Cheap, cheerful and safe tuning options for a 6.5TD -94?

[Bushido]

Hi all!

The name's Anton, and I'm new to the forums! Nice to meet you all

Please pardon a noob question that's probably been asked a lot before, but I would like some tips and recommendations for cheap, reliable, simple and moderate tuning options for my 1994 Chevy silverado 6.5TD 4x4 truck. Tried searching the forums but couldn't find anything that answered all my questions, so I thought I'd just start a new thread myself.

I'm not looking at making any monster modifications or gaining hundreds of HP, I just want something simple and mainly cheap and hopefully gain a little bit of power, torque and fuel economy Only problem is, I have no experience with these things what so ever... What should I look for? What options do I have? Do I look at tuners, chips, computer programming devices or what? I don't want to look at changing a lot of hardware like the turbo or so, I'll stick with original. And as such, it is imperative that whatever I do get doesn't mess with the reliability of my car. I've got a stock automatic gearbox, stock turbo, stock compression (I do have a homemade 4" exhaust from the turbo downpipe and back though if that makes any difference... Not very pretty but seems to work and sounds really nice) and I absolutely don't want to have to mess about with any of the original components, not to mention damaging or destroying them... So, what options are there that are safe, simple to install and give a moderate improvement of power and fuel consumption? I should probably mention that cost is of the essence and I really don't have a lot to spend... I don't want any cheapskate options that don't do shite, but I would like to spend as little as humanly possible for a working quality product. Again, not looking at anything fancy. Just a little bit of improvement will do, for now

First of all, with rick of making a fool out of myself... Do these really work at all?
http://www.ebay.com/itm/NEW-DIESEL-...ts=Make:Chevrolet&hash=item484615d90d&vxp=mtr

I'm very sceptical against such miracle devices as they are often complete humbug (or at least their effects are often greatly overexaggerated). But if these don't work, then what is there that does and what is the difference? Can I get any decent tuning stuff for say sub $100 or what am I looking at realistically?

Any and all help is much appreciated!

Cheers,
Anton.

 

[red]

for initial performance and fuel economy gains start with the exhaust. a good 2 1/4" or 2 1/2" crossover pipe (connects your driver side exhaust manifold to the passenger side) and a 3" downpipe (where the exhaust goes after leaving the turbo) will help alot.

Another thing that you will need to do if you havent already is to relocate the PMD off of your injection pump and into a nice, cool location. The PMD is the little black electronic box that controls the injection pump (basicly). It doesnt like to get hot, and gm put it right on the motor where it will get hot. Many people here mount the PMD in the front bumper with a heat sink attached to it. Others route it inside the cab or into the air intake box. Thats not for performance but for reliability

 

[Bushido]

for initial performance and fuel economy gains start with the exhaust. a good 2 1/4" or 2 1/2" crossover pipe (connects your driver side exhaust manifold to the passenger side) and a 3" downpipe (where the exhaust goes after leaving the turbo) will help alot.

Another thing that you will need to do if you havent already is to relocate the PMD off of your injection pump and into a nice, cool location. The PMD is the little black electronic box that controls the injection pump (basicly). It doesnt like to get hot, and gm put it right on the motor where it will get hot. Many people here mount the PMD in the front bumper with a heat sink attached to it. Others route it inside the cab or into the air intake box. Thats not for performance but for reliability

Thanks very much for the tips! I'va actually just had the crossover pipe replaced. The previous one was rusted all the way through and all the exhausts were escaping through the rust holes so the turbo had no pressure to speak of at all. I welded up a new one from parts of the old one plus some pieces of scrap stainless piping, and it worked wonders! My pipe is probably nowhere near as efficient as it could be though seeing as how it turns rather sharply and is not really "well made", but I'll try and redo it better next time and hopefully that will give something! Does it matter how big the pipe is or could I make a new one out of say 3" pipe? Or will that have a negative effect on performance?

The PMD has already been relocated and now sits in a heatsink module in the driver side engine bay (opposite of the air filtwer box) And as previously stated, I've built my own 4" exhaust from the turbo downpipe and back (still has the standard downpipe though, and then it tapers slowly up to 4". Seems to provide free bfreathing for the turbo, but again it's probably not perfect. Might redo it sometime in the future.

So, what's the next step?

Thanks for the help!
Cheers!

 

[Suburbank2500]

Hi Anton, and welcome.

Fill in your truck specs/mods in the signature, makes it easyer when helping you.

