I'm really waffling here on the direction I want to go. Basically, my build is a street driven 71 Monte Carlo with a 454 big block that I plan on fitting with a CXracing big block twin turbo kit (t76s) running on e85. However, I can't decide whether to go EFI or Blow through. I'm weighing the pros and cons. Here's where I'm at.


Blow through; The only major hardware I would need is the Carburetor that I would purchase custom built from csu or whoever. My fuel system is up to the task otherwise. I would like to run e85 as well. My major concern here is the maintenance for a vehicle that sees a lot of down time. E85 doesn't play well with those conditions in carb applications. I couldn't get the tune dialed in as precise as EFI. Nevertheless, I'm still considering this option so possibly recommend me a Carb builder to consider.

EFI; Much better tuning and Driveability characteristics. I'm already familiar with EFI tuning via various software and laptops. Better monitoring for optimum performance and health of the engine. The challenge is largely the cost to piece together the right components but which is less of a concern than the installation. The actual EFI system is not a concern, it's the fueling system that would need a complete overhaul from the tank forward. Running E85 in a twin turbo big block really requires heavy fueling and exorbitant cost to do it right. I had considered the FiTech fuel command center, but with ethanol, it wouldn't even support my N/A big block. That leaves me with a lot to shop and pay for, then an extensive installation process. I have not ruled this out, but it's a lot to swallow to convert.

Anyway, help me make a decision. If I choose an EFI, what would you recommend. I'm liking what I'm hearing from fitech, but I also find the FAST offerings enticing. I plan on a low boost setup with high compression for street driveability.

Another possibility which I wouldn't mind is to get the turbo setup up and running on a blow through carb, then later on down the line, I could make the switch properly to efi. I always like having more projects and then it wouldn't seem so overwhelming.

Here's my build thread for reference.
https://www.theturboforums.com/thre...e-(The-Dark-Knight)-BB-Twin-Turbo-aspirations

 

depends on what you (and people around that help you) are more comfortable with. I have done both and like both.

In my opinion the major advantage to EFI is:

1. Cheap spark power via GM LS coils
2. Datalogging
3. computer control over spark

I can make a carb do whatever I want within reason for a relatively warm weather hobby car. The MSD 6530 is a great set up ....but for the same price (less really) I can have a microsquirt unit control GM LS coils, data log...and have over boost safeties....and run a carb.....that is what I intend to do with the next mini project on my Mustrolet.

I like carbs with E85...due to the increase in the fuels residence time in the intake tract....and no injectors to clog or corrode (search E85 goo). I have had great luck with E85 in a couple homebuilt carbs...the only difference in maintenance is I drain the carbs at the end of the year (for winter) which really should be done with gasoline too...but Im lazy..lol

 

Thanks for the response.

My friends have EFI tuning experience and I've become somewhat proficient myself in that regard. However, I'm a better tuner than I am at wrenching so weighing this out is challenging.

Nevertheless, I am interested in this setup you are working on. Please tell me more or direct me to where I can find out about this.

I've looked at the 6530 and that's definitely in the conversation.

On E85, I'm familiar with the "goo" that's troublesome with injectors, valves, etc. Crossing my fingers that my other turbo vehicle running e85 doesn't have issues, but it's been running ethanol for 4 years without incident.....except for blowing through clutches because too much torque.

 

https://www.theturboforums.com/thre...et-(redneck-stuff-inside)?highlight=mustrolet

My first E85 build...this will be the one getting microsquirt or megasquirt 2 to control spark

https://www.theturboforums.com/thre...-E85-GT4294-budget-minded?highlight=mustrolet

Build i did for a buddy

https://www.theturboforums.com/threads/365663-72-Chevelle-496-Twin-T72-s?highlight=mustrolet

Another blowthrough build

https://www.theturboforums.com/thre...460-Microsquirt-on-the-cheap?highlight=Nordic

My most recent EFI jet boat build

Unfortunately life gets in the way of me going to the track a lot and my local track worships bracket racing and the test and tune is a joke.....I need to drive about 1.5-2 hrs away to tune at a track that is decent...so there is a lack of track data in my builds unfortunately.

Let me know if you have any questions

 

sounds like if you are more familiar with EFI....and would have to PAY big $$$ for a carb....I would go straight for EFI via megasquirt if I were you.

The carb way is attractive to me since I can do all the mods myself and save some money (swap meet carb moded for less than the price of new injectors)...there is no way I would pay ~$1000 for a carb

only thing that sucks about EFI for big blocks is the cost of the intakes or the carb style intake with the expensive ass 4 bbl style throttle body...thats why Im using carbs as throttle bodies for my EFI jet boat project....I couldnt stomach spending ~$500 apiece on a throttle body

 

I did a lot of reading up on Megasquirt and I like how much information is out there on tuning for it. However, it seems like a lot of parts I'd have to gather to make this work for me. Again, to run EFI and e85 especially, it's the entire fuel system overhaul that intimidates me.

That being said, I'm not against putting some coin into this project, but obviously, funds are not unlimited. One other possibility I'm thinking of to keep initial cost down is to run the Fitech fuel command center (fcc) on regular pump gas. Then I'd be able to run my choice of EFI and possibly switch to E85 at a later date. Believe it or not, one thing that has me apprehensive is my horrible gas mileage and small 12 gallon fuel tank. I made a couple short trips after a fill and it was already time for refueling. For e85, I would really want a 20 gallon tank from Tanks,Inc (I think) that's built for in tank fuel pumps. I suppose that could be a later project.

I also noticed a guy in the classifieds selling a 750 blower through e85 carb for $800. That's an option......if I want to fuel up every day I drive.

 

The megajolt is what im about to install on my 4cyl. Seems like a pretty good option for spark control for very little out lay. Can do coil on plug if wanted. I think the ms3 has more spark control options for full sequential rather than wasted spark, but im sure it would be fine. Has user defined outputs im going to use for crutch setup brpv thingys. Has map sensor etc 10x10 ign map

 

I'm really leaning towards fuel injection right now but just don't trust the fuel Command Center for my fueling needs. I may have found a solution that will not be too imposing of an installation process. Tell me what you think.

What I have right now are dual electric fuel pumps hooked up in parallel. They both are powered by a manual switch. I found this fuel pump that would literally be a bolt in replacement. Tell me what you think.
https://m.summitracing.com/parts/msd-29257

What I was thinking is purchasing two of these pumps and running them in parallel just like I run my current pumps. Basically in regular driving situations I run 1 pump but when it's time to have fun I switch on the other pump. Doubling up on this particular pump in parallel would double the flow and I would have all the fueling I would ever need no matter what I did. Besides if one pump fails the vehicle would not be stranded just like has happened to me before . This pump even offers kits to upgrade to E85 if need be. Provided I install the regulators and filters properly do you think this looks like an adequate idea for my fuel. If I don't get much response about this it may be better to start its own thread so we'll see.

 

Though there's not many voters in the poll, the results are unanimous for EFI. In weighing the pros and cons among other discussion, this might be my best option in my situation. I can run e85 or switch as needed much more conveniently with EFI. Besides, to run e85 with a blow through carb, the cost for the carb is about the same as the Fitech EFI I'm interested in getting.

 

Go to FiTech and check out there EFI systems. You can run E85 and boost on certain models, they also won't break the bank. They have the same features as everyone else.

I am doing blow through and EFI upgrade on my 351w.

Slows