Im swapping to front mount and I need to know what downpipe to use. is bigger always better? The truck will stay with the current setup until I run a boost motor and Id like to get something for the long run.

 

Yes. 3"-5" has been used.

 

I'm running a 3.5 on mine and love it!

 

Rule of thumb is 1.25 x the exduser of the turbine. So a MP T70 has a 64.5mm exhaust wheel, so 64.5 x 1.25 = 80.62mm/25.4 =3.17"

 

ok newton with all your physics and ****! haha! listen to this guy cause he def knows what he is doing.......

 

3.5 would prolly suit ur needs well

 

the largest turbo im planning to run would be a T70 or a T76. so going with a 4 downpipe wouldnt hurt but a 3 would seem a little small.

 

Two words..........



Pressure Differential

 

cliff notes

 

Aren't 4" diesel kits easier to find than 3.5"? Not that it matters, but finding a nice mandrel bent peice than clears your rear axle is not always easy - I know that there are a lot of 4" kits out there. I used a 4" kit for a 99-02 Dodge Cummins, every thing up to the downpipe fit great, I only had to add a 45 at the turbo. thats my 2 cents.....