8 valve T5.5 conversion

[Burnsside42]

Very Cool - any pics of how you have that Di mounted over the plugs? It looks strange - but you had to make it work anyway it could.

[s900t8v]

these were old pictures when I was mocking it all up

I just brazed the holder up, it was never the cleanest job I did but I converted my 8v to trionic in about 5 days DURING uni after K jetronic failed... Didn't have that much time considering I study Medicine lol

[Burnsside42]

May want to consider a heat shield to protect the DI from the exhaust.

[s900t8v]

yeah lol I know

easier said than done

[Aferthas]

Great to see another 8v conversion!

I'll hijack this thread for a bit, if OP doesn't mind (tell me and I'll start a new thread instead):

I've been restoring my old 900 8v, and I've decided to switch from K-jet to LH-jet 2.4 during the final stages now that I'm done with all the other stuff
(I know, T5 is way better, but I happened to have a spare LH 2.4 including a complete wiring loom).

Now, I'm planning to use the original distributor ignition system, and from what I've gathered in this thread, it's tach output is a sine wave.
The tach output from the Hall distributor is fed to the ignition amplifier (sometimes called ignition power stage) and I'm wondering whether anyone has any data on the tach waveform output from the amplifier.
From what I've read, LH 2.4 wants a square-wave signal on the tach input.

Will I be able to feed the tach signal from the ignition amplifier (pin no. 7 on the Bosch module) directly into LH 2.4, or will I need to convert it to a square wave?

I'm planning to log the waveform using a small piece of software me and a fellow engineer has written using an Arduino and a Qt program to see the waveform whilst I'm cranking the engine, but it'd be nice if anyone a-priori has information about the original tach waveform. (Also, I'll be glad to share the logging software.)

Like OP, I'll also need to manufacture a fuel rail, but I'm wondering whether it's really necessary to modify the intake manifold to make the fuel injectors fit more snugly and deeper.

I thank you beforehand for any and all insightful comments

Happy cruising and a friendly greeting from Sweden!

[s900t8v]

na original tach signal is a square wave, comes from the ignition amplifier. - Your confusion may have arisen with the discussion about the speed signal (how fast the car is moving) which is used by the cruise control system and by T5 for deceleration enleanment/fuel cut etc...

you should have no problems feeding the starndard tach wire into Lh. Use a wiring diagram or pull apart your dash and piggy back onto the tach wire (follow the printed circuitboard) or do whatever you've planned - it should be right

yes you need to modify the intake manifold as the injectors sit too high, the spray pattern is wide (at least on redtops it is) and the injectors (if not sitting in the airstream) will douse the injector ports causing poor fuel atomisation, increased fuel economy poor running an the risk of detonation.