Hey everyone. I have a question with hp loss
I lowered my truck and had to cut out the old tail pipes for clearance. I dont usually drive hard but I noticed it sluggish when I floor it and was wondering if its because it has no tail pipes. the truck is an 05 with the stock 5.3 automatic automatic and has long tube headers full dual 3in with x pipe and 2 magnaflow mufflers and dumps before the axle. I like the way it sounds now but if it helps I would have the muffler shop make new tail pipes. Thats the exhaust it came with when I bought it. I feel like the 3in dual exhaust might be too much for a stock 5.3 especially with no tail pipes

 

I personally don't see how making the tailpipes shortler caused any loss of power. I mean you already have the exhaust going through headers and x-pipe plus 2 mufflers before going to the dumps.

 

I doubt you could gain enough "back pressure" by adding a few feet of tail pipe to matter even if that was an issue.

Now if the exhaust is truly to big.... time to throw a cam or supporting mods onto the engine so that it needs that large exhaust

 

Check for any engine diagnostic codes.
Unlikely but possible it has a knock sensor code or something crazy and it decided to happen at this point. Code like that will pull alot of timing and well, make it sluggish.

 

exactly what I was thinking 😎

 

Yes its been having the knock sensor code.
I wasn't aware that it pulls timing out when that code is on... thank you Ill look into it

 

It feels different but unless you measure before and after performance, you have no hard evidence that it really did slow down. Take it to the track and make some passes.

 

Oh yea it can pull up to about 10-12* or something like that. Makes quite a difference. Especially with the initial throttle tip in.

 

Probably psychological... you're hearing all that extra exhaust noise and your brain thinks "louder = faster" The opposite from hearing a super quiet system where your brain hears an almost silent 5000 RPM and you think the engine is hardly working.

It's sorta like a beginner using a dual action polisher correcting paint. The higher the buffer speed setting, the louder the tool, then the hand speed moving the machine increases automatically. When this happens you are no longer abrading the paint efficiently. Sometimes you have to resist what your brain is actually telling you

Yeah getting tailpipes to fit over the axle and under the bed is a tight fit on dropped trucks. I have the SE true duals and the tails in the kit wouldn't fit. I drove it dumped for a week or so and it was to much for me. Had my muffler guy bend me some tails and added a couple Vibrant resonators before the mufflers... sounds great inside and out.

 

yes at first I thought my mind was playing tricks on me. Cruising felt it little slower but I didn't think much of it till the other day I smashed the gas going 60pmh and nothing like no increase in acceleration rpm didn't go up much and it didn't down **** like it should because it just wasn't accelerating enough. I think is what someone said avobe that if the knock sensor code is on it pulls timing out of and it makes sense.. oh and my truck is not loud like most with no tail pipes