Hi Guys
Those of you who have build a A12 suckthrough turbo engine. Can you please give me details about the following:

1. What did you do to drop the compresion.
Preferably the cheapest option. I don't
want to use a different crank or cylinder
head. Maybe a decomp plate?
2. What must be done to the timing on the
distributor and the vacuum advance.
3. I have a spare set of A12GX flaptop hitachi SU's. One set the one is a little worn on the inside next to the bush and butterfly. So the butterfly does'nt seal properly. The other one is still usable. Can I use this SU or must it be the larger Jaguar SU that must be used.
Any other info appreciated.
Those of you who did this. What was or is your engine specs and what power did you get.

Do you think a 4 speed will hold up if I do not do clutch dumps at high revs, but do boot it when in gear through all the gears.

Don't worry, I am not going to do this to my GX but plan on getting another sedan.

I might be able to get my hands on some old Uno Turbo, turbo's, as well as various other small turbo's...

Methinks I can also get my hands on a set of 40 Webber sidies, and/or a 36 DCD7 Webber, all good for this application...

If you do decide to and get around to this, let me know...

Ok, I read a bit through the search.
Just answers to the following:
Will the GX SU do the job or must I get the Jaguar ones.
With drawthrough, do you struggle to get it started. Why I am saying that, the carb is far away from the engine and must now be sucked for a while, I think, before it finally gets to the engine.
Do you guys think a normal 4 speed will hold with no burnouts just full throttle when clutch is fully engaged.

In my draw through setups ive had no problems with hard starting once mixtures were sorted. I think the gearbox would live if you were gentle and didnt drop it back a gear roughly and plant it or slam gears, cheap to replace anyway Good luck, i no topgear managed 100rwkw with basic a12 so anythings possible, cant wait to lean on my setup in the future!

My suck thru carby is 1 3/4" SU off a jag. In the morning, you need to crank it a little more than normal, but only for the first start of the day. I run a standard 56A gearbox and haven't had any problems yet.

Why would you choose to lower your compression?
I don't think you need to.
High compression is a good thing...the only downside is that it leaves less room for error,meaning fuel and timing.
If you do lower your compression you'll end up with lots of lag before boost.