6.2 Performance
 

I know these threads are mostly dominated by the 6.5's but I was wondering what people have done to increase performance of their 6.2's. Whether it be horse power gains or better fuel economy.

exhaust, turning up the pump for more fuel, and more boost. 6.2 and 6.5 are the same basically except 6.5s came with efi and 6.2s didnt. whats nice with the 6.2 is you can unlock free power just with turning the fuel screw compared to efi 6.5s that need a computer reflash. you need gauges though so u dont blow up your engine

0k, so about the exhaust. Stock I have dual exhaust. Aside from removing the muffler to run straight pipes what would you do? 3 or 4 inch? X pipe? Go to single?

do you have a turbo?

No turbo, so far as I can tell its a bone stock 6.2

I'm intersted in what this thread comes up with. I just bought an 86 Suburban with a 6.2 that I would like to step up in performance this next summer.:humm:

Chev6.2 where in Washington you located at? I'm over in the Tri-Cities:rocking:

There's not alot you can do with a 6.2. The biggest improvement would be to add a turbo and turn up the injection pump.

So what's involved with tuning the injection pump? What results are you looking for?

without a turbo you cant really make a whole lot of power. they make headers but thats about it. turning up the pump wouldnt due much because you dont have any air to really burn it. it would just make black smoke.

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but if you really want to make more power putting on a turbo is really easy. all the manifolds and intake swap directly into the 6.2 so all i would do is a go to a junkyard and look for a turbo'd 6.5. you will need gauges and a turbo master but if you keep it under 10 psi till you get new gaskets and turn the pump up a bit you will have a lot powerful truck

The only way to safely boost the 6.2 or 6.5 is with the EFI since it takes into account the boost pressure to increase the fuel supply. The bad part is that i have been told that the 6.2 or 6.5 are not really a good candidate for really turning up the boost because the bearings are not quite as robust as some other diesels. I think years ago Banks had a turbo system for the 6.2 but it was limited ti about 2-3 pounds because Banks found out that any more and bad things started to happen the engine. I haven't kept up with all that so I don't really know where the whole story ended. The 6.5 gets away with a bit more boost because I believe they lowered the compression on the engine and probably some other things as well.

You can turn up the fuel on the 6.2 or even the 6.5 engines that came with the mechanical injection pump. I have one on my 6.5 and did turn up the fuel about 1/6 turn. The process is rather involved, try googleing for 6.2 diesel fuel injection increase. There are a couple of good writeups on the process. Not for the beginner mechanic or too faint of heart. Great fun doing it in a van. I don't think the results were worth the work, yeah it did do a bit better but not that much. Then again I kept it to the slightly gray smoke, not full black and wasting fuel.

Here you go this is one of the better set of instructions
Turn Up the Fuel on a 6.2 - 6.5 GM Diesel Mechanical Injection Pump

There are alot of ways to gain performance, mileage and drivability. The two best upgrades? Turbo ( I run a banks, and it is fantastic) and a GearVendors overdrive. You can get quite the economy with these two additions. As far as turning up the Injector pump, it's alot of work for little gain. It also tends to make the engine run hotter. An electric lift pump can also make the truck much easier to live with; easier starts, less bleeding problems.

I have the electric pump. Installed that when I did the original conversion and have enjoyed the benefits immensely. Would love to have a turbo but have not found one for a van. Then again I stopped looking years ago due to frustration.

do you need a special electric lift pump or does it need to put out the right psi ? could it be for the tank? or inline let me know
:scare2:

No you don't need a special lift pump. The one on the engine will work but I decided to take it off and block off the hole with a plate and use an inline pump from the parts store. This does two things. One it keeps from having a problem with the engine oil getting diluted if the diaphragm on the pump gets a hole and Two it makes fuel filter changes very easy since all you have to do is turn on the key to fill the filter after a change. Keeps from possibly burning out a starter by cranking too long to get the mechanical pump to fill it. :tu:

If you are converting a vehicle that had fuel injection in it then you will have to take the tank out and remove the high pressure pump in there and replace it with a section of hose and the stock sock filter that goes on the bottom of it. Not a big deal at all and you can use the wire that went to the original pump to run your in line replacement. :jump:

I got an 84 6.2 with a banks sidewinder turbo set up, stock it had maybe 2" dual exhaust but I opened it up to a 3" straight pipe and I can feel a little bit more power :jump:

Yeah, the turbo is the way to go. Keep boost under 10 lbs anf egt under 1100.

I call BS
I have a 1992 6.2 n/a I custom built a 4" exhaust 7" tip turned up the fuel pump and added a 6.5 turbo intake to delete the erg and converted to amsoil synthetics
it added tons of power and great fuel mileage

You can get improvements to the 6.2, but will not match a turboed 6.5 that has been similarly tweaked especially if the GM turbo has been scrapped for a better turbo like the ATT. A great build is a 6.2 bottom end with a 6.5 turbo upper end, cost is lowered mpg from a 6.2 n/a to a 17-20 mpg avg depending on final drive ratio a little more with 3:42 and a little less with 4:10s

