High Stock EGT's!!!

[Forrest Nearing]

interesting stuff Keith... thanks!



Forrest

 

[Greg Boardman-RIP]

Kieth,

Have you seen any of the new boxes yet (t/d)?



Just wondering how EGT's are with them running on kill?

 

[JHardwick]

Kieth,



Could a secondary bypass be implemented like that used in a constant flow injection sysem? That would get rid of the backwash.

 

[KLockliear]

Greg, have not seen a test T/P box yet.



JH, explain what you mean by backwash?

 

[BigDaddyMC]

Nice to have Keith on line concerning this topic. Thanks!



I live here in LV and have talked to Keith several times on the phone and more spefically about the boost elbow and his thoughts on it. I'm not sure if it is still the case, but DD does't include the Boost Elbow w/their box. I started without the elbow, did some testing and quickly found that in my experience it was DEFINITELY WORTH IT. Without the elbow, temps were extremely unmanagable. With the elbow, temps dropped almost 200* and things were very nice



Keith, I don't want to start a fight or argument, but can you please tell us about some of your testing with the Edge EZ box. You and I have different opinions about the elbow, but never the less, the kind of testing you guys do is priceless! Maybe you can talk to us about the limits of stock turbos on our trucks. You and I have talked about this before in the shop and on the phone. VERY interesting stuff. If I'm not mistaken, you already have an aftermarket turbo for are trucks... ...



Thanks Keith!

 

[KLockliear]

We tested the original EZ with and without the boost elbow on Lawrences' truck when it was stock, pulling his 14k 5th wheel up Potosi (long 7% grade). With the elbow, EGT's were about 50-75* hotter.



Joe Donnelly did the same test with his trailer and found roughly the same thing. Definitely hotter with the elbow. This is why we don't include it.



We've had an upgraded turbo for the 03/04 since last January.

 

[JHardwick]

Originally posted by KLockliear

When running with big injectors (remember our 563hp run? ) when you back off with the pressure up that high, the pressure would actually overpower the gaskets on the relief valve and spray diesel all over the engine compartment.

On a constant flow infection system, such as what we run on our alcohol injected sprint motors, we have 3 bypasses to set fuel mixture.



Main bypass to set overall mixture.



High speed bypass to lean the motor down as the pump keeps building pressure and the motor wants less fuel at the big end ... . 8500 or so rpm.



And a secondary to relieve all that pressure if you have to back out of the throttle for some reason at the end of the straightaway.



All of the bypasses have poppets with a selection of different weight springs and orifice sizes varying in . 001" increments for fine tuning, but the only function of the secondary is to relieve the "backwash" of fuel during a quick shut down.



Think of screaming across a lake with twin 502's WOT ... ... . now shut the throttles down quickly ... ... ... ..... all that water (diesel fuel) coming over the stern (gasket) is the "backwash", LOL.

 

[Mopar_Mudder]

Originally posted by KLockliear

We tested the original EZ with and without the boost elbow on Lawrences' truck when it was stock, pulling his 14k 5th wheel up Potosi (long 7% grade). With the elbow, EGT's were about 50-75* hotter.



Joe Donnelly did the same test with his trailer and found roughly the same thing. Definitely hotter with the elbow. This is why we don't include it.



We've had an upgraded turbo for the 03/04 since last January.

That is interesting seeing as their have been people on these boards that complain of the EGT with the EZ. Then when me and other have told them to put the boost elbow on they say it helps considerably.



I guess maybe on a stock truck that doesn't have the exhaust or intake to take advantage of the more boost it could be a problem. Personaly I run level 4 all the time with the elbow and the EGT's are easy to control, this is pulling 30,000 gross.

 

[JHardwick]

Coming home tonight unloaded and stomping 6th square in the a@@ it was all I could do to get over 1000*. Granted, I redline at 90 because of the gears and it was 25* outside temp.



I still don't understand how a turbo being inefficient will increase intake temps.



I still don't understand how a turbo being inefficient can cause turbulence at the valve head after it has passed 2 conduits and an air-to-air.



I DO however see how an inefficient turbo can cause high EGT's by a restricted exhaust flow getting the boost up to 40#.



What gives here??



As soon as this new box comes out and somebody can give some anwers, I'm going all out ... ... ... ..... @35,000 miles I'm not concerned about warranties and EEP kinda screwed me on my initial purchases of aftermarket parts.



Screw me once and it's your fault, screw me twice and it's MY fault!

 

[BigDaddyMC]

We should probably start another post on this exact subject but here it goes... .



When a turbo starts to become inefficient, it does start to create more heat. Even though it might produce 40psi, it might take 55psi of load to make it produce that 40psi.



The misnomer is that it will gain more heat than it is able to expell. While the equation might be linear in nature, the result isn't quite as simple. while we might create more heat, we're removing it faster than it can be produced. In other words, more heat will be generated but volume wins up to a certain point. When the turbo becomes too inefficient, it will surpass the volume capability.



Now I will concede that I may have the one truck that does this.....



Tell you what I'll do Keith... . I live in Vegas. I've got plenty of time on my hands.....



I'll bring my truck down to your shop along with my Toy Box (8k empty). I'll bring my stock elbow and my boost elbow. You can drive. We'll take two trips "over-the-hump-to-Pahrump". It will take no more than two hours. YOU CAN DRIVE! I'll do all the work. I'll provide you with lunch, and beverage. All I ask is that you report the facts, and speak of me well when you report back.



do we have a deal?

 

[KLockliear]

JH, think of your turbo's efficiency like this... Let's say that from 0-10psi, it creates 10* of intake air temp over ambient per # of boost. So that means it makes 100* over ambient to make 10psi.



Then lets say it makes 15* of intake air temp per # of boost from 11-25psi, so at 25psi it has created 325* over ambient. At 25psi, it's efficiency starts dropping off and now it creates 25* of intake air temp per # of boost from 26-30psi. Now, this last 5psi added 125*... so now we're up to 450* above ambient.



Now lets look at 30-35psi and say it make 35* per # and from 36-40psi it makes 50* per # of boost. So at 40psi, we now have 875* of intake air over ambient. See how that gets worse as we go up?



Now, obviously these are some made up numbers to make a point, but that is the way it works. As you start to get away from the highest efficiency of the compressor map, you make more heat per pound of boost. At a point, the extra heat offsets the extra CFM you have put in the motor.



BigDaddyMC, I'll take your word for it. You are not the only one that said that EGT's went down. Perhaps contact Joe Donnelly... he's got enough free time to play with... maybe he'll be up for the test riding.