Another Day at the Dyno and Further Problems

[zedturbo]

Here is an approximate measurement taken at the outer face.

5085.JPG

29mm or 1.141 inch

Only 29???
I thought it was bigger... well shite, now I have to remove the head and port the intakes to 35mm, as I can't sleep at night knowing there is an unnecessary restriction in there.

[Witchita Linemen]

I suspect you're right. It kind of defeats the purpose of the 35mm TB's if it only get's choked up by the intakes, right?
What about the exhaust? Mang, did you open up that end too? From what to what?

[Mang]

Running a bog standard exhaust spider but did do a bit of amateur gas flowing for many hours. Made some valve guides though (cant remeber why i made them instead of buying them- there wioould have pbeen some logic at the time. Actually the spider turbo plate is a one off and I altered the way it flows into the turbo. I will try to find some images
In reality I wish I had put in bigger exhaust valves and one of YBs fantastic set ups with an external waste gate. Still there’s always next year and the year after. (Actualy next year I am starting to restore a car, mini 850 I have owned since I was 18)

I am having a nightmare linking images so will do as URLs
The turbo attachment plate image is pre - linishing and polishing and welding - I cant find a mirror finish image sorry

https://image.ibb.co/mYv8sS/IMG_6112.jpg
https://image.ibb.co/fop7mn/IMG_****.jpg
https://image.ibb.co/cdnosS/IMG_6111.jpg

[Kawadoodle]

Ahhh! Warms the cockells of my heart!

[Witchita Linemen]

Ha! That looks like mine, but much cleaner.

[Lorcan]

I suspect you're right. It kind of defeats the purpose of the 35mm TB's if it only get's choked up by the intakes, right?

The 1100 throttle bodies taper down in diameter from the butterfly, as do the ports. The butterfly plate itself is a restriction to flow and the idea is to get the biggest intake size possible and taper it down to the size of the inlet valve, which again, is a restriction in itself. On a turbo the biggest restriction of all is the turbocharger which is why we start with fitting larger exhaust valves, the highest lift cams we can get away with without causing excessive overlap, and the biggest turbo we can get away with without causing excessive lag.