Wrenchero, I have been down this road, listen up. I do not have all the golden ticket answers but I do think I can help a little bit. Since your doing pretty OK now, and do not mind experimenting which is key, I’ll tell you all what I did.
i dont have any experience with tq's. any good comments out there
Ether of the TQ’s you have there will be fine. IMO, the electric choke model would be better to use and easy to hook up. I managed a best of 18 but normally found 16-17 with that carb on a 400/727-3.55 set up in my B body. Only other mods were a Holley street dom & headers fired by a chrome box.
But truly, no matter the carb used, state of tune will rule.
i guess i shouldnt complain too much.it runs great,super low maintenance, and it runs great on 87 octane.i met a guy at a show with a challenger with a 2bbl 318 challenger who got over 20mpg.he told me i should put a 7 1/4 in it.too bad i threw one out 25 years ago??
No no no, stay away from that person! Post holiday s picture up so we know what *** hat to stay awat from.
Bad advise that will yield no real result.
Nothing like going backwards and paying a fee for it.
Revoke his MoPar card now!
Report him to ththe man club for review on his man card!
hello all.i know most guys are looking for more power but i am looking for better mileage.i have a 68 satellite convertible that i take trips with.it has a stock 318 2 barrel with stock cam,stock exhaust manifolds,dual 2 inch exhaust,8.75 rear with 2.76 gears and 904 trans.it gets 16-17mpg on the highway.should i be happy with that or should i try to do better.i have 2 thermoquads i was thinking of trying. a 9185 318 truck carb and 9801 mopar universal thermoquad with electric choke, and edelbrock performer intake.i dont mind messing with it because i can always go back to how it was.thanks for any input.
Cost vs. return? Do you care?
I didn’t. The search for knowledge is never cheap, and perhaps not easy at times.
What I did on my stock 360/904-8-1/4, 2.76 geared rear in my ‘79 Magnum to achieve a max of 20 mpg’s and normally 19, from top to bottom was;
Earlier OE trap door air cleaner
600 AFB on the OE iron 4bbl.
Dual exhaust @ 2-1/4 into twin high flow cats that were legally needed at the time, H pipe, turbo mufflers to the bumper. Ignition was a junk yard truck distributor fired by a MSD 6. I also installed a MP viscous fan. If that freed up HP, for mileage, IDK but I needed a fan so I hired that MP fan.
Tires were 245/60/15 on all 4 corners.
While this list is not a huge help I hope it helps. Obviously it has room for improvement!
If you drive your car everyday. As your main car even in the cold, I suggest a regular factory air cleaner to help in warming up the car. An open element air cleaner will deliver easier breathing which translates into more power and mileage.
The intake could be less restrictive. While the OE unit is a rock solid part, an aluminum unit can help with additional free breathing.
For the 318, I have found the Performer is as good as the OE iron. The LD4B is better. I would like to try the rpm up top myself even though there is a slight rpm off set. But IMO, an improvement will be found on the hwy. Around town, not so much. Again, IMO.
Exhaust. Headers should improve mileage. But I can not verify this on my engine testings. On your engine, I would move to a 2-1/4 pipe size with an H or X pipe into a Dyno Max super turbo muffler.
Again on carbs, no matter what carb you have on top, make sure that your cruising rpm state of tune is excellent!
The only draw back to the use of the TQ is tuning parts or there lack there of. And if the bowl brakes or warps due to heat, it’s kind of done then. A good working TQ is really hard to beat and if you have a good one, your in luck.
The TQ is my favorite carb hands down. Great for stock to the fun and flexible street strip rides.
Need a new carb?
I suggest ether the AFB or better yet IMO a AVS. The tuneable secondary air door is a real nice item.
If your a Holley only guy, you’ll need nothing more than a simple 1850/600cfm carb.
Make the best effort in the carb tune and the distributor tune. Once you have all of that dialed in and running and operating at its best, I now say, add the MSD for the final edge.
Have fun and good mileage hunting!