The Racetractor. The End.

[Piggy]

id be really scared to run that manifold not being equal youll get hot spots can could cause damage. Any reason why you used big tubing and not 1-1/4" ?

well most people be scared to tune an idi.
A lot of people be scared to rev a tuned big heavy 2.1 xud11.
Most wouldn't even bother taking the time to fit a GTb2 because they are scared....

 

Anywho, why is it 1.5" and not 1.25"? Cost and suitable size basically. The exhaust ports are somewhere in between 1.25" and 1.5". The flange for the head (which was cut by a squirrel on red bull with a jigsaw not even close to a pro job) was cut to size (or as close to, assuming the squirrel was also blind) using the exhaust gasket. And with the head port matched to the gasket, if I had used 1.25" tubing, it would have caused a restriction at the head face. 

Considering I am running a stupidly oversized 2.5" extension pipe from the original cast peashooter mani...this will be a vast improvement.

Plus, tuned derv's in general have little gains for equal length. It's boosted don't forget, a high revving N/A petrol would indeed be a different matter. 

I was going to go for a log manifold but managed to get this pipework real cheap so I went this route. (an equal length be amazing, sure, and someone did offer to try and make one for me...but there really isn't enough room also for one. If you look at that pic, it seems squished, but I rekon it still may foul on a couple of things and some water pipes may need "adjusting")

Don't be scared....