Moved pyro sender - WOW! (high EGTs)

[Darel]

I installed a full set of new Auto meter gauges yesterday, and I figured while I was at it I'd move the pyro sender from post-turbo where the PO put it to pre-turbo. Uh-oh. 1300 degrees is the magic number, huh? I'm there before I even get the pedal all the way to the floor (empty, unloaded). This is not good, considering that around here we have a constant 40+ mph headwind (always seems like a headwind anyway), sometimes up to 80 or 90 mph on certain stretches of highway. Basically, last week I had to back off on the gas because my old post-turbo pyro was at 900 just due to the headwind, and this is unloaded, tailgate down! Can you imagine a truck putting out 25 pounds of boost just to push its' empty nose though wind? How in the hell am I supposed to pull a trailer with this?

I've got Scotty air and a full DTT transmission upgrade kit and valve body on the way. Will they help enough once installed? Maybe that TDR badge on the grille is creating wind resistance...

 

[Snow man]

if your hitting 1300 that easy,you might have a plugged cat,is your motor stock. To tow in 40 mph headwind,you have to expect high EGT's,and slow down,you cant drive 60 with a trailer in a 40 mph headwind and expect it to not have high EGT's. you'll need full throttle constantly.

 

[Darel]

Guess I should change my sig so I don't have to keep retyping, but right now all I've got is a 230/605 plate slid all the way forward and an aftermarket TC. Frankly, compared to what a lot of you guys have done to your rigs and looking at the "campers" (read: outdoor mansions) you pull with them, I don't see why mine is such a problem. As I said, Scotty air and DTT transmission en route.

Darel

 

[illflem]

Sometimes the pyro probe will get damaged from reinstallation because of the way the outside collar crimps down on it. Many manufacturers say not to adjust the depth of the probe after the first tightening to avoid this. Does the gauge read near outside temp when cold and read around 250-300° when idling? Other than that I would say clogged cat or restictive air filter. If all else fails slide your plate back some or buy TST plate.



Your KDP contained?

 

[The patriot]

I'd look into the cat. Maybe time for a 16cm2 housing. I was gettig high egt's just after installing the 370's. Piers told me to shorten the arm on my wastegate. Much better now.

Eric

 

[Snow man]

sliding the plate forward is no good for EGT's,your better off with a stronger plate. My 96 had the same #6,and it was almost impossible to get into EGT trouble after the cat was gutted. Dont check into the cat-yank it off,and punch it out,get rid of that restriction. how much boost are you getting?

 

[Jim Fulmer]

EGT's

Darel, if you have that plate and only making 25lbs I would bet that is about right, I don't understand the 25lbs mine made 28 out of the box with the same plate then jumped to 32 with the 16cm then to 34 at max rpm's with the 3k springs. You mentioned that you had the DTT stuff in, what happened to you EGT's with the mad during gear changes. See signature, hope to have it done soon as parts are already on order.



Jim

 

[RColston]

? Intake/EGR?

Darrel



If you have an EGR valve on that truck ( im not sure about non california trucks 96-98 ) there is a restriction in the intake manifold that will not let enough air into the engine when you increase fueling with an aftermarket plate or large adjustments of the stock one. Check into this, you may have to install a federal manifold, OF COURSE I WOULD NEVER SUGGEST MODIFYING THAT ABSOLUTELY NECESSARY EGR SYSTEM!!!



Rick C. :-{} these are great

 

[Pthomas]

need input!

what exhaust system ? stock?

what turbo exh housing? stock?

 

[Deezul1]

Slide your plate back . 030- . 040 and I bet the EGTs will go down a lot.

 

[Darel]

Couple things:

I was pulling 25 lbs to get it uphill in a headwind. At WOT it'll make 34 or so. Stock exhaust and turbo. No EGR valve on non-CA trucks.



I'm thinking about going with a straight-pipe kit, will this help? I know sliding the plate forward is part of the problem, but frankly I like having more power and would like to find a way to keep the EGTs under control without having to sacrifice power. What's this deal about shortening the wastegate? Will that make it open sooner or later?



DTT stuff on order, not installed yet. Will that make a difference? What difference will the KDP make in temps? No, it's not contained (at least not by me) as far as I know.



Oh, and it was a brand new pyro probe, I'm selling the old one (it worked fine, though) as a full kit with the 2 gauges and mount I replaced. It's on eBay if anyone's interested, http://cgi.ebay.com/ebaymotors/aw-cgi/eBayISAPI.dll?ViewItem&item=1803893649



Thanks everyone!

 

[Snow man]

if you like extra power,trade your fuel plate for a stronger one,the 12v doesnt like lots of fuel at higher RPM's,i think they said it becomes very inefficient above 2500,and if you continue to add fuel,(slid plate)the EGT:s will skyrocket,it sounds like your making more heat than power now.

 

[SlyBones]

I agree with the others about getting a stronger plate, and moving it back to the stock position, maybe . 030 - . 040 more forward than stock position. But not full forward.



DTT stuff will be like having a new plate, but I dont think will help lower EGT's. Its gonna transfer those EGT's into a lot more go.



Fixing the KDP ( Killer Dowel Pin ) should not add, remove, or change Power, EGT's, Mileage etc. Its a fix to prevent an alignment pin from working its way loose and destroying your timing gears and case. You should have this done.



Things to help lower EGT's, and the order I would do them. Mostly based on cost versus effectiveness. The experts may want to adjust order for us. Depending on the thread you read a 4" exhaust and AFE Mega Cannon for example reduce EGTs nicely. But the air system is 1/2 as much. So I rate it higher. But what good is it with a plugged exhaust, so at minimum get the cat out of there and get flow thru muffler.



1. Remove Cat

2. Flow Thru Muffler

3. Air Intake System

4. Full 4" exhaust

5. Larger Exhaust Housing

6. Bigger/Better Turbo

7. ATS 3pc pulse manifold

8. Banks twin RAM intake ( ?? )

9. Ported and Polished Head

 

[Darel]

Thanks SlyBones,

Didn't think the KDP had anything to do with temps, just engine longevity. I do plan on taking care of it eventually.

Not sure if I posted this above, but in addition to the DTT transmission I've got a Scotty air system on order. I've heard that makes for a nice drop in EGTs, let's hope so. Just took it for its' first highway run with the new pre-turbo pyro, and at about 70 mph I'm running around 700-800 degrees (unloaded, tailgate up).



Now a question about straight-piping: Can I just cut out the muffler/cat section of the exhaust with a Sawzall and replace it with truly straight pipe, or are there some bends or offsets in there that necessitate a custom-bent pipe? I've crawled under there to look and it seems pretty straight, but that doesn't mean something's goofy, like the cat inlet is 2" off center from the muffler outlet or something. Also, does anyone know offhand exactly what diameter pipe I'll need (large enough to sleeve over the ends), so I can search it out beforehand and not have my truck laid up for 2 or 3 days?



Thanks again!

Darel

 

[illflem]

Darrel, the kdp has nothing to do with your problem. I was asking since you are just up the road, wondering if you wanted to use the jig. Take care of it soon if you haven't.

 

[Darel]

Sure, I'd love to get it taken care of. How could I go about getting the jig from you?

Darel

 

[Darel]

BTT. Still curious about that straight-pipe.

 

[The patriot]

Hey Darel, are they Isspro gauges? I'll most likley bid, if I can find out how.

I'd like to get another pyrometer to match mine, so I can have pre, and post turbo readings.

Eric

 

[Darel]

Patriot,

The pyro is Isspro, the boost is Auto Meter, both worked fine when I pulled them and include everything, including senders.

Darel