1999 6.5L Performance upgrades

[scot5146]

Hey everyone-

Ok well this is the story I have moved from the 6.2l diesel section because my 1987 Suburban blew up and i am tired of dumping money into it so its going to be a parts rig...

Anyway my NEW (at least to me) 1999 K2500 suburban 6.5L diesel with 100k on it just pulled into my driveway and shop...

Now I am excited to put on some upgrades to get the best combo of power and towing ability as well as mpgs...

SO ANY SUGGESTIONS ON WHAT I SHOULD CONSIDER DOING TO IT....?

It was regularly maintenance and has no issues, the past owner is the original and a good friend of mine...

I was thinking of 4 inch down pipe/ exhaust, cold air intake... And curious about water/ methanol injection (has anyone used it and is it safe for a diesel)

Maybe a upgraded cpu from heath or ssdiesel etc... Any ideas? oh and a special thanks to everyone who helped me try and fix my old 87 6.2L...

[6.5 Detroit Diesel]

Do the four inch. It will make a world of difference along with a good d/p. sounds like your on the right track to start.

following the exhaust, get a program done for the truck in conjunction with some sort of turbo control.

personal opinion is to use heath or kennedy. ssd sucks.

i am working on a different intake system for our 6.5's, but if you are keeping the stock box, get a good filter. current CAI on the market are pretty crappy. they will work if you port behind the marker light, otherwise, they draw air from a hot area.

w/m injection can be used safely. i ran a system on my truck that made a huge difference in cooling and with a 30-35% methanol mix made a very noticeable difference in power. most guys would run like a 10% mix on the 6.5's.

If your still looking for some more power, then hi-performance injectors in conjunction with your program.

while your doing all this, don't forget your cooling. w/m injection will take care of that, but if you don't do that, look at upgrading your cooling system.

good luck with the burb'!

[6.5 Detroit Diesel]

oh, and i didn't ask, but i am guessing the PMD is relocated?

if not, you can extend it.

make sure the ground remains running to the pump or you won't get a start.

i moved mine in behind the drivers headlight. keeps it cool and out of the way.

[Kennedy]

Gauges first, then exhaust, chip/programming, and injectors.

A 4 " exhaust will gain you nothing but noise over a 3.5" system.

Make sure that the raidator is clear.

[ted2020]

What is the advantage of relocating the PMD?

[6.5TDTahoe]

Not made ! 3 in. mandrel bent is is the largest down pipe made & will fit.. The rest can be 3 or 4in. STANS in washington state has the complete kit. Enjoy your new ride.

[AllThumbs]

I'm currently in the middle of a project, I'll let you know how my stuff turns out and maybe a help to you in deciding what to do. The good part is, all this stuff bolts on and you can do it one at a time and see how each part helps. I do have a pickup instead of a burb, but I don't think that makes a lot of difference.

[scot5146]

Thats all great ideas, just what I am looking for, but bare with me because I am still new to diesels...

Q: what is the PMD and what does it do? why do I need to move it?

Thanks again

Mike

[AllThumbs]

PMD - Pump Mounted Driver. It is the electronic controller for your fuel injection pump. They generate a terrific amount of heat and if not kept cool will fry. One of the biggest problems with the 6.5 TD. Moving them to a remote, cool location extends their life (good since they are expensive). You can't run without one and anything that will extend their life is good. Costs to move them to a cooler place. Costs more and is less convenient to replace if you don't.

[6.5TDTahoe]

The 99 Suburban, trucks has the best & final cooling system up grade courtsey of GM The cooling fan,fan clutch & f an blade was the final 6.5 upgrade by GM. . check the thermostats to see what the part numbers are. Should be AC Delco/ or GM 192 degree version. Original equipment GM12559936 or Delco131-103 part numbers. These engines are intolerant of temps over 205 degrees. I Recommend a well lighted capillary tube gauge & you watch the gauge!!!!

[6.5 Detroit Diesel]

Not made ! 3 in. mandrel bent is is the largest down pipe made & will fit.. The rest can be 3 or 4in. STANS in washington state has the complete kit. Enjoy your new ride.

well aware of that fact. only way to do a 4" is a completely custom system.

whether or not a 1/2" will make a difference is really up to you.

if you are just doing light towing, you shouldn't really have any issues with EGT's. i have repeatedly pulled 10K+ without any issues and only have a 2 3/4" straight exhaust and a GL4 program.

to each his own, just sharing what i have done to all my trucks and what has worked for me with EFI and MFI.

[16gaSxS]

Gauges first, then exhaust, chip/programming, and injectors.

A 4 " exhaust will gain you nothing but noise over a 3.5" system.

Make sure that the raidator is clear.

I'm with John........

[scot5146]

thanks everyone! I found a exhaust system and I am in process of relocating the PMD...

How about CPU upgrades and Cold air intake, any specific brands to buy/ watch out of etc...

also my rig seems to be running very cool, maybe (180*) is this OK?

Thanks Again

Mike (New Guy)

[93GMCSierra]

thanks everyone! I found a exhaust system and I am in process of relocating the PMD...

How about CPU upgrades and Cold air intake, any specific brands to buy/ watch out of etc...

also my rig seems to be running very cool, maybe (180*) is this OK?

Thanks Again

Mike (New Guy)

Where you located, if you live in cold climate and dont have sometype of winterfront on then that is very normal.

[scot5146]

I am in Oregon/ Washington on the westside so it never really gets that cold... So is that still an ok temp for normal operations? 175-180* ish...

cold air intake... Suggestions on brands for a 6.5 TD?

Thanks

Mike

[AllThumbs]

I've had your same question on cold air intake and have been told the 1999 stock is a good as you can get. I bought one and can't believe the size of the filter. You might see what choices there are out there for filters, I'm putting an Amsoil on mine.

So far on my project, I have new injectors, new glow plugs and 4" exhaust. I have not had any real time yet to drive it, but what little I have, the difference is startling. I'm well pleased.

Performance chip and intercooler next. They are here but not on yet.

[suburbanK-2500HD]

Where du you plan to install the IC.

[16gaSxS]

I am in Oregon/ Washington on the westside so it never really gets that cold... So is that still an ok temp for normal operations? 175-180* ish...

cold air intake... Suggestions on brands for a 6.5 TD?

Thanks

Mike

HMMM, someone could have put 180 degree thermostats in, some folks do that for towing. If you replace them with standard 192-195 IIRC you'll get bit better MPG's and you'll run at the designed temps.

[scot5146]

HMMM, someone could have put 180 degree thermostats in, some folks do that for towing. If you replace them with standard 192-195 IIRC you'll get bit better MPG's and you'll run at the designed temps.

thank you very much thats what I was looking for, does anyone know the
AC Del-co part # for the thermostat for a 99 6.5 TD?

Thanks everyone for all the help, you all are fantastic!

Mike

[scot5146]

My 1999 Suburban that I have been asking about has 2 thermostats???????

I took it into Mac's radiator here in Vancouver WA and had all the coolant flushed and the radiator serviced...

I found out that I had 2 thermostats... SO are my temps correct or is something screwed up?

I am constantly running at about 170* it is not even half way on my gauge between 160 and 210* I figured it had lower temp thermostat maybe the owner before me put in for towing or something...

Come to find out it has 2 of them and after the shop replaced them with OEM stock (NEW THERMOSTATS) I am still running the same temps....

IS THIS NORMAL?

The main reason I am asking is because I am in process of lots of upgrades, but I dont want to overheat / underheat my motor...

1999 K2500 Suburban
6.5 TD, 116k miles

Thanks Again:
Mike