6.5 BOV
#1
02-24-2016, 10:48 PM
6.5 BOV
I replaced my banks 6.2 with 6.5 GEP block and am keeping the banks set up.
My 6.2 regularly hit 12-14 pounds of boost and I threw a few rod bearings.
I am going to fab up an new intake/pipes and I thought about adding a blow off valve.
Since the banks doesn't have a wastegate, I thought a BOV would allow me to control the amount of boost.
I am guessing this isn't popular since I can't find much on it.
Any ideas?
13
My 6.2 regularly hit 12-14 pounds of boost and I threw a few rod bearings.
I am going to fab up an new intake/pipes and I thought about adding a blow off valve.
Since the banks doesn't have a wastegate, I thought a BOV would allow me to control the amount of boost.
I am guessing this isn't popular since I can't find much on it.
Any ideas?
13
#2
03-03-2016, 10:48 AM
No BOV for the 6.2/6.5 not required, that is a gasser item that has throttle plate that goes closed on decel and the turbo needs to vent off via a BOV .
a 6.2/6.5 has open intake nothing to slam shut on a throttle decel IP just stops sending less fuel to injector and it can handle any "extra air" still in the turbo as it spools down.
Why/how were you running that much boost not good for the 6.2 or even 6.5 if running sustained boost at those levels.
GM cuts back fueling and opens waste gate on the 6.5 turbo to maintain around 6 psi max sustained boost 2-3 is normal cruise boost allowing for excursions to 12-14 psi but PCM does not allow for sustained boosting there.
Above 10 psi on a hot day and IAT really climbs fast and since you don't have an IC like later DI engines have the cumulative effect is not good if running sustained boost.
The Banks turbo kit was/is a marginal performer better than no turbo, since to have 6.5 block now maybe look for somebody that swapped out their waste gated GM-8 turbo for a better one, convert yours to the GM turbo with a mechanical waste gate control or my personal favorite the ATT turbo with no waste gate.
You did not say your goals/use of the truck towing/daily driver ??? that might help to better define where to spend your $$$
The Banks not having a WG is not the issue, heavy foot is
, as soon as you let off the foot/accelerator less fuel to make the exhaust gas turbo starts reducing boost.
It would be interesting to get a drive gas pressure reading of the Banks turbo at high speed, high exhaust back pressure can cause extra stress at high boost, similar problem 6.5 turbos have running sustained high boost, ATT is a lower back pressure turbo less stress on engine mechanical parts, HXs also less back pressure.
You also may have just gotten some "tired iron" hi mile issues when you "upgraded" to the Banks kit, did you also "turn up the wick" on the IP for more fuel ? Any Ideas what EGTs you were running ?
a 6.2/6.5 has open intake nothing to slam shut on a throttle decel IP just stops sending less fuel to injector and it can handle any "extra air" still in the turbo as it spools down.
Why/how were you running that much boost not good for the 6.2 or even 6.5 if running sustained boost at those levels.
GM cuts back fueling and opens waste gate on the 6.5 turbo to maintain around 6 psi max sustained boost 2-3 is normal cruise boost allowing for excursions to 12-14 psi but PCM does not allow for sustained boosting there.
Above 10 psi on a hot day and IAT really climbs fast and since you don't have an IC like later DI engines have the cumulative effect is not good if running sustained boost.
The Banks turbo kit was/is a marginal performer better than no turbo, since to have 6.5 block now maybe look for somebody that swapped out their waste gated GM-8 turbo for a better one, convert yours to the GM turbo with a mechanical waste gate control or my personal favorite the ATT turbo with no waste gate.
You did not say your goals/use of the truck towing/daily driver ??? that might help to better define where to spend your $$$
The Banks not having a WG is not the issue, heavy foot is
, as soon as you let off the foot/accelerator less fuel to make the exhaust gas turbo starts reducing boost.It would be interesting to get a drive gas pressure reading of the Banks turbo at high speed, high exhaust back pressure can cause extra stress at high boost, similar problem 6.5 turbos have running sustained high boost, ATT is a lower back pressure turbo less stress on engine mechanical parts, HXs also less back pressure.
