Has anyone done a comparsion of the mean street 800HP capable FItech vs a well tuned carb for that particular combo?

I did back to back quick fuel vs. FAST TBI self learning years ago...It actually took me a while to get the FAST system to the same ET as the carb. Got to pick the right WOT AFR and get the squirter shot right.

When I was done, they were within .03 of each other.

I have the 1200 FITech, but all the throttle bodies only flow ~830cfm, so take that into consideration. The ET was very close to my 950hp Holley, fuel mileage took a lot of work to get to where I was with a 750 vac sec carb. A lot of tuning decel fuel cut, leaning out part throttle cruise, etc

So the ET is achieveable, but with more tuning and a laptop? would you do it again with the FItech? fuel injection is neat and i like the functions but Im getting decent at tuning my carb...but gasoline all over my intake is not exactly ideal when changing jets

Get some quick jet change fuel bowls. They make it much easier.

i just did a comparison with a 440 pump gas street engine with a 6 pack, 950 quickfuel and Fitech 600 . Just like anything right out of the box none of them run optimum. With Tuning on the Dyno the Fitech was 11HP above the other two keeping everything else the same.

Max Weg

i just did a comparison with a 440 pump gas street engine with a 6 pack, 950 quickfuel and Fitech 600 . Just like anything right out of the box none of them run optimum. With Tuning on the Dyno the Fitech was 11HP above the other two keeping everything else the same.

Max Weg

Get/make a little catch can or buy a fuel catch from Summit...........here's the deal, once you establish the jets(restrictors) needed for your combo then you MAY only need to make changes if you make major altitude changes otherwise the bleeds help bunches in shaping the curve to your needs.............

One advantage to EFI: it's closer to what you want in changing the fuel curve to match your torque curve.

An FI manifold can includes shapes and volumes that will not suspend fuel droplets and would cause fuel distribution issues with a carburetor. Example: Ford 5.0, where the air from the TB reverses direction in the plenum. Sometimes this is worth some power, but it depends on the manifold design.
As long as the runner velocity is good, the plenum can be significantly larger without penalty, slowing down air motion, which allows air to better follow the vacuum signal from the cylinder on intake.

I sure like the dry intake on multi port.. I gained
torque on my 416.. by a fair amount

When it comes to fuel systems on cars didn't NHRA require Pro Stock to switch to EFI systems several years back with no hood scoop sticking up into the wind
If I'm remembering correctly no one has gone faster with the new EFI systems than they did with carbs. on tunnel rams, correct
My message is nothing good comes easily
I have a friend who has built several Chevy Pro Street cars for his customers and he likes the Fi Tech throttle body systems a bunch, so much that he is going to remove the two Carter 600 CFM Competition carbs from his 6.71 blown pro street car and replace them with two Fi Tech throttle bodies and change it over to Fi tech EFI

Maybe if it was level playing field EFI might be
quicker but no scoop and rpm limits can have a
edge

Didn't NHRA institute the 10,500 RPM rule years ago?
As far as the current scoop size and location that should have helped those cars, especially in high gear

I thought that 10,500 rule started with the EFI,
they were turning higher with carbs

Fitech doesn't have to use a lap top its a small hand held. Its been cold here and my accel pump circuit wasn't up to par this morning. It has had a low speed hesitation in cold temps last couple days until it was warmed up. In 30 seconds I had the lean hesitation gone.

The reduced RPM limit came at the same time as the switch to EFI, along with a mandated wheelie bar height if I remember correctly.

The scoop also didn't help as it's picking up warmer air from the track surface vs. the original pro stock scoop location.

Wow, anyone else remember "fastest car wins"?

Alrighty, ill stay with my holley. Maybe on the street car ill try the fitech next year.

Yet another "rinse, repeat" of IROC: everyone has the same car, remember?

.03 does not seem like a lot when you consider the extra dollars and parts required for EFI.

But it could be the last time you have to mess
with it.. I've been real happy with my Holley
EFI multi point after I made some wiring changes
and I do love the aspect that if I want to change
something its just a few clicks on the lap top

On a carb, there is no wiring to change. And whatever happened to the guy on this site that was running EFI and the system crapped out? Never heard what the problem or the fix was. At least, if a carb goes bad (and I doubt it will go bad enough, fast enough that it will quit running), you just borrow your buddies carb and keep going. Who keeps extra injectors, TPS, MAP, Temp, O2 sensors with them?

It was one wire that was routed wrong... very
happy now and I wouldnt go back to a carb.. and I
have a few of them in the shop.. will probably
sell all or most of them.. the nice thing about
EFI is if I want to change to E-85 today its just
a couple of clicks and its done.. not like when I
first swapped over to E-85 and I can go back and
forth if I want to in a few moments

...with the right setup [Ethanol sensor], you don't even have to click a button to switch. Pretty slick!

True but I dont have it so its a couple of
clicks to change over

I just use a cut up little Comp Cams break in oil can & take the front bottom, drivers or rear passenger, lower bowl bolt out first & drain it into the bottle. It keeps the intake free or fuel.

...but on the Chinese built fuel injection systems, I can't help, I like carburetors & the ease of operation and the simplicity they give.

Depending on what fