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Tune up on 8.1l 496 cu engine

  #1  
Old 05-15-2009, 08:22 AM
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Default Tune up on 8.1l 496 cu engine

Hello, new to the forums and hoping I'm doing this right.

A few years ago I purchased a beautiful 02 K2500 Suburban with the 8.1l and allison tranny combo; its the best truck I have ever had. I now have 115K miles on it and unfortunately up until now have not had the money to do much to it except oil changes. I'm now ready to do some maintenance; due to the high dealer costs will need to do this myself. So I'm hoping for tips/guidelines and am posting since I read through the whole Silverado forum and didn't find anything.

1. What do I need to do to tune up/maintain the 8.1?
2. I'm planning on switching out the stock instake with a CAI; changing the MAS to a Granantelli and adding a Airraid TBS. Any suggestions on any of this?
3. I'm also going to swap out the stock plugs with E3 Diamondfires; and Granantelli spark wires. Any issues here? Do the coil packs need to be replaced too? I haven't dug around the back side of the engine too much; but is there a dist. cap/rotor that I need to replace?
4. And yes, I'll be replacing the O2 sensor as well as the pvc filter. What else do I need to do?

I appreciate any real world 8.1 experience in tuning and help with this somewhat different engine config than I'm used to.

496Burb
 
  #2  
Old 05-15-2009, 01:30 PM
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There isn't a distributer to replace and the coil packs should be fine. I would replace the spark plugs and wires and do the CAI. Maybe put a better exhaust to help it breath a little better. The mass air flow sensor and throttle body spacer really aren't worth the money unless the the MAF is going bad. A custom tuner is the best thing to do performance wise at the price. Has your truck had any times the check engine light came on? I've always wanted a truck with an 8.1 and six speed trans.
 
  #3  
Old 05-15-2009, 09:38 PM
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Thanks for the input. Got a good deal on the MAF so I'll put it on. Supposed to let 60% more air through than stock. The truck is stock at this point and has never had any check engine lights come on; the dealer I bought it from offers free oil/lube so as long as they stay in business I'll be there. Regarding the tuner; I've read a few different opinions here; will have to dig into that more to see. Initially thought about the Hypertech Hyperpac; very expensive but liked the capabilities of it. Then again I've never used a tuner before so my own thoughts aren't worth much. As for the engine and tranny combo? It's just flat out the best. My own issue with it is that I get a little agressive on the road and want to race cars in acceleration; so best thing for me to do is to change mentally. Other than that it's always got power. Oh; and yes I did see the new Edelbrock/Muncie offering of the 555 cu in.....oh yeah.
 
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Old 05-16-2009, 12:03 PM
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its good to do a lot of that stuff to it but I wouldnt put an aftermarket MAF sensor on it. the stock one flows all you need it to even with its screen in. The problem with restriction is mainly within the tube running from the TB to the MAF. replace it with an airraid tube or do like you said and get an air intake to help solve that.

I really like the 8.1's my dad had a 03 sierra 2500hd with that motor. it would pull like a diesel and run like a powerful gas motor. but that was when gas was over $3 so it got sold.

get you a custom tune from blackbear, westers or wheatley to unleash some true power within it.
 
  #5  
Old 05-17-2009, 03:26 PM
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I've heard the same about the stock mass air flow sensor flowing just as much as an aftermarket one. The screen actually helps it run better because it straightens the air flow to the throttle body. I took the screen off of the mass air flow sensor on my old car and I kept having issues with it later. The check engine light usually came on and the car would surge when I was slowing down. I replaced it with a new MAF and it ran much better and my fuel milage got better too. There are people that buy them but I've never heard any feedback from them about how they perform. I'd like to see pictures of that Suburban though!
 
  #6  
Old 05-18-2009, 10:46 AM
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Everything that I have read about the Bigger, Badder (aftermarket) MAFs is that in order for them to work you really have to get your truck tuned for it. And most people that have them with out a tune said it is a big waste of money. I have been reading about them myself and everything I read leads to the same conclusions.
I have a Hypertech Programmer 3 and a Superchips Flashpaq. They both gave me some more power, but out of the 2 of them the Superchips seems to have given me the most, but I am ready to move up to a true tune, plus other mods 1st... underdrive pulleys, headers, cam,... another new exhaust since my catback system finally rusted out.
Oh as far as plug wires go... stick with the stock factory plug wires unless you are building a bigger badder beast out of that 8.1. The factory plugs handle quite a load. The after market plug wires are not as good as they claim.... Spark plugs that is all up too you. I am going back with regular ol' Bosch platinum plugs. That is what I ran in my 90 model and will run in my 04...
once again I have been reading....
Hope this helps.
 

Last edited by timber74wolf; 05-18-2009 at 10:49 AM.
  #7  
Old 05-20-2009, 01:04 AM
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Aftermarket MAF sensor only if you are changing out your intake to a bigger one and bigger throttle body. And then if your are running a bigger cam. Makes no sense to make the computer pull in more air if your not gonna pour more fuel. And the only reason to pour more fuel is if you have a bigger cam. With the stock cam you will just make the engine run lean. The stock MAF sensor is good for a few steps up cam. Port and polish your own throttle body to increase throttle response. And also a nice less restrictive intake tube to add. Doin that, your gonna need to push more exhaust out. Not much but maybe a cat back. The less restrictive you make the exhaust, the more low end torque you will lose, but you gain it on top end. To fix that, I would add a 2600 stall. Go with electric fans, NGK spark iridium spark plugs. I put them on mine and help a lot with throttle response. The spacer helps with that set up. After all that, get a tune!! I guarantee you will gain more torque than you would doin all that to a 5.3.
 
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