cprmn14

iTrader: (3)

It pays Back in fuel economy I'm sure. Lol

ZONES89RS

iTrader: (2)

Believe it or not, the difference is negligible. Efi is slightly better, no huge gain when tuned like it should be. But easy cold starts, and something anyone can get in and drive is a big plus for a many.

ZONES89RS

iTrader: (2)

Alrighty then, got the harness halfway complete as far as cosmetics. Can now start an kill the car from the interior. Was idling when fired up but now it wants to die since I hooked the alternator up. I'm sure I can set the idle soon and fix that as well as insall the O2 sensors to make it line out. The battery may be making the alternator do its job too soon.

So, she is looking way better than the rats nest that it was. Still plenty left.

irocdls1

if i may ask where did you get those headers !!!! and did you have clearance problems with them did you modify anything.... and if i could have the part # on those i would appriciate it...

ZONES89RS

iTrader: (2)

They are simply BBK 98-02 F body headers. Something like 275$ and are a direct replacement for manifolds of the same vehicle.

89rs454

Hey zone did you ever get the speedo to work? How did you do it i'm in need of a little help.

ZONES89RS

iTrader: (2)

No, not yet. Have not tackled that issue in this part of the swap.

Z28ricer

iTrader: (2)

If the car in your info is correct you're going to need the abbott cablex to drive the speedometer.

On a 90 like this, simply hooking up the LS1 pcm output to the in dash wiring to the speedometer does it.

89rs454

Thanks man.

ZONES89RS

iTrader: (2)

Drove the car today after a install of the aftermarket water temp. Did great, still need to wire the fan into the ECM. Direct wired it for test drive, got up to 230, but that was all. Sure it had a small water pocket to work out.

I will say, smoked the rear right from a dig. From a roll it hauled pretty hard for a 5.3. Trans would not shift at WOT, so I need to see where the rev limiter is in relation to shift point.

cprmn14

iTrader: (3)

Video?

ZONES89RS

iTrader: (2)

Will have something when the exhaust goes on. Sounds like crap till then. Still needs the O2s installed as well.

1bad91Z

iTrader: (1)

About time you FI'd a 5.3 !! You are the king of carb'd truck motors

ZONES89RS

iTrader: (2)

Lol, EFI still sucks when putting it into something it did not come in.

89rs454

Give it time and the gas mileage will prevail.

mw66nova

iTrader: (13)

my old 305 combo got 22+hwy, with a 4000 stall lock up converter, 4.10 gears, 28" tires, and a 650 double pumper. i'd imagine that a well tuned carbed ls motor would do similar, if not better, especially with highway gears.

89rs454

650 double pumper gets 22 miles per gallon. Do what? This is beyond all comprehension. Was you feathering the throttle all the way to the liquor store.

mw66nova

iTrader: (13)

doubt if you'd like. i'm a data ***** man, and i crunch those numbers every time i fill up. the combo would net 16mpg mixed driving conditions, and 22 strictly hwy, like what you might see on a road trip. i had a 700r4 with a 10" 4000 lock upstall converter from ati. the car ran consistent 12.5's with a best of 12.31@108mph

DeltaElite121

A guy I know gets consistant 22 MPG highway in a 69 Chevelle with a 396 in it. I believe it. Another friend of mine has a 92 Corvette and he averages 37 MPG on highway.

Amazes me what some of these cars are capable of.

89rs454

Congratulations man, i didn't think the ole 4 jet double pumpers could pull that off. I'm sure the the average mile a gallon is skewed just a bit though imo.

mw66nova

iTrader: (13)

i'll be really honest man, the mileage went UP when i went to the mechanical secondary versus the vacuum secondary. a lot of it had to do with throttle responsiveness and driving style. the secondaries would open on the VS carb under engine demand, so i had no control over it really, except to just go real easy on it and hope i didn't get into the secondaries any. with the mechanical secondary, the linkage was progressive, and wouldn't touch the secondaries until 30% throttle or so. since the secondaries have a return spring on them also, i could feel the throttle get "heavier" under my foot when the secondaries began to open, thus making it easier to stay out of the secondaries. it was awesome going from 14/18 to 16/22.

a lockup converter definitely helps.

skewed? meh...exaggerating these numbers gains me nothing man

89rs454

Your the next Einstein defining the next logic of physics. Your way off on your numbers. I crunch numbers because my computer does it for me, and feeds me back the information.

mw66nova

iTrader: (13)

can you try that statement again? i don't understand what you mean by my numbers are off...

89rs454

Your going to keep backing up this claim?
My stock 305 Tbi got 16mpg that's in city 20hwy. That's enough to call that bul*sh*t.

mw66nova

iTrader: (13)

Sorry about your luck

89rs454

Luck my *** 90% of people honest with carbs are lucky to get 17mpg on highway. There's your luck.

Z28ricer

iTrader: (2)

Even if mileage was a wash, trying to argue for a carb is just silly.

I've torn down numerous engines, the mileage difference is rediculous, and its no wonder so many older people i've talked to are afraid of engines / cars with 120k, and think they're worn out.

I've torn down carb'd engines with 75k, shiny walls, done, and LT1's with damn near 300,000 with the crosshatch on the walls.

