dimebag

look, what im getting at is 1. even with the o2 compensation you are thinking will do the trick. in theory is great, but the system simply cannot compensate that much... it just cant do it, sorry

and as adder said, sd+boost, just wont happen

thesource

Can they work ? Yes
Will they work correctly ? Probably not
Are they needed ? No

I do not suggest leaving any modified combo speed denisty unless you have a tuner that can burn you a chip specifically for your combo .