fastolds

I had a quadrajet built for my car around 6 years ago (last time I had the car out) and finally got to try it. Don't remember what forum the guy was from but it was built to my cars specs. Here is the result.
Quadrajet ran around a 13.2 quarter mile at 105 mph. Doggy off the line and bad hesitation prior to hitting the secondaries.
Holley ran 13.07 at 105 mph with it still being doggy off the line but no hesitation.
Keep in mind that other than bumping the timing around on each one, no further tuning has been done.
I fear the 3:50 gear is preventing me from getting a hard launch and hitting the 12's besides the further tuning needed.
Installing a better working tach and will run some tests before changing gear and or current maybe non functioning 2800 stall.

wr1970

My 1970 442 went high Twelves with a 355 rear gear 3600 stall 3750 lbs me in it.I don't think your 350 rear is your limiting factor.Your carb dose and maybe some other problems.Need more info.

RocketKid70

That Holley serves up a big gulp of fuel. Maybe that first, big slurp is a little much right off launch? What condition is the Quadrajet in? Has it been rebuilt or gone through? Maybe the accelerator pump is damaged or dried out?

fastolds

I built this 78 cutlass back in 2000 and 2001. Never tuned it in nor do I drive it so there are many things that need looked at and tuned. The Quadrajet was built in 2006 by a guy from an olds forum. It sat until this last week in a box in my basement. I always ran my 850 double pumper with no issues or hesitation anytime I stomped on the gas. It just got up and go. My friends have given me so much crap about the car just sitting all these years so I decided to get it out for a memorial run for a friends brother and that leads me to the comparison of run times for each carb. I changed the distributor from an MSD mechanical to a vacuum as well. My tach is crap so the new one is coming in today. Tons of work to do as I am hoping to run during BOP day at Cordova drag strip in October.
I still think the Quadrajet would be a good carb to run if I had someone close that knew how to work on them as I am more familiar with Holley.

wr1970

Let's hear more about the motor.Why did you give up on the msd?What is your weight of car you in it? Also how is rear end setup does it spin on the line out of the hole?There should be no bog at any time.

fastolds

I basically just switched from a full mechanical MSD to a vacuum MSD. Never messed with the springs in the mechanical and thought the vacuum would be more street friendly. In the new MSD, I changed the springs to a light blue and light silver I think and put it the advance stop for 28 degrees. Would have to double check. Timing needs to be reset again. I made one last pass at the drag strip and just advanced it by site and went. My 60' times are over 2 seconds. My other car with a 350 had better 60' times.

1970 455 bored .030 over. Forged pistons, balanced assembly, 8 quart oil pan, E heads that have been ported/polished,port matched and have the heat riser filled in with zinc alloy, roller tip rockers, rhoads variable lifters, performer intake that has been port matched and center divider modilfied, roller tip rockers, 850 double pumper, MSD distributor/ msd 6AL and coil. 2 1/2" exhaust out the back,Griffin alumimum radiator with an electric fan, tranny cooler with electric fan, hooker headers, engle cam( IN 522 EX 541) ( duration at .050 lift IN 230 EX 240) GM 400 trans with shift kit and deep pan, moser engineering ford 9 inch with 3:50 gear, 31 spline axles, auburn pro series posi.

wr1970

You are killing the engine performance with that small exhaust.You have to be spinning off the line for 60 foot to be that bad.Why not add race dumps?You have good enough engine parts to run deep 12's .My guess if everything was set up right around a 12 .30 12.50 range.

chadman

That car should go mid 12's easy. I see no major issues with your parts selection. I just think you need to approach tuning this thing systematically. One thing I see that I don't like is your 28 degrees of advance in the distributor. I like to see more like 15 degrees mechanical advance. For starters I would set it up for 18 initial and 33 fully advanced.


I personally like Holleys as far as performance goes. I just find them simple to tune and they just work. I know some like the Q-Jet but I'm just not a huge fan.


Your MPH is indicating that you have the power to run 12.60's so it's just a matter of figuring out how to use that power more efficiently.

Erinyes

After spending six years in a box, my first thought is that the accelerator pump has dried out. Check that before spending time looking deeper.

wr1970

If he had a good carb mph will go up et will be much better and 60 foot is just plain sorry.

chadman

Maybe, maybe not.



