More Power and Better Fuel Economy Thanks to Tuning and Overdrive! Ep.71

Square Force 1 is my 1989 GMC Sierra R30 cab and chassis square body truck that was converted for enclosed car hauling duty over 30 years ago. It's powered by a 454ci V8, which is backed by a Gearstar Performance Transmissions Level Four 4L80E tranny and a Yank billet converter. Prior to swapping the original TH400 three-speed transmission with the new four-speed, the truck averaged 5.5 mpg during a 5,300 mile coast-to-coast road trip. During this episode we'll address some tuning issues with the 454 and then road trip the truck with the new trans. After the mods the truck nearly doubled it's fuel economy; We achieved a best of 9 MPG and a worst of 6.5 MPG. This video will show you how to find Top Dead Center on a four-stroke engine, how to diagnose a malfunctioning vacuum advance distributor, and how to read the timing mark on spark plugs. Hopefully you learn something or just laugh. Thanks for watching!

Want overdrive for your ride? Visit Gearstar Performance Transmissions:
Want a better distributor? Visit Summit Racing for all your speed parts:
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  • I would just pull the motor and put a twin turbo Cummins in it

    Hunter EvansHunter EvansPřed 5 dny
  • I feel like you guys are Ecomodders!! I actually really enjoy the MPG content. Would like to see more mileage focus content. Maybe some aero mods and some carb tuning. There is a lot you could do to improve MPG. Hope you do more. Thanks for the content.

    Ted AlexanderTed AlexanderPřed 5 dny
  • There is no me without you...if you have any questions feel free to ask or email me! Thanks

    coverman66coverman66Před 5 dny
  • when is roadkill gonna start agin

    Holley SchulteHolley SchultePřed 7 dny
  • You ought to go EFI next

    a456987a456987Před 7 dny
  • If you put a 3rd gen. Cummins in that truck with a smarty jr tuner. Ill bet youll get close to 18 mpg. Easy.

    Michael CuffMichael CuffPřed 8 dny
  • You guys need to get a racing Pontiac

    the gameing corner akathecoolestthe gameing corner akathecoolestPřed 8 dny
  • Standard Chevy pre LS firing order.

    kellsarahkellsarahPřed 8 dny
  • My buddy gets 12-13 miles per canadian gallon out of motorhome and its a POFSHAT. So, yes you are right in the ballpark. Next, you need to add a good HHO kit to it

    ChiefJustice MiddletonChiefJustice MiddletonPřed 9 dny
  • Need some chrome fender skirts on one of your next episodes who's with me...

    TheShadowOfMusic86TheShadowOfMusic86Před 10 dny
  • You should look into some kind of wind deflectors to put on the back of the box. Some of the trailers I haul for my company have them and it makes a noticeable difference in fuel economy.

    Hungry MooseHungry MoosePřed 10 dny
  • What the hell? Almost 9 mpg in a 40ft long brick that's probably 8 tons loaded with a carbed big block and straight 80's factory setup other than the overdrive and distributor but that's still basically 80's tech. And I get MAYBE 1 or 2 better in this damn 01 6.0 with the same 4l80e and unloaded. Other than the 10 gallons of water I have to carry til I finally put a radiator in it. Already had to do a water pump right before the cap cracked so not getting in a hurry. I don't know what GM did with these first gen vortec 6.0's but they suck on mileage.

    Sixth LordSixth LordPřed 11 dny
  • Thank God Finnegan still posts on CH-visions & doesn't charge for his vids...

    Dumbest OysterDumbest OysterPřed 11 dny
  • I'm doing the same this with an 85 454 camper special right now.

    Brian BayerBrian BayerPřed 11 dny
  • And this was owned by a race team. Hahahaha.

    Brian BayerBrian BayerPřed 11 dny
  • if democrats were watching this they would loosing their shit because your happy with 9 mpg!

    f r e e b i r df r e e b i r dPřed 12 dny
  • Setting records...✌

    Phil BPhil BPřed 14 dny
  • 14:32 Robo-mike

    King BonesKing BonesPřed 15 dny
  • Time for an LS. Maybe an 8.1 big block....

    T BoneT BonePřed 15 dny
  • timing mark on the ground strap of teh spark plug??? Who knows this stuff??!! Thanks, Dave,.

