Q-jet to edelbrock swap

[hotrodoldsman]

If the electronic Q-jet is properly tuned it will make as much power as any carb you use, the computer controlled ignition can make way better decisions in micro seconds than you can in in 10 minutes, assuming you have the correct program for your combo. At wide open throttle the computer has no effect on the carb and resorts to pre determined curve settings for the ignition. I've tried it both ways and my background is street tuning, drag racing in the sixties and early seventies and SCCA Trans Am racing a '76 Firebird Formula in the seventies. Modern equipment, properly handled will trump any old school combo anyone can build and tune. And I'm not a modern whiz kid, I'll be 59 in August. :wink:

I think it mostly comes down to what system you want to learn and your individual preferance, plus it depends what the car is being built/used for... and with todays tech, I absolutly agree, BUT, I do not agree when talking '80s tech. Todays cars may make adjustments in a microsecond, the 80s, not so much... maybe a half or a third of a second is more like it! Back then the systems were not for power but for emissions and mileage, not that todays techs are not for these, but they have had the time and demand from consumers that 185 Hp is not acceptable performance for ANY performance car , no matter what mpg it gets! And as far as what decisions my car makes... I want my foot telling it all it needs to know, I hit the gas and it follows the timing curve and fuel jetting that I decide, not my computer reading my foot , then deciding how much power is efficiently availible. But thats just me.


Craig

 

[Bonnewagon]

I personally shitcanned the computer and everything that went with it in my Bonnewagon. BUT, I had a complete 79' pre-computer 301 with all the trimmings, AND I have 40 years of Pontiacs under my belt. So I was completely at home removing all the computer stuff. If you know your sh*t, by all means go ahead, but If you don't understand the concepts of how old cars worked, I say just leave the car alone and keep it stock. Why ask for headaches?

 

[hotrodoldsman]

I personally shitcanned the computer and everything that went with it in my Bonnewagon. BUT, I had a complete 79' pre-computer 301 with all the trimmings, AND I have 40 years of Pontiacs under my belt. So I was completely at home removing all the computer stuff. If you know your sh*t, by all means go ahead, but If you don't understand the concepts of how old cars worked, I say just leave the car alone and keep it stock. Why ask for headaches?

I'll be the first to admit that when I was de-computerizing my 307, I really didnt know what I was doing at all, but I had the drive and I learned from alot of good people and wouldnt trade that understanding of the old way for anything... you gotta know how they did it back in the day, before learning how they do it now! Hell, the timing tab was missing on my 307 so I was shown a odd solution for a pinch! I timed it by having a buddy brake-stand the car just before tire spin for load and advanced it untill it started pinging then backed it off and set! A bit cave man but hey, some old-head tricks work! Ran great! And with some further curve adjustments, ran even better!

 

[Randy_W]

My point was his car isn't going to make a single horsepower more with non computer stuff, nor run a bit better if his ecm is working correctly. Under wide open throttle the timing goes to a preset advance, want more, add in initial lead and you'll have it. The carb is just a Q-jet at w.o.t. No electronics at work then. So why not take advantage of the computer's ability to fine tune during normal driving? By the way, those eighties computers were slow by modern standards but actually made several hundred to several thousand decisions a second, not 3. Modern units do tens of thousands- millions per second. :wink:

 

[hotrodoldsman]

My point was his car isn't going to make a single horsepower more with non computer stuff, nor run a bit better if his ecm is working correctly. Under wide open throttle the timing goes to a preset advance, want more, add in initial lead and you'll have it. The carb is just a Q-jet at w.o.t. No electronics at work then. So why not take advantage of the computer's ability to fine tune during normal driving? By the way, those eighties computers were slow by modern standards but actually made several hundred to several thousand decisions a second, not 3. Modern units do tens of thousands- millions per second. :wink:

Well you goof with those '80s computers , reguardless how fast it is(HP drag car or simple street cruiser), I want my car to run how my foot tells it at part throttle as well as full! If electronics were always the best way, everyone at every track (as well as everyone with a mechanicaly improved classic car for street use) would use them... period... instead, no one does. I guarantee you take a perfect running computer controlled '80s V8... even tuned past factory but with factory parts, you give it the old school treatment and tune that, you WILL make more than just a single horsepower more. Bet on it!

