HOW TO: Q-JET TUNING FOR BIG POWER GAINS PLUS STOCK PONTIAC 400 Q-JET INTAKE VS EDELBROCK-WHO WINS? 

I have been racing Pontiacs since I was 16 in my 69 GTO. Of course the first thing I did after a set of headers was add an aluminum intake. I put on a Holley Street Dominator and lost almost a second in the quarter mile. I didn't know much about jetting so there might have been some to gain back but I just put the stock intake on and it was back to mid 14's. That was in 1984. There was a guy who raced a Catalina wagon at that time with mostly stock parts and he ran consistent mid 13's. I was always impressed with him. Fast forward about 5 or 6 years and I was back down at the track with a 455 out of a '76 Bonneville in my GTO. I had outfitted it with a Comp Cams 270H, Edelbrock Performer intake and a Holley 800 plus better Hooker headers. It ran very consistent 13.9-14.0. For an engine with 7.6 to 1 compression I thought I was doing great. The same guy who had raced his Catalina wagon back in the 80's now had a 71 LeMans wagon with the T41 package which is essentially the GTO front end. He had added 72 grills for some reason. Anyway, he was now running lower 12's with his mostly stock 455. He came up, looked under my hood and said, "if you ever want to go fast come talk to me." So I did. He had a home made, photo copied hand out of every change he had made to this LeMans wagon since he first got it with a 350/2bbl. I mean everything including every aluminum intake available at that time. The Performer RPM wasn't out yet. But believe it or not the cast iron 68-72 intake manifold out performed even the stock Pontiac aluminum H.O. intake. They look almost identical. But Jim was a very winning bracket racer. He had separated the water crossover from the rest of the intake so he could do manifold changes at the strip very quickly to verify his results in real time. Of course we are talking a mild Pontiac engine build. His combination was a basically stock 455 short block, either #96 or 7K3 400 heads which gave him around 9.6 to 1 compression. 041(Ram Air IV) blueprint camshaft but with Rhoades lifters and 1.65 rocker arms. A stock 68 to 72 iron intake with a 1" carb spacer and an 800 cfm Quadrajet with #74 main jets and .032 secondary rods. If he couldn't get correct secondary rods he would chuck fatter ones in his drill press and grind them down. HEI ignition, Hooker headers with 18" extensions, a 3.31 rear gear, a TH400 with a Corvette L88 spec torque converter and a cold air induction system that drew from holes he cut in the cowl. His best with this combo was about 11.90s with a race weight of 4070# on Amoco 93 octane. His shift points were at 5500, never any higher. He had every thing laid out in the papers he gave me. I duplicated the combo and put it in an 80 Turbo Trans Am I had bought as my daily driver. Using O.E. parts was way cheaper than the aftermarket parts I was always buying so for a broke 24 year old it was great. To my delight I went out and ran a bunch of 12.0's with a 3700# race weight. In 1992 that was a fast car. And it idled like a bone stock car, was well mannered in traffic and got excellent fuel mileage, almost 12 mpg, lol! The track was KCIR just outside Kansas City and the man was Jim Hand. He suffered a stroke a few years back but last I heard he was still showing his 67 GTO at car shows and his son was still racing his wagon but that's been a couple of years. He eventually switched to a Performer RPM. According to him it didn't run any quicker than the stock cast iron but it was more consistent. Although he did eventually build a 474 stroker with an aftermarket cam and was in the 11.70's or so. He has a couple of poor quality videos on RU-vid from before his stroke. If you're a Pontiac guy they are a good watch. He also wrote a book that is unfortunately out of print but it can be found on eBay occasionally. I have learned from Richard Holdnener that engines are all the same, they all respond to increased airflow exactly the same. So with that knowledge it must mean that Pontiac really did have some good engineering back in the muscle car days if the stock parts did so well for so may years. Especially when you consider the small block air flow from the regular cylinder heads.

Came for the Q-jet. Stayed because it's a rare Pontiac vid.

I love the sound of a WOT Q-JET in the morning!!

ALL Pontiac V8s had "air-gapped" intakes. They had valley pans that kept dirt out and hot oil off the bottom of the intake. It's such a righteous performance weapon that the aftermarket was forced to make air-gap manifolds for all other engines.

