they are good, but seriously check out walking j designs. especially if you plan on a computer for sure their kojo tune is custom and has great reviews. heath is pricey and fairly generic. i have a heath and like it but for 100 less you can get a kojo and probably more power, swell walking j is the only supplier of an after market turbo. for about 1200 you can get his turbo and tune with heat shield etc and from heath you can get a turbo master which just bumps up boost and his best tune for like 600 with probably much less power. you have a lot of choices. but with 6.5's its best to buy smart as they aren't like cummins or dmax and almost any company can make you power. you want good products , and well thought out mods. my .2$

 

woo! i get 20 cents instead of 2! hehe.

as for this whole idea:
it gets to wait. found out today I may need back surgery (my spine is perfectly straight! YAY! oh wait. . .) and, well, axle disconnects are there for a reason. . .when they don't work, bad things can happen.
so are slipyokes. when a guy forgets to grease those, bad things can also, happen.

.

did check out walking J quick though. 1200 bucks for a new turbo, intake and tune eh? that's not terribad, considering heath want's something in the 700 range for a GM4. I'd get the exhaust from heath, their's looks good and has a muffler of some form. that'd bring it to about 2 grand. then there's other reliability related things I'd have to get. A different balancer is up there. maybe some better cooling (sadly, my 95 doesn't have the whole dual thermostat, 130gpm cooling system a 97+ has, it's on my list) if things start getting hot in the coolant temp side of things.
different head studs are still on there, despite this WalkingJ turbo claiming lower boost with more power. mainly because, I know fro a damned fact I'm gonna go get a Turbo Master kit for the 150 bucks it'll cost, and turn it up some anyway.

but like I said, this all has to wait now. which is, admittedly, kinda ******* ****. I was really looking forward to getting elbows deep into this thing, even though I've never done anything like it and am kinda flying blind.

 

you should change your s-code intake to an f-code, that will gain you around 5 hp because of increased airflow, then find a K-47 airbox which came on all the 2500 and up trucks after 1996, it is the best airbox you can put, and it costs peanuts at the scrapyard, then do your glowplugs and injectors... glowplugs dont give power, but a hole in the piston certainly will reduce your power... and whatever you do, DO NOT turn up your boost with a turbomaster on a gmx turbo ( i refer to the gm turbos as pressure pumps) this is the quickest way to blowing your head gaskets... the idea was given to swap out for a cummins turbo, good idea, but stay away from an hx-35w, unless you lower your compression to around 18:1... try and find yourself a H1C non waste gated from a 1st gen cummins, make sure it is the one with the 18cm housing..... take the kojo tune, and with this turbo you will see 15 psi at WOT, with low drive pressure... excactly the same numbers as the A-team turbo that walking j sells... and swapping head gaskets is a good idea as the first thing to do, put on a set of .010" felpros with ARP head studs... depending on the health of your bottom end, the motor should run along time like this..... but you will not find 300hp at the wheels with only 2500 bucks and bolt-on goodies, the key lies deeper inside....

 

we have run 20 on a stock engine, they hold it well enough, the weakpoint being the lack of head bolts, i would disagree however that they are just plain weak, on another forum we follow a member who is boosting 45-50 psi into a 6.5l... the steps were taken by him to make the motor more able to handle it... and swapping out to a more efficeint turbo goes along way to keeping the motor healthy, you must keep in mind that the turbo used on the 6.5l stock have pretty much the same A/R as the OEM turbo on your MB.... it is a drive pressure nightmare on a 6.5l..... power can be made from this platform, and dollar to dollar it can be done cheaper than on a cummins..... it just cant produce the same numbers....

 

Well, first thing we have to realize here is that the 6.X engines were never meant for big power, but mpg.

That means it's a light duty diesel at best. There are some very real limitations in the design. You have to remember that as delivered from GM, they already have upped the original power by about 40-50%. That's big jump all in itself.

Now, your L56 (L65 is the "F" program) was rated from the OE at 180 @3400 rpm. Keep in mind, the OE's measure this on an engine dyno in perfect conditions with a factory fresh engine and they'll tweek the heck out of it to get it "just right" for peak numbers. Their numbers is suspect for a production block at the best of times. With your couple things and mileage, you're probably (personal guess) sitting somewhere around 160-170 at the crank. Maybe tickling the factory rating if you're lucky. The wheel power will be around 10-15% less due to drivetrain losses (takes HP to spin that slush box, more if you've got a transfer case in the mix also).