 

[Randy_W]

You're entitled to your opinion but I believe you are comparing apples to oranges. With internally near stock or mild performance engines, if properly functioning the factory electronic parts will make as much power as aftermarket carb and distributor will. Yes it can be modified beyond that. But you can also bolt in an LS3 and six speed. In the end if computers were not better than right feet, then every NASCAR, NHRA pro division and every other form of pro racing wouldn't be using them by the dozen. But keep living in that belief that you can think better and faster than the pcm. My '67 Impala SS with an LT1/4L60E swap and 3.08 gears was more than a second quicker than a stock '67 SS 427 Damn those computers! :wink:

 

[snowmangaggift]

I recently got my self a 500 cfm edelbrock carb to replace my stock Q jet. I read the little "before you install" paper and it says do not replace an electronicly controlled Q jet with this carb. I have a ec q jet, is there any way i can still use the edelbrock? or is it a defs no no?

I'd toss the Comp Qjet, just my opinion.
When I still ran my 307(now in safe storage) before my 455, I replaced my CC carb with a 600 cfm edelbrock and switched the computer controlled distributor too, they are not hard at all to tune, and I could not belive the power difference(woke that 307 right up!). I myself do not like the idea or feel of a computer making adjustments and decisions about how my car runs, and forget tuning the computer yourself , I'll take a screwdriver, timing light, and a jet kit... those, and an afternoon of learning the basic old school ways around an engine(no tuner or reprogramming involved!) and your G body will run better than it ever did! Also, just for the record and to no offence to anyone , I am not some crazy old-head stuck in the "60s... I'm only 29. 8) But when your deling with an old school motor(which I hope we can all agree that even the lamest small block olds/chevy/buick all ARE!) the old school ways just work. Save the computers for the motor designed around IT, not the computer around a old V8! Just my 2 pennies!
Craig

so if i replaced the distributor with a different one its all good? and what distributor should i use?

 

[Randy_W]

Don't forget the torque convertor lockup switch, if you insist on spending the money for this at best, sideways move. At least make the lockup function work. :wink:

 

[snowmangaggift]

Don't forget the torque convertor lockup switch, if you insist on spending the money for this at best, sideways move. At least make the lockup function work. :wink:

lol good point, i dont have the time nor the funds to make a very expensive "sideways move"
Off to the rebuild drawing board!!
thanks guys

 

[hotrodoldsman]

I recently got my self a 500 cfm edelbrock carb to replace my stock Q jet. I read the little "before you install" paper and it says do not replace an electronicly controlled Q jet with this carb. I have a ec q jet, is there any way i can still use the edelbrock? or is it a defs no no?

I'd toss the Comp Qjet, just my opinion.
When I still ran my 307(now in safe storage) before my 455, I replaced my CC carb with a 600 cfm edelbrock and switched the computer controlled distributor too, they are not hard at all to tune, and I could not belive the power difference(woke that 307 right up!). I myself do not like the idea or feel of a computer making adjustments and decisions about how my car runs, and forget tuning the computer yourself , I'll take a screwdriver, timing light, and a jet kit... those, and an afternoon of learning the basic old school ways around an engine(no tuner or reprogramming involved!) and your G body will run better than it ever did! Also, just for the record and to no offence to anyone , I am not some crazy old-head stuck in the "60s... I'm only 29. 8) But when your deling with an old school motor(which I hope we can all agree that even the lamest small block olds/chevy/buick all ARE!) the old school ways just work. Save the computers for the motor designed around IT, not the computer around a old V8! Just my 2 pennies!
Craig

so if i replaced the distributor with a different one its all good? and what distributor should i use?

As long as its either an older stock distributor(pre 1980s era) or any aftermarket(Accel/MSD/Mallory etc.). In my 307 I got a used factory HEI from a '75ish olds, I would recomend a new cap/rotor/coil/module etc., but having said that, I got it for nothing in a trade. Had I seen one of the Accel distributors then, for the money(once you figure in all the rebuild parts for the used one), you really can't beat it(you will still need a HEI coil but everything else is new). I recently put an Accel HEI in my '72 Buick Riviera with a 455, and quality wise I was very impressed, the Accel one for my buick was like $250ish. The Accel part # for our olds is is 59113, Summit Racing has it for $217. But looking that one up, there is a Summit brand one for $160, I have used alot of Summit brand parts and would not be scared to use one in my car! Kinda hard to even lean toward a used on for that kind of money... Plus, as I'm sure you know, all HEI distributor caps, rotors, and coils are the same, so you are really only commiting to using the distributor bodyand shaft from summit for the long term!