01-15-2009, 12:35 AM | #1 |
Registered User
Join Date: Feb 2008
Location: Grande Prairie Alberta
Posts: 261
|
increase torque
my engine has no balls when it comes to lower rpms. whats a good way to increase engine torque without spending much money.
__________________
eh 1970 Chevy C20 daily driver 1975 GMC Jimmy 4x4 project 1966 GMC C10 Dad's project |
01-15-2009, 12:38 AM | #2 |
"the other guy"
Join Date: Oct 2008
Location: Olivehurst California 95961
Posts: 901
|
Re: increase torque
what type of manifold are you running? single plane will kill low end performance. also what head/cam combo?
__________________
God Said,"Building A 10 Second Import Is Like Coming Out Of The Closet, In The End Ur Still....."EXPLETIVE" |
01-15-2009, 12:40 AM | #3 |
Eat My Rust
Join Date: Jan 2007
Location: Cypress, Texas
Posts: 3,362
|
Re: increase torque
Manifolds > Headers at low end torque.
A stock intake will often times yeild better low end torque then aftermarket ones aimed at more upper end HP. |
01-15-2009, 12:58 AM | #4 |
Senior Member
Join Date: Sep 2004
Location: Terrell, TX
Posts: 1,967
|
Re: increase torque
For your headers, best bet is shorty headers with small tubes [1 1/2"] and exhaust pipes no bigger than 2 1/4"....2" is better for low end torque.
A daul plane manifold that gets best performance at 1500 rpm and up will do fine. Edelbrock's Performer EPS does this. If you really want to move when towing or hauling, get a mild cam that comes in around 1000 rpm. I have this setup on a mostly stock 350....moves nicely off idle for a 4300lb truck with 400 lbs in it daily [me and a few tools].
__________________
Kelly '05 GMC Sierra SLE Z71 Bone stock except for new bed rail caps. |
01-15-2009, 09:18 AM | #5 |
Registered User
Join Date: Feb 2001
Location: Wetumpka, Al, U.S.
Posts: 8,892
|
Re: increase torque
What motor is in your truck?
__________________
Kevin Special Thanks to All who have helped on the TRUCK! My Pass Time Show http://s129.photobucket.com/albums/p...Chapter1-0.mp4 So Far my best Times are: Motor only: 6.44 1/8 @ 104.13 10.39 1/4 @ 125.83 Nitrous Times: 5.785 1/8 @ 118.65 with a 1.336 60ft 9.168 1/4 @ 142.58 with a 250 shot dead out of the hole! |
01-15-2009, 09:23 AM | #6 |
Eat My Rust
Join Date: Jan 2007
Location: Cypress, Texas
Posts: 3,362
|
Re: increase torque
|
01-15-2009, 12:47 PM | #7 |
Hittin E-Z Street on Mud Tires
Join Date: Nov 2004
Location: Greenville, SC
Posts: 23,090
|
Re: increase torque
What rear axle do you have?
__________________
Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride American Born, Country by the Grace of God 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications! |
01-15-2009, 01:44 PM | #8 |
Registered User
Join Date: Jan 2007
Location: Topeka,KS
Posts: 778
|
Re: increase torque
For what you got I would have to say your cam is the problem. It must be a top end cam. I'd put the lowest or next highest (from the lowest) RPM range perf. cam they make.
|
01-15-2009, 02:12 PM | #9 |
Registered User
Join Date: Feb 2001
Location: Wetumpka, Al, U.S.
Posts: 8,892
|
Re: increase torque
I would say the cam is the problem also.
__________________
Kevin Special Thanks to All who have helped on the TRUCK! My Pass Time Show http://s129.photobucket.com/albums/p...Chapter1-0.mp4 So Far my best Times are: Motor only: 6.44 1/8 @ 104.13 10.39 1/4 @ 125.83 Nitrous Times: 5.785 1/8 @ 118.65 with a 1.336 60ft 9.168 1/4 @ 142.58 with a 250 shot dead out of the hole! |
01-15-2009, 06:21 PM | #10 |
I am a Referee of life.
Join Date: Jun 2000
Location: Greensboro N.C.
Posts: 13,992
|
Re: increase torque
I agree with the cam.The biggest performance mistake most people make is to overcam overcarb an engine.Rather than matching components for the overall type of performance they go for the "Bigger is better" plan that doesn't work for anyone but goverment.
