Air filter & CNG performance

[tanny159753]

Im stuck with a cultus on CNG and was wanting max performance.

HAve installed bosch 4 tip plugs but hardly any performance increase.
Also I have advanced the timing. Is there any such thing as over advancing in CNG as I have turned the timing as far as it can go at the distributer cap? Lots of knocking when on petrol but OK on gas.

My main question is air flow. For better performance, you can get cone filters which are designed to cram in more air into your engine. More air in, better combustion. Even better if you route in external colder air rather the hot air from around the engine because the cold air is more denser than hot air hence you get a larger quantity of air into the engine. Basically the emphasis is MORE air, BETTER performance. Why then for CNG are we being told to partially block the air intake so that LESS air goes into the engine to give us better performance? Is it true and if so what is the technical explanation behind this? If true, why are we told to clean the air filter every week to get better performance?

If I install a cone filter on my cng cultus, will this make it slower?

[spectra]

If u install a cone filter your car wioll not be able to even idle on CNG.

I dont know the technicalities but this is what it is.

[Nashit]

this is a major problem that everyone useing cng faces. there is no restriction in the air intake of my car n it runs fine without it. can any expert plz shed some light on this topic caz i was also plannig to install those conis intake kits.

[tanny159753]

It doesnt make sense. Does the methane gas (CNG) not need air to burn in?

[SER_GTR]

hello!
sho said it deoes need air...without its uncombustionable....reason i think is that here CNG when filled have already get some air in it...as might u see differnt avg at different pumps and also on same pump sometimes...so its air ratio thats messing around with all....thats why they brocked air flow bcz getting much air will unbalanced air/gas mixture resulting in lean mixture.....so i think that why its blocked....
nowdays...my new 1.5L Nissan engine was giving me very bad milage...so i am messing out wil all air and timing......
Thanxx

[tanny159753]

Is this true? Does anyone know if air is mixed withed the gas at the pumps? If so, what ratio of air is supposed to be mixed???

[SER_GTR]

hello!
unfortunately there no way we can check it out like we check out petrol is 1 litre or not by getting it in 1 litre bottle...so we can't check it out...the car said it....its very much possibe to get CNG ratio changed....oil air and gas i listen makes that all mixture of CNG....so the ratio is dependent on station and also on pumps gas supply...
here in karachi...gas quailty is pretty much bad as compare to isl and adjoining areas..
Thanxxx

[bilalahm]

This is no myth guyz, this is a reality that air intake has to be restricted to get better performance on gas. I couldn't go for the turbocharged charade engine JUST because of this reason when I was doing an engine swap.

[nossee]

Does the consumption reduces in winters? I installed CNG kid early dec 05 and the first cylinder (45KG) gave 140 KM approx. After that it kept on reducing and yesterday i got only 90 from the same. I got filled the cylinder last night at 11.30 and the gas pressure was very high. But in the morning I was surprised to see that the pressure has dropped. The gas station is hardly 1.5KM away from my home. There is no leakage in the KIT. Any idea wht's goin on with a brand new kit and cylinder.

[nossee]

Does the consumption reduces in winters? I installed CNG kid early dec 05 and the first cylinder (45KG) gave 140 KM approx. After that it kept on reducing and yesterday i got only 90 from the same. I got filled the cylinder last night at 11.30 and the gas pressure was very high. But in the morning I was surprised to see that the pressure has dropped. The gas station is hardly 1.5KM away from my home. There is no leakage in the KIT. Any idea wht's goin on with a brand new kit and cylinder.

[nossee]

Does the consumption reduces in winters? I installed CNG kid early dec 05 and the first cylinder (45KG) gave 140 KM approx. After that it kept on reducing and yesterday i got only 90 from the same. I got filled the cylinder last night at 11.30 and the gas pressure was very high. But in the morning I was surprised to see that the pressure has dropped. The gas station is hardly 1.5KM away from my home. There is no leakage in the KIT. Any idea wht's goin on with a brand new kit and cylinder.

[nossee]

Does the consumption reduces in winters? I installed CNG kid early dec 05 and the first cylinder (45KG) gave 140 KM approx. After that it kept on reducing and yesterday i got only 90 from the same. I got filled the cylinder last night at 11.30 and the gas pressure was very high. But in the morning I was surprised to see that the pressure has dropped. The gas station is hardly 1.5KM away from my home. There is no leakage in the KIT. Any idea wht's goin on with a brand new kit and cylinder.