Has anyone tried running throttles on the A14 on long runners?
What effect did it have on the power and torque curves in comparison to stock?

I'm looking for as much low down torque as possible to suite the usage of the car.
Doing gymkhana (autocross) with my A14 equipped 1200 sedan.
Speeds are low and only use 1st gear, but 1st is getting too short with the improved traction. So want to run 2nd gear. Obviously then we'll mostly be using the lower rev range 2000rpm up.

Got this picture from the photo album.



@lamb_daiquiri - How did it turn out?

edit: I'll try to mount the injectors as close as possible to the head, again to aid low down torque and response.

rule of thumb long runners suit what you want, but dont think anyone here would have run an a-series with short and long in a like for like test to tell you the difference

im wondering what diff ratio your running, maybe changing to a 4.9 centre will give you much better results anyway

All the reading material that I've managed to get hold of suggest that long runners is what I need.
Just wanted to hear from someone with actual experience what their thought are.

Regarding the change:
I'm using a E30 rear suspension with a 4.46 LSD. I can go to a lower diff ratio ie. 2.93 to get a long 1st gear.
But with the 4.46 using 2nd, I would still have the option of changing down to 1st in the really tight stuff, something that you can't do with a really long 1st.

Locally in RSA I haven't been able to source a diff with a higher ratio than the 4.46 yet.

Ideally I would try and position the throttles between the head and the bend in the above picture.
That way one can play with the overall runner length by changing the length of the velocity stacks.

That's my manifold. I haven't finished the airbox or anything else to fit it yet so I can't tell you how well it works. I was aiming to have the 2nd harmonic kick in around 5500-6000rpm with that setup, the 3rd was a bit lower. THis'll give you a rough guide to start with http://www.bgsoflex.com/intakeln.html, the runner length includes the port length, carb length and all that as well.

Yeah, I found this pic in the photo library that you posted.

That website you posted was one of the many in my research.

I'm thinking of doing something similar but having the throttle closer to the head and then playing with the velocity stack length to tune the torque curve to whatever suites our application the best.

I was really hoping that you would have tested it already...

Any idea of when you would be finished with this?
I'm interested in your opinion on the concept.

I'm increadibly slow with this project, it's been going almost 2 years so I wouldn't hold my breath. I don't get much time on it.

Having the throttles closer to the head would work fine, better throttle response and being able to fine tune your torque curve with different velocity stacks is a good idea. The challenge is finding room in there for them. If you keep the throttle bodies as close to the head as you can and put some 180 degree bends on the velocity stack side you can adjust them to whatever length you want over the rocker cover. Get in and have a go! The calculator will give you a starting point and you can tune from there.

Some more modern engines have some clever designs. There's a Ford that has a rotating part in the manifold to adjust the runner length on the fly, there's a few designs that open ports to change the tuning. I saw a formula SAE intake that had a rotating trumpet (like the Ford) to change the runner length. That all requires a lot of effort though, much easier to use forced induction (I assume that's not an option).

Have fun!

I've been meaning to get my A14 on EFI for more than a year myself.
The ignition side is done, only the fueling to do now.

My twin SU's (Sorry, Hitachi's) has decided that they are about to go on pension, so I need to sort the fueling before they fall over completely.

It's going to be interesting to see the effect.

hey i'm not far from you [ bellville] You can give me a call and check my t/bodies ---bike t/bodies --shaun 0824857669

nismo1, post a pic of your setup.

Are you running a long runner intake?

Any before and after dyno graphs of your setup.
I'm not interested in figure but rather the shape of the torque and power curves.