Hmmm..
Where to start.
OK. First off that is incorrect that the 6.2 lower ends are weaker. In fact the 660 blocks were thought to be the strongest next to a Navistar 506(aka Optimizer/P400).
a 6.5 Turbo setup does not "Bolt on". It can be "made" to fit without alot of effort.
The main issue depends on what body style your truck is. If it's a GMT400(88+ not including 1 ton or K5) yeah it will pretty much bolt right on.
If it's in an older square body...there will be issues . Main one being whether or not you have A/C. Also depends on what year 6.2 and the angle of the injs .
Let's assume worst case scenario and it's an old Square Body, has A/C and has the long style injs.
First issue is the turbo will hit the a/c box.
You either have to ditch the a/c or I have heard people use a modified a/c box from an s10.
Now the long injs hit the ex manifold turbo side so you need shorties and it's still damn tight. You will use many many 4 letter words trying to get the exhaust manifolds on as they nearly touch the frame. Exhaust gets tricky too. Too much to type ight now but most run the main exhaust on the outside of the frame. That is what I did. Drivers side manifold hits the oil lines so either move the oil lines or use the 6.2 manifold and fab a crossover(what I did).
I would strongly recommend Doing the headgaskets. it's easy to do with all the manifolds off. the crap ass printo seal HG's that GM used on 6.2 don't seal worth a crap and the fire rings suck. use 6.5 HG's with ARP studs and you can run 14 lbs of boost easy. You can turn up your existing IP . If you want even more fuel, I swapped my IP to a 4911 of a 6.5 and turned it up. It rolls some coal but damn that truck will run and I see little difference between a DS4 6.5. The DS4 puts out a bit more fuel and the timing curves are controlled better but the sacrifice is reliability. The DB2 is way more reliable. My truck weighs around 7,000 lbs and it runs like a raped ape. Even towing and I have long said the GMT400s run hot because the grilles are poorly designed and too much rap stacked in front. I have owned many 6.5 GMT400 trucks and everyone of them could run hot and high egts. I CANNOT get my 6.2 over 1,000 and that is pushing it hard and even towing it never has gone over 200 although I am running a HO 6.5 cooling system.
Anyway my elbows and hands hurt(damn tendonitis)so chew on that for a bit and ask away.

I am sorry I really hate to piss people off but to say all 6.5/6.2s are week in the bottom end just because you read it or because you can’t build one right! SORRY!
I am one of those people who bleave that the factory did a little better job on mine and that there is no task too hard to handle! I have nothing to ask you or any one easel but not just to say you Esperance makes all 6.5/6.2s bad well that just stupidity not fact
FACT MY STOCK 6.2 before mods with (highway gear) had no problems hauling my z71 with 5.7 at 70 mph with no problems unlike (I CANNOT get my 6.2 over 1,000 and that is pushing it hard ! ) chew on what your own a pos ! Lol great sell it so someone who knows a little bit more about their truck!
The 6.2 and 6.5 from 1992 are all the same the bore is it the problem is they kept the crank too throws boost and too much fuel at it and yea it’s a time bomb! Even under full tow mine will only puff a little I have had it on a dino for 3 weeks straight to know what I know now!
Yep I broke it too but only mudding a turbo and a 6.5 ip turned 3/4 a turn! So yea they are WEAK compared to a Cummins!

SO I SAY GO BACK TO SCHOOL! COME BACK WHEN YOU HAVE NEW INFO!
Its a chevy not dodge (mild power) not balls to the wall power house !

A guy that runs a diesel shop here in Spokane dynoed a little over 300 horses with a 6.2, I know he has propane injection and an hx40.

Look up Davis Diesel and ask for Jeff if you want details on the setup.

You quoted me but I did NOT say they were all weak ????
I said the 506 Blocks were which is a known fact. I assure I have been to diesel school and have worked on them for many many years.

Calling BS to what ? that a turbo addition is not good for the 6.2 ?

MTL, you misunderstood.....
 

Ok, MTL, I do believe you misunderstood Ace's post. Read it again, with my paraphrasing.


"I have owned many 6.5 GMT400 trucks and everyone of them could run hot and high egts. I CANNOT get my 6.2 over 1,000 [egts] and that is pushing it hard and even towing it never has gone over 200 [degrees F] although I am running a HO 6.5 cooling system."


"Anyway my elbows and hands hurt(damn tendonitis)so [think about] that for a bit and ask [questions]."

His "chew on that" was not meant as a "stick that in your pipe and smoke it" sort of phrase.

Aces, correct me if I'm wrong.......

To be honest I don't know what MTL meant. I was agreeing that a 6.2 can be built.

I don't think he knows what he meant. He made two statements at the top, and then contradicted himself at the bottom.

i built a 6.2 in a K5 blazer, i used short injectors, and all the turbo parts off a 6.5 turbo moter... and it would out run my 95 Z71 6.5 turbo truck (that i had also heavly modded) any day of the week... wish i had kept it.. 24mpg was nice:argh:

Banks still makes turbo kits for the 6.2. My dad put one in his '83 Suburban, and was getting up to around 15 lbs. of boost, and a WHOLE lot more power! Actually, the 6.2 with a banks is a considerably higher performance engine than a stock turbo 6.5. As long as you have the tougher, military style 6.2, there's no need to worry about blowing anything up. these are ridiculously tough engines.

You could buy new injectors, turbo it, fuel pump, lift pump. But if I were you I would just buy a 6.5 they are easier to make more power from.