Just intalled 4" turboback..wonder if i should have went 3.5" DP?

Lococoin · #1 Sat, February 20th, 2010, 12:08 AM

I just finished installing a 4 inch magnaflow turboback exhaust with straight through muffler on my 2000 superduty 7.3 6 speed. I use it mostly for towing or hauling and am worried about loss of lower end torque.

How much torque on average do you lose with a 4" DP?

I have read that i should have lower EGT's vs a 3.5 inch. Is the loss in torque worth the gain of having lower egt's?

Right now i am regretting going full 4", as I did not realize there would be a change in low end torque.

Any insight would be appreciated.

Thanks!

Robert6401 · #2 Sat, February 20th, 2010, 06:37 AM

The loss in low end torque does not outweight the gains of lower EGTs and faster turbo spooling. You did the right thing, don't worry. If you don't already have a chip, having put on the 4" system is going to be much better for you when you do. Enjoy it, and try to get out of this buyers remorse.

***cleatus12r*** · #3 Sat, February 20th, 2010, 10:23 AM

Loss of torque?
HA!

There will be a slight reduction in flow velocity in the immediate junction between the turbine housing and the downpipe but in a 7000# lb. truck you'll never notice a couple HP at low RPM.

If backpressure is good, then I should be able to pop wheelies once I get around to doing the "potato stuffed in tailpipe" mod.

Lococoin · #4 Sat, February 20th, 2010, 10:54 AM

That's good to hear! Thanks guys.

Buddy Starr · #5 Sat, February 20th, 2010, 11:20 AM

4 inch Turbo back on a Super duty is the right way to go!!!

majek5 · #6 Sat, February 20th, 2010, 01:16 PM

Quote:

Originally Posted by cleatus12r

Loss of torque?
HA!

If backpressure is good, then I should be able to pop wheelies once I get around to doing the "potato stuffed in tailpipe" mod.

Does that really work?

***Longshot270*** · #7 Sat, February 20th, 2010, 01:46 PM

Quote:

Originally Posted by majek5

Does that really work?

I'm not exactly sure about the gains from it because I know someone who did that potato mod on a guy's jeep but it still drove home the same as before...but his exhaust was ported from rust which I assume removed all of the performance gains from the potato.

***907DAVE*** · #8 Sat, February 20th, 2010, 01:57 PM

Quote:

Originally Posted by longshot270

I'm not exactly sure about the gains from it because I know someone who did that potato mod on a guy's jeep but it still drove home the same as before...but his exhaust was ported from rust which I assume removed all of the performance gains from the potato.

He probably did it wrong!

You are suppose to hammer it in with the end of a broom handle, you have to get it in there as far as it will go for max HP.

***Longshot270*** · #9 Sat, February 20th, 2010, 01:59 PM

Quote:

Originally Posted by 907dave

He probably did it wrong!

You are suppose to hammer it in with the end of a broom handle, you have to get it in there as far as it will go for max HP.

Or maybe it was just a magical jeep, that thing blew more black smoke than half of the diesels...and it ran on 87 regular!