NITROUS OXIDE ( nos / n2o ) advice forum

Hi, I hope that someone out there can help. I have a 1998 toyota hilux 2.7l 3rz motor. I has a fresh rebuild about 2 weeks ago. I have had the car converted to LPG and petrol (only one fuel at a time). the problem i am having is the air inlet is 67mm ID and the gas ring mixer is 43mm ID, so when I run on LPG it runs fine with plenty of power but on petrol it has no get up and go. can anyone tell me how to get around this as the gas installer has no idea. and by the way I live in Queensland Australia.

any advise is appreciated

2 options;

1) Fit a bigger ring that doesn't restrict the airflow when on petrol, because as you have it now it's not lacking fuel, it's lacking air. Also you may think its good now but I'd expect a MUCH better result on propane if the feed ring was as big as the original TB bore, because allowing more air in will allow you to add more fuel and that means MORE POWER!!!

2) Fit a Y piece before the TB and have the propane ring fitted to one leg and the other straight to atmosphere. You then need a flap which can be switched from one leg of the Y to other, so that when you run propane the large bore leg to atmosphere is closed and when you run petrol the small bore leg is closed.

Option 1 will give you the best results on both petrol AND propane.

BTW unless you bought the propane kit 2nd hand, whoever sold it to you doesn't know what they are doing, because there will be different size rings for different applications and OBVIOUSLY the size of ring you've been supplied is NOT suitable for your application.