Too Slow/Q-Jet question
 

As many know, I’m trying to put a stocker together in time to make Orlando. Went and tested today and everything went great! Car seemed happy, suspension was locked in, and the car was very consistent. Only issue is it’s too slow. Only managed an 8.20 off the NSA 8.26 index in pretty solid air after draining a quart of oil. I think it might be ok in Orlando but I know the car will lose time in the 1/4 vs the index in the 1/8th. I’m looking for more ways to speed it up, even if only a little bit. I’m told I could look into an M200 trans instead of my TH350 which I’m open to. Any input there would be great. Additionally, if there is anybody out there with a similar combo (‘80 305 Chevrolet) what are you guys running for jet size? My carb seems to have already been gone through and loved on as it idles great, launches well, and never misfires or stumbles. Honestly the plugs look good too but I’d still like to double check against why others are running. Mine currently has two 65 mains at 6.5 psi fuel pressure, I’m curious if that’s close to what others are running. Any helpful input would be welcomed, I really wanna go in 2 weeks but if I can’t go 13.00 I there’s really no point.

Re: Too Slow/Q-Jet question
 

I have a metric 200 that was originally built by Turbo Action that Leon Miranian is rebuilding it right now if you are interested. $2,800. Check to see what your converter is flashing to.

Re: Too Slow/Q-Jet question
 

I had as much as 6 tenths difference between my good carb and another name carb that seemed fine but ran slow and after much trial and error found 3 qjets that were from .05 slower to .10 slower even though they made more HP on the dyno. All were set up the same metering rods and hangers. All were known builders.

Re: Too Slow/Q-Jet question
 

Tough to say what it flashes at on the hit as first gear is so short, but it falls back to around 5100 on the gear changes. Might be in touch about the trans though, thank you for the heads up. Will the converter and shifter work for that transmission swap as well?

Re: Too Slow/Q-Jet question
 

I don't really have the funds to buy a name brand, brand new Q-Jet, but do you know of anyone in the NC/SC area that can at least go through one and tell me what I have? From what I understand and the previous owner of the car, my Q-jet was gone through, rebuilt, and ran well on another combo, but truthfully I do not know enough about it to say if that's true or if it's right for my combination. If there is even tenth to be found in the tune-up, that'd be all I need. I'm already under the index in good air, but as soon as I get to marginal air, I'm in trouble.

Re: Too Slow/Q-Jet question
 

With a 65 jet in the front it must not have primary metering rods. What rod and hanger are in the secondary’s? does it have a fast throttle plate? Have you worked with the speed of the air flap on the secondary?

Re: Too Slow/Q-Jet question
 

Good morning to all,
I have walked through your shoes and spent many years learning to go fast.
I made a lot of mistakes as did many others on this forum. That said, you might be able to answer a good many questions by going to a dyno, put the engine on it and run it! You will spend a few dollars here - but what you will learn in one eight hour day will help more then you now know. Yes - I know the cost is substantial , but when someone ( like a Mfg. ) asks you a question, you can answer them and produce HP & Torque numbers and that's what people need to see in order to help you.
If you're guessing , then thats about all they can do too.
You might think that is extreme but you'll find out information it would take a whole season to find out.
Just my 2 cents from over here on a little Rock off the coast.

Respectfully,
Henry Kunz 1534 H/SA

Re: Too Slow/Q-Jet question
 

Could not answer any of these question right now. I only had it apart long enough to replace the needle/seat and float. Set the float up best I could based on resources I found online. Is there a good resource on looking at what I have and determining what's in it? I'd be happy to take it apart and measure everything just so I could have a baseline starting point. I just worry about taking it apart so far I can't put it back together. Granted, I suppose that's about the only way to learn how.

What is a "fast" throttle plate? Also have not messed with the air flap but I know that it does open at WOT, just not sure how much or how fast.

Re: Too Slow/Q-Jet question
 

Where are you? Division 1 ?
Mexico?
If we knew then maybe we could recommend someone that could to help you at the (1/4 mile) track.
Who was the previous owner of your car?
Who built your 350 trans?
Does it have a 2.74 low gear?
What rear gear?
What rear tire?
Where's the other tire and brake?