  • The first time I saw the new paintjob, was at a red light about 15 miles away from AMS and the truck passed by on the way to an event. I didn't get to go to the show but it was still awesome just seeing the truck for a moment

    ShBeeBoShBeeBoPřed 16 dny
  • Dude you are like a bolt on EFI kit away from double digits

    Patrick BurkePatrick BurkePřed 16 dny
  • This truck is so rad.

    SanctimoniouslySanctimoniouslyPřed 16 dny
  • What happened with jlow

    Jesus HernandezJesus HernandezPřed 16 dny
  • Now stick a GV overdrive in there and take it to 11 :D

    ABOlsen69XABOlsen69XPřed 17 dny
  • That moment when you get worse gas mileage than a Semi.

    PistonBullyPistonBullyPřed 17 dny
  • Why don't you try Holley Sniper EFi or similar?

    PooWafflePooWafflePřed 18 dny
  • Will this show be sold out like Roadkill? Then will we get told that episodes will be released after Motor Trend rakes its fans for money? Asking for a friend. Because I've pulled my subscription to all things Roadkill associated.

    Burt SegalBurt SegalPřed 18 dny
  • Should do a LPG conversion- perfect application. LPG/Propane is cheaper and is 100 octane.

    justinjoyit13justinjoyit13Před 19 dny
    • you also burn through it much quicker.

      benzlover55benzlover55Před 16 dny
  • I think a duramax would do this thing great

    Justin BrimJustin BrimPřed 19 dny
  • You should put a dirtymax in that one lol

    Nos16_13 WantedNos16_13 WantedPřed 19 dny
  • you know it just hit me at 10:20 while looking over this truck with the hood up, did you buy this truck as it reminded you of the white trucks they used in the first two cannonball run movies?

    Kavinsky SmithKavinsky SmithPřed 19 dny

    J BusinessJ BusinessPřed 19 dny
  • Run Auto-RX engine oil treatment through it (following the exact instructions), combined with Chevron Techron fuel additive and you'll hit 10 mpg.

    aviva las vegasaviva las vegasPřed 20 dny
  • Pretty sure that store at 13:50 was over in Dawsonville. Loving the progress on the truck brotha, been looking for it for awhile now lol y'all are so close! Lol love from Gainesville!

    TonkaTruckkTonkaTruckkPřed 21 dnem
  • I can't believe a giant big block powered truck with the aero of an office building can't get better MPG than 9!!! LOL.

    ScottScottPřed 21 dnem
  • ' no wonder why why this man use a cap on the head and black tint sunglass on the eyes

    bestamericabestamericaPřed 23 dny
  • You would get MUCH better mileage if you put a smaller diesel in it....

    madjimmsmadjimmsPřed 23 dny
  • For me, an new-age European mechanic, this diagnostic part sounded like some straight up medieval shit xD ~40yrs of difference

    KoyotBravoKoyotBravoPřed 23 dny
  • How did he mate a 4l80 to a 454? I thought you could mate the newer engines to the older transmissions but not the newer transmissions to the older engines.

    Steven VanheelSteven VanheelPřed 23 dny
  • Just get a diesel engine in it you get better pull and mpg rate on long run .You just wasting money on gas. Member diesel got more tq than gas engine and use way less rpm then gas . That means less fuel using on mpg.lot more tq. Than gas engine. If was me i put a duramax disesl engine in it.

    Joseph WisemanJoseph WisemanPřed 23 dny
  • Is it not common knowledge these days on the how's and why's of ignition advance mechanisms? I mean it is great he is explaining it, but I thought this was more known to most gear heads that grew up with this stuff.

    thejunkmanthejunkmanPřed 24 dny
  • now get some more badass arrow-d accessories, get rid of the giant mirrors and check the tire pressure.

    Fred FlynstoneFred FlynstonePřed 24 dny
  • It needs a Diesel Engine in it!

    Ri LeRi LePřed 24 dny
    • No. It needs a stroker crank and a blower on top.

      ABOlsen69XABOlsen69XPřed 17 dny
  • Should diesel swap it

    Water ToastWater ToastPřed 24 dny
  • EFI , roller cam with roller rockers , headers and a Gear Vendors would be a good start to better mileage. Also a set of better flowing heads. Sadly GM put "peanut port heads" on the 454 which made no sense.