What is the Km on your truck.
K-47 Aitfilterbox will feed it with more air.
New injectors depending on your km, will fresh it up, and probably be good for mileage to.
There is a various numbers of tuning around, the ebay tune you looked at is probably "no good"
If you want a tune, make it right and get a programmed E.prom, they come in variuos stages a will be fitted to "your" truck, not some universal resistor that doesnt take care of whats needed for a safe, and functional tune.
When tuning its not enough to raise the boost, the truck need the correct amount of fuel, timing+++

 

[Bushido]

Hi Anton, and welcome.

Fill in your truck specs/mods in the signature, makes it easyer when helping you.

What is the Km on your truck.
K-47 Aitfilterbox will feed it with more air.
New injectors depending on your km, will fresh it up, and probably be good for mileage to.
There is a various numbers of tuning around, the ebay tune you looked at is probably "no good"
If you want a tune, make it right and get a programmed E.prom, they come in variuos stages a will be fitted to "your" truck, not some universal resistor that doesnt take care of whats needed for a safe, and functional tune.
When tuning its not enough to raise the boost, the truck need the correct amount of fuel, timing+++

Hi, thanks very much!

Ah, good tip! I'll get right on that!

It has run 230 000 kms and seems to be healthy. Nice and steady idle and very prompt throttle response.
It currently has one of those Open type conical air filters (like a KN filter, but not that brand). It is open both on the outside taper and the inside for increased filter area and looks like this: http://www.biltema.se/sv/Bil---MC/Bil-tillbehor/Tuning/Filter/Sportluftfilter-universal-33230/
The connecting hole is 3" and fits snuggly directly onto the turbo (going to move it to the original air filter box location for cooler air). I do however have no idea if it actually helps or restricts airflow compared to the original filter box... It's just what came with it when I bought the truck.
I understand, I'll add new injectors to the list of things to be done!
Yeah, I assumed that much. Sounded a lot too good to be true (which often means that it is).
Thanks for the advice! Please pardon a beginner question, but what's an e.prom? Where can I find one that will fit my truck (does it need to be programmed on site or does it come with a variety of general pre-programmed settings?) and how much do they generally cost?
Yes of course, and I'm looking to do it right Does a proper tuner take care of it all, or do I need to know what I'm doing in terms of adjusting the pump for more diesel etc?

Thanks for the input, I appreciate it

 

[handcannon]

Basically, the eprom is a computer chip that will alter some of the running parameters of the computer.

The 94 and 95 trucks have a computer that has removable eproms which makes it easy to change them. There are several places to find aftermarket single tunes, performance, towing, economy, etc. Heath Diesel, Kennedy Diesel, etc. Even one you'll find on e-bay (he happens to be a member on this site) that has multiple, switchable tunes on one chip. He is not a vendor on this site so by not mentioning his name I'm hoping to not get him or myself in trouble here. Do a little bit of searching on this site and e-bay and you'll find him.

By the way, the tune is what can adjust fuel flow through the electronic IP.

Don

 

[Bushido]

Basically, the eprom is a computer chip that will alter some of the running parameters of the computer.

The 94 and 95 trucks have a computer that has removable eproms which makes it easy to change them. There are several places to find aftermarket single tunes, performance, towing, economy, etc. Heath Diesel, Kennedy Diesel, etc. Even one you'll find on e-bay (he happens to be a member on this site) that has multiple, switchable tunes on one chip. He is not a vendor on this site so by not mentioning his name I'm hoping to not get him or myself in trouble here. Do a little bit of searching on this site and e-bay and you'll find him.

By the way, the tune is what can adjust fuel flow through the electronic IP.

Don

Ah, I understand! Thanks for explaining! I'll see what I can find, hopefully there's an option that works allright yet is withing my budget

Ok, I see. Then the question is just if my pump is electronic... Didn't the 94s have two different pumps, one electronic and one mechanical? What if I have a mechanical pump, does that limit my options?

Cheers!

 

[ak diesel driver]

2 diff pumps both electronic. the odd one is a 5068. also your PCM is behind the glove box

 

[Bushido]

2 diff pumps both electronic. the odd one is a 5068. also your PCM is behind the glove box

Thanks very much for clarifying!

I found the interchangable tune chip, very tempting but a little expensive at the moment... Are there any cheaper alternatives, or is that one as good as you're gonna get for the money?

 

[1995yukon65]

I run one of the multi tunes in my truck, had it optimized for a larger turbo just haven't put said turbo on yet. It's a very nice setup and simple to install. It's nice being able to adjust it from economy right on up to lots of power without having to actually change chips around. I also used to run a heath tune and that was really nice too.

