This is the second post on this topic becasue i wasnt getting much in response to my last post so i will delete the other one and post this one with a better title to see if i can get some help. I have a 2002 1500 2wd 7" Fabtech (I hope to soon change it to a long travel kit) Silverado with 35" BFG tires. I already up graded to a stock 6.0 and supercharged it with a Maggie Radix MP112 with a 3.1 pulley. It has Doug Thorley short headers, art carr built tranny, 42lb injectors, inline fuel pump,a 40k cooler,stock cats,a flowmaster on it and everything else is pretty much stock. I really don’t think that the headers are hold me back but if they are I will yank the mother fu*kers out! I know I will have to upgrade the rear gears but it just still feels like something is missing. I can still smoke the tires with no problem but my truck is only making 343hp/350torque i did a little search and found people with a similar set up makeing a lot more hp/torque so what the fu*K is going on! I had taken it over to vacaperformance to check it out and make sure everything and by what they said "it running in tip top shape".I did a little search and am finding people with about the same mods as me making more hp/torque WTF! What is going on i was going to start upgrading parts but i need to find out what is going on with my truck. What kind of test or what should i be looking for? I always use 91 octane. i am really not sure what to do I have not had the time to really do a search and read sorry I am currently working 6 days a week and really would appreciate any input besides "use the search button". I am trying to upgrade my gears some time this week.

 

thats not bad IMO for a stock 6.0 with a 112 on it. LT headers and a free flowing magnaflow will help alot though. the 35's are hurting it too. was the dyno in 2nd or 3rd gear? converter locked?

 

I think it's about right given the mods. With 35" tires, the 6.0 would probably put down 250ish rwhp.

 

Sounds pretty close to me. Try some lts and dyno it with smaller tires

 

your tires are taking a lot of your power

 

yeah you tires are stealing about 80hp. Allen dynoed a truck with 35's and then with stockers i believe and its a huge loss.

 

Plus with the 35s, I bet it was dyno'd in 2nd gear (cause I wouldn't want to be anywhere near a full 3rd gear pull with those tires). That also lowers numbers. A 3.1 pulley on a 6.0 might be 5.5-6 psi, so I'd say that was about right.

 

who does your tuning and do you have a cam?

 

I remember seeing a procharged GTO gaining 50rwhp by adding some headers and your flowmaster is probably choke n you up compared to a straight through style. I think the biggest problem is the tall heavy tires though. Sounds like it would be a fun setup to drive the way it is!

 

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