Depends what test you are getting done, if you get EPA'd they test at 3/4 maximum revs and it is a WOT test! Our diesel landcruiser just failed with 103db!
There are no systems off the shelf that will assure you meet the 90db limit! Mine is one of the quietest skylines on the road and i reckon i will still get done if the test is required!
Custom is likely to be the only way.
Your plates are my username
You cannot Edit the first post once it is up, you may be able to ask a Mod to do it for you but people with a proper interest should read the whole thread anyway
This is NOT an answer you are going to get to help you! Every car is different and has different needs, there are SO many variables that is just wont help...
You shouldn't need to go any bigger than 1000cc injectors mate, not for that power level... The whole issue I had with my car was caused by the injectors, not the style, not the size... Just the wrong part number supplied by accident...