Re: Too Slow/Q-Jet question
 

Your shifter should work depending on what you have. Converter will not work as the trans is set up for a metric input. Get ahold of Leon Miranian on the carb as well. He does all of my stuff.

Re: Too Slow/Q-Jet question
 

Q-jets aren't really "cut and dry" across the board. Some carbs are good with a little work, and others are slow no matter how much effort is thrown at them. If the money isn't there to send a carb out to be built by one of the "gurus," then I would suggest buying the Quadrajet book by Cliff Ruggles. I surprised myself with how much I was able to accomplish with some basic mods to a bone stock Q-Jet. I believe what was meant by a "fast throttle plate" means the linkage was made to open the primaries and secondaries at the same time, unlike the stock progressive linkage that opens the primaries a decent amount first before opening the secondaries. The 1-1 linkage carbs tend to not drive around as well, but some swear by them being faster. As far as tuning goes, the car will tell you what it likes and doesn't like. MSDs can cause plugs to look good even when things aren't so good. I would suggest taking some "swings" at jetting, rods, and trying a few different hangers if you have some. Even if what you already have ends up being the best, at least you'll learn something.

Re: Too Slow/Q-Jet question
 

If you come to Orlando I will be there. I wound glad to take a look at what you have. I can show you what a fast throttle plate is. And how it works. It is a linkage modification that brings the secondary in faster. You want the secondary and air flap to open as quickly as possible with out getting a bog. Sound like your carb is basically a stock Q jet. Even if you don’t bring the car come out and we can meet and talk

Re: Too Slow/Q-Jet question
 

As much as I think it is ill-advised, knowing I could get some help or expertise there would make it worth it. I have been planning on coming all winter so I'll probably bring it just to get a grade point and participate. I'll link up with you when I get there. Shoot me a PM if you don't mind.

Re: Too Slow/Q-Jet question
 

Don't really need to speed up secondary opening if you are two stepping it off the line.
I don't think we know that yet, either.

Re: Too Slow/Q-Jet question
 

D2, and don't mind the ambiguous profile. I race out of Charlotte, NC and hope to go to the Darlington 1/4 mile test next Saturday.

The car has changed hands multiple times since it last ran, best I can tell it last went down the drag strip in 2015 or so. I do not know who last ran it. No idea on TH350 builder or first gear, but I know it and the converter came out from behind another 305 of similar combo so I'm 90% sure its 2.74 first gear.

5.38 rear gear on a Hoosier 30x9 C06 radial.

If you need any more info please send me a PM, I don't want to hash every minute detail of the car out and make the entire forum listen, but I do genuinely appreciate all the people who have reached out or chimed in!

Re: Too Slow/Q-Jet question
 

Just gonna give it to you straight …. Just because your car runs close to the 1/8 mile index DOES not mean it will run close to the 1/4 mile index AND have you weighed the car yet ??? Number two ..:: stockers are all about RING SEAL .. just remember that. … Cheers…..:):)

Re: Too Slow/Q-Jet question
 

Oh yeah, sorry. I am not using a 2-step at this time. I could switch to one if you thought that might help, but I've heard it's slower to use one.

Re: Too Slow/Q-Jet question
 

I have the car at race weight. Weighted class is N/SA and for my combo according to class racer info that's 3534 with me in it. Currently have it at 3560 with my 4 corner scales.

Mark Lewis put the engine together for me, I think he did a great job with what he had and I trust the rings are sealing properly. I haven't noticed any extra blow-by, the valve cover breather has 0 signs of oil comin out of it after 4 1/8 mile passes.

Also, I understand that this car will not backhalf and pick up time in the 1/4. I figured I'd have to go at least .10 to .15 under the 1/8 mile index to get under the 1/4 mile 13.00 index for N/SA

Re: Too Slow/Q-Jet question
 

I really like this attitude. I'm absolutely not above trying to make changes. Like you said, at the very least I might learn something. I do not have any extra hangers or rods to try though, do you know where I can get more components to try?

