2010 LC9 5.3 need more torque Mod's?
 

2010 CCSB LTZ 6spd auto 3.42 ..........looking to build more low end torque for towing .......any and all advice appreciated

Planned Mods ...... 3.90 or 4.10 gears

Black Bear Tune

Doug Thorley Tri Y headers 1 5/8 primary pipe 2.5 collectors

Magnaflow 5x 22 3"muffler to replace stock muff

Am I missing any major mod to build more low end ?

I realize displacement is the real answer but this is the truck I have ..... my DD truck not concerend with making mor power above 4500rpm

your stock manifolds will make more power down low than LTs. but with LTs your mid/higher rpms will actually do better for passing and such forth. id go 1 3/4" LTs vs 1 5/8" but thats me. also look into a torque designed cam IF you decide to go that route. the 3:90/4:10s is a good idea. the tune is good too. an UD crank pulley wont hurt you either IF you dont wanna do a cam anytime soon

Gears is what is going to help you out the most in this situation IMO.

Like Kenneth said, Long tubes are more top end but still do give you more power thru the power band.

Intake could help but its just a small mod that you probably wont see as huge as a difference as you would with gears.

I love the LSX engine platform but they will always produce peak torque near 4k. That leaves you with three options to make any drastic improvements in your towing capability. 1-Boost, If you can afford a positive displacement supercharger, you get the perks of a big block with none of the draw backs. 2-6.0/6.2 swap, A salvage yard 6.0 or 6.2 would increase power under the curve and might be done for less money than a blower if you can do the install yourself. 3-Trade in for a 2500/3500

Thanks for the input, appreciate it ..... YES I agree the 5.3 is a small motor and will never make great torque down low I have a 04 with a 5.3 and 3.90 gears so I have pretty good idea what it can't and can do towing .....Just bot new 2010 so want to mod it with the right stuff for towing ..... I knew this would be the best place to ask ..... and yes in the end a Whipple might be needed .....still have mixed feedback on a SC for long towing ........I dont tow often but when I do its 1000 mile one way could be an hour or 2 into a headwind that where I need more torque to keep truck in OD current 5.3 likes to berunning at lest 2300 into a headwind in OD .........hoping the new 6 spd will help withthat
I have no need for a street racer I have a car for that ...... this is my DD and I am good with a stock 5.3 for that one of the reasons I did not go 6.2

Headers ....... Interesting comments re pipe size ........I see suggest to go 1 3/4 but that stock manifold will be better than the header down low .......

I have the Doug Thorley Tri Y headers on my 5.3 now and was planning to buy another set for the 2010

Size 1 5/8 primary 2 1/2 collector ........ this style of header "Tri Y " (been around almost since beginiing of headers ....originally designed for small displacement engines in heavy vehicle to build torque)

my thinkling is this sizing/ style would be better than stock manifolds + improving torque / power down real low only losing out to true 4 tube larger pipe LT 's when you get up past 4-5000 ... Comments on that ?? still think I should go to a 1/3/4 headr ??

I dont see many on here ever mention those TRi Y's ........

What are you pulling that you NEED to boost your torque #'s so much?

Good question ..... enclosed car trailer ...... 7000lbs ........ to be truthful I dont "need " more torque if I learned to tow slower and accept the impact of headwinds .......but I would "like" more ........ my current 5.3 does fine 75% of the time just trying to see if I can improve the tow capability on this new truck

I have seen several dyno write-ups comparing primary sizing on the 2010 Camaros, and while they have nearly a full liter more displacement, the dyno showed no loss of low end torque going from a 1 3/4" to 1 7/8" to 2" primary but continued to gain top end power. These tests didn't include any comparison to stepped, tri-y or shortys so there may still be validity to there claimed low end gains.

Yes I would agree with that ...I have seen the same thing on my BBC when we dyno'd different header sizing ...........but as you say we are talking a bigger engine with larger TB / intake/ valve size and redlines pbly far higher than 5000rpm
I am open to going to a 1 3/4 header if it truly has advantage over the 1 5/8 but my assumption is the smaller pipe size will build more exhaust velocity / torque down low .idle to say 4500 over a 1 3/4 header on same displacement ........

I'd stick with the Doug Thorley Tri Y headers, the 2.5" collectors will help with more TQ lower. Since you have the 6sp, I would easily go 4.10s if not a little lower, but I doubt you will be able to hold 6th gear while pulling. Next have Justin set your tow haul up the way you want and as much timing as low in the rpm as you can.