Hello. New member. I have a 86 M1009 CUCV blazer 6.2 j-code non emissions motor. I am looking to add a turbo to the blazer for some more power. I have a donor 96 k2500 with a 6.5 that was totaled. The question I have. Will the GM 5 turbo work well on the 6.2 or should I look at other turbos for the swap? The truck is used mainly Offroad. Trailered most of time. I’ve added 40” Bogger’s with steel wheels with rock rings and inner air bead locks. So they weigh 180lbs a piece. The little 6.2 really struggles to turn them
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86 CUCV 6.2 turbo?
- Thread starter Ratkilr
- Start date
Will L.
Well-Known Member
Yes turbo the 6.2. No don’t use the gm turbo unless it is your only option.
Either ATT turbo or hx35/40 hybrid.
I added a gm6 to mine and it is nice the rig can move normal now, but the gm is just too small.
Pics of your ride are more than welcome btw.
You’ll need to turn up fuel screw in the ip, and get turbo injectors instead of n/a ones.
Are you familiar with the pitfalls and fixes for the 6.2/6.5 platform?
Either ATT turbo or hx35/40 hybrid.
I added a gm6 to mine and it is nice the rig can move normal now, but the gm is just too small.
Pics of your ride are more than welcome btw.
You’ll need to turn up fuel screw in the ip, and get turbo injectors instead of n/a ones.
Are you familiar with the pitfalls and fixes for the 6.2/6.5 platform?
ak diesel driver
6.5 driver
I would think for offroad only, as in slow speed, the GM5 would be a good fit
FellowTraveler
Well-Known Member
If I remember correctly the gear-sets are 3.08:1 in that application unless you changed them out.
Will L.
Well-Known Member
@Ratkilr if my take is wrong here, speak up.
The gear ratio is a good point, what gears?
The gm5 would be ok if it was just a trail rig for offroad. But I get the feeling with the tires and wheels being what they are he needs a ton of torque on bottom end, but HAS to play in the mud where he lives. Mud = high sustained rpm.
The hx35/40 is probably better than the ATT thinking about it.
Unless he is running a decent stall, which I doubt.
Hummers with REDICULOUS gearing and 160 pound tire/ wheel combo at 37” tall with 5.21:1 final ratio cant get the power it needs from the gm6 for where he most likely plays- so I really think if he is going to turbo anyways- sell the gm stuff online and get a big boy turbo and let it breathe like it should.
Biggest regret of owning my hummer for the last decade and a half was once I finally put on a turbo, using one I knew was too small because it was more convenient and a little bit cheaper. I would have been better off not driving it at all for 4 months to save the gas money to pay the difference for the better turbo.
Ratkilr- do it right the first time. Just because you have the parts will have you wanting to upgrade before Christmas.
The gear ratio is a good point, what gears?
The gm5 would be ok if it was just a trail rig for offroad. But I get the feeling with the tires and wheels being what they are he needs a ton of torque on bottom end, but HAS to play in the mud where he lives. Mud = high sustained rpm.
The hx35/40 is probably better than the ATT thinking about it.
Unless he is running a decent stall, which I doubt.
Hummers with REDICULOUS gearing and 160 pound tire/ wheel combo at 37” tall with 5.21:1 final ratio cant get the power it needs from the gm6 for where he most likely plays- so I really think if he is going to turbo anyways- sell the gm stuff online and get a big boy turbo and let it breathe like it should.
Biggest regret of owning my hummer for the last decade and a half was once I finally put on a turbo, using one I knew was too small because it was more convenient and a little bit cheaper. I would have been better off not driving it at all for 4 months to save the gas money to pay the difference for the better turbo.
Ratkilr- do it right the first time. Just because you have the parts will have you wanting to upgrade before Christmas.
smokymtn65
Well-Known Member
Welcome, what part of TN?
Jaryd
Extremely Deplorable
Yes we need pictures.
Boggers are one of the best looking tires in my opinion.
Boggers are one of the best looking tires in my opinion.
Consider the GMx turbo's are good from cranking RPM of 150-200 RPM till 2200 RPM. After 2200 RPM they are an Asthma Attack where the engine is fighting them to breathe. High back pressure keeps heat in the engine the cooling system has to deal with. If your offroading and in 4 Low is always below 2200 RPM than the GMx or Banks turbo will do. The second you step over 2200 RPM you are better off NA - Without a GMx turbo. Bigger turbo's like the ATT and HX40II won't light off till 2000 RPM, but, pull like a freight train till redline and beyond.
