Do you guys recommend upgrading my fuel injected 5 speed 86 x1/9 to dual DCNF 40 weber carbs? what would it take, and how many parts would need to be changed for me to make this happen?

apart from the uno turbo engine which is close to impossible to get here in US, i think the dual webers would make a substantial upgrade.

thanks guys.

if it was me, twin 40's would be lower on my list. Are you using the car on track days and what exhaust you running? As you are already running on injection i'd look more towards fitting a megasquirt ecu, euro spec head and cam, and an scs exhaust before i'd consider chucking in the bosch just yet. Could do with throwing any of the fed spec crap out the window as well. And even after that you'd need to upgrade your rubber at the back (205's should fit at the back.) But as i say, thats just me

Most of Phil's comments are spot on - the seeming lack of power can be overcome through relatively minor tuning upgrades of the fuel injection system and base tuning of the head itself.

From a racer's perspective the single biggest tuneup is the driver not the car, followed by the suspension of the car and then the power train.

This becomes more true as a car shifts from "underpowered" to "overpowered" as is inevitable when tuning the car up. Here the handling of the car and the driver's abilities become more and more significant.

On the road it tends to be a slightly different matter - you aren't throwing the car around at corners on the very limit of handling as it is the surest path to an accident. Straight line performance becomes more important but those factors of suspension and driver are still vital. More importantly it tends to be much cheaper to tune the driver and suspension up.

In terms of driveability - completely aside from the raw performance aspects, a pair of twin 40s is really going to struggle to match what can be achieved with fuel injection - especially mapped fuel injection (instead of the analogue system you have to start with). If you absolutely have to use this arrangement you are far better off switching to throttle bodies.

well lets put it in a tight b*stards perspective...

£350 per DCNF + manifold + new filter + jets + rolling road. = not much change out of a grand. and your car will flood round hard left hand turns.

£200 for a megasquirt ECU + filter + rolling road. = not much change out of £400, your car will not bog anyware and you don't have to buy things like jets when you upgrade the rest of your engine.


Cheers Jim, I learn from the best ;-)