Agreed. If he just gets that part figured out he will be well into the 12's.

wr1970

You might be right but at 3750 i went through the exhaust around 108 at 12.58. his engine is similar except for carb mine is a speed demon. My car weight was checked at a grain elevator scales twice same weight.Then when i was at et finals in denver the weight was checked again and it matched.So those grain elevator scales must be correct.Some guys like holly's i don't.Some guys like Quadra jets i don't. What i have been thinking about buying not convinced yet is a quick fuel. Looks like a holly but several racers swear they are better.I was thinking his car might be lighter if not 12.60 maybe closer to what it can run.

chadman

Quick Fuels are basically a blueprinted Holley. They are nice for the money.

fastolds

Installed new Auto Meter tach so now testing Stall converter as it is advertised at 2800 but stalling more like 2000. Old tach jumped all over the place. Can coverters go bad? It worked 6 years ago when I put the car away. It was brand new prior putting in storage. Don't remember brand but is a 10" with ballooning plates.

wr1970

I am going to throw this out there! My 2800 stall converter made my car push threw the beams foot braking it at around 1500/1600. Now when i put the tranny break in later it stalled at 2800 like it should.That being said i think your converter is working.

chadman

X2

fastolds

I built a 350 for a 75 cutlass I had and I put in a B&M 3000 rpm converter. It launched at just over 3000 rpm. I assumed with this big block I could expect the same. You are telling me I should not expect the same characteristics? My best friends brother builds transmissions(builds mine) so this leads to me taking a converter training lesson soon!
Or...... Maybe I should just get the 68 convertible I really want!

Rallye469

The stall speed of a converter isn't a given.
You need a certain amount of power to get it to stall where it should.
You are down on power...at least off idle.

Do what Chad said and get that thing timed where it should be.

- did I miss what mufflers you're running?
2.5" exhaust with a decent muffle is fine. So are those gears.

-pete

And as far as carb...
Everyone here knows at least one Quadrajet magician who can make them run like a Swiss watch.
The rest of us use the Holley based models.
I love my quick fuel. Basically because they set it up perfectly and I don't have to.

oldsmoboogie

Where do you live? I also go to Cordova drag way.

fastolds

Fulton

fastolds

I don't remember what the heck I put on for mufflers. That was back in 2001. If I dig far enough I am sure I can find the receipt!

fastolds

What RPM should the initial timing be set at? I used 1000 rpm and 14 degrees initial when it ran the 13.07 best time of the night. Need to recheck total.

fastolds

I like this picture

fastolds

Here are the timeslips.Car #F236

wr1970

I still think you are having chassis tune problems the 60 Foot is not good. What tires/slicks are you running?What shocks? Air bags? I think your carb is still a problem.Can you borrow a good 750 from someone?Also check that timing. Check fuel pressure.How much play do you have at the carb before it start to work.I am talking cable adjustment.

fastolds

It is just doggy off the line and on the street. Stock shocks with coils that have compressors to pull down the rear. Fuel regulator set at 7psi at Idle and am going to reset timing. I don't have a 750 available, everyone has bigger that I know.
I have some things to review on it then write an update. Looking at a quick fuel carb so maybe I just buy one.

wr1970

The stock shocks is part of your 60 problem.What about the front shocks are they stock?

fastolds

Stock I believe.
Checked the jets in the 850 and had 76 in front and 81 in rear. Now the darn rear pump is leaking. I seen some 750's have similar jetting while researching.

wr1970

You need 3 way adjustable shock to get better weight transfer to the rear end from the front.Stock shocks do not transfer weight unless they are wore out.It is called cfm for a reason. Your carb maybe putting to much air to the engine. You can have the same problem with the wrong intake like a victor on a stock engine.The engine is just a pump over power the pump it don't work as well.Now i am not saying the 850 will not work i just think a 750 would work better for your combo.You can under carb a engine also.Just something to think about.Get rid of those shocks. Can you take a good picture of your rear suspension?Chadman you need to chime in also between both of us maybe we can get him in the 12's where his car should be.

Wayne Shipley

I'm thinking that a well-prepped Q-Jet will out perform the Holley. I've run a 10.07 @ 135 plus with Q-Jet. What's more they are very consistent.

