Zedric

I agree with you about that for sure. As far as "just do it" goes, when I started this thread I was after some info on different ITB brands and setups. I didn't want to spend a heap of money and later wish I had bought something else.

Have you heard of that weird psychological disease where people are sexually attracted to inanimate objects? I think I have that now!!!

GTR Skyline RB26DETT is twin turbo but has ITB's, SR20DET with quad TB's, it's all about air flow. The better you can evenly distribute air flow to the cylinders the more accurately you can control A/F to each cylinder. Equal length runners on an intake manifold work the best, but with turbo systems you should have a plenum the size of the volumetric efficiency of the engine at the very least. If you have one intake at one end of a manifold that has to feed six cylinders, how could you expect it to feed all cylinders evenly? It just wont. If you have a large enough plenum to store that above atmospheric pressure, it will be even across the six butterfly's and when you crack the throttle you will have an even flow of air to all cylinders. No setup is perfect, that's why those who are seeking 1000hp ditch the ITB's and just use a single very large TB with a single very large turbo. And you can bet that driveability and low emissions are the last thing on their minds.

Like I said it's obviously a fuel pressure regulator setup. I don't think I would be comfortable with a drain-plug feed, although it's worked on motor bikes for god knows how long, but a bike tank is allot easier to keep debris free.

Yeah, you can just cut it off. The point is why is it here in the first place. The only thing I could think of is a very crude fuel pressure regulator, since it is in the return line. I have a big problem at the moment because I have HS6 SU carbs and they have a return line from the fuel bowls and if they aren't returned to the tank without the restriction the front carby just pisses out fuel. I know it could just be a needle and seat problem but how do I know? These carbs aren't meant to be on this engine but the hitachi's didn't have a problem with this fuel pressure, so I'm thinking needle and seat in the fuel bowl.

I have to disagree on the smooth running L motor thing. You might be too used to massive cams. I can remember 18 years ago I used to rock up to friends houses and they would freak out thinking they were being raided by the police because the only cars that sounded as smooth as mine were brand new police cars. I would love to even see these cars that you have mentioned, you name the time and place and I will be there, either way I'm going to spend big $, because there is no other way to achieve what I want.

@ $690 per carb and $700 for a decent manifold + dyno time how could it be 1/4 the cost. I know ITB's and a state of the art ECU + ancillaries will be much more expensive, but 4X? I've heard so many times on this forum that smooth idle, less emissions and such aren't worth the extra $, I thought that the most power through the greatest efficiency and lowest emissions with the smoothest operation was the goal of anyone serious about the internal combustion engine. I remember arguing with someone about forced induction and remember them saying " it's only for race cars that don't care about fuel economy" so that's why the diesel electric trains that operate up north are both turbo charged and super charged, because they don't care about economy? I'm a Le Mans fanatic and you can bet that economy wins races. Anyone that knows anything about engines should know that the higher the compression ratio the better the economy and power for a given amount of fuel, that's where precise fuel delivery comes in, detonation kills engines. When I was a kid a 10:1 comp ratio was considered high, now 10:1 is inefficient by most OEM standards as fuel metering as well as precise ignition timing with a good Knock sensor just in case allows higher compression ratios safely.

Here is a pic of the end of the fuel line.[/img]

I think the 0.5% gain is a bit unrealistic when you consider cold start, closed loop idle control, barometric correction and zero flat spots through the entire rev range, lower emissions, better fuel economy etc...?

I have a 76' 260z 2 seater and the return line might look OK but if you have a close look it has a tiny hole in the end of the steel line just after it swings around the rocker cover back to the tank. I'll take a pic and post.

Yeah I agree, but the whole point of having triple ITB's and a high end ecu is to be able to get that little bit of extra refinement that is beyond the physical capability of a carburetor setup. That's why I'll be wanting to see you about an engine rebuild and a fuel delivery solution.

I can't wait to see some pic's. I love seeing triple setups, they're just awesome. I looked at a youtube vid of a 240z with triple Mikuni's on a dyno and the sound was just fantastic, and I'm hoping triple ITB's sound just as cool.

Your sig says taped bore?lol. Anyway, you haven't changed my mind. I know that this is the most expensive route but I also believe it's the best. I would love triple Mikuni's but no carburetor can compete with EFI when it comes to accurate fuel metering and overall flexibilty (funny, I thought it was spelled 'carburettor' but spell correction is telling me otherwise).

Hi, for what it's worth the factory 260z alloys have all the specs on them. 5 1/2-J x 14 15. The 15 is +15mm offset.

Hi, do you have any 240z carbs or 260z inlet manifolds?

Mate I just put together a Whole piece about every thing and when I posted. It vanished. WTF!!! No more. I carefully went through every aspect and in one click it was gone.

Hi everyone, I may not be a new member but this is my first post. I was looking at some OER triple carbs and for around $2,700 for carbs and manifold it looks like a good deal. But I really want EFI and the OER L6 ITB kit is $2,700 and they look sweet. Has anyone had a look at the Extrudabody L6 kit, does anyone know if they're any good? I was also thinking about the EFI Hardware kit but I think it's a bit expensive @ $3,700. And when I saw one of there setup vids I could see allot of flex in the linkages, that put me off a bit. Anyway any help from someone with experience in any of these products, please let me know your thoughts.