Building my supercharged 2l

[7/77GTV2545]

I am currently in the process of supercharging my 77 gtv... i have three engines to play with... I am using the existing aircon bracket modified to support the sc12 toyota blower, plumbing this into a smallish intercooler infront of the radiator and into the origional air intake. i have got my hands on some turbo seal kits for my dellortos and am currently building two sets from NA models.
However actual turbo DHLA40 dellortos have a sealed atmosphere vent on the top but I have seen this on a turbo delta car with boost pressurised lines to these vents any ideas?

Does anyone know if it is possible to reshape the combustion chamber to avoid or reduce pinging? as I am going to do a head service anyway

These dellortos were used for turbo applications and therfore can be tuned to opperate with variable boost requirements.. does anyone have any ideas with regard to changing jetting? do i even need to?

Has anyone done this?

[buzzed]

Hi,

I am also doing a supercharger conversion!

We should def swap ideas and theories.

Reshaping the combustion chamber - Not that I knw of, its really decided by the valve angle...the massive dome is not ideal as we know.

That said, there are many things that can be done to avoid detonation.

1. reduce comp ratio - drop in some twin spark NA pistons...they fit, and drop the ratio down to around 7.5:1

2. run rich mixtures - helps cool the charge

3. retard ignition suitably

4. run 98 octane - depending on your use , run shell vpower racing, its 100 octane

5. intercooler - you are running one, run a decent sized one, and ensure that you duct the airflow so that it has no where to go but through the cooler.

Do all of these things and detonation will be the least of your worries...it'll be the walking wet liners :-)

Benica's in Vic are the people to speak to about tuning the delloto carb, and you can be almost certain that they changed jetting in them...but that is a guess from me. If you ask them nicely they may give you some tips...otherwise, keep your eye out for an old turbo motor with the carbs on it.

email me at mbarrenger@optusnet.com.au if you want to chat more about your project....we can swap ideas>
cheers
Mike

[alfahaka]

Quote:

Originally Posted by 7/77GTV2545 However actual turbo DHLA40 dellortos have a sealed atmosphere vent on the top but I have seen this on a turbo delta car with boost pressurised lines to these vents any ideas? These dellortos were used for turbo applications and therfore can be tuned to opperate with variable boost requirements.. does anyone have any ideas with regard to changing jetting? do i even need to?