Re: Too Slow/Q-Jet question
 

Apart from asking around the racing community, there are a few places to buy qjet parts. I bought primary jets, secondary rods, and needle and seats through jegs, with the brand being "JET Performance." Ebay is also a good resource for hangers, jets, and rods. Something I've seen done is if you don't use primary rods, you can screw in Holley jets in place of the rochester jets. The threads are very close, but not identical. This is not advised if you ever want to try rochester jets and primary rods ever again. So far I've only ever 2 stepped with a qjet. If you ever decide to "chill down" your engine, make sure to try it first when it isn't important. Especially footbraking, qjets sometimes need a little different tuneup when trying to leave the line at very cold engine temps.

Re: Too Slow/Q-Jet question
 

Quadrajet parts.com has some rods and hangers last time I looked. Also if there is a carb rebuild shop anywhere near your location they might have a stock of them. They are getting more difficult to find.

Re: Too Slow/Q-Jet question
 

Q-Jet builder Mike McDonald will be at Orlando. He will be crewing for Kevin Wells. Kevin has a blue G/SA Nova #3106. Mike will have parts and will get you steered in the right direction.

Re: Too Slow/Q-Jet question
 

My comment here would be that the more info you share here, the more feedback you'll get.
There are many other ways to pick up some ET besides in the Q Jet.
Of course Mark Lewis can help with that ,as can Mike McDonald

Re: Too Slow/Q-Jet question
 

Well, you are in pretty good hands with Mark helping you. On top of that he is a great guy….Cheers. :):)

Re: Too Slow/Q-Jet question
 

You need to try another q-jet for comparison, I thought I had a good one, borrowed another and was 2 tenths quicker. Also, most jet tuning is with secondary rods.

Re: Too Slow/Q-Jet question
 

What Model is your 1980 Chevrolet?

Re: Too Slow/Q-Jet question
 

I'm not a real Q-Jet tuner, but I question the 6.5 lb fuel pressure.
N/S area vs the small float
What do the experts say about that?
I have had Q-Jet customers that are very particular about regulator location and fuel line routing to the carb...
OK What you say Q-Jet experts??

Re: Too Slow/Q-Jet question
 

6-6.5 PSI is what I run for fuel pressure. You need minimum 1 gallon of fuel delivery at the carb in less than 30 seconds. I run a Magna Fuel regulator dead head with #8 line from the cell to the carb. Regulator is mounted on the fenderwell I have one of those Chinese summit pumps that is similar to a holley blue pump. I have run 9.90 with my set up. My carb was built by Jim Boburka.

Re: Too Slow/Q-Jet question
 

I have 2 spare Q-jets in my trailer, plus the one on the car, built by the 3 major builders, two of whom have now retired.

I have actually had a case where a carb ran great two weeks ago, would not qualify the car.
Yet, the carb which ran like poop 2 weeks earlier, ran the best ET ever.

I also have one which will get my down the track, significantly under the index, every time.

Getting the rods and hanger correct for race day can be a challenge.

There is no easy answer and really no cheap solution.

Re: Too Slow/Q-Jet question
 

I also have an inline fuel filter after the regulator between that and the carb. Tim Stick advised I 86 that and he's probably right. I put it there because the car had been sitting for a long time and there was a bunch of gunk and trash in the tank and line. I cleaned and flushed everything best I could, but I stuck a filter on it to catch anything I missed just to be safe. I plan to remove that as soon as I get to work on the car again.

Re: Too Slow/Q-Jet question
 

Have not checked flow from my pump, but I'm going to check that today too. Mine is a Holley Blue pump but it's ancient. -6AN line from regulator to carb through an inline filter.

Re: Too Slow/Q-Jet question
 

That's the next step, I've got another intake and carb on the way from Tim Stickles to try. Super awesome nice guy willing to loan it to me to try. Said he'd give me an option to buy it if it works out better.