4 Low WOT going up sand dunes for example is over 2200 RPM. The other extreme is low speed rock crawling.
I run an ATT and stalled it with a Yank converter. I floor it, smoke, then the engine hits 2200 RPM, wait for it, and the ATT lights off. then the smoke is replaced by tire smoke even with a trailer on it. I use 4WD to safely back a trailer because it will hang on a curb and then break the rears loose backing up a driveway. 2WD gets hairy quick with the rear end walking around in reverse with a trailer on it.
Turbo is just one part of the puzzle, others have pointed out the diff gear ratio, and I suggest the converter stall speed will allow bigger turbo's. Other turbo's are now out there like @n8in8or quick rig, but, I haven't run them.
Final thought is this is a short stroke High Speed Diesel. It's not a low RPM lug the piss out of me long stroke Cummins or 180 RPM container ship diesel engine. the 6.2/6.5 doesn't have the HP to backup the torque at low RPM! Without a turbo (or good turbo) the TQ falls off at higher RPM making it a real SOB to get power out of. Rev this engine up with a good turbo and it will give you a better experience than attempting to lug it like GM did with the POS GMx turbo's that really belong on a 4 cyl engine.
4 Low WOT going up sand dunes for example is over 2200 RPM. The other extreme is low speed rock crawling.
I run an ATT and stalled it with a Yank converter. I floor it, smoke, then the engine hits 2200 RPM, wait for it, and the ATT lights off. then the smoke is replaced by tire smoke even with a trailer on it. I use 4WD to safely back a trailer because it will hang on a curb and then break the rears loose backing up a driveway. 2WD gets hairy quick with the rear end walking around in reverse with a trailer on it.
Turbo is just one part of the puzzle, others have pointed out the diff gear ratio, and I suggest the converter stall speed will allow bigger turbo's. Other turbo's are now out there like @n8in8or quick rig, but, I haven't run them.
Final thought is this is a short stroke High Speed Diesel. It's not a low RPM lug the piss out of me long stroke Cummins or 180 RPM container ship diesel engine. the 6.2/6.5 doesn't have the HP to backup the torque at low RPM! Without a turbo (or good turbo) the TQ falls off at higher RPM making it a real SOB to get power out of. Rev this engine up with a good turbo and it will give you a better experience than attempting to lug it like GM did with the POS GMx turbo's that really belong on a 4 cyl engine.
Thanks for all the fast reply’s. The blazer has a Dana 60 and 14 bolt axles out of a m1008 with 4.56 gears lockers front and rear. We busted the aluminum 208 tranfercase early this spring. So I just added a 203/205 doubler. Truck rarely sees any rpm over to 2200. When I had the 208 in the truck it wouldnt pull high4 In uphills or any thick mud. I know the doubler is going to help a lot. But I would still like more low end grunt. And sense I picked up the totaled 6.5 I waesnt sure if the turbo would be good or bad for the 6.2. I know I can’t run more than 10lbs of boost to the 6.2 or blow head gaskets. I’ve already added guages and a EGT gauge. And turn the pump up a little over a 1/8 for now. Oh I live in Clarksville TN. Once again Thank you for all the reply’s. 
I added the Escalade third row seat for the kids so they could have a shoulder belt. They were getting beat up pretty bad in the factory seat. I know the turf is kinda weird but it really helps on the heat that thing puts out though the floor. It’s like riding in a oven in the summer!!
@Ratkilr Let me save you some heartburn about B.S. 6.2 myths. Lets call this the myth busters post.
ECT over 210 is asking for it.
Confirmed. Rings loose their temper resulting in blowby - affects many IDI engines like the Ford 7.3 etc. You watch one guage and thats engine coolant temp. 6.2 and 6.5 like to crack to death especially heads getting hot.
EGT around the melting point of aluminum will s#it melted pistons out the exhaust.
Busted! Although a bad injector will melt a piston with low EGT... I have attempted to s#it pistons out the exhaust sustained 1550 EGT towing a grade for miles and only scorched the turbo blanket. This on a non-coated 6.2 piston bottom end. Note ECT was in control at and under 210. EGT tells you how hard its working, maybe to downshift, and where the turbo might melt - a really high number.
10 psi of boost is the limit of head gaskets.
