Fastest 8.1 Thread...
10-28-2011, 10:07 PM
#32
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As for the other question. It's yes and no.
Full bolt ons a 8.1 to a 6.0 they probably pick up the same power. But if you do something off the way like I did a big turbo on a stock motor I don't see a 6.0l making the power.
Before I did the turbo I had wished I had gone with the 6.0l just because there are no real parts for the 8.1l at that time. The big difference in them is towing and bragging right. Big block always sounds better than a small block. We have a 6.0 truck. 8.1 suburban and. 6.2l denali.
The 6.0 was and is a total dog. Also when u up a load behind it the 6.0 sucks on hills. Stock to stock the 6.0l would be wide open with 4.10 gears pulling a mountain where as the 8.1 is just lugging along at a faster speed and in od. Both do fine towing they just get the job done different ways
As for oil some say they some say they don't. Mine uses a little oil but but not enough to worry about. All big motors use some oil. The issue with the 8.1l is the dip stick isn't correct. It's the aNd one used in the 6.0l. Also the low oil indicator for the dummy light is the wrong spot. On mine, beads and drews the still will show its out way low on oil and the truck has 6 quarts left. Also the low oil light comes on at 5 quarts. It's a flaw from gm. Only way to know true oil loss on would would be to refill empty quarts after every oil change. Also they are built to use oil it says it in the owners manual. When I first got it I thought I had major oil issue as well but the gm guy told me I typed above. It get mine to full mark on the dipstick with it running and everything circulation it take 7.5 quarts. If I'm not mistaken at some point there was a topic on this and other mention that the owners manual is wrong for the 8.1l in suburbans on the amount of oil. So 99% of the places that change the oil don't fill it up all the way so you leave a quart or more low to start with. Then she u check it you like holy shot I've used some oil. Ad in the dipstick and now you are really low. It happend to me. I hit the local Buick store for oil change. I didn't check it when I left. Drove 500 miles that night and the light came on. Stick showed it was out. Took almost 3 quarts to fill it up. Next day we covered 1200 miles and it didn't use any.
If I had to do it all over again today I would skip the 6.0 and the 8.1 and do the 6.2. But my trucks range from 10 years old to new. 01, 04 12. With that said I'm thinking about finding a totaled 2500 with the 8.1 and swapping it into something light.
Full bolt ons a 8.1 to a 6.0 they probably pick up the same power. But if you do something off the way like I did a big turbo on a stock motor I don't see a 6.0l making the power.
Before I did the turbo I had wished I had gone with the 6.0l just because there are no real parts for the 8.1l at that time. The big difference in them is towing and bragging right. Big block always sounds better than a small block. We have a 6.0 truck. 8.1 suburban and. 6.2l denali.
The 6.0 was and is a total dog. Also when u up a load behind it the 6.0 sucks on hills. Stock to stock the 6.0l would be wide open with 4.10 gears pulling a mountain where as the 8.1 is just lugging along at a faster speed and in od. Both do fine towing they just get the job done different ways
As for oil some say they some say they don't. Mine uses a little oil but but not enough to worry about. All big motors use some oil. The issue with the 8.1l is the dip stick isn't correct. It's the aNd one used in the 6.0l. Also the low oil indicator for the dummy light is the wrong spot. On mine, beads and drews the still will show its out way low on oil and the truck has 6 quarts left. Also the low oil light comes on at 5 quarts. It's a flaw from gm. Only way to know true oil loss on would would be to refill empty quarts after every oil change. Also they are built to use oil it says it in the owners manual. When I first got it I thought I had major oil issue as well but the gm guy told me I typed above. It get mine to full mark on the dipstick with it running and everything circulation it take 7.5 quarts. If I'm not mistaken at some point there was a topic on this and other mention that the owners manual is wrong for the 8.1l in suburbans on the amount of oil. So 99% of the places that change the oil don't fill it up all the way so you leave a quart or more low to start with. Then she u check it you like holy shot I've used some oil. Ad in the dipstick and now you are really low. It happend to me. I hit the local Buick store for oil change. I didn't check it when I left. Drove 500 miles that night and the light came on. Stick showed it was out. Took almost 3 quarts to fill it up. Next day we covered 1200 miles and it didn't use any.
If I had to do it all over again today I would skip the 6.0 and the 8.1 and do the 6.2. But my trucks range from 10 years old to new. 01, 04 12. With that said I'm thinking about finding a totaled 2500 with the 8.1 and swapping it into something light.
10-29-2011, 01:39 PM
#34
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With conventional oil, 1 quart per 3000 miles is 1 quart per oil change roughly. All my 350's did that.
The 07+ LY6 6.0 is pretty much an LQ4 with L92 heads its rated at 353 hp.
The 6.2 is rated at 393-403hp depending on what its installed in.
The 6.2 works well, but some of its percieved gains come from tha trans ratios as well.
Obviously the .2 extra liters helps with breathing due to the extra bore.
I really think the 8.1 really shines in a towing application, in a performance application there is a tad more room for debate.
peace
Hog
The 07+ LY6 6.0 is pretty much an LQ4 with L92 heads its rated at 353 hp.
The 6.2 is rated at 393-403hp depending on what its installed in.
The 6.2 works well, but some of its percieved gains come from tha trans ratios as well.
Obviously the .2 extra liters helps with breathing due to the extra bore.
I really think the 8.1 really shines in a towing application, in a performance application there is a tad more room for debate.
peace
Hog
10-30-2011, 12:38 AM
#35
A lot can be said for a really good tune as well. I have my tune really dialed so I see almost no KR at all at any rpm which is a challenge on the 8.1`s. I spent a lot of time on the VE table and tweaking the spark tables to get everything just so. And I have left it open loop ever since. I am running what's in my signature and pull consistant 13.60`s in the 1/4 at about 100mph. That's on 6lbs of boost. I burn no extra oil between changes either and the breather tube under the intake is still in place.
10-30-2011, 09:06 AM
#37
Pretty sure that blocking that tube will not net me much more boost then I already see. Several people who have built custom 8.1 setups (including boat guys) do not see much over 6lbs due to the ineffeciency if the 2.3L blower when mated to the 8.1. The kit should have came with the 3.3L from the get go. Sure, I might get another half pound or so by blocking that tube but at the cost of having to spin the blower up far to high. The 2.3L blower just cant handle the load.
I have bounced the idea back and forth of camming it, or heads, or some other things but the truth is I'm am so damned happy with its performance and reliability at this point I don't want to jinx it.
10-31-2011, 06:54 PM
#38
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Yes the TB has the breather in it. There is a bypass hose in the air intake kit that Whipple uses to direct fresh air from the intake tube directly into that port.
Pretty sure that blocking that tube will not net me much more boost then I already see. Several people who have built custom 8.1 setups (including boat guys) do not see much over 6lbs due to the ineffeciency if the 2.3L blower when mated to the 8.1. The kit should have came with the 3.3L from the get go. Sure, I might get another half pound or so by blocking that tube but at the cost of having to spin the blower up far to high. The 2.3L blower just cant handle the load.
I have bounced the idea back and forth of camming it, or heads, or some other things but the truth is I'm am so damned happy with its performance and reliability at this point I don't want to jinx it.
Pretty sure that blocking that tube will not net me much more boost then I already see. Several people who have built custom 8.1 setups (including boat guys) do not see much over 6lbs due to the ineffeciency if the 2.3L blower when mated to the 8.1. The kit should have came with the 3.3L from the get go. Sure, I might get another half pound or so by blocking that tube but at the cost of having to spin the blower up far to high. The 2.3L blower just cant handle the load.
I have bounced the idea back and forth of camming it, or heads, or some other things but the truth is I'm am so damned happy with its performance and reliability at this point I don't want to jinx it.
11-01-2011, 08:25 AM
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wow my post sucked... i hate this web page when using a cell phone..
I tell what i woud liek to do with a 8.1L.... Fine a totaled truck or sububran.. swap that drive train in to a camaro, or nova, or chevelle... slap a turbo on it and ride....
So far on mine i went from 18.9 to a 14.5 once i get the reduced power to quit tripping it will go 13's... Im pretty impressed for a 9,000lbs big tires and stock gears..
Whippled, you will not get the 6 psi if do heads and cam.. also the cam doesnt sound all that mean like it does in smaller motors... you cant even tell i have cam in mine.
If u decide to do something else to that truck, sale the whipple and slap a 72-76 mm turbo on it... set it on 9 -10 psi and hold the hell on..
I tell what i woud liek to do with a 8.1L.... Fine a totaled truck or sububran.. swap that drive train in to a camaro, or nova, or chevelle... slap a turbo on it and ride....
So far on mine i went from 18.9 to a 14.5 once i get the reduced power to quit tripping it will go 13's... Im pretty impressed for a 9,000lbs big tires and stock gears..
Whippled, you will not get the 6 psi if do heads and cam.. also the cam doesnt sound all that mean like it does in smaller motors... you cant even tell i have cam in mine.
If u decide to do something else to that truck, sale the whipple and slap a 72-76 mm turbo on it... set it on 9 -10 psi and hold the hell on..