I was wondering what the avg drop for you guys that are around 300-350HP is when going to a larger exhaust.

If you never changed could you post what you EGT's are on hard emtpy runs and how fast you peg the pyro when towing, if at all. I know this is a loaded question but I just need a little info.

The reason for me asking is im thinking of going with jammer 3's and turning the box off to tow. I dont want to go with a bigger turbo and was thinking how a 5" straight would lower temps.

Thank Alot,
Jamie

 

Doubt if you will see any egt difference at all going from a 3" to 5" with 350 hp.

 

Mine has the muffler replaced with a piece of flex. With the random junk in the bed and the shell camper and half fuel I sit around 7200#. Level ground I can't get over 750(post turbo) at any point (no box). Have not got to try it loaded yet. Weekend after next I hope to put about 8K and see how see does. There is a decent climb nearby (approx 6%). I back out around 900 at about 90MPH. That is from 50MPH in 5th gear.

Randy

 

I went from 3" straight to 5" straight to stacks. Didn't notice much of an EGT change at all. This was before the 370's though. What happened was it atually hut the low end just a hair. My theory is that the exhaust cools to quickly due to expansion which causes less turbo spool. But anyway, I'd save your money and go with 4"

 

natnlchamp, Im curious, why you would turn your van aakin box off to tow?

Im studying and trying to learn about the different boxes and injectors, Im thinking maybe a van aakin and im trying to study what injectors to purchase.

 

I saw a good 100 degree drop going from 3 to 5 inch.

 

its a challenge to get egts to really climb with 5 inch exhaust

 

I plan on going with the Jammer 3's (100HP) and from what ive read here at DTR with my stock turbo, towing with the box and inj would be too much fuel, not enough air. The box has a boost fooler which would be left on but less fuel, just the 100hp sticks. I dont want to upgrade my turbo thats why EGT's are an issue.

I figured that with a larger exhaust i could help my cause.

 

I can't get over 1100* pre-turbo with my setup. I ran the 3 inch straight pipe for a day with the box and injectors just to see how much egt's would drop. Towing about 10,000lbs I saw about a 125* drop. Empty it only dropped about 75*, but I havent been over 80mph with the box and injectors because my tires are bald and the ground is covered with ice.

 

Guys,, Bill is right on with the advice that larger exhaust is not needed, if you are not going over 350 to 400 hp the larger exhaust is a luxury exspense. Goodluck,,,Rick

 

whats the sound difference between the 3" and the 5"

Thanks Alot for all the input