Dave Siltman

If you think Q-Jets are junk, attend your local NHRA points meet or National event and wander into the pits where the Stocker and Super Stocker guys are. Then take a look at what is sitting on the majority of the GM cars. Hah! I will bet every penny in my pocket you didn't think those guys had Q-Jets, or 4GC. Saturday I just saw a '64 or '65 Nova running 10.40s in SS/J with a 327 and a 4GC. Don't knock the Q-Jet. The biggest "PROBLEM" (I use the term with sarcasm) is that they are misunderstood! I know just enough to get me in trouble so I don't do my own. I leave it to the "Master" for I am just a "Grasshopper"!!!

wr1970

So dave what do you think about the op using a quick fuel 750 carb on his engine instead of the 850 holly to keep this thread on subject.

Dave Siltman

There are far too many variables that need to be addressed to give an honest answer to that question. First of all, if the engine sat for six years and the valve springs weren't backed off prior to the storage, they are suspect at best. Next, the timing is far too low and like another member suggested, 35 total is more in the ballpark. There was no mention of a torque converter; a TH400 with a shift kit? What are the gear ratios in the trans? Stock 1st gear? What suspension mods? See where I'm going here? I think with a good tune, a decent converter, a pair of Hooker Competition headers (even through the mufflers), more rear gear, and a "good" Q-Jet, that car ought to run 11.80s or better in good weather on a good track. You can't just say Q-Jets don't work or they DO work with the lack of needed information here. I'd say give me that car, or use my suggestions and the track might be asking you to leave for the rollbar rule (11.49 or faster). That car can be made to hook on oil with just a few tricks and not a lot of money.

fastolds

I have never needed to tune a car beyond general adjustments but I am also very capable of learning. I have built a few cars in the past but they were just 13 second street cars running SBC. I run my own machine shop and work as an engineer full time at another company so not the smartest but can be taught. So here is where I am at;
Just checked the timing. 10* initial with vacuum advance off at 900 rpm. Jumps to 28* at around 2000 and maxes at 31* at 2500. Too fast??
I ordered today.
1. Ordered 3:89 gears, install Thursday.
2. Having dumps put on exhaust. Install Thursday
3.Ordered custom built Q850 quick fuel to my cars specs including above gear change. Be here Monday
4. Ordered k&N flow through top air cleaner
5. Going check/adjust roller tip rockers.
6. Going to fix PVC valve when I pull covers.
7. Cutting hole in hood for air flow. ( have steel scoop welded on for that reason)
8. Hoping like hell I make the right decisions!!!
9. What am I missing??

wr1970

The shocks 3 way adjustable set front 90/10 .90 to release 10 for compression. Rear is different more compression less release not sure what i set them at it was years ago.Maybe 30/70. I am glad you are working on a plan what tires are you going to run?Do you know compression ratio?How deep are the pistons in the hole?

fastolds

I can work on the suspension after I understand what I am dealing with. The compression is a mystery as I purchased forged pistons. Forged Piston # L2323F piston with a .142" dish and compression distance of 1.735. Tires are in question right now. I have the old SS Mickey's now

Dave Siltman

Are you driving this car on the street or racing it! And by racing, I don't mean trying to compete, I mean Friday night test- n- tune. If you say you haven't had to tune a race car, then some of what I/we are suggesting might not mean much to you. I say that it s helpful and educational way as the art of gone tuning is just that..... An ART! I have a close friend who found 40 horsepower on the chassis dyno by playing with jets and timing. 40 horsepower! Try to read as much as you can about the NHRA Stock and the old Junior Stock guys and how they tuned. That is your assignment for now. You will be very surprised how TUNING ALONE can find HIDDEN HORSEPOWER!!!!!!!!

fastolds

Just test and tune and on the street. I have already had johnny law stop by while testing the line lock. This brings back so many memories and of the lost driving privileges. We had a chassis dyno shop not far from me but they closed up. Blew up too many motors I guess.
I have been reading and researching so the assignment continues.

BlackGold

Blasphemy!!! Don't you know that horsepower can only be added by bolting on parts?!

70rocketpilot

I find this thread very enlightening and am interested to see how this turns out. Although I can't offer much help to Fastolds, I thought I'd throw my 1 1/2 cents in. My brother and I run a 75 Cutlass at the local strip in Denver. We have about the same setup, Olds 461 cu in. with a 850 Q jet I built and modified, TH400 and 4.10 gear. Our Cutlass runs 12.80 @105mph with 1.76 60 ft times. I don't think that's too bad based on the fact our track elevation is usually around 8000 feet.