 

[red]

Does it matter how big the pipe is or could I make a new one out of say 3" pipe? Or will that have a negative effect on performance?

And as previously stated, I've built my own 4" exhaust from the turbo downpipe and back (still has the standard downpipe though, and then it tapers slowly up to 4". Seems to provide free bfreathing for the turbo, but again it's probably not perfect. Might redo it sometime in the future.

So, what's the next step?

Thanks for the help!
Cheers!

with the crossover pipe you dont want to go too large because your exhaust coming from the driver's manifold loses velocity, creating turbo lag. 2 1/4 and 2 1/2 both provide good flow and velocity. With 3" I think you would lose too much velocity, but I don't know if it has been tried.

Good with the exhaust, but replace that stock downpipe. If you take a look at it you will notice that it appears to have been crushed from the factory, very restrictive.

 

[Bushido]

I run one of the multi tunes in my truck, had it optimized for a larger turbo just haven't put said turbo on yet. It's a very nice setup and simple to install. It's nice being able to adjust it from economy right on up to lots of power without having to actually change chips around. I also used to run a heath tune and that was really nice too.

Sounds good! I'd like to get a tuner one day, wuestion is just if I should go for the six version switchable one or be satisfied with something cheaper yet less versatile...

 

[Bushido]

with the crossover pipe you dont want to go too large because your exhaust coming from the driver's manifold loses velocity, creating turbo lag. 2 1/4 and 2 1/2 both provide good flow and velocity. With 3" I think you would lose too much velocity, but I don't know if it has been tried.

Good with the exhaust, but replace that stock downpipe. If you take a look at it you will notice that it appears to have been crushed from the factory, very restrictive.

I understand. Mine is currently 3" overall, but the end bits (the ones that attach into the headers) are stock. I've just replaced the middle bit so to speak. Probably very unefficient, I don't have a pipe bender so I had to resort to cutting and welding which means lots of sharp angles. I did however try and compensate for the unefficient flow by wrapping the entire thing with rockwool insulation in order to preserv heat and speed up the gas flow. Seems to work allright, my turbo sounds like this:
http://www.youtube.com/watch?v=MDDVTvDEmk8

I have noticed, yes. Will try to get it replaced as well

 

[sathackr]

Sounds good! I'd like to get a tuner one day, wuestion is just if I should go for the six version switchable one or be satisfied with something cheaper yet less versatile...

Go with a switchable one...I have one and wouldn't have it any other way. Quite nice to be able to drive a well mannered fuel efficient vehicle, then at the flick of the switch let loose the dragon..whether for towing or just to show off. It's by far the best option for a multi-use vehicle. The single-tune chips seems to be in the $300-$400 range. For just a bit more you get a much more configurable product that is custom tuned to your vehicle and preferences.

For other mods...I'm still new to this but from what I gather, these are the things to do, top to bottom from cheapest to most $$, numbered by importance. For power increase per $$ spent, my multi-tune chip has been the best money spent so far.

(1) Test lift pump, do lift pump mod. ($30)
(7) If it's cold or gets cold where you are, glowplug override (tuning chip negates the need for this) ($30)
(8) High idle switch ($30)
(4) Feed the Beast (fuel line upgrade) ($80)
(6) K47 Intake ($??)
(2) PMD Relocate out of the engine compartment (VERY IMPORTANT) ($100 or $300 with new PMD)
(3) Exhaust (Looks like you've already started this) ($500)
(5) Turbo upgrade. Stay away from GM-X turbos ($400-$900). Your engine will thank you. I know you said you don't want to mess with the turbo, but it is one of the biggest restrictions on this engine.

There are some other upgrades that I haven't evaluated yet...water pump upgrades, fan/fan clutch upgrades, inter/aftercooler/WMI.

If you're going to be pushing it hard at all, an EGT gauge is a must, high EGT is one of the main killers. An upgraded turbo will reduce EGT as well as intake temperatures and possible negate the need for an inter/aftercooler/WMI kit.

My list isn't at all complete but is the main things I've planned for my 1995 6.5.

 

[Bushido]

Go with a switchable one...I have one and wouldn't have it any other way. Quite nice to be able to drive a well mannered fuel efficient vehicle, then at the flick of the switch let loose the dragon..whether for towing or just to show off. It's by far the best option for a multi-use vehicle. The single-tune chips seems to be in the $300-$400 range. For just a bit more you get a much more configurable product that is custom tuned to your vehicle and preferences.