I've got a 98 that is not exactly stock (K47, 4" exhaust, 2.5" crossover, Turbo Master, new 6.5 optimizer, WMI, Heath program, etc, etc) and I'm around 200-215 hp at the crank measured with "dynolicious" (highest number measured was 208 HP). Not the best way to measure, but better than guessing at performance numbers based on what you've "bolted on". I also couldn't get it to hook for 10-15 feet (nothing but tire smoke from a standing start, no matter how much you feather the throttle) which effects the numbers. Launching with boost is even more pointless. The numbers may be a smidge higher if I could get it to hook.

(Torque X RPM) / 5252 = HP

(500 X 3400) / 5252 = 332 HP

3400 is getting into the redline too. Not a great idea with 350,000.....

500 ftlb is a lot to ask from a design that was originally made for 257 lbft (6.2 release). Those are VERY big numbers in the 6.x world (Lower than most stock numbers from the OEM's nowadays). Very few have gotten anywhere close to that number and it isn't cheap....

SSDiesel isn't exactly the best place to buy from out there. The same or better parts can be had elsewhere cheaper. Lots of complaints out there on the web too.

Diamond eye is about the best bang for your buck for exhaust. 3" from teh turbo into a 4" with a stainless muffler. Pipes are mandrel bent and fit well (I have on on my truck) but they're aluminized steel.

Intake: find a K47 box (factory RPO code) or the S&B box is a nice alternative (S&B may even be better than a K47). Gets a bit dicey if you start swapping turbo though. May or may not fit. Stay far away from the open element style filters that draw air from the ambient air in the engine compartment. Absolutely pointless....

I wouldn't bother with the resistor. Each step only give you .3 mm3 of fuel. So if you go from a #5 to a #9 it's 1.2 mm3 of "extra fuel". Assuming your engine even has enough swirl and O2 left to burn it properly, it's not enough to notice.

A good place to spend some cash would be Heath Diesel's PCM reprogramming. It's not going to turn it into a firebreathing monster nor will it get you to 500ftlb, but it will wake the truck up nicely. Budget for a Turbo master if you go that way, his program is designed to use one. It DOES NOT like the factory vacuum wastegate system....at least mine didn't. Overboost conditions....

So will an ATT and a kojo program from walking J (around $1200 last time I looked).

If I were you, I'd shoot for the 400-ish ftlb mark. That will make a 6.5 feel nice and peppy.

But it will take some serious cash to gain that 100 ftlb more.

I wouldn't worry about the rest of the driveline holding up, the block will most likely cry fro mercy first. Although, with 350,00+ all components are suspect to failure at any time. Not just with increased power output, they're all tired at this point and can just give up the ghost without warning. Remember; light duty diesel, this ain't no half mill mile capable 6BT....

I dumped a good bit of cash into a block with about the same mileage as you have and was rewarded with a piston crown crumbling. Just too old, too many cycles and it was tired. These things don't last forever (that's why I've got a new Optimizer from GM parts, I'd have had something else but I was stuck in a bad place at the time and had no choice but a new replacement) 350,000 is nothing to sneeze at from a light duty diesel.

As much as we may not like to hear it, if HP is the goal; save your money and buy a better platform to start with (IE:cummins, stroke, DMax). I'm not trying to be negative about the 6.X's, just realistic (IE: $$$$$$$$$$$$ for smaller gains).

My truck, including price of the vehicle and the labor/new engine is in to my wallet for about 16,000-17,000 smackers. Now look back up the post to the numbers I posted it produces......now back at the price in this sentence. Can you get there cheaper? Sure can, but not on a 350,000+ mile unit....

Best advice if you're serous about chasing Hp is to drive your high mileage 6.5 as is, save your money and buy that better starting point when you can.

You'll be there easier and money ahead in the long run with a better starting point. You'll also be poised to surpass your HP goals if you lean that way.

I like my truck and it does what I ask of it (check sig pic), but it's pretty close to the limit of it's potential. It's got maybe another 100HP and 50-70 lbft left in it before it gets to the point where it's high strung and unreliable.

If I had it to do all over again, I would have bought something else with more potential from the get go.....

 

i get it from personal experiance.... around here to buy a cummins truck, need to put minimum 3000.00 for a first gen. truck with no mods... can pick up a 6.5l truck for less than 1000.00, put an exhaust, chip, air filter,new head gaskets, arp head studs and used hx-35 or comparable turbo on it, and make 225 rwhp reliably all day long, and still have money left over to do other things too it out of the 3000.00... i did not say it would make 400hp, those words came from your mouth, i just said that I could make comparable (i guess i should have said stock cummins) power reliably with a 6.5l for cheaper than a cummins..... it is not for nothing tha the 6.5l has a bad rap, as everyone says its junk.... good for me though i guess, makes trucks and engines cheaper....

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hey GW, nice to see you here in the morning...LOL.... turbonator signing off, need to go and work.....

 

Not morning here....and I'm just minding my own business thank-you-very-much.