what are the pros and cons of switching to efi, how much of a mpg increase do you observe? hp increase/decrease?
All depends on what you want to do and how well you can tune it. Peak to Peak HP if you are an ace with the carb and an ace with EFI will likely be the same. Here are the advantages I feel of EFI: Timing Controls - Having better timing controls usually fatten up the low and mid range torque curves (and associated HP). With the timing modifications you should be able to lean the engine out for better mpgs (something I'm starting to work on this week, after two years of essentially leaving the timing table alone) Make Changes quickly without getting dirty - If you are a drag racer, you can make a pass, make the change and be ready to run again in less than a minute. Conversely, testing out in the real world, I'm fond of making runs down desert roads, make a change without even unbuckling my seat belt, and making another run to see how the change worked out. Barometric correction: I drive regularly from 7500ft down to sea level. That's a huge variation in air density that the carbureator does not like. It has to run rich at 7500ft if it's going to run normal at sea level with out changing stuff. Side benefit of the EFI is most come with a Data logging ability. So maybe factor that into the cost side in Carb vs. EFI. What's a carb, timing controller and a datalogger cost together? It's not apples to apples comparing them on just the fueling side, carbs are usually cheaper because they do less. I'm still a novice in the tuning department. I have no idea what HP I was making before or after. So far my mpg's are exactly the same as the Q-jet and HEI, but there is a ton of room for improvement in my tune. Cold start up, low rpm cruising, and low-mid rpm power are much better. Though admittedly I did not spend anytime setting up the Q-jet. The best 1/4 mile run I made with the Q-jet and points was low-16's @ ~95mph cause it kept vapor locking the carb in 3rd gear. I made a 14.7second at 100mph with BFG's, no traction and popping a head gasket =P A lot of top contenders in Hot Rod's dragweek run an EFI system, so it's got to work. I might be a bit bias =P
Pro's: Infinitely tuneable (depending on which system you use) More power under the curve Better mpg (depends more on your entire drive train and the type of system you use) Con's: Expensive You'll never be "done" tuning If you're going to do it, do it right the first time and spend the time and money to get a fully tune-able mutli-port EFI system. You wallet and sanity will thank you in the long run. I personally didn't see an increase or decrease in gas mileage going from the stock QJ to the Powerjection III system I have now. The power increase was noticeable but i have no dyno#'s or track times to back it up, only seat of the pants. Honestly, if you're looking for more power AND better gas mileage, get an over drive transmission(or a 5/6 speed manual), some headers, and a well calibrated Q-Jet and call it a day.
"You'll never be "done" tuning" Ain't that the truth! I know people who dyno tune the engine, runs great, gets great mpg's, and the hardest part for them is leaving it alone, lol. Lots of self control is needed once it's right to not screw with it. I've had it right a few times, and managed to screw it up and forget which save file had the "good" tune in it =P
i have a new in box powerjection III TBI kit for sell for 1300 shipped. if interste shoot me a pm or post in my forsale thread linked in my signature for another 200 i'll consider adding an electric fuel pump(for n/a apps) and a pair of summit fuel filters (100micron SS filter and 10? celleuse prefilter) another 50 for a comp engineering sump for your tank This would practicaly be everything needed for you to switch to fuel injection, only thing you'd still have to buy would be a fuel pressure regulator which you can pickup cheap through summit..
i'm getting a vendor over pro-touring to make me a dominator mpfi package up and to convert my intake for the injector bungs and fuel rails
Opinions for EFI for big-block V-8 ? (Re: efi) Dear V8 Buick fans, I just got my hands on a Buick 430 V-8 salvaged from a 1967 Buick Electra. I'm planning a "drivetrain transplant" into my 1965 Buick Special Wagon. Since I also fear the cost of gas and am fed up carburetor "voodoo," I've been pondering the EFI upgrade. However, what opinions I've heard are clearly mixed. As some folks here have tried, I gotten a suggestion for the Retrotek Powerjection System. The other suggested systems I've gotten is for a port-tuned system by Accel 77010W (which requires modifications to an aluminum intake manifold). I've also gotten a suggestion for an Accel version of the throttle-body fuel injection system, the Accel 77135D. I got interested by all this from the TA-Performance intake manifold/EFI combo: This didn't seem like such a difficult scheme to get some really modern driveability (and I hoped better fuel economy). My speedy attempt to glean all the wisdom on V8 Buick suggested that people's experience with this has been mixed. Is that the overall consensus? Has there been improvements in the hardware and software so that getting a car going with EFI is now easier - or not? Do folks have other recommendations as far as EFI vendors and products? I certainly would be interested in all opinions before I commit myself to anything serious (as in $$$) :grin: Sincerely, Edouard in Orinda, CA
In terms of fuel saving if you do the math it will take a long time for most older cars to ever recover the additional dollars spent on the FI conversion. Of course, if it is a regular driver it will take less time. But this is not how most older cars are driven. If you get a pro built carb that has been test run and dialed in close on an engine you cannot go wrong. Get one from the guy that wrote the book.