For other mods...I'm still new to this but from what I gather, these are the things to do, top to bottom from cheapest to most $$, numbered by importance. For power increase per $$ spent, my multi-tune chip has been the best money spent so far.

(1) Test lift pump, do lift pump mod. ($30)
(7) If it's cold or gets cold where you are, glowplug override (tuning chip negates the need for this) ($30)
(8) High idle switch ($30)
(4) Feed the Beast (fuel line upgrade) ($80)
(6) K47 Intake ($??)
(2) PMD Relocate out of the engine compartment (VERY IMPORTANT) ($100 or $300 with new PMD)
(3) Exhaust (Looks like you've already started this) ($500)
(5) Turbo upgrade. Stay away from GM-X turbos ($400-$900). Your engine will thank you. I know you said you don't want to mess with the turbo, but it is one of the biggest restrictions on this engine.

There are some other upgrades that I haven't evaluated yet...water pump upgrades, fan/fan clutch upgrades, inter/aftercooler/WMI.

If you're going to be pushing it hard at all, an EGT gauge is a must, high EGT is one of the main killers. An upgraded turbo will reduce EGT as well as intake temperatures and possible negate the need for an inter/aftercooler/WMI kit.

My list isn't at all complete but is the main things I've planned for my 1995 6.5.

Your list is very detailed and a very good place to start I think, than you very much for sharing!

Seems I've got soem options then! I think I will save up for one of the switchable chips, seems to me like everyone who's got one really loves it and that must mean something. Just need to get myself another job, and then I've got work to do!

Just a hypothetical question: What kind of HP gain are you looking at when you complete the list? Do you think you'll need to do something about the gearbox etc or will the original drivetrain stand up to the improved power?

 

[sathackr]

I have no clue about HP gains...that's not really my goal so I haven't been paying attention to the numbers claimed by each modification. From what I read on the forums(fwiw) It seems about 250 rwhp is towards the top end of what these engines can reliably make without serious internal modifications and even then you have to do everything "right"

My goal is to increase the overall efficiency and reliability of the engine, improve my mileage, and occasionally tow an 8000lb boat/trailer. I don't intend to modify the rest of my drive train. From what I understand the 4l80e is a pretty tough transmission and the 14bolt rear ends are nearly indestructable.

I'll qualify this all with saying I've only been here a few months and only know what I've been reading and learned since then, so don't take much of what I say to the bank without verifying it yourself.

 

[Bushido]

I have no clue about HP gains...that's not really my goal so I haven't been paying attention to the numbers claimed by each modification. From what I read on the forums(fwiw) It seems about 250 rwhp is towards the top end of what these engines can reliably make without serious internal modifications and even then you have to do everything "right"

My goal is to increase the overall efficiency and reliability of the engine, improve my mileage, and occasionally tow an 8000lb boat/trailer. I don't intend to modify the rest of my drive train. From what I understand the 4l80e is a pretty tough transmission and the 14bolt rear ends are nearly indestructable.

I'll qualify this all with saying I've only been here a few months and only know what I've been reading and learned since then, so don't take much of what I say to the bank without verifying it yourself.

I understand. It doesn't really matter what kinds of gain you'd make anyhow, their just numbers on a paper. What matters is how the truck behaves, and if you'd have to sacrifice reliability for power I'd rather not temper with it. As I said, I'd rather not mess too much with the hardware because that'd mean a lot more work and extra modifications needed to be done (if you up the power too much for the drivetrain to handle and all that I mean). It's easy to get carried away... What I'm looking for is more of an optimization rather than actual "MORE POWER!". I think your list is a good place to start if you're going in that general direction

Thanks very much man, I appreciate the input

 

[cHEAVYGUY]

Good Thread Guys. I'm currently weighing my options like you Bushido. I'm focusing on PM (preventive maintenance) and the codes i got. So my list kinda looks like this.
1-Code 78 - Low Boost From Turbo. Check Vacuum Components Replace Whats Needed
2-Replace Hydro Boost - Leaking from breather hole under it
3-Transmission Service Fluids Filter And Clean Electrical Grounds
4-Add Grounds From Engine Block To Frame
5-K-47 upgrade
6-Exhaust
7-Visual Stuff Paint and etc...

Good Job Bushido and Good Luck

 

[great white]

http://www.thetruckstop.us/forum/showthread.php?35689-DIY-BD1-Programming-Burn-your-own-chips!