I miss the q-jet noise in movie police chases lol

I love the Q-jet. Great driveability, good fuel economy, good power. A well tuned Q-jet is pretty great.

"There was a guy who raced a Catalina wagon at that time..." Of course that had to be the one and only Jim Hand. Jim helped me with key tips on modifying the chambers on the #62 heads I run on my 406 Pontiac engine. I ran the Performer intake EGR model for a few years but swapped back the factory dimpled iron intake when the 62s were installed along with roller rockers and new larger duration high lift camshaft. The modified engine wanted that factory manifold and it fits under my 79 TA's shaker hood.

Love the box reminds me of the days back when I was a kid ❤

I hope this will finally get a whole bunch of people to listen to me and stop putting performer intakes on their Pontiacs The Q jet on a Pontiac will usually like between 11.8 and 12.3 The next part on the oiling system most likely somebody put the super duty high-pressure oil pump on it that’s usually too much oil pump for the Pontiac usually the regular Melling M 54DS Oil pump is adequate with a small shim behind the spring and making sure that the oil pump hole is a half an inch you can use a drill to do that check your pump plate clearance that’s the most important thing and running a thick gear plate that will give you more consistent higher idle oil pressure especially when it’s hot

I got 3 Q-Jets in service on all 3 of my 80s model Square Body pickups, plus a 4th in the garage as a spare for my 86 K2500. Want to get all 4 rebuilt, but that's time I just don't have.

I have a feeling me and Richard would get along very well together. We both eat/sleep/breathe engine tech!

The oil bypass in the oil filter adapter is known to hide trash behind it. Many builders will clean it out and shim the spring/disc setup.

I love the Quadrajets! Always ran them on my street engines because the were more streetable with better throttle response and power.

This is great! Just finished building my LS2 in my 2005 GTO, and now I'm upgrading my .030 over 350 Pontiac in my '71 Lemans while I save up to build my 400 block into a stroker. Love tuning the Q-jet and can't wait to see what my 800 CFM Q-jet, a set of mildly ported #16 heads, headers and a roller cam can do to wake up that motor.

I've built BBCs in 496 that made over 600 hp on a reworked 800 cfm Qjet. Great carbs.

My buddy had a rusty Cutlass Supreme Brougham with a thumping 400 Pontiac and Q-jet. It would lay a big smokey patch all the way down the street.

Here in Australia q jets were std equipment on our local v8 from 1968 to 1986 . I recently witnessed a Holden 253 V8 make 304hp @ 6200rpm with a Holley 650 DP with good afr on a std inlet. So after installing a overhauled full emissions q jet we only managed a lowely 256 hp and it was was too lean. Out with the CX needles & in with the AN needles resulted in 274 HP @ 6000RPM & still lean. Bigger needles again , this time BA . Power peaked at 304HP @6200rpm. Some more fine tuning to the idle circuit & a minor adjustment to the float level resulted in a 306HP @ 6200 rpm. The owner of this engine wanted the engine to look stock so he insisted that the Quaddie had to stay & be on the money with the Holley, DONE.

worst thing i did to my GTO was swap the q-junk for a holley. lol Q-jet big secondarys would almost feel like lil turbo lag for a split sec then off like a rocket. Constantly re-adjusting floats on that tempermental holley Think i even dented my fender doing the all the way in then 3 1/2 out then thump on the fender look for the small drip. Never seen much differances in intakes i even had a few with the front coolant port cut off so i can easy fast swap and not mess with the coolant I usually ran the Torquer single plane probably wasn't best overall performance vs the duelplane performer but looked way more badass

Thanks for putting this on for me so I'll stick with my stock manifold

You need to put a Quadra jet on an LS motor that will cover all basis for maximum butt hurt

Loving the Pontiac coverage! Thanks !!!

