air intake problems
 

i just found this site and i think it its fantastic. anyway, a while ago i replaced the stock air filter on my 81 datsun 280 with something my friend and i customized out of pvc piping and one of those cone filters. i noticed that it has been backfiring now. could it be that now the fuel mixture ratio is off, or maybe something else? what should i do?
thanks

It might be an vacuum leak around any of the hoses or connections...check the connection to your new filter you just put on. That might be the problem. Also check around the air flow meter as well for leaks.

Chris

The problem is probably that you're fabricating an intake out of something that takes your feces to the sewer. There are performance companies that spend money on something called R&D (research and development). You can't just use your Home Depot card and expect to make some "fantastic horsepower marvel". I can't believe that I'm even replying to this. Waste of my time.

Give the man a break. I think it´s kind of cool with low-budget solutions. Learning by doing!

Is the backfire from the intake or exhaust? Is it sputtering and causing bad driveability? If it's just a slight "putt" sound in the exhaust don't worry, free flowing mufflers and intakes will make the car putt on occassion. Happened to every car I've owned. I think it's normal. But if it causes problems then yeah it's probably a leak. Custom intakes on a low budget are awesome too. It'd be easier if companies did make stuff for the Z's, but they're so old that they don't see them as a good market anymore. Custom is the way to go! :D
John 82ZXT

Ok, whatever. A curved PVC pipe vs. the $100 powdercoated metal pipe I bought from Motorsport do exactly the same thing: Hold a K&N filter. There is no research or development in the intake piping, although I wouldn't go too large of a diameter if you're using the factory air flow meter.

An air leak will only effect your engine if it is after the air flow meter. The pipe you put on will not bother the mixture. Check the connections between the meter and the throtle body and all the hoses that plug into that housing.