Hoping to keep old-warhorse in normal service (Re: efi) Thanks Jim for your very reasonable comments, I actually tried to crunch the numbers but it depends to two impossible to judge parameters: how much better fuel economy you'll get and how much higher the price of gas will go. With very optimistic assumptions of the improved fuel economy, you might pay back for this in as little as 33,000 miles. More realistically through - you are likely to at least recover the cost of EFI over the life of the engine assuming the maintenance on the system doesn't spiral out of control. However, your key point is probably correct for at least 80-90% of classic cars out there. Old cars are more for show than for go. That's the difference in my case (if nothing more than wishful thinking). My wagon is literally the family heirloom that has been working for the family since 1968. I'm really hoping to keep the car in that role. Even if it doesn't get out everyday, I want to handle things like weekly shopping chores and so on. So even if I'm not going to recover the investment, I'm feeling the itch in order to make the car a pleasant, hassle-free driving experience. The bottom line is that the ol'Buick wagon has been losing out to our "brand new" 2000 Buick Century and I want our 65 to be at least closer to that sort of pleasant driving. Call me a sucker but . . . . anyone hanging on to a 45 year old car is a little . . . different! :grin: Cheers, Edouard
yes, its alot easier now aday to get a decent tune from the get go, due to alot of the kits having a self tune ability like the powerjection III "retrotek" o have for sell tbi will do you well, and is far the easiet and cheapest anything mpfi (multi point bank to bank)or sfi (individual cylinder injection) will be about double the cost, and most likely more then a tbi kit
Re: Hoping to keep old-warhorse in normal service (Re: efi) I've got roughly 20,000 miles on my EFI system in a year and a half. So it's safe to say I drive my Buick :3gears: I have yet to beat the mpg's of the Q-jet though ou: though I have consistently matched it. I have lots of lessons to learn with tuning though, and am just really stepping into the timing. This last weekend, on a 700 mile trip, I matched my Q-jet mpg while towing a trailer with an engine on it, by significantly advancing the ignition timing and leaning out the fuel, had to watch for detonation, especially while towing with 3.08 gears, but I have the fine amount of adjustment capability to handle that, while cruising down the road no less! Got to love straight never ending empty Nevada highways. I just purchased the intake set up from TA, not their whole EFI package. It'll probably never pay for itself with my tuning abilities :Smarty: but I have EFI people convinced I should be getting at least 4mpgs, and I think I should be 8mpgs more from previous combinations with Q-jets and standard distributors. But I didn't do it to save money (does anyone build a Buick to save money:idea2, I did it for drivability and mpgs. I can in a single one way 500 mile trip go from 7500ft elevation to sea level, carbs don't like that too much and at the same time I'd like to make that 500 miles without having to stop for fuel. It theoretically could save me money as a fringe benefit, but it's not the primary reason. Then to top it off. I LOVE telling people my car has a Fuel Injected Buick 455 with a 5-speed manual:3gears: You can check my build from the link in my signature. That being said. At some point I'm going to try and do a dirt cheap EFI conversion on my Centurion. I think I can get the full cost down to around $600 on a multiport system. Doing more fabricating myself and less purchasing ready to go parts. My T-bird cost me around $800 with a 670cfm TBI (in place of a 600cfm Autolite).
Like i said above, you'll get more bang for your buck going with an overdrive transmission. That's where most of your mileage gains will be had. As far as getting your moneys worth consider this: I currently get 9.5mpg, drive roughly 30miles a day, and usually fill up at the 20 gallon mark. At 3$ a gallon I'm spending roughly 4547 a year on gas. Now if I could increase my mileage to just 12, and nothing else changed, i would only spend 3600 a year with a savings of 947. So, it might take a while to recoup whatever you spend for an EFI system or overdrive trans. That can't be the reason you do it.