Busted! the TTY head bolts and lack of them get about a 200k life give or take. Reuse of single use TTY bolts doesn't help this reputation. Combined with high ECT many bolts just fail and let the HG's pop. Factory 6.5's run up to 14 psi. I ran this with TTY bolts. 17+ psi because boost sensor pegs at 17 when doing high EGT run, 24 psi on HX40II, and 15 on the ATT with ARP head studs.
I have found the edge on some things and have the carnage to prove it. Just saying : save some heartburn from old B S. Myths.
ECT over 210 is asking for it.
Confirmed. Rings loose their temper resulting in blowby - affects many IDI engines like the Ford 7.3 etc. You watch one guage and thats engine coolant temp. 6.2 and 6.5 like to crack to death especially heads getting hot.
EGT around the melting point of aluminum will s#it melted pistons out the exhaust.
Busted! Although a bad injector will melt a piston with low EGT... I have attempted to s#it pistons out the exhaust sustained 1550 EGT towing a grade for miles and only scorched the turbo blanket. This on a non-coated 6.2 piston bottom end. Note ECT was in control at and under 210. EGT tells you how hard its working, maybe to downshift, and where the turbo might melt - a really high number.
10 psi of boost is the limit of head gaskets.
Busted!
the TTY head bolts and lack of them get about a 200k life give or take. Reuse of single use TTY bolts doesn't help this reputation. Combined with high ECT many bolts just fail and let the HG's pop. Factory 6.5's run up to 14 psi. I ran this with TTY bolts. 17+ psi because boost sensor pegs at 17 when doing high EGT run, 24 psi on HX40II, and 15 on the ATT with ARP head studs.I have found the edge on some things and have the carnage to prove it. Just saying : save some heartburn from old B S. Myths.
Last edited:
Will L.
Well-Known Member
Awesome truck. Don’t hide the floor grass- that’s wild and different. Heck, you could drive barefoot and feel like strolling through the park on a cozy day. If it’s how you like it- enjoy it- don’t worry what “they” say. Half of them drive hondas so what do they know.
With those gears and tire size, and the slow top speed you drive being trailered everywhere- yeah you could get away with the gm baby turbo. I hate saying it. But only because there are much better options out there.
All the mud on that truck, I inow you are runninghigh rpm to do that. A typical play day with a video camera on the tach would tell ya he story.
If you do go gm turbo, at least do 4” exhaust so it can breathe some. Plan it out so you can swap out a bigger turbo later.
With those gears and tire size, and the slow top speed you drive being trailered everywhere- yeah you could get away with the gm baby turbo. I hate saying it. But only because there are much better options out there.
All the mud on that truck, I inow you are runninghigh rpm to do that. A typical play day with a video camera on the tach would tell ya he story.
If you do go gm turbo, at least do 4” exhaust so it can breathe some. Plan it out so you can swap out a bigger turbo later.
FellowTraveler
Well-Known Member
OMG, That's one awesome Blazer......perhaps the best I've seen lately.
FellowTraveler
Well-Known Member
OH, I didn't see you are new to this forum 'so a warm welcome.'
On another note perhaps a good sized low oost blower/supercharger would be a better choice because boost is instant and I suspect that would be best for your application, however it would be a custom fabrication effort and kits are just too damn expensive IMO.
On another note perhaps a good sized low oost blower/supercharger would be a better choice because boost is instant and I suspect that would be best for your application, however it would be a custom fabrication effort and kits are just too damn expensive IMO.
Can you purchase a passenger side manifold from banks. If a GM turbo would work? Which one would be the best one to have? I know I’ve read a lot about the factory manifold won’t fit and read it will fit with double gaskets-machined spacer and so on??? I want to do this ONE TIME & RIGHT so any help would be greatly appreciated. I am going to switch injectors just havent bought any yet. I’ve got a lot of experiance with gas motors from supercharged to NOS small and big blocks. Like i said before it’s my first diesel and I know 6.2 will never be a Duramax and it’s not the most powerful thing. I just want to help it out@Ratkilr Let me save you some heartburn about B.S. 6.2 myths. Lets call this the myth busters post.
ECT over 210 is asking for it.
Confirmed. Rings loose their temper resulting in blowby - affects many IDI engines like the Ford 7.3 etc. You watch one guage and thats engine coolant temp. 6.2 and 6.5 like to crack to death especially heads getting hot.
EGT around the melting point of aluminum will s#it melted pistons out the exhaust.
