if you're reading this, Keith!)

Steve I understand the honesty of modern EFI but you'd have to admit those Jenvey's look so right in there. I'm biased though as the look and sound of Webers were the dream growing up, even on other marques!

The parts list on that Emerald site looks excellent too! Very impressive and complete!

[pigboy306]

Late to the party. I injected a tr7 with speeduino based system . I used the tr7 manifold and made a plenum with single body throttle body. Keep it simple.
The car was night and day difference against carbs. Very noticeable on club runs. It ran 137 bhp on a dyno nothing else much done.
I am now going for a sprint head in and injectors.
The manifold I had machined . Although with hose tails I am having a fuel rail made as well.
Speeduino is a great system allowing you to tune or self tune on the fly.

[new to this]

You can buy fuel rails from Trigger wheel .com, i made my own setup still got to buy the ECU then try and get it started
Dave

[yorkshire_spam]

Late to the party. I injected a tr7 with speeduino based system . I used the tr7 manifold and made a plenum with single body throttle body. Keep it simple.
The car was night and day difference against carbs. Very noticeable on club runs. It ran 137 bhp on a dyno nothing else much done.
I am now going for a sprint head in and injectors.
The manifold I had machined . Although with hose tails I am having a fuel rail made as well.
Speeduino is a great system allowing you to tune or self tune on the fly.

Nice work!

[Sprintparts]

This my set up. A Weber manifold with a set of Aliexpress DCOE ITB's.

[yorkshire_spam]

This my set up. A Weber manifold with a set of Aliexpress DCOE ITB's.

That's really nice and neat!

[Sprintparts]

I don't know who you are doing your "timing" but this is what I am going to use.



BMW M20 EFI crankshaft damper. I already had a crank to damper adaptor in my spare parts bin from one of my old race motor set ups. (use a different damper these days). I believe that these adaptors are now made in the UK (Sprintspeed). Sensor is from a Renault Clio 2, only because I have numerous spares for my Clio race car.



Due to the scarcity of Sprint distributors, I have used a TR7 (late model electronic) body with a sensor for the home signal trigger.

[pigboy306]

Timing is using a trigger wheel to the Sprint crank pulley. I did similar with the tr7.

I have now got a fuel rail




The car starts and runs now. The idle though is very lumpy, i have read this can be an issue with sprint engines, although i am still hunting for any air leaks.

Moving forward I think coil on plugs will be a nice addition. Anyone fitted Coil on plugs?

[Sprintparts]

Moving forward I think coil on plugs will be a nice addition. Anyone fitted Coil on plugs?

Yes.

Here is a photo of the mock up. Coil packs are from a Mazda/Ford V6 3 litre engine. Aluminium spacers are bolted to the cam cover so the coil pack and be secured. Must say that the engine is still to be fitted to the car, so only a "theory" and not a proven concept.

[cliftyhanger]

Due to the scarcity of Sprint distributors, I have used a TR7 (late model electronic) body with a sensor for the home signal trigger.

May I ask why you need this as well as a timing wheel?

[Sprintparts]

Due to the scarcity of Sprint distributors, I have used a TR7 (late model electronic) body with a sensor for the home signal trigger.

May I ask why you need this as well as a timing wheel?

For sequential ignition and fuel, rather than batch fire (wasted spark).

[cliftyhanger]

For sequential ignition and fuel, rather than batch fire (wasted spark).

Gotcha!

[pigboy306]

Due to the scarcity of Sprint distributors, I have used a TR7 (late model electronic) body with a sensor for the home signal trigger.

Ooh i like that very smart and tidy mine isnt so smart but works none the less.

[pigboy306]

Moving forward I think coil on plugs will be a nice addition. Anyone fitted Coil on plugs?

Yes.

Here is a photo of the mock up. Coil packs are from a Mazda/Ford V6 3 litre engine. Aluminium spacers are bolted to the cam cover so the coil pack and be secured. Must say that the engine is still to be fitted to the car, so only a "theory" and not a proven concept.

Seeing you are in Australia I may not have found the correct plug but were these the ones you were using? https://ebay.us/m/PJk5DT