Has anyone had a straight through 4'' (Donaldson & no cat), gone to a 5'' turbo back and noticed a drop in EGT's while towing?

Thanx.

 

Anytime the beast can breath better it runs cooler.

 

A bigger flowing intake makes more EGT difference. 4 to 5 inch has a lot bigger volume potential but at 20psi intake you are probably making 25 to 30psi of exhaust pressure so 4 inches is tons ...that said .... I have a stock downpipe to a 5 inch short side exhaust and I run very cool...and loud....Towing....I am louder than anything other than a Harley with a blow pipe at full throttle. ks

 

yikes, that's loud!! jm, i would say try the whistler intake but looks like you already spent some money on a K&N. What size piping does the K&N use? The whislter uses like 6" and pulls a great deal of air in. I guess you could try to modifiy your K&N to pull cooler air by shielding it more from the hot air around the motor...

 

Absolutely no change in egt's whatsoever.
Not worth the money, the time or the droan IMO unless your headed for the 600hp range.

You do lose a bit on turbo spool but not really enough to be concerned with.

 

5" was worth the money to me just for the tone. Other than that not worth it in terms of performance for 99% of the people out there imo.

 

Good information. Thanx everybody. For now I will stick with the 4'' and not think about it anymore.


Thanx.

 

5" has dropped egt's on my truck anywhere from 150-200 degrees every time!!!! For me well worth it!

 

Was that from stock exhaust or from a straight through 4''?

Thanx.

 

FWIW, on my '93 I went from stock 3.5" with MagnaFlow muffler to full turbo-back 4" with straight through Donaldson and saw no difference in EGT's at all. I was sure going to a 4" downpipe and exhaust would lower EGT's but it didn't.

The stock 4" can support 500hp no problem.

 

That was from stock 4" with an aftermarket muffler. But the 5" system's I've had bell right at the exhaust elbow so it is truely a 5" system.

Very true!!!

 

is the 4" turbo back very loud? the one with the muffler say like a mbrp or silverline or something? i thought the truck already came with 4" or am i wrong?

 

Your 05 does have 4" from the turbo back from the factory. The silverline muffler that I used to have was quiet (actually too quiet for me). No noise in the cab and only slightly louder outside.

 

I have no cat and the long Nelson or Donaldson (forgot which). Exhaust tone is like stock, no exhaust noise. I actually want a tad more exhaust noise. I like to hear the motor a tad. Now, the megacabs have a straight through muffler/baffle right after the rear axle (FYI).

 

so the 4" exhaust would be sensless to go with huh? well is the 5" with the muffler decent or way too loud? i dont guess one 4" would be better then the next. i already did away with the muffler doing away with the muffler and the cat would be a bit much lol ive heard one of those. any info is greatly appreciated thanx