One great video. You Really Know what you're doing. Thank You Old Combat Vet Tom

My guess is that the oil pump pick-up fell out of the pump and now the pump is drawing the oil from the higher position of the pick-up hole. This would allow the pump to draw in "air" when the pan level drops with rpm. It would be much more noticeable in the car with acceleration induced G-forces for sure. I would not "Band-Aid" this condition with increased oil levels only. That could lead to high rpm aeration of the oil which is another way of mixing "air" with the oil and losing hydraulic oil wedge protection. Drain the pan and run a boro-scope up the drain hole to check and see if this is the case.

Thank you for the Pontiac content!

A built Q Jet is the closest thing to efi you can get

very nice, great testing Richard

Had a couple qjets. Love the throttle response and driveability of those carbs

The sweet sweet sound of Poncho Power!

Q-jets are awesome! That’s what I had on my 150 mph 1967 Ford Galaxie 390 with gt 390 cam and 428 police interceptor intake!

The regular Pontiac Performer usually makes less power than an early stock 4 barrel iron intake. Unless you add a 1” open spacer to share the plenum. 👍

Originally one of the most powerful Pontiac intakes was the Holley Street Dominator. Later another, small company, made a racing version of it, with sightly larger runners and that wasn't long ago. The Pontiac has a wimpy oil filter bypass. Often they are blocked off with a threaded plug, for full time filter flow. The other approach is to trim a coil or two from the oil filter bypass spring. This is supposed to keep flow up, bypassing the filter more often and increase power(?).. The Pontiac oil pump suffers from cavitation. Melling has made several different versions of Pontiac oil pumps over the years to try to address this.

Long as you gut them out of unnecessary vacuum bs and linkage, set the tension on vac secondaries, maybe raise the meter rods they are the best! And best part is don't gotta literally take them apart to do any of that 👌

I had a 800 (850) Q jet on my Chevy 454 (462) on a Edelbrock rpm Q jet manifold, had to swap rods and jets, made air doors spring loaded worked great, left my Holley only friends scratching there heads in disbelief but it being a spread bore I was spinning tires when it opened up, tried the 3bbl 750 Street Demon and ran great with open spacer with choke removed but was a tad to small, Now I'm running a Proform street 850 and is excellent but makes equal wot power to the Q jet, great comparison video.

DB is the stock 400 secondary rods and it supported 340+ hp. AX rods are way to much. You need to re-jet the primaries. Also primary metering rods are changeable as well. Stock jetting is 72 and primary rods are mid to high 40's. You can go up a jet size and or put low 40's primary rods. CV secondary rods are really good on a motor built like this. There are so many adjustments for q-jets. They are great carbs

When I was a teenager one of my friends had a 70 caprice 350/th350.. can’t remember what was wrong but we fixed the secondaries. Adjusted the TV cable so it was full extension at wot flipped the af lid… thhaaaaaWahhhhh!! Felt like gained 100hp

Q jets are the best all around carb ever made for fuel. Milage and power too Rochester put a lot of engineering into them to get a well rounded streetable long lasting w out problems carb that is still used to this day by many guys they can perform just as well as any Holley or edelbrock carb and last much longer doing it also give you better milage when yoh stay out of it

Restrictors in the lifter galleys will help with the oiling problems. Pontiacs with high volume pumps pump too much oil to the top and starve the bottom end.

Those Pontiacs are beautiful engines

Looks like your QJ is a late 70s (emissions) carb, which I believe are mostly 800 CFM. And Cliff R. says he likes them to modify. Maybe he did that one. But I had a hard time following your test results here. I remember you sayin the 400 with the stock intake, and QJ made almost 350 HP. Then with the aluminium addition, you "lost" quite a bit, then improved it with richer sec. rods, but I don't think it was even close to the stock intake, and unmodified QJ. Or do I have that wrong.

Need some mild Olds 455 testing with iron heads, mild flat tappet cams like the Pontiac. :)

Q jet is great, but I have switched to a street demon 3 barrel. Its awesome. Crisp throttle response and great drivability and gas mileage like a q-jet , but new and much more simple to work on and tune. And bonus it sounds like a q-jet 👍

Single plane intakes will pretty much require at least a 1" spacer or you will be WAY down on power on one of these engines. It's even worse with the Q-jet as the huge secondary throttle plate stick too far into the plenum areas causing turbulence and distribution issues. I did a back to back dyno test with a Torker 1 intake against a 1971 Pontiac cast iron intake. The test engine was a 455 topped with #48 heads and RAIV camshaft. We LOST 59 horsepower replacing the iron intake with the Torker 1. Yes, not a typo 59hp when we went to the Edelbrock Torker intake!....