There are too many other advantages to EFI, and with a thirdgen, and LT1's or LS1's its really silly to go with a carb setup over EFI for the cost.

mw66nova

iTrader: (13)

it wasn't luck my friend, it was the result of a lot of time tinkering and tuning. spending time at the track, and on the road getting it right. i didn't just plop it all together and have everything work in perfect harmony.

comparing the stock tbi to my setup isn't exactly apples to apples...the gm tbi unit left a lot to be desired, and the ecu was extremely primitive.

i will say, there is a lot of benefits to efi, and i will be the first to admit that my results are unusual (albiet, i could duplicate it, it wasn't luck). my car had terrible cold temp manners till the car was up to operating temps and smelled like fuel routinely. those things wouldn't have been a problem if it was efi. as a young guy with no money, i wanted my cake and eat it too, so i spent a lot of time making what i had work.

believe me, don't believe me, whatever.

Z28ricer

iTrader: (2)

For the record i'm not calling bs on the 22 mpg on that setup.

Its perfectly possible i'm sure with enough effort and time. IMO

89rs454

I don't believe you, however i love your work, that doesn't mean you don't deserve criticism. I just want you to know that what you said is just plain wrong period. Your crunching numbers with your mind, not with a computer. And your delusional.

mw66nova

iTrader: (13)

crunching numbers with my mind? look man, my bachelor's will be complete in may in applied mathematics. it's not hard to compute mileage.

n=number of miles drive, g=gallons of gas consumed, so you do (n/g) and whamo, mileage. if i go 200 miles and only use 9 gallons, that's 22.2222 mpg.

i don't understand why you think i'm delusional. i have timeslips (somewhere, this was like 6 years ago) of the car going into the 12.3x's several times, and i computed mileage every fill up, averaging 16mpg in mixed conditions, and road trips would do 22+. why would i lie about this?

89rs454

I just proved your delusional. Prove me wrong.

mw66nova

iTrader: (13)

you're going to have to be more specific...why am i delusional again? because i am confident i can do math in my head?

89rs454

DONE!

mw66nova

iTrader: (13)

looking back at some old threads about the 305 build, i have left out an extremely important piece of information that made the car do what it did: the weight. it was 3220lbs with me in the car when i did all of this.

86White_T/A305

Wow talk about criticism lol.Why is it so hard to believe a carb cant get mileage? Carbs have come a long way in the aftermarket for not only power but economy.The only thing with a carb setup is you need careful time invested to maximize both..on a properly setup motor under it.There are alot of guys getting very respectable mileage out of carbs..but ask them how long it took to dial it in first in trying various settings..springs..etc before it was right.

Not many can tune a carb right and thats the problem..guys throw them on and just dump fuel and adjust wot with a wideband and call it done.

ZONES89RS

iTrader: (2)

The. Iggest issue with a carb in history is every idiot that thinks all carb setups are not capable of economy is they look at the majority applications they came on and are used for. Steep gears and no overdrive. A th350 with 4.10 gears with a carb will not get better than mid teens if you are lucky. If you have not tried this with EFI, guess what, same results. I see poorly tunes ls1 cars that don't get better than 17, that doesn't mean my friends that get mid 20s with a cammed LS are liars, just a better tune and setup.

I got a max of 22 mpg with my 6.0 with a Trex and a 750 mechanical carb on the freeway. Doubt if you like, a T56 double over drive is a beautiful thing. I had a better final drive than Matt and a engine that requires less throttle to propel the car due to torque output. Many have doubted my "claim", I don't care. It is not a claim, but a report.

Last I checked I beat the car to school and back and sat in traffic 2 days and still hit 17. So unless you claim the pumps are off at every random fuel station inflating my numbers, all I did was divide the mileage by the added fuel from a full tank to the full up on my phones calculator. Personally I think a EFI setup would have gotten 26 or so, but hey, I was not leaned out for reserve I was shooting for max power draggingthatass.

Carry on.

xpndbl3

iTrader: (5)

wow.......this post. you know a tbi computer was ANCIENT and its fueling control sucked?


how about this....even while it was shooting for 14.7:1 a/f ratio, I can make a carb run 17:1 a/f at light loads.....so what do we get??? better mileage. I'm delusional too apparently. It's about creating a more efficient package overall. Crap stock manifolds and poor flowing exhaust along with a crap intake package don't lead to great mileage either.

1nasty86

iTrader: (5)

im sure we can all agree on this....

89rs454

Well now i think i just hit a brick wall of grunts. mw66nova is a highly respected member here on Thirdgen, and i disagreed with him getting 22 mpg out of a 650 double pumper. I'm wrong. carry on, and i'm sorry for the hold up.

ZONES89RS

iTrader: (2)

You know a carb only used the fuel you let it, just like EFI, do I do not understand why it is so hard for you to get. A 4 barrel carb, mechanical, does not open more than 2 barrels at part throttle cruise, just sips fuel unless the bleeds and jets are way off.

1nasty86

iTrader: (5)

he said he gives up... no need to keep kicking a dead horse...

DancesWithDeath

iTrader: (1)

Yup you'll just ruin the meat. Let me go fix my ****** and we can fire this puppy on the grill.

loomdog32

When I opened this thread, I thought it was gonna be about a 5.3LS Swap into 90. I didnt think I would find a thread about bashing fuel pumps and mileage on carbd motors...

Looks like a nice LS build. Also some good info about fuel pumps (despite the bashing). Always nice to see a thread with a complete build (well, running and assumed complete) and valuable information for others looking to start a build of their own.

ZONES89RS

iTrader: (2)

Trying to finish it, my buddy drove it home, but we still need to wire in the fan and the brake switch somewhere and allow the converter to unlock when the brake it pressed. He is just glad it is where it is as of now. Had to go back in and turn off all the unused setups like EGR, rear O2s, ect ect. Now she fires and runs, drives great. Tuned to shift at 6000 and it runs pretty hard. I need to take pics of the Y pipe and all just to share.

89rs454

Please don't cook my meat, you would spoil the party.