Busted! Although a bad injector will melt a piston with low EGT... I have attempted to s#it pistons out the exhaust sustained 1550 EGT towing a grade for miles and only scorched the turbo blanket. This on a non-coated 6.2 piston bottom end. Note ECT was in control at and under 210. EGT tells you how hard its working, maybe to downshift, and where the turbo might melt - a really high number.
10 psi of boost is the limit of head gaskets.
Busted!
I have found the edge on some things and have the carnage to prove it. Just saying : save some heartburn from old B S. Myths.
That is a nice rig!
The 6.2 is the equivalent of a 305 gasser. Turbo'd it's the same 200 HP as a 1995 350, but, more torque.
Look at the 6.5 manifold airflow abortion blowing the drivers side past two 90 cylinders and the two cylinders both have 90 degree exits. Then the tall 6.2 injectors at the wrong angle. After you get it on the damn engine with spacers etc. it won't clear the 80's body on the passenger side and further fit issues with crossover. Even with short 6.5 injectors and spacers the manifold is coming off to change injectors.
Banks doesn't make the manifolds anymore. @Burning oil could ask them. Used kits pop up now and then. Way better choice than the 6.5 OEM krap.
They used to make belt drive blowers for the 6.5. Maybe some still around used.
Far as I am concerned the GM turbo's are scrap metal. Wasted a small fortune in fuel trying to move air and heat through them. I have a problem with limiting an engine to below 2200 RPM, but, I never do that slow offroading. So I would look for a supercharger kit or a Banks kit. Further follow up with some others that have a really tight turbo because I go all out redline needing every HP I can get out of the thing. Time is money esp. with DOT rules limiting time.
Again these engines don't like to be lugged at low RPM and good luck getting the auto trans to allow any throttle (that would light off a turbo) without a downshift to over 2200 RPM. With that little power needed, honestly, I wouldn't bother going through the trouble to put a turbo on at all. The "trouble getting the big tires moving" says "geared wrong" and you will be needing the higher RPM's. Perhaps a 4:1 low ratio transfer case would be a better choice than a turbo. Difference between belching smoke low RPM lugging up the climb or easy throttle on engine at 3600 RPM redline burning clean.
Sand dunes are known to overwhelm electric fan kits due to hitting them WOT in 4 Low on some rigs I have worked on.
The 6.2 is the equivalent of a 305 gasser. Turbo'd it's the same 200 HP as a 1995 350, but, more torque.
Look at the 6.5 manifold airflow abortion blowing the drivers side past two 90 cylinders and the two cylinders both have 90 degree exits. Then the tall 6.2 injectors at the wrong angle. After you get it on the damn engine with spacers etc. it won't clear the 80's body on the passenger side and further fit issues with crossover. Even with short 6.5 injectors and spacers the manifold is coming off to change injectors.
Banks doesn't make the manifolds anymore. @Burning oil could ask them. Used kits pop up now and then. Way better choice than the 6.5 OEM krap.
They used to make belt drive blowers for the 6.5. Maybe some still around used.
Far as I am concerned the GM turbo's are scrap metal. Wasted a small fortune in fuel trying to move air and heat through them. I have a problem with limiting an engine to below 2200 RPM, but, I never do that slow offroading. So I would look for a supercharger kit or a Banks kit. Further follow up with some others that have a really tight turbo because I go all out redline needing every HP I can get out of the thing. Time is money esp. with DOT rules limiting time.
Again these engines don't like to be lugged at low RPM and good luck getting the auto trans to allow any throttle (that would light off a turbo) without a downshift to over 2200 RPM. With that little power needed, honestly, I wouldn't bother going through the trouble to put a turbo on at all. The "trouble getting the big tires moving" says "geared wrong" and you will be needing the higher RPM's. Perhaps a 4:1 low ratio transfer case would be a better choice than a turbo. Difference between belching smoke low RPM lugging up the climb or easy throttle on engine at 3600 RPM redline burning clean.
Sand dunes are known to overwhelm electric fan kits due to hitting them WOT in 4 Low on some rigs I have worked on.
ak diesel driver
6.5 driver
If that thing has a body lift the stock turbo manifold might fit.
Yes its got a 1inch body lift. I had to put it on to get the body to clear the doubler transfer case. Its really more like 1 1/2 almost 2 with the new rubber mounts and 1 inch aluminum slugs. You really don't know how worn out and smashed your 30+ yr old mounts are until you pull them out to put new ones in!