Oh oh great content btw

You should have just adjusted the float first. Your bowl is running dry, before your secondiary throttle blades open up fully. So, by the time it kicks in (smashing the gas/ flooring it) your already running too lean. When at Low speeds or rpm's your fine, but when you need to get on the interstate/ highway via the side ramp or passing, there is minium to no power on your top end spectrum. Bigger Metering rods help alot, but next time try adjusting your float first then start changing metering rods.👍

Always use a High perf oil pump on Ponchos.

Oil pressure I glad u brought that up . Of course the engine is just sitting still so it not like you have high g taking off and then letting of at the end of a run and the oil goes the other way..I think a accusump or what ever they are called helps on that . On all the engines I know of a Harley is one Oil level can bite you in the butt with sumping . . I not sure what is going on with the oil pressure but less at higher rpms I'd not a good sign. I not a Pontiac guy but I think I saw a shop on utube that specializes in them . The therm o quad or what ever it's called by Mopar is pretty good size . I like the smaller primary for just cruising. I Thanks for the videos

I think it just has something to do with the factory Pontiac style oil pump, and possibly the way the galleries are designed.

Open the plenum on the iron intake like the performer and notch the divider wall between the secondaries about 1 inch long and quarter inch deep. Worth a few ponies.

Holy crap

We used to have a milk crate full of qjet, we just swapped carbs until it seemed to run best LOL.

Love them Q-jet carbs.. WAaaa

Sweet

I'm gonna say that box was on the shelf for 15 years

Richard when will you start testing the Trophy 4? I want to see this!

I prefer quadrajets on everything up to all except the most spicy of builds. Up to 450hp give me a qjet and nothing else

There's a reason all that dust was on the box apparently

Every time I get a rebuilt Pontiac I have low oil pressure the first 500 miles. I think that break in bearing grease gets on the ball and spring in the oil pump.

If you own a Pontiac, you know when it’s a quart low. It drops 10 psi at 3500+ when it’s a quart low even with the pickup being 3/8 from pan bottom.

A healthy pre-emissions QJet is a keeper. Gonna be hard to find one that is calibrated for a healthy engine like that one and still have tight throttle shafts. The vast majority of wrecker QJets are gonna be late model emissions units and you have significant tuning ahead of you. If it wasn't this way I doubt there would be as much aftermarket carburetor variety as there is.

How many oil releifs to partly fail? Pump, filter, and filter adapter? Run the tests with an Accu-Sump and/or an external cooler to calm the fluctuation.

I grew up with quadrant Jets rebuild a bunch of them bought a couple new ones specially for my 68 Pontiac GTO with a 400 HO. I never liked them I called them quadraguzzles they were all right when they were new and before stuff wore and started getting warpage but after a while like my halliburton mechanic brother said just throw them in the junk bucket and start all over with a new one.

Team Q-jet 😎👍

When on a dyno you don't have the g force affects on oil. I've always found running most engines at the add oil mark gave a gain in horsepower. I believe pontiac changed oil capacity in 1968 from 7qrts to 6qrts. Might be a incapable dipstick to oilpan

A little help if you don't mind, before I was Ford blue thru and thru I was a Chevy GM nut !!! Quadrajets suffer from some slight problems No 1 they made several different needle and seat assemblies that are interchangeable but have different flow rates (a valuable way to combat fuel starvation problems) No 2 the primary metering rod's are soft brass and wear fast along the metering edge changing the fuel air ratio on the primary side. No 3 the power valve spring is small and loses it's tension causing the power system to either not function and or perform badly !!! And the power valve Piston is prone to corroding and sticking (a very common problem in Quadrajets !!!) These variables make the Quadrajets perform very poorly if not corrected before tuning the carb. I love Quadrajets !!! Don't over tighten the bolts either YOU'LL WARP AND DISTORT THE AIR HORN, MAIN BODY AND THROTTLE BODY, CAUSING THE CARBURETOR TO BECOME USELESS, the main reason Quadrajets become quadrajunk.

