Does a 1989 7.3 idi need back pressure ?
 

Hey y'all I got a stock 7.3 idi I wanna do a 4. Inch str8 pipe with a 6. Inch tip it's a non turbo so do I need to go smaller pipe ? I want it to roar down the road !!

I have 3"downs into a 4" @Y and 4" all the way back ..... check out my pics in my album ..... also put a Diesel Power muffler im running Dynomax , and it sounds awesome ...... put a 14X6" K&N under the hood also ...... you will love the sound and it will make more power and economy too..... im averaging about 17 / 20city/hwy:rocking:

so is it ok to run 4 inch str8 after the down pipe or do a 3 inch to a 4ich with a 6 inch tip with out any problems ? or will i lose to much back pressure and cause probelms has any 1 had any probelms with it ?:humm:

just go 4" and put a muffler in there.... WAY TO LOUD WITH OUT !!!!!!!

Even with a muffler u can hear me 3 or more blocks away ...... like I said im running a Dynomax Diesel Power muffler and it sounds great..

My buddy has a 93 runnin mo muffler he just ran 2 1/4 into 5" all the way back

oh man .... too loud for city though ..... guess im gettin old .... @ 34 ... I hope not:td:

His ain't really all that loud either