we are going to start fabbing a TT kit for my buddies older N/A chevy deisel- he has full bolt ons and we where wondering how the computer will know when to add more fuel- he is going to get a wideband a/f ratio guage- what should a deisel run @ as far as a safe a/f ratio????

mainly we want to know how to add more fuel to accomadate the twin holset garrett t04e 60trims...

 

AFR on a diesel is constantly changing. You should tune with an EGT gauge.
As far as the PCM "knowing" it needs more fuel. You will need to tell it. With bigger injectors, or more fuel pressure, etc.....
Diesel engines work much differently than gas.....
Gas you control the RPM with a valve in the intake. IE a throttle blade, or carb.
A Diesel is controlled by fuel. You want it to go faster you give it more fuel. So in reality, only Diesels have "Gas pedals" ("Fuel Pedals"), Gas engines have a "Throttle valve controller pedal", or a "Intake air Pedal"...........

 

I bet the diesel guys would be able to help ya, ask in that forum too

 

what about extra injectors?

 

The fuel is high pressure, I don't know exactly what you would need to plumb more injectors. I think you could replace the stockers, then work on the pressure and flow.

 

Also, are you staging to turbos? What are the goals? Any pics?

 

If it's an older 6.5L then I'd probably not waste too much money on it. Not because they aren't decent motors....but because they can't handle the power that non-turbo/turbo diesels that followed it do. Brother has a Tahoe with a 6.5L TD and I've done quite a bit of research on it. Basically the motor is nearly maxed out from the factory....some performance gains to be had but nothing like the PSD's, Cummins, and Duramax's get.

 

Blown 333 is right, sorry but you should leave that one alone. The fuel system can't produce enough fuel pressure or volume to make bigpower and it won't last if you try to. You would have to upgrade the injection pump, injectors, exhuast, intake system, heads, lift pump, valvetrain, so on and so forth... You would be better off to try a cummins conversion or a duramax swap.

 

Easiest thing to do would be to spray some propane. Your best A/F gauge for a diesel is your tailpipe.. No smoke means you're too lean (which is a good thingin a diesel), thick black cloud of death means you're too rich (not good for a diesel). A light haze is usually what you want to have. As far as the computer goes, normally there is a MAP sensor that tells the ECM how much boost there is, however since you're starting out with a N/A, I dont think the one on your truck will read into boost. Best bet would be to try and find a ECM out of a turbo 6.5L.
The 6.5L injection pump insnt that hard to modify if you find the right person who knows what they are doing. You could also hone out the injectors, but EGT control would be a big issue with doing that. A good starting point for the fuel system is a high pressure/ high volume transfer pump, like a FASS system..

 

Well put, it is nice to see someone that doesn't think the thicker the black smoke the better. That is the way these country boys around me think and then they don't understand why we blow past them like they where sitting still while they are pucking out the cloud of death because they think it is cool. HAHA