Originally Posted by Revman
Well when you only have 204bhp you tend not too slow down too much tbh! It was actually much better on the faster longer tracks where the gearing wasn't such an issue. Interestingly it had really good torque from even below idle speed, someone put a post recently saying that TBs have less torque than the standard inlet, but that is utter nonsence. Having developed and supplied both the Supersport, the Babydoll and the factory Duratec/Sigma/Zetec TB conversions they all made more torque everywhere than standard.

That car was the development vehicle for the Supersport (not the Prototype, that was owned and raced by the factory although I did do many thousands of miles in both during development). I bought it off the factory after we finished the Supersport, kept it for a couple of years and then I sold it many years back now (and regretted it but the wife wanted a new kitchen or something) to a very nice chap in Scotland. I think he improved it quite a bit, no idea if he still has it. if it is still known it would be nice to know what happened to it.

Pity you had to sell it, hopefully the new kitchen is very nice. Coincidentally I am currently making a new drawer for the kitchen. She wanted a new oven and the drawer below was the wrong size, so far three new ovens and I will have four drawers made to fit under it. Maybe if I am lucky the next time she gets a new oven it will the same size as a previous oven and I can reuse a drawer. However she assures me she loves this new oven so will not be replacing it.

Originally Posted by Heinz
The P4SS actually had the too long 3.7 differential. The 4.1 was extra money. But the sound was a beautiful thing. To be honest, after three years I sold the car because it was damn loud, especially because I had my P4SS changed to be a LHD. With that I was sitting on the same side as those STBs, which is much louder as a driver in a RHD car. I know because I was a passenger in my car sometimes. The bonnet acts as an intermediate acoustic damping device for RHD cars. Here is a video from 2012 near Bozen.

Now you have me worried. My MGB has STB's on the passenger side, meaning it will be louder for the passenger, great when I take my son or most guys for a drive but I expect my wife will be very grumpy if it is what she considers a loud car. Hopefully I can short shift and drive it gently when she is in the car and not get in trouble.


Originally Posted by Montegue
Thanks to everyone who responded to this one, here's what we came up with in the end, I hope you agree it's somewhat of an improvement over Morgan's adapted Mondeo exhaust manifold on the left?


Before jumping in to answer the third and final question, it's worth considering that inlet manifold design and the effect runner length has on the production of torque has been well understood for over 70 years ;)Dave.

Yes your new one for Monty looks the best, very similar look to what they have fitted to my MGB with the 4 pipes merging into two and the one about halfway down the gearbox..
[Linked Image]

I remember reading an article on the new XJ12 engine being developed, they found longer intake manifolds helped the engine produce smoother power. If I understand correctly you have basically built what is one throttle body into a chamber with very long runners equal length as a long intake runner length is not possible under the bonnet of a Morgan (or most cars) when using STB's. The idea being that the long runner gives more benefit that you get from STB's. From my understanding the benefits of STB's is that you get better throttle response especially at partial throttle due to them being at atmospheric pressure rather than a partial vacuum in the intake manifold, I assume your chamber will have a partial vacuum? If that is correct then a chart is not going to necessarily show throttle response going on and off the throttle which is more of a driver feel than total power being created.

Looking at old OMEX brochures they sell different length throttle bodies and different length air horns. When you are saying there is a benefit to having a longer runner length which I have heard before and I am sure is correct I am wondering whether the length from the throttle to the inlet or the length of the horn make the most difference.