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Vortec Chevy Upgrades that do something?

Discussion in 'The Garage' started by sled_dog, Aug 23, 2005.

  1. sled_dog

    sled_dog 1 ton status

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    Anyone have any upgrades to a Vortec 350 Chevy that do anything?

    Doug Thorley headers only claim like 8ft-lbs of torque and like 5HP increase. Hardly seems worth the time or expense. As I look around the only things I can see worth doing to it are, cam, blower, or head port work(the least worthwhile unless one of the other two is done). Anyone have experience with something actually improving power? I have the restrictor plate thing removed from my throttle blade, that and removing the silencer box is all thats done to the rig right now.
     
  2. MattK

    MattK 1/2 ton status

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    have you looked into custom computer tunes? there doesn't seem to be much aftermarket for vortec motors, but i hear over and over that a custom tune is one of the best bang for buck mods out there. plus several of those people will do free upgrades when you mod something else on down the road.
     
  3. sled_dog

    sled_dog 1 ton status

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    yeah but I don't want something that would advance timing and make me run on like 89 or 93(gas is just too expensive to do that on a 17mpg vehicle). I will talk to some of those shops on FullSizeChevy and see what they offer.
     
  4. Mad-Dog

    Mad-Dog 1/2 ton status

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    Hey Sled_Dog, the hedders themselves (full length) are only the beginning of the gains that can be realized from a properly designed and tuned exhaust system..........the scavenging effect created by the system as a whole has a bigger impact on drawing air/fuel into the cylinders than the piston does on it's intake stroke.
    remember that the engine is nothing more than a giant air pump, so the more efficiently it draws air and pumps it out the more power it will make and will also increase mileage to boot, don't overlook the importance of a good exhaust system as 1 of the first most important mods in the search for more power and mileage.
    A blower is out of the picture as it takes power to make power (belt-driven).
    A modern set of heads will really wake that motor up when used with a modern cam grind, most stock engines use a dual-pattern cam......STOP
    i don't want to get started on cam selection until you tell me what you want the truck to do........That was close.
    The stock TBI manifold and heads are very restrictive and will limit power production in a big way.....the TBi unit itself should upgraded when the manifold and heads are changed.
    When it's all said and done then you can recalibrate the PROM chip to work with the newly installed mods......... :bow:
    I don't have a fuel injected motor, but i do love the ease of tuning the fuel curve that fuel injection provides when used with a standalone ECM such as the Mega-Squirt unit.....hook up the lap-top and start driving while tuning the cal-maps.....sweet
    Good luck bro :bow:
     
  5. sled_dog

    sled_dog 1 ton status

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    STOP, step back and reread boss. I don't have a TBI truck. This is a 1997 Vortec 350. Not a Vortec head TBI motor. I'd love to learn to reprogram myself, but seeing as this truck is a DD(well not right now but will be again) and Tow rig I don't think it best to test and tune on. I understand that exhaust is a full system, the thing is I could believe that the stock setup is pretty unrestrictive and well balanced. From the factory it has manifolds that aren't the ugliest littlest ones I've ever seen, that dump into 2.5" pipes that each have a catylitic converter on them, that is then all joined way back at the muffler, from the muffler it all goes out a 3" tailpipe. Of course I will put a new muffler on there, likely a dual in, single out like the stock one is. The biggest issue I have seen with the Vortec rigs is this, there is NO aftermarket injector"s". Guys running big displacement(ok 383), and a blower have installed a secondary injector in a throttle body spacer to add the needed fuel.

    So to recap, it has Vortec heads(modern design), camshaft(I don't know but its a 97 so I'd say its modern, and of course its roller), and the exhaust isn't that restrictive seeming. IN the end I think I'm gonna have to be happy with the power it has now. Its the most powerful truck I've daily driven so thats good, but you know, always want some more. Maybe a camshaft is in order... Have to talk to the guys on FullSizeChevy, see what they are running and figure out what the stock cam specs are. Try and find a nice simple cam that could operate under factory tune, maybe the LT4 factory cam would work out... too bad I sold the one I had.

    I think really to do anything more is going to require really tearing into the engine. I should just stop being stupid and be happy. Sooner or later I'll throw a blower on it and then I'll be really happy. Loss of horsepower to a blower is a relative thing. Sure you may lose say 40hp to a blower but when its adding 100-150HP, wtf do you care? The big thing is, I live in Pennsylvania, towing around here SUCKS. Hills are evil, and a blower would be a nice way to avoid buying a Diesel(can't afford a new Diesel truck and I don't want some old used one), and still have some nice towing torque.
     
  6. daleearnhardt01

    daleearnhardt01 1/2 ton status

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    Westers Tune........search it up on FSC, that site may be full of crap but there is some good info if you sift through all of it...
     
  7. dyeager535

    dyeager535 1 ton status Premium Member

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    Yeah, I'd say leave it alone. :)

    BUT, from the specs I was given awhile back, the Vortec cams (at leats 5.7L) are extremely mild, like .420" lift. There's a lot of room for improvement if that's the case.

    Of course, that's a typical bottom end cam made for moving a lot of weight, but I'd still expect to see a lot of power gains from a cam change.

    I think if you look at the L98 motors (thirdgen camaros and the corvettes, yes I know, thirdgen this thirdgen that) you'll see that even though they were "performance" motors, some cam changes make huge differences. You've got the LT1 intake, I'm sure you've been to thirdgen.org, I know I've seen some real serious comparisons of different cam grinds compared to stock.

    Heck, sdpc2000.com got 400+HP out of a TPI'd Vortec motor and no tuning IIRC, I'd expect the same results if not better from your motor, with some mods.
     
  8. tavis

    tavis Registered Member

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    CAUTION! don't take the stock heads over .420" lift .... the self-guided rocker system gets VERY VERY upset.....

    T.
     
  9. dyeager535

    dyeager535 1 ton status Premium Member

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    Why would the guided rockers care?

    Unless the rails hit the locks/retainers, there is no difference between that and "normal" rockers and more lift that I can see.

    First time I've heard of higher lift making a difference.
     
  10. sled_dog

    sled_dog 1 ton status

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    the stock springs can't go above .450, thats all I know bad with Vortecs and cams. Think you are off on the guided rockers comment.
     
  11. Blue85

    Blue85 Troll Premium Member

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    Yeah, blowers really cut back on an engine's output power. :rolleyes: Anybody who has one, especially on a small block chevy, should send it to me. :D Oh wait, I almost forgot to mention in the same paragraph that turbos don't take ANY POWER AT ALL to operate! :haha:
     
  12. Thunder

    Thunder 3/4 ton status

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    If you want to make power in a Vortec without head work and machining I can only say one word One word :Whipple

    Oh BTW you can go up to about .450 lift in a vortec. May have to grind a little and enlongate the holes in the heads the pushrods go thru so they dont hit the sides. Any more lift than that and you run into coil bind and maby PV clearance issues depending on waht pistions you are running.
     
  13. sled_dog

    sled_dog 1 ton status

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    looks to be the way to go. Especially for towing performance. Would suck to change those driver side plugs...

    Looking around, Procharger is probably the way to go. Intercooled pushing a few psi more on boost and centrifugal so it takes up less room underhood.
     

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