Throttle Body Injection on EA81 Turbo

[asra]

I"ve been running a turbo with a 2" SU now for about 40 odd hours. I"ve just had the turbo done up and I am a little concerned that the fuel is being leaned out a little too much with the carby. Is there another carby more suited to this application or has anyone got any info about fitting throttle body injection to it. Have attached pic of my setup.

[bones]

Thats about the best carby ice making machine i think i ever seen

[asra]

No bones never had any problems with ice. Have seen a fair bit of moisture on the outside of the carby. The turbine end of the carby acrtually got loose on the bearing housing. Took the needle out of the carby yesterday and had a go at filing a bit off it. haven"t gone for a fly yet. Run ok in the shed. Will keep you posted. Tell me why you think it would ice up.

[asra]

Well I went for the cheaper alternative, got on the internet and found a site that showed what part of the needein the carby was used under power, took the needle out and attacked with a small fire and piece of emery tape. ( This was the area of the needle about 2/3 of the way doen the needle) Went for a fly yesterday and presto - so red manifolds. Was able to tune my engine a bit better at idle now also. I guess I should check my plugs next to make sure it isn"t running too rich.

[tonydenton]

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[maulonir]

Tony,The Turbo drawing through the carb expands the air. When you expand a gas it cools. Obviously the turbo draws alot more air through than a normally aspirated engine so creates a lower pressure causing the air to expand alot more than if it was normaly aspirated increasing the chance of icing. Not sure how much heat would transfer through to the carby from the turbo as the cold air going through the turbine side of the turbo would be taking alot of heat out of it.Baz, I have the same set up to go into a single seater except I have a 1 3/4 SU on it and I reckoned the same as bones, that it will be excellent ice maker. I have only run the engine on the ground but it the carb gets very cold very quickly so was going to put a carb heat arrangement on it.rob

[asra]

Rob, I"ve done about 40 hours now and haven"t had any problems with icing. Wouldn"t mind that number thanks Tony. Mind you after I check the plugs, I might not have to touch it because it is running pretty good now I reckon.

[Russell]

Turboed a ea81 many yrs ago...............loved itOk...........on the suction side of the turbo, make up a small "hot box", this then divided into 2 compartments, the bottom compartment is linked into the soobs water circulation, above this is mounted the carby. This then warms the carb and surounds .......never ever did i get icing and with the temps and humidities of NQ it was excellent.In fact, warming ingoing air benifits performances as well...........this was setup by guy who was servicing bathhurst race cars them days.BTW............don"t get greedy with boost presures..........10 max

[metalfab]

i was running a webber carb as a blowthru setup on a ea81 turbo,despite a considerable amount of time and effort it continued to leak fuel(on to the exhaust),because of boost pressure, about 6psi,i have since changed to direct injection on the inlet ports on the heads,and using a wrx throttle body it has solved the problem and is much more responsive.i never had any icing problems using blowthru setup,if you are interested send me your email address and i will send some pics,i cant yet work out how to post them on this site.thanks,chris.

[aussie_paul]

In fact, warming ingoing air benifits performances as well...........I thought that cooler, denser air gave a performance increase, not warmer thinner air. Have I got this a##se about.

[asra]

Your dead right cooler denser air, that"s why we have intercooled and aftercooled engines. Also remember PV=nRT.

[Brian]

Cold dense air makes for better performance both for the engines and rotors !! I"m not sure how cold you can go for optiom performance ????However, it is correct that the actual carby [for those with antiquated engines

[tonydenton]

baz,
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