So you want to buy a Box for your truck....

[JR2]

I thought I would post a link here to a list of "power enhancment" boxes made for our trucks. If you click here you will be taken to a thread that has a link to a list of boxes and some usefull info about each of them. The data was provided by the makers/sellers of the boxes and sent to me when I requested the info from each one.



***As a disclaimer I will say that some of these boxes add alot of fuel and can cause problems to an otherwise stock truck. This data is just provided for you to be able to compare each box.



Oh ya, Welcome to the TDR.





JR2





**Edit** It appears that the website I host the file on is down. The guy that runs it is out of town on his honeymoon... give it a week or so and it wil be back. Sorry.

 

[GCraig]

Hummm,

I have been mildly curious about these "tuning boxes" but am hesitant to slap one on until I understand these engines and specifically the fuel systems much better. Having performed a lot of modifications to a gasser car with fuel injection I have a basic understanding. With that being said we know that an internal combustion engine is nothing more than an air pump. To get more power you have to get more air and fuel into the combustion chambers. I know that many of these performance enhancers can be misleading in their claims. Which lead to my questions.



In stock trim do these Cummins engines "REALLY" have enough extra fuel delivery capacity in the pumps, fuel lines and injectors to safely increase the power level beyond stock? And if so how much before the stock fuel delivery system reaches it's limits? What are the normal steps taken to increase fuel delivery?



What about the turbo-charger, I am assuming these tuning boxes also increase the boost level by altering the wastegate control. How much extra capacity is in the stock turbo before it too must be upgraded?



How is the stock exhaust system in terms of restriction to flow? Most factory exhaust (at least on gassers) are very restrictive and one of the 1st. items replaced when trying to increase performance.



I am a newbe to these diesel powered trucks and would appreciate anybody with experience that could help me learn. Thanks for any help you can offer.

 

[Amianthus]

I was new to this too.

Originally posted by GCraig

Hummm,

I have been mildly curious about these "tuning boxes" but am hesitant to slap one on until I understand these engines and specifically the fuel systems much better. Having performed a lot of modifications to a gasser car with fuel injection I have a basic understanding. With that being said we know that an internal combustion engine is nothing more than an air pump. To get more power you have to get more air and fuel into the combustion chambers. I know that many of these performance enhancers can be misleading in their claims. Which lead to my questions.

You are correct that you have to get more air and fuel into the cylinders to get more power. However, because a diesel doesn't have a throttle (in the classic sense), it gets all the air it needs all day long. You just need to moderate the fuel. A gas engine operates on a 14:1 ratio (pretty sure), where a diesel may idle at a 30:1 and run full out at 3:1 (okay I know that's absurd, but you get the point). So fuel is what you need to add. But there's a catch. In order to get the fuel to burn efficiently, you need to add more air. That's where the turbo comes in. Inefficient burning results in soot, higher EGT's, and could result in engine damage. So the turbo forces more air into the engine to get a more complete combustion.

In stock trim do these Cummins engines "REALLY" have enough extra fuel delivery capacity in the pumps, fuel lines and injectors to safely increase the power level beyond stock? And if so how much before the stock fuel delivery system reaches it's limits? What are the normal steps taken to increase fuel delivery?

I can only speak for the 24 valve in specific, because that's what I have, but I can tell you some things about diesels in general.

The Cummins 24 valve is sold by the HP, not the engine. Cummins programs the engine per application. So you may have a 175 HP engine program, or a 300 HP engine program. With virtually the same components (fuel pump being one of them). There are guys on this board that are running 500+ HP on the stock injection pump. So to answer your question, yes. The system has the ability to add significant amounts of fuel above stock. You just have to know how to do it.

What about the turbo-charger, I am assuming these tuning boxes also increase the boost level by altering the wastegate control. How much extra capacity is in the stock turbo before it too must be upgraded?

Yes, the extra fueling increses boost. But not quite how your thinking. The fueling box itself doesn't alter the wastegate operation. It is set at 21 psi (give or take) and is completely mechanical in it's operation. So the engine has no control over the operation of the wastegate. If you were to add a ton of fuel to get more HP, the wastegate would operate and your boost would stay at 21 psi. Because you won't have the necessary air charge in the engine, you will see a huge increase in EGT's. That's bad. More boost means lower EGT's. But you have to mechanically alter the wastegate to get the turbo to produce more boost. The stock turbo (HX-35w) is efficient up to about 35 psi. Beyond that, you are just wasting energy by spinning it too fast and making more heat. This also results in higher EGT's.

