2nd Gen Non-Engine/Transmission 4" or 5" exhaust?????

[Wyomingcowboy]

Which is better for lowering egt's?



I am not interested in noise whatsoever. In fact, the quieter the better. I am, however; interested in drastically lowering egt's. Right now I often hit 1250 with little or no weight into a high wind. Is 5" overkill with my stock turbo?

 

[Woodenhead]

From what I've read there are no benefits for 5" over 4" until you start making over 500hp. 4" will do do just fine for you.



Not sure if you'll see a "drastic" change but if you're currently running a stock exhaust with cat converter and stock muffler and go to a straight or flow through 4" system it will definately make a difference.

 

[cArNiVaLwOrKeR]

Im thinking about going to 5inch straight

 

[PRout]

Just went through this predicament recently. Here is one thread you can plod through if interested: 5 inch exhaust - Drone with 2 mufflers? - TDR Roundtable

Lessons Learned after doing the research and the work:

Same as stated above, 5 inch is unnecessary unless you are running HIGH HP. 5 inch will be a challenge to make quiet without some annoying resonation or drone. This will spark some debate because everyone has different tastes as to how loud is acceptable. Finally, after several changes to my new Banks 4" system, it is now quiet "to my liking" and EGT's are at least 100* better than a stock system overall. You can feel some minor difference in throttle response as well.

For the simplest solution with all your questions answered, just call Rip. It's what I SHOULD have done & followed through with. I would have saved money and time getting it right. :-laf
Rip's webpage: Source Automotive Performance Diesel

 

[Vaughn MacKenzie]

A 4" exhaust will help, but what the exhaust does more than anything is put the piece in place which lets you add other upgrades which will help your EGTs more than the exhaust alone, such as a better turbo and intake.

 

[Dave M]

You need to get a high flowing air intake also (as Vaughn has said). I see in your sig you have K&N FIPK (w/outerwear). I assume that is a high flow intake. If not then get one. If you still see high EGT's you may need to change the tubo housing to 14 or 16 cm or change turbo's (also as Vaughn has said).



This is not from experiece (others will chime in that have experience here) but from what I've read. Also you should remove the cat if you have one and that is practical for you. I have also read that if you have EGR that may be a factor in HP and EGT's.

 

[PRout]

1250 sounds kinda high for running empty just into a headwind. Would have to question the accuracy of the gauge, or is there a boost leak, or are the RPM's too low?

Out of curiosity, what level injectors are being used, and is the exhaust system still stock?

 

[Wyomingcowboy]

everything is stock except for the air intake and hypertech tuner. I have questioned the accuracy of the gauge myself, but there is NO way Quadzilla would sell me something that doesn't work!?!?!?



Actually, I am still waiting for a fuel pressure reading with my stupid POS quad recon. I have the sending unit in and will install it this week sometime. Last chance saloon for me and quad.



But ya, it reads real high in the wind and empty. With a <1K camper on the back it was 1300+. I am wanting to hear REAL bad that the exhaust will help!!

 

[PRout]

My guess is the tuner is providing the extra fuel for the higher EGT's, and the camper is causing a lot of wind drag then.

IMO, the 4" exhaust isnt going to be a "miracle cure", but it should lower temps around 150*. Maybe someone here would have a better tested figure than mine since mine was changed in stages.

Yeah, you definitely should have a boost mod like an elbow or j-hook depending on your turbo type to allow for more boost. Also a boost module of some sort to fool the ecm (usually come with most timing boxes). Or does a hypertech tuner take care of that with progamming? Also, hopefully, it gives a mild timing increase to help with EGT's.

I'm sure you are keeping the RPMs up over 2000 for flow, if not, you might want to give that a try.

When I had a pop up camper on my truck with DD1's & a VA box, using the stock exhaust with just the muffler removed, I pushed into some pretty good headwinds, but dont think it really ever got past 1100 much so maybe the gauge is reading a little high, or there may be a boost leak.

Might need to go to a bigger turbo housing as mentioned above, but there is a point of diminished returns there as well, and you trade lower EGT's for more lag and smoke on takeoffs.

 

[16919]

I had a hypertech on mine back in the day... I couldn't get it past 1100 turned all the way up with my foot on the floor. Something is not right... .

 

[Wyomingcowboy]

It very well may be the egt probe/quadzilla POS. It never reads below 31-32 either. Even when it was -5 outside? I don't have much faith in it.

 

[SRadke]

You'll likely find yourself dissappointed in the egt reduction gains from an exhaust system. They do sound good though... .

 

[MAllen1]

I will agree with the no benifet with the 5". I had a 4" on mine and running 1300 with other stuff on my truck, went with a 5" and still running 1300. What did help with me was when I went to banks and bought that elbow that opened the exhaust up from 3. 5 to 4", it bumped it back down to 1150.