What is the difference between some ones own (race) engine and the engine from the big tuners. If tuning is not allowed and all the engines are the same then why would some rent an race engine?
Everyone says that its beter but WHY? What do they find what an normal engine builder doesnt find?
Think the difference from a box stock engine (any engine) and a tuner engine is attention to detail and dialing it in for the environment/element. This could include ignition timing, port timing, spark gap, carb pop-off, ring gap, piston matching, reed inspection, gasket inspection etc… without doing any “machining work” or dancing around gray area’s a tuner will just ensure that its setup to work efficiently. In theory you could do this all yourself if you have the correct tools and formulas.
Not sure of the different specs USA use to Australia, but IAME (X30 in particular) has been very solid parity from engines out of the box. That’s not to say there isn’t a few that are slightly better, but I feel like X30 has been decent in Australia.
My engine that I’ve used to top qualify and win races at the Australian Titles was out of the box, ran in on the trolley 2 x 10 mins idling, and never saw an engine tuner.