You also may have just gotten some "tired iron" hi mile issues when you "upgraded" to the Banks kit, did you also "turn up the wick" on the IP for more fuel ? Any Ideas what EGTs you were running ?
#3
03-03-2016, 03:21 PM
"Why/how were you running that much boost not good for the 6.2 or even 6.5 if running sustained boost at those levels."
My J code 6.2 was original to the CUCV. I added the banks kit and only turned the IP up to 1/4 turn as per the instructions. But it might have been turned out before hand. I am running a 4.88 gear with 37" tires and 700r4. The truck would hit 12-15 PSI regularly and hit 17 PSI when I first installed it. I drove it for over a year and ended up throwing a few rod bearings from the heavy foot you referenced. EGR never went over 1000. These results are not typical so I really can't explain why it would be packing that much boost.
"You did not say your goals/use of the truck towing/daily driver"
I will never tow with this truck. I DD a duramax - enjoy working on older chevy trucks. Since I live in CA, diesel trucks or diesel titled trucks are the only ones worth messing. My time has been spent on a LS3/NV4500/Doubler swap into a diesel 85 K30 with 40", king coilovers and 4 link before I blew up my K5 6 weeks ago.
A while back I parted out a 96 one ton with a new 6.5 that the guy had built with a Navistar GEP block. I bought some heads and had them worked over. Converted the truck 12v so I could run the serpentine. Using a ported HMMV intake and fab'd up a custom intake as the banks intake + J code (dual plane) didn't flow well. New IP from a 93 to keep with mechanical and 3" down pipe to 4" straight pipes once I ditched the banks muffler.
The truck came with a stock turbo but I am going to run the banks kit just to see how it will perform.
My thoughts are with a new block, 6.5 HMMV injectors, new IP pump, heads, HMMV lower intake, custom upper intake and ditching the banks air box the truck will perform.
I was looking at adding mechanical BOV on the intake pipe to limit boost as the Banks doesn't have a WG. It doesn't seem that complicated or I could just watch the boost gauge and not just mash the skinny pedal.
I will have back together today or tomorrow, so I will let you know how it goes.
13
My J code 6.2 was original to the CUCV. I added the banks kit and only turned the IP up to 1/4 turn as per the instructions. But it might have been turned out before hand. I am running a 4.88 gear with 37" tires and 700r4. The truck would hit 12-15 PSI regularly and hit 17 PSI when I first installed it. I drove it for over a year and ended up throwing a few rod bearings from the heavy foot you referenced. EGR never went over 1000. These results are not typical so I really can't explain why it would be packing that much boost.
"You did not say your goals/use of the truck towing/daily driver"
I will never tow with this truck. I DD a duramax - enjoy working on older chevy trucks. Since I live in CA, diesel trucks or diesel titled trucks are the only ones worth messing. My time has been spent on a LS3/NV4500/Doubler swap into a diesel 85 K30 with 40", king coilovers and 4 link before I blew up my K5 6 weeks ago.
A while back I parted out a 96 one ton with a new 6.5 that the guy had built with a Navistar GEP block. I bought some heads and had them worked over. Converted the truck 12v so I could run the serpentine. Using a ported HMMV intake and fab'd up a custom intake as the banks intake + J code (dual plane) didn't flow well. New IP from a 93 to keep with mechanical and 3" down pipe to 4" straight pipes once I ditched the banks muffler.
The truck came with a stock turbo but I am going to run the banks kit just to see how it will perform.
My thoughts are with a new block, 6.5 HMMV injectors, new IP pump, heads, HMMV lower intake, custom upper intake and ditching the banks air box the truck will perform.
I was looking at adding mechanical BOV on the intake pipe to limit boost as the Banks doesn't have a WG. It doesn't seem that complicated or I could just watch the boost gauge and not just mash the skinny pedal.
I will have back together today or tomorrow, so I will let you know how it goes.
13
