Not yet, but I will give it a go tomorrow. I also have some different length Velocity Stacks.

I have just come back from a test drive and the amount of fuel I have had to add to the tune from 3500rpm to 8000rpm. it just needs more fuel everywhere but especially from 3500-5000. So it must be producing more torque.

It feels so much better, it starts pulling from 3500-4000 you feel the cam kick in strong at 5000 then bang it hits 7000-8000 pretty quick. can't wait for the Dyno.

I had a look at your previous dyno graph. To pick up torque either side of the 5000`ish peak you could try a total length of 22" (560mm).

With this length you would get the 3rd harmonic at 4000 picking up torque from 4000 to 4500 and the 2nd harmonic at 6000 with another torque increase between 5750 and 6250.


It might be a bit hard to get 22" under the bonnet and you might lose a couple of hp right at the top because of the additional restriction. still could be worth a try if your dyno time isnt too expensive.

How did you get on today?

It is made from 35mm motor bike throttle bodies with injectors inbuilt.

Then a custom 35mm inlet manifold with 32mmx35mm inlet to head. Steel one at the moment until tested on the dyno.

I have kicked the throttle bodies up to reduce entry angles through the valve, and then added a 110mm long 36mm tapered velocity stacks with redline socks.

This is the first setup


































Followed by this

Hi rally1200, looks good! I think you have done the right thing going smaller in diam. looks like there is a bit of adjustment for length in the velocity stacks, great idea! you`ll probably find you need to add even more length for best midrange, around 21" total if you are tuning for the second harmonic.
I`d love to hear how you get on...

Cheers

All of them look awesome and well engineered,

I'd love to be in your parts bin...

My eyes hurt from all the porn in this thread.

Total length at the moment is about 300mm. I am looking at trying to tune for the third harmonic. Inlet manifold is about 100mm throttle body is about 50mm and VS is 110mm plus about 50mm in the head.

I have only street driven it so far but i run an O'2 sensor with my Wolf 3D and have need to add a heap of fuel in at 4000-5500rpm but it still seems ok at 8000rpm.

Dyno time booked in for monday. (can't wait)

I can't wait for you to send some of the spare gear up for testing on the 1000... :D

Hey i'm designing QTB at the moment, what Calc did you use for calculating intake lengths. Also what rpm did you tune for, peak torque?

Cheers
Nick

I have used this wesite

Exhaust Length Calculator

My cam timming is Exhaust Open/85 Close/58 RPM set to 5500 and 349cc/cyl

But it still recommends smaller exhaust.

Exhaust is JTS 4-2-1 headers modified to 2 1/2" collector and 2 1/2" all the way.