Good idea . . . just one thing wrong with it! (Re: EFI) Hi Jason and V-8 Buick fans, It is actually a great idea . . . . . Just one thing wrong with it - I had already planned on it! :laugh: I discovered that a 200-4R swap for the car's existing TH350 was relatively painless (any opinions to the contrary?) So I'm already committed to upgrading to a hardened transmission to go along with the just-acquired 67 Buick 430. So that's already factored into the hopeful savings column! I've gotten all sort of good advice about cams, exhaust, and other goodies to try boast fuel economy. A good many of these ideas I'm already committed to. Getting an Electronic Fuel Injection system would simply make one more step toward trying to get this old wagon to perform as well as it possibly can. It's not like I'm going to keep ahead of the technology race, but I hope to improve the car enough so that I'll feel a lot better using it for the sorts of things it used to do day-to-day in its "youth." Thanks for all the good ideas. If folks have any other clever tricks as gas starts heading for four bucks a gallon I'm there will be plenty of interested listeners! Is there anyone who doesn't need to save a few of theses? :dollar: Cheers, Edouard :beer
Hello and welcome. It seems like you have the funds to do this right the first time. Here's what i would recommend: 1. Figure out what grade of gas you want to use and figure out your engine combination to give you the proper static and dynamic compression ratios to allow you to run that grade. 2. Figure out what heads you want to use and get them flowed. 3. Unless you're going for all out horsepower, I would stick with an aluminum dual plane. It will keep the low rpm air speed high in the ports and act most like a modern efi manifold that a single plane. Plus, it will help keep the torque down low where you're going to need it. 4. Get your block straight. Oil mods, bigger pickup, crank scraper, grooved bearings, stock rods with ARP bolts, forged pistons, rings, etc. 5. Call TA and talk to them about your efi goals and have them custom make a low lift hydraulic roller cam to maximize mpg's. 6. Good flowing exhaust, headers might not necessarily be the best idea but usually will flow better than manifolds. 7. Overdrive trans (you already have this) with proper torque converter. 8. Finally, your efi setup. Depending on how much you want tune, I would pick a MPFI system regardless with ignition control and of course the proper system components to support the whole thing. If it's not a self learning system, take it to a competent tuner and have them dyno tune your engine and wallah, you're done. Obviously, there are cheaper ways to get tot he 90% solution, but this is what I would do if I had the money. No matter what, good luck and we're all here to help however we can.
I have never come to grasps on how much people think they can make there 1960-70s bloody V8s sip from a coffee stir stick straw. I mean come on here we have so many variables that prevent this from being achieved. The technology of EFI has come to the point where we have endless tune-ability that really allows us to control every facet of how the engine runs. Impressive, most definitely, but we cannot forget that with the 40-50 years of advancements the engine itself has come a long way as well. Engines of today can get away with running leaner than stoichiometric (14.7:1) and in turn less fuel is better fuel economy. Before you know it the EFI that we know with a throttlebody is going to disappear because direct injection will in essence make a gasoline engine a diesel! Back to this fuel economy thing. You are only going to get so much. A five mpg is probably the usual with going to a basic EFI system. We really should not be looking at this though. If you cant afford gas then why do you have a muscle car? What ever happened to Making more HP? The benefit that we should be looking at the most with EFI is drive-ability. You want the pleasure of hopping in your car starting it with confidence and taking off to the bar, show, doughnut shop, or track and maybe blow the doors off one of the neighborhood rice rice fart can import kids. The most important thing in EFI to me and hopefully you is HP and not only top end HP but over the entire RPM range. Which brings be back to the point of... 1. Chill out :bglasses: 2. Spend your :dollar: on your already expensive hobby 3. :3gears: Drive it! Because you are not driving a Prius. 4. Enjoy what you have created. :beers2:
I wonder how long it will be before someone offers an aftermarket EFI with some kind of displacement on demand system. The LS engines get great gas mileage on the highway because they are running 4 cylinders. I bet the mpg increase with that type of system would be much bigger. Of course the system would have to be multi-port. But I'm not sure what else is essential. It would probably be best to have one coil per cylinder controlled by the computer. Would it hurt the engine to have a spark in a cylinder without fuel? Is there anything else involved beyond turning off the injectors to certain cylinders? John