__________________
The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil" |
01-15-2009, 06:57 PM | #11 |
Registered User
Join Date: Jun 2008
Location: South Florida
Posts: 11,375
|
Re: increase torque
I would look at two items :
rear end gears and what cam do you have... I agree that sometimes you can over cam a motor killing it's low end torque and power.
__________________
Get your facts first, and then you can distort them as much as you please!!!!!. Sylvester's build thread >>>http://67-72chevytrucks.com/vboard/s...ht=big+rebuild |
01-15-2009, 08:46 PM | #12 |
The Early Chevy Van Man
Join Date: Dec 2008
Location: Seattle, WA
Posts: 76
|
Re: increase torque
What camshaft, what intake, and what carb are you running? what are your rear gears? I agree with the posts above that state you may be overcammed. Bigger is not better for a street driven heavy vehicle with a small v8. Big cams sacrifice low end torque for mid-upper RPM power.
Another thought: Maybe the HEI is not timed as well as it could be? Consider your initial advance as well as mechanical advance. Perhaps swapping to lighter springs in the HEI would help to bring total timing in earlier. Also check out your vacuum advance... is it even working? look for vacuum leaks on the engine... that will definitely hurt performance! Maybe the carb is not jetted as well as it could be? Maybe the secondaries are not opening soon enough?
__________________
64 Chevy Van 65 GMC Handi-Van 99 2500 silverado 4x4 ext cab |
01-15-2009, 09:55 PM | #13 |
Registered User
Join Date: Feb 2008
Location: Grande Prairie Alberta
Posts: 261
|
Re: increase torque
i couldnt really tell you what exactly what the engine has cause the po did all the mods to it before i bought it. it has 4.11 gears, the timing is set to 10 tdc at idle, cant remember what the total advance is, im planning on switching to manifold vacume soon but i dont know what it does to engine performance. over the weekend il probably pull the valve covers to get the head numbers. i was thinking of gettin a gm aluminum intake cause a good friend of mine said they are one of the best manifolds out there, hes runnin them on his 67 c10, his 80 vette, and i think his dad has them on his 72 cheyenne. heres some pics to see what i know i have.
__________________
eh 1970 Chevy C20 daily driver 1975 GMC Jimmy 4x4 project 1966 GMC C10 Dad's project |
01-15-2009, 11:00 PM | #14 |
Registered User
Join Date: Apr 2006
Location: Warrenton VA
Posts: 144
|
Re: increase torque
Cadillac 500. GM 502. GM 454.
Just kidding. All the above info is right on the money.
__________________
'71 C-10 with 5.3 LS2 cam & NWC T5 - Patina King! '83 Jeep Cherokee w 5.3 LS9 cam & SM465 NP208 swap in progress '92 Volvo 960 wagon w 5.3 LS7 cam & WC T5 swap in progress '79 Porsche 911 SC '48 Spartan Mansion 30' travel trailer '10 Porsche Cayenne S - Daily |
01-15-2009, 11:56 PM | #15 |
Registered User
Join Date: Feb 2001
Location: Wetumpka, Al, U.S.
Posts: 8,892
|
Re: increase torque
gm sells a cam they call a 300hp 350 cam and they work well without killing all your torque.
__________________
Kevin Special Thanks to All who have helped on the TRUCK! My Pass Time Show http://s129.photobucket.com/albums/p...Chapter1-0.mp4 So Far my best Times are: Motor only: 6.44 1/8 @ 104.13 10.39 1/4 @ 125.83 Nitrous Times: 5.785 1/8 @ 118.65 with a 1.336 60ft 9.168 1/4 @ 142.58 with a 250 shot dead out of the hole! |
01-16-2009, 07:11 PM | #16 |
Aluminum slot wheels rule...
Join Date: Jan 2006
Location: Maine
Posts: 6,211
|
Re: increase torque
My 350 in my GMC has a Crane "truck-power" cam, headers with 2'' duals, edelbrock intake and a holley 600 4bbl, and for a big old truck, she friggin flys!!! I'm thinking about a different set of heads though, I think mine now are holding my engine back alot, powerwise.
PS...cam specs are .427/.454 lift...look up Crane truck power cams in either a jegs or summit catalog, it'll be right there. Last edited by JAKES 68GMC; 01-16-2009 at 07:15 PM. |
Bookmarks |
Thread Tools | |
Display Modes | |
|
|