How is the stock exhaust system in terms of restriction to flow? Most factory exhaust (at least on gassers) are very restrictive and one of the 1st. items replaced when trying to increase performance.

For mild BOMBing, the stock exhaust isn't really all that bad. It's pretty beefy from the factory. But if you are thinking of modiying your truck more, a 4" exhaust would be in order. If you really want to go all out, 5" can be had for a price. If you suffer from some sort of envying disorder, there are a couple of places you can have a 6" system made. Cha-ching!

I am a newbe to these diesel powered trucks and would appreciate anybody with experience that could help me learn. Thanks for any help you can offer.

I hope this helped some. The best thing I can tell you is to watch the forums for a little while, do some searches about whatever aspect of this diesel you want to look up and read them. You will have it all explained to you quite well. There are some guys on here that have forgotten more about diesels than I'll ever know, and thier advice is valuable. Best thing is just to read. You will probably understand more about your truck than the dealership you bought it from in less than six months. Maybe you might want to consider looking up some members in your area and meeting with them. There are some great people on this board.



If I muddied the waters above, drop me a note and I will try to correct it.

 

[TxDieselKid]

GAUGES GAUGES GAUGES!!!! You have got to get gauges before you add a "wild" fueling device. One like an EZ are fine, but if you want TST PM3, then you need gauges. Some boxes like the Blue Chip FMS have them built in.



Andrew

 

[mberry]

Excellent post Amianthus(sp?)!



I do have one thing to add though.



A gas engine operates on a 14:1 ratio (pretty sure), where a diesel may idle at a 30:1 and run full out at 3:1 (okay I know that's absurd, but you get the point).



A stock average everyday gas engine is in the 9:1 compression ratio range. The 24V diesel is at 17:1 at idle. I do not know how much that ratio increases with boost, but it may very well run at 30:1 with full boost.



Absolutely gauges first before anything else! My only other advice is to do your research before you get your truck, yourself, and your wallet, into serious trouble.

 

[GCraig]

Amianthus - Wow!!!! Great information, thank you very much. Your reply must have taken considerable time to prepair.

 

[Amianthus]

Not quite what I meant.

The 14:1 is the air to fuel ratio. Not the compression ratio. In a gas engine you need to have this ratio to have proper performance. But a diesel gets all the air it needs. Hence you wind up with variable ratios based on fueling.



TxDieselKid has a good point. Your first mod should be gauges. I would recommend an EGT gauge (0-1500), Boost (0-50 psi), and a fuel pressure gauge (0-30 psi). These gauges would make trouble shooting easier and will also give you a more complete understanding of the dynamics of your engine. They are a must in any case.

 

[amsoilman]

We recently had the 2nd annual dyno days here in Utah, and I can tell you the Cummins 5. 9 can develope some serious power!



"Heber Ram" has a 2001 6 sp. that was dyno'd at 586. 6 HP & 1,465. 3 lb/ft torque! This was accomplished using different injectors, an "Edge Comp" box, an HX-40 turbo and NOS. Without the NOS the HP was 402. 7 and 917. 6 lb/ft torque!



Very impressive!



Wayne

 

[GCraig]

Re: Not quite what I meant.

Originally posted by Amianthus

The 14:1 is the air to fuel ratio. Not the compression ratio. In a gas engine you need to have this ratio to have proper performance.

I thought that is what you meant but It's a little more than proper performance. With a gasser engine if the A/F is too low than the engine will run rich resulting in a loss of performance, and if the A/F is to high it will run too lean which could result in burned pistons. A/F is especially critical with forced induction.



But a diesel gets all the air it needs. Hence you wind up with variable ratios based on fueling.



So if I am understanding correctly there is no throttle body or throttle plate on these Cummins engines and the intact tract is fully open at all times to the discharge of the turbocharger. No wonder the A/F is all over the board.



TxDieselKid has a good point. Your first mod should be gauges. I would recommend an EGT gauge (0-1500), Boost (0-50 psi), and a fuel pressure gauge (0-30 psi). These gauges would make trouble shooting easier and will also give you a more complete understanding of the dynamics of your engine. They are a must in any case. [/QUOTE]



Yes that was a good recomendation and gauges have been ordered and recieved.