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djjjr42 · 04-17-2008, 06:42 PM

Nice omp rod, I used a coat hanger!

Ok, well you will still need to tune and change jets based on the season for optimum performance and to get the most out of the carb, denser cold air needs more fuel.

Robert knows his stuff. I will add that any recommendations as fas as specific sizes will just get you in the ballpark. Keep in mind that if you change the venturis, you will also have to change the jets. Different size venturis will yield different performance characteristics. The 36's will give you more low end grunt, but you will lose out on higher RPM power, in fact it will take pretty much forever to go from 6k to 7k rpm, lol. You wouldn't need to go lower than 36, for sure. On the opposite end of the spectrum, going without any venturis (making it a true 45), you will lose low end torque big time, but it will scream like a banshee in the upper RPM's. You'd think it's going to stall out between shifts though, it's pretty rough! So for me, I got a set each of 36, 38, and 40, and a bunch of different main jets and air correctors. I also got 3 different sets of idle jets. I will try to get out in the garage in the next couple of days to see exactly what I have, I can't recall off the top of my head. But in essence you can tune the car to run with different size venturis, it's all about your personal preferences for performance and drivability. Is it your DD or just a car for fun?
The DCOE flows more air than the stock Nikki, so if you take more in, more is coming out. How optimum the air / fuel mixture burns is what the tuning is for. The engine is basically a glorified air pump, so once you've opened up the exhaust, the stock carb becomes a restriction on how much air you can pull in.
What color is the smoke? Black smoke means its running too rich. It will also reek of fuel.
I don't know what your budget is, but if you want to start out cheaply I would just order some main jets and air correctors from ebay, Pierce manifolds is on there. Get a few sizes of each, some smaller and some larger than what you've already got.

04-17-2008, 06:42 PM	#9
djjjr42 Rotary Fan in Training Join Date: Feb 2008 Location: Bishopville, SC Posts: 32 Rep Power: 0	Nice omp rod, I used a coat hanger! Ok, well you will still need to tune and change jets based on the season for optimum performance and to get the most out of the carb, denser cold air needs more fuel. Robert knows his stuff. I will add that any recommendations as fas as specific sizes will just get you in the ballpark. Keep in mind that if you change the venturis, you will also have to change the jets. Different size venturis will yield different performance characteristics. The 36's will give you more low end grunt, but you will lose out on higher RPM power, in fact it will take pretty much forever to go from 6k to 7k rpm, lol. You wouldn't need to go lower than 36, for sure. On the opposite end of the spectrum, going without any venturis (making it a true 45), you will lose low end torque big time, but it will scream like a banshee in the upper RPM's. You'd think it's going to stall out between shifts though, it's pretty rough! So for me, I got a set each of 36, 38, and 40, and a bunch of different main jets and air correctors. I also got 3 different sets of idle jets. I will try to get out in the garage in the next couple of days to see exactly what I have, I can't recall off the top of my head. But in essence you can tune the car to run with different size venturis, it's all about your personal preferences for performance and drivability. Is it your DD or just a car for fun? The DCOE flows more air than the stock Nikki, so if you take more in, more is coming out. How optimum the air / fuel mixture burns is what the tuning is for. The engine is basically a glorified air pump, so once you've opened up the exhaust, the stock carb becomes a restriction on how much air you can pull in. What color is the smoke? Black smoke means its running too rich. It will also reek of fuel. I don't know what your budget is, but if you want to start out cheaply I would just order some main jets and air correctors from ebay, Pierce manifolds is on there. Get a few sizes of each, some smaller and some larger than what you've already got.