Also I will be running a compression and leakdown test after work today to check the health of the engine. It's got a mediocre ring package similar to circle track setups (that's all I had when I took it to Mark) so the rings should be sealed already. I will bring it up to temperature and cool it down before I perform the tests. Might take a while but at least I'll hopefully be able to rule out the rotating assembly.

Re: Too Slow/Q-Jet question
 

Well cheap is relative lol, but I'm learning quickly that's a far fetched idea in this class. No big deal, I still think I can be at the track even with a few minor upgrades for less than 13 large.

Re: Too Slow/Q-Jet question
 

All that should work if it’s mechanically in good working order. Check the flow before and after the filter. If the flow is low with the filter you might need to take it off. I do not run a filter and never have. I am real careful to keep my fuel system clean.

Re: Too Slow/Q-Jet question
 

station wagon 2S 305/180

Re: Too Slow/Q-Jet question
 

[QUOTE=Adger Smith;692814]I'm not a real Q-Jet tuner, but I question the 6.5 lb fuel pressure.
N/S area vs the small float
What do the experts say about that?
I have had Q-Jet customers that are very particular about regulator location and fuel line routing to the carb...
OK What you say Q-Jet experts??[/QUOTE


Quadrajet fuel pressure depends on the needle & seat size. They are available from .110 - .150. The .110 can handle more pressure than the .150. My choice is the .135 for all applications. It has been used in two of my Super Stock customer's cars who have run in the 8 second zone. You can safely run 6 - 6.5 with it but I have fast customers who only do 5 - 5.5. You will have more problems with too much pressure than too little. A well designed fuel system will go a long way in not creating problems you may attribute to the carburetor. Locating the regulator ahead of the carburetor and allowing inertia to work for you is a plus.

Re: Too Slow/Q-Jet question
 

Update on some of the things mentioned yesterday:

-In order by cylinder #, here are the compression and leak down results from last night where compression is first and % leakage at 100 psi of pressure is second. Testing was done while the engine was warm and leak down tests were performed at TDC for each cylinder:
150/94 155/92 145/93 150/94 155/97 146/94 155/96 145/90

-I flowed the fuel line into a 1 gallon bucket and it took 37 seconds to fill it up

-I took the fuel filter apart and checked it for junk. It had very little if any trash in it. It's a very high micron filter so I don't see it as a restriction, so I put it back on the car. I'm not hell bent on having it, I just like the peace of mind

-the regulator is mounted on the fender well and the fuel line runs straight across the engine bay to the carburetor perpendicular to the direction of motion with a -6 line. Given the flow rate I feel comfortable I don't have a fuel delivery issue, but if you disagree please let me know.

-also, I went back and slow-motion watched the in car footage from the runs and at no point during the run does the fuel pressure drop below 6 1/4 pound. This tells me that despite the Gs of acceleration, my pump keeps up/doesn't care about it.

-As I stated yesterday, I've got an intake and carb coming to try, curtesy of Tim Stickles (thanks again man, you're a stud!). I'm anxious to see if/how much better it is than the one I have now. It could be all of the problem or none of it. Just don't know yet.

Re: Too Slow/Q-Jet question
 

You can take this for what it’s worth but ONE gallon in 37 seconds is not desirable. I believe you have an issue there considering you are feeding a Q jet . Also, there is a huge difference between VOLUME and PRESSURE.

Re: Too Slow/Q-Jet question
 

True but I now have answers to both questions. Pressure never dips and volume is decent. Y'all really think 2GPM isn't enough to feed a 250hp 305? I'm as green as can be when it comes to racing stock and Q-jets but I still find that hard to believe. Maybe I can back-to-back it this weekend with and without the filter and see if it makes a difference. I'll let everyone know one way or the other.

Re: Too Slow/Q-Jet question
 

Also, there's a difference between battery voltage and alternator voltage.
It sounds like you have a stock tank inside the quarter panel.
In that case , you're also fighting inertia and siphon issues.
Fuel cells don't cost much on Ebay. You will need to place it inside a metal box on a wagon though.