All us Pontiac guys knew why that box was dusty.

I think its the by pass valve coming open, its a common thing to block that valve close , with a threaded plug

Surprise you didn't have a front intake leaf with that front bolt missing the one that pulls the intake forward. Also slot the rear secondaries the one that has the spring is on slots will make it run richer they will activate the accell port sooner.

I have a bunch of bad ass Pontiac parts to donate for this sort of thing.

1980s Lee Maxi Filter!🕺🏻😄🏁

Should have cut the divider out of the intake manifold.

Qjets forever For reals

Did you adjust the air spring turn 3/4 or slightly less?

💪🏽✌🏽🙏🏽🤲🏽....where the skool and how much is tuition....im reddy fo' class 😂🤔

Those valve covers are gorgeous. Who made them?

Are you gonna try the Performer RPM Intake? what fuel are you using? as this should be over 10.to 1..Thank you for the PONTIAC testing!!!

Proof that stock cast iron is still superior to the aftermarket alums trash...

50 years I have been telling people to Tune The Carb (s) thanks Richard great smack in the face….. just like Cher!!! Ha Get Over It.

The only intake that works good on Pontiac is the old torker that u can’t even get anymore

It's too bad that there is not an after market intake that i can use in my 76 trans am

Hey how are you doing man I'm a huge fan of your RU-vid channel I was just wondering can a quadrajet carburetor runs with big cams engine

Did you test the "tuned" qjet on the factory manifold?

Need some gmc motor home olds 455 metering rods 😆

I may have missed it somewhere, but is that a stock oil pan? What is the normal capacity of that pan? Thanks. Really interesting the stock carb and manifold does that well.

Do you have the heat riser blocked at the intake? It's usually worth about 10 hp plus will help prevent vapor lock.

What is the year vintage on that Pontiac 400? I'm guessing it's a pre smog motor? Love to see what it'll do in a 2nd gen. Firebird/ Trans Am body?

I’ll bet the stock intake made more power than the Performer

Been a pontiac owner most of my life, they take 6 qts of oil, not 5 like most cars..

How in the hell did you get 300+h.p. on a stock 400 engine what year was that motor i had mine dynoed and got 221 hp and 322 torque at the rear end does it actually lose that much power through the drive train

Why was the timing cover to intake bolt left out?

The oil pickup fell off.....the oil pump.

Did you run the cast iron factory intake with the AX rods?

Should you tune your Qjet? Well should you tune your EFI?

Well now I wanna know what it did with the stock intake but with q jet tuning lol

Do u think the weight savings of an aluminum intake weighing 672 thousand bazillion pounds less than the factory piece will be enough to offset the power loss over a quarter mile?

I have a 69 GTO 400 with OEM block, intake and Original Quadrajet numbers correct carb that has been rebuilt several times. The CAM is a HO Racing (HC01) version of the 068 Pontiac cam with higher lift, nothing radical. The problem i have is the exhaust gas smells rich with mild normal driving. It is to the point of making my clothes smell after driving car with the windows down or sitting at red light gets stinky. I don't have a huge budget and hate to go to fuel injection. The car idles well at ~750 and runs great and I was wondering if changing the primary jets/rods to a smaller size would help this. The bottom well plugs have been sealed. Any thoughts on this?

The first thing I would need to know before I did anything with any Carb- is the CFM rating of that particular Carburetor. That's the first thing you need to let your viewers in on... Is the Q- jet a 750 cfm is it an 800 cfm? What exactly are we talking about here??

Edelbrock looks almost SP2P style with those narrow looking runners, why the edelbrock leaned the carby out really needs to be investigated.

Most people do not know that the RAIV aluminum intake, is exactly the same as the cast iron intake internally. No difference in runner size!

Who’s Oil?

Do what you want with a QJet but it has vacuum secondaries and no accelerator pump.....a dyno will no show real world response. It's no going to match the response of an Edebrock hi rise with a Holley 750 or 850 double pumper.. That waaa you're so happy with is lack of fuel and the car doesn't go anywhere...