    TJ9709TJ9709Před 25 dny
  • I’ve never gotten a notification for this channel and I’ve been subscribed for years.

    ROB PROB PPřed 25 dny
  • another huge problem is the new gasoline has a boiling point as low as 80 degrees at our atmospheric pressure. Fuel injected doesnt have this problem because it is under pressure, but carbureted has no pressure in the bowls

    Hammerjockey RadiosHammerjockey RadiosPřed 25 dny
  • That's a badass rig.

    Christopher FettChristopher FettPřed 25 dny
  • ls swap it lol

    juan restrepojuan restrepoPřed 25 dny
  • Not to mention it's fully loaded this trip. That's hella impressive.

    Nick CarpenterNick CarpenterPřed 25 dny
  • My Jack Russell loves the channel

    Terry BroadwayTerry BroadwayPřed 26 dny
  • That qaudrajet though 👌

    Merritt SMerritt SPřed 26 dny
  • bet that motivates you to do even more work on the truck, awesome win

    JFK64 KennedyJFK64 KennedyPřed 27 dny
  • where did you get the griswald truckster wipers from?

    GmJunky87GmJunky87Před 27 dny
  • When you say "15 degrees advanced," for example, that's crankshaft degrees, correct? So moving the distributor 5 degrees would result in 10 degrees of change, if I've figured that correctly.

    Jeaux BleauxJeaux BleauxPřed 27 dny
  • Being from the uk find this video fascinating feel as though ive learned something

    Liam BrennanLiam BrennanPřed 27 dny
  • Put a Edelbrock Pro-Flo 4 EFI System on it! Sequential Multi Port injection and timing control for 1900 bucks!

    Joakim VikeJoakim VikePřed 28 dny
  • now move the wing and get into the double digits

    Mr. BrownMr. BrownPřed 28 dny
  • Mike Cotton is such a fucking douche. Why do you keep putting that asshat in your videos? Dave is cool, Cotton is a dick.

    irflyerirflyerPřed 28 dny
  • Add a wideband o2 meter, punch out the plug in the top of the Q jet and adjust the part throttle mixture to get some more mpg.

    eixreixrPřed 28 dny
  • Truck would be just Perfect with a Duramax Diesel Conversion with a T1000 Allison 6 speed behind it .

    William DruebertWilliam DruebertPřed 28 dny
  • Any idea how this 1989 truck wound up with a carb 454 in it? Supposed to be TBI

    91CTD91CTDPřed 28 dny
    • Obviously the guy who bought it had some common sense. That late 80's TBI is about as bad as the 80's Holley "EFI". A Holley HP system with a dual plane MPI manifold would be a better choice for this application.

      ABOlsen69XABOlsen69XPřed 17 dny
  • Can't you improve again the mpg with a better wing,or a better install. You need to test its effectiveness and see if it's working where it's installed with a smoke machine and some piping,or if you can get a windtunnel. Its shape looks like pretty bad : it's more a big downforce shaped wing,and not that much and aerodynamic improving wing. Get one from a freight truck

    michaelovitchmichaelovitchPřed 29 dny
  • Enjoy your new Prius you hippy chicks. MPG improvement is for sissys 😃

    Michael LoweMichael LowePřed 29 dny
  • 12Degrees initial, 36total at 3200 rpm. Limit can to 10. I think 46 would be too much for lean cruise. You spent the money to build it. Now spend some money and tune. Get an independent look at your whole combo. You never know. Still having fun?

    Shoeless bShoeless bPřed 29 dny
  • THOSE WIPER BLADES! I had those on my truck when I was in high school in 1984! LOL!!! KEEP 'EM ON THERE!

    Dave ArthurDave ArthurPřed 29 dny
  • Replace that white and black vacuum check valve tee (by the firewall above the dist) with a new one. The glue seam always starts leaking, they are a worthwhile 2$ from the Dorman aisle at any auto parts store. Many an elusive vacuum leak can be stopped with that one piece

    Anon YmusAnon YmusPřed 29 dny
  • Take a trip to Hobgood NC

    Trevor PhillipsTrevor PhillipsPřed měsícem
  • Take the race winnings and go fuel injection. Gain another 3 mpg. Enter double digit mpg territory.

    Dennis LongDennis LongPřed měsícem
More Power and Better Fuel Economy Thanks to Tuning and Overdrive! Ep.71