Donations towards server fund so far this month.

 
£0.00 / £100.00 per month
Page:
Home > Technical Chat > Optimium Runner & throttle to valve length.

alaskanow0

User Avatar

1434 Posts
Member #: 8466
Post Whore

Mansfield

17th Apr, 2015 at 08:21:56am

I was wondering if any off you technical guys could help me out. I would like to know what the optimum runner length is from valve centre to trumpet on my Itbs for my 7 port NA build.



Spec is

1293cc standard stroke
300degree cam
12-1 CR
36mm inlet
31mm exhaust
36mm throttle bodies and runner ID
Peak torque est. 110ft/lb 5600rpm
Peak Power est. 135bhp 7700rpm
Rev limited 8k
Current length is about 220mm , I'm think something like 350mm may be somewhere about right.

As a part of increasing the runner length I'm looking at spacing the butterfly back, as it did with my 7 turbo build as below. Any advantage in increasing the valve to butterfly by 50-70mm.



Class C 3rd Place Avon 2011 14.18 @101mph

Joe C

User Avatar

12307 Posts
Member #: 565
Carlos Fandango

Burnham-on-Crouch, Essex

17th Apr, 2015 at 09:09:17am

350-400mm

On 28th Aug, 2011 Kean said:
At the risk of being sigged...

Joe, do you have a photo of your tool?



http://www.turbominis.co.uk/forums/index.p...9064&lastpost=1

https://joe1977.imgbb.com/



Turbo Phil

User Avatar

4625 Posts
Member #: 20
My sister is so fit I won't show anyone her picture

Lake District

17th Apr, 2015 at 09:10:34am

When I calculated mine with a very similar spec to yours rpm and cam wise I got around 300mm. There's a few calculators online to work it out.

Phil.

Edited by Turbo Phil on 17th Apr, 2015.

WWW.TURBO-MINI.COM

Home > Technical Chat > Optimium Runner & throttle to valve length.
Users viewing this thread: none. (+ 1 Guests)  
To post messages you must be logged in!
Username: Password:
Page: