No,I think it's not the solution.
I could win this qualifying with your car or with the Subaru but not with mine.I suggest to take out the Celica for five laps with my settings and let's compare the results.
I will try out the other cars at home I promise.
So here I am.
I tried the qualifying with the RX-7@Motegi with Drew's settings,312Hp/1122kg.
Total time : 9'35.288
Fast lap : 1'53.042.
With more practising and a little bit more consistency I could be able to do 1'52.8-9-ish lap times,the limit is somewhere about 9'33 with this car.
With Marty's settings,it could be a little bit better.
So I can say that there are no problems at all with the initial settings.