GM 350 HP/Torque

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Ok, I have a GM 350 with a four barrel quadrapuke carb, dual exaust with headers, an RV cam, and cherry bombs for mufflers... it's got good power, but not as much as I think a 350 should have, it's geard at 3.73-1 in the axles and it has 33-1050-15 BFG/AT's on it... I'd like some ideas for more Horsepower and low end torque... if I cant get both i'll go more for the torque... so any suggestions plz fill me in... I don't really have a budget right now, anything goes, just start throwin stuff out there for me please.... but, if you have something cheap and easy that will help all the better.

posted by  BYOB-EPIPHANY

33/10.50's?! Is this a truck? You need a lower gear if you want to get off the line faster. :mrgreen:

posted by  stepman

I turn 33-12.50's just fine with 3.50's and my stock 300-6, hopefully it'll be alot better after my build :hi: .

When was the last time you gave it a good tune-up? If it's been a while start with that. When was the last time the carb was gone through? Another thing you can do is advance the timing a far as it'll go without detonation.

As for better torque you can't do much more than you have without getting into the motor. You can raise the compression for torque and horepower (and economy at that), but may have to run higher grade fuel.

You could run a more aggressive cam which will give you more power higher up, then you regear deeper to bring the power band into your driving range so you get the bonus of more torque at the motor, and then even deeper gears to put even more to the ground than before. But you pay in mileage and idle quality.

What is your final goal for this thing? daily driver, play toy, and what about driving is important to you? off the line or going fast?

Justin

posted by  Hoxviii

well, I have a lot of plans for this thing, the reason why I'm looking for more power is I plan on putting 37s or 38s on it after some driveline mods... right now it is geard at 373-1 in the axles with a 208 gm transfer case (not sure on the numbers for that) But in order to handle 38's i'm going to drop corporate 14 axles under it with 488 -1 gearing.... I don't really need much high end power, mostly low end tourque for hill climbing...... I appreciate all the input i'll look into it. Oh, and i'll definately start with the tune up lol... it's been a while... my dad rebuilt the engine when he got it which was a good 2 years ago... it hasn't been driven terribly hard though.

posted by  BYOB-EPIPHANY

if you gear right you can use high end power down low, but you'll be able to watch your gas gauge drop :wink2:

Say you make 100 lbs of torque at 2000 RPM (easy numbers), with 3.73's you would have 373 lbs of torque at the ground at lets say 10 mph in 1st gear.

::NOW::

what if you built the motor so now it made 200 lbs but at 4000 RPM. with the same 3.73's you'd put 746 lbs to the dirt, but it would be at 20 MPH instead, VERY out of range if you intend to offroad it.

::BUT::

say you swap those 3.73's for 7.46's.
You would now be putting 1,492 lbs to the ground at . . . 10 mph!
Three times the torque at the same ground speed BUT at twice the revs. Hence the being able to watch the gauge drop.

Proper gears CAN make up for a mismatched motor. It's not teh way i'd wanna do it, especially if it's a DD.

Justin

posted by  Hoxviii

I'll tell you from experience that going from a stock tire to a biggy kills torque.My 1999 Chevy Z71 went from 15.8's in the quarter to 17.5 after lifting it 3 inches and going from 265-75R16's tp 335-70-16s.

posted by  TurtlePimp

It was the lift and wheels. Lifting the thing gives you a wacky angle for your driveshaft and you loose craploads of power and wear out your u-joints twice as fast :banghead: 3 inches is ok, but these d%!# heads that lift it 16 inches are crazy and they don't even do any off roading in it. Just think they look badass :screwy: :banghead:

posted by  DodgeRida67

Actually it was a body lift,so driveline angles were unaffected.Just lowered the affective gear ratio(numerically)

posted by  TurtlePimp

Should have told me you used blocks, hehe :banghead:

posted by  DodgeRida67

well, I do plan on going to moab with it and such... I don't want it to be a street machine, only street worthy... thanks for all the input ladies you've been a big help... I have no Idea what tourque my engine puts out right now... but plans are... 37's geard at the axles at 4.88 with a 6" suspension lift 3 inch body... I do have a custom front driveline built for a 6" inch lift but have no Idea if i'll need a custom rear or if I can just drop my transfer case or what... once again, thanks for the help. P.S. i'm a bit tipsy right now so if any of this doesn't make any sense feel free to B**** Slap me ;)

posted by  BYOB-EPIPHANY

damn man, 9" lift just for 37's?!! Talk about top heavy. If i were you i'd figure out the minimum lift needed to get the tires to turn lock to lock and just trim the fenders to get the rest. Otherwise you'll be going over everytime you get up on a rock. Hope you invest in a good cage. BUT, if you're running in the mud lift away, get it as high as you can. fewer parts in the mud the better.

Here's a lift comparison. stock my truck will take 33's and squeeze 35's (barely). flare the fenders and pull about a 2" lift and i can run 35's all day. 4" and trimming will run 37's, and 6" plus trimming will take me all the way to 44's. In the rocks DON'T OVERLIFT. In the mud DON'T UNDERLIFT.

Justin

posted by  Hoxviii

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