Quote Originally Posted by itix View Post
Does anyone here in the forum know much about Tommis group N building before he stuck his nose into the Toyota operations? How good were his cars? Did/do they have any known issues? Etc etc? That would leave us with an indication of how well they could do.

Akta er, pojken!

In Group N they could have made the best Group N prepared cars possible and if the basic car has some serious desirn problem there is only so much that can be done..
Example is in Group N Subaru they are stuck with the Subaru EJ20 motor basic dimensions and of course position far ahead of the front axle..
The EJ20 motor (I have built 3 for rally) has a cylinder bore of 92mm...And must breathe thru a 32mm restrictor....
32mm mean the poor thing will not be happy to make revs above some point---a problem for all Group N4 cars...so as we know, they all make the motor into a "mid-range torque monster" and to do that you begin with making much higher static compression ratio and funny turbocharger pressure ratio..
There the size of the bore at 92mm becomes a problem that cars like most modern desigs do not have when they have bore size between 85 to 86mm. Those engines can tolerate much higher cylinder pressure with much less chance of detonation simply from the distance the flame must travel to be complete (in the time allowed).

So Tommi M Rally could do everything perfect on a GroupN Subaru, and still have problem with great results because of things completely out of their control.

So careful and not take things out of context..

( I don't know if you are intimately familiar with the bore/stroke of the typical engines that have done so well in the 2 liter days...but all the best were around 85mm bore and 89 stroke, or many were clustered at 86mm bore and 86mm stroke---I build engines.... )

God Jul till alla rally dårar därute i världen.