intake runner lenght with ITBs discussion

[Bean]

IMHO fitting an airbox (with fresh/outside enginebay air duct) will result in far more better results for cooler intake chare than any insulation between head and manifold...

[mc68]

jondee86 Wrote:

Jimmi The Kid Wrote:I will place my injectors at the end of the stack - oldschool formula 1 trick...

I have looked at mounting injectors at the mouth of the stack, because
of the more efficient fuel vapourisation. Obviously it works well for any
kind of racing where the throttles are wide open most of the time.

However, my research indicated that there are some drawbacks when
using this system for a car driven on the road. It seems that having the
fuel on the "wrong" side of the throttle butterfly is not so good for idling
and low throttle opening. And probably cold starting will also be difficult.

I'd be most interested to hear from anyone who is using this system on
their road car... and not just as secondary injectors that only come into
action at WOT !!!

Cheers... jondee86

If you look at formula atlantic 4ag's you see they all run secondary injectors infront of the stacks.

Obviously cold start isnt an issue, or is drivability in an open wheeler.

ust check the overall length, and the offset on cylinders 1 and 4 vs 2 and 3

[jondee86]

mc68 Wrote:Just check the overall length, and the offset on cylinders 1 and 4 vs 2 and 3

Been a few bikes using those staggered stacks for a while. It's said to
help broaden the torque band. So, like thermal insulators throttlebody
spacers and Irridium plugs... every little bit helps

Cheers... jondee86

[BOOMEX]

And what do you guys thinkabout those type of adaptor inlet manifolds?

http://cgi.ebay.co.uk/Toyota-4AGE-4AG-16...2eaafe5be2

[Bean]

looking at the quality of the piece in the pics IMHO they are not worth it the T3 one is about 50$ more but have a close look at the inlet side in the auction pics you'd need to do quite some adjustments on those as they are 'hand made'

[NoHachi]

mc68 Wrote:If you look at formula atlantic 4ag's you see they all run secondary injectors infront of the stacks.

Obviously cold start isnt an issue, or is drivability in an open wheeler.

ust check the overall length, and the offset on cylinders 1 and 4 vs 2 and 3

Jup, secondaries are ok, but notice that they also run primary injectors aimed at the valves.

[Jimmi The Kid]

Where do I messure the ideal runner diameter? Is it the throttle valve or what does it means?

[Bean]

usualy you take the diameter of the throttleplate unless there is a huge size difference in your runners compared to the throttleplate than you would use an average

[Jimmi The Kid]

Thank you. I messured my AE111 ITB's to 45mm, and this should be close to my target

[4000GT]

Im presuming you are using a plenum as well? Trumpets alone without a plenum lose a nice amount of mid range power and torque.