retarding the cam

[megaladon6]

my car has a ton of torque at the low end, it's fun but i'd like to have a slightly less touchy throttle. it spins the tires with less than 1/4 throttle and i still have the stock converter in. how much of a difference will retarding the cam make?
it's a 9.8:1 383ci w/vortec heads, compcams xe274h-10, performer intake, and presently a holley 4175 carb.

[68Formula]

Take about 4° out should make it a little less touchy.

[pdq67]

I'd install it "straight-up" at 110/110 and see how much lowend I pulled out of it for starters!

pdq67

[megaladon6]

well comp cams grinds them 4* advanced and it's installed on the "centerline" so i think 4* retarded would put it to "straight up".
how much does 4* move the powerband? i'm just wondering if it's gonna be worth it to try since i don't have a 2-pc timing cover.
sorry if i have the terminology wrong, this is my first build so i'mn still learning.
the car has plenty of low end torque (it spins the tires below 2000rpm) and it's on the stock converter. i plan to go to about a 2400 stall so i assume (there's that word) that i won't need power to start till 2000 or so, not off idle.

[GetMore]

For a little background, the tires are low performance, bald, dryrotted 10 year old tires, and the future plan is to go to a 275 or so tire instead of the 215s on it now.
Plus, the suspension is worn and is being replaced.

Any questions on the current ease of lighting it up?

[megaladon6]

actually the tire are not low performance (i wouldn't call them high performance either) or completely bald and less than 5yrs old. still it's extremely touchy starting off, and has more than enough power under 2k.
jason, i'll bet you that it stiil does it with the new tires and suspension.

[megaladon6]

well i win the bet. the car has new rear tires (225), tubular rear arms, lowering springs, bilstein shocks, and new front suspension parts and still spins the tires with little throttle.
so how much does retarding the cam move the powerband?

[stariontech]

retarding the cam 4 degrees should shift the torque about 200 rpm higher.

[megaladon6]

that's the answer i've been looking for!!! that small a change huh? guess i'm not going to bother. thanks.
would the smaller primaries of the q-jet going on make it less touchy?

[dstryr]

that's the answer i've been looking for!!! that small a change huh? guess i'm not going to bother. thanks.
would the smaller primaries of the q-jet going on make it less touchy?

Just buy wider tires :P

[megaladon6]

i'm getting there.

[gen3bu]

the q jet will be worse.
bigger and stickier tires!
more cam ([email protected]) intake for starters, 112 lsa.
2500 stall 10" converter with 2.3 str.

[megaladon6]

why is the q-jet worse?
i can't change the cam , i wish i could.
i'm getting a stall when i can afford it, around 2500, but what is the 2.3 str?

[gen3bu]

the quadrajet has very small primaries. the smaller primaries have great response and part throttle low end torque. a holley will slightly reduce off idle torque due to its larger diameter primaries.

str = stall torque ratio. it affects how the converter feels off the line. you will also want to get a smaller diameter converter due to its higher efficeincy at the same stall speed.
http://www.converter.com/q7.htm

[gen3bu]

How can a 12" torque converter and a 9.5" torque converter both achieve the same stall speed?
5. Two different sized converters can have the same stall speed, but the efficiencies will vary greatly. A converter pump will tend to have a higher efficiency when its blades have a positive angle to them. The positive angle feeds the most amount of fluid to the turbine. The more fluid you feed the turbine, the harder it pushes on it. The harder the turbine is pushed, the more torque is transferred to the transmission. For a 12" converter that normally stalls at 1600, to be converted to a 2600 stall, most converter builders will bend the pump blades back to a negative angle to feed less fluid to the turbine. This means the pump will have to turn more rpms to force the turbine with the same amount of fluid as before. As you can imagine, the efficiency starts to drop off rapidly as you bend the blades more and more negative. You will lose rwhp. A 9.5" converter stalls higher because it generates less fluid by virtue of it's smaller size. It takes more stall to achieve the same amount of hydraulic force of a larger 12" converter. Good thing about a 9.5" converter is that you can achieve very high efficiency in higher stall applications because the pump blades still maintain a very forward pitch to them (positive angle). So in essence, by bending the blades negative on a 12" converter, you are turning it into a heavy, inefficient, higher stall converter in comparison to a smaller diameter converter.

http://www.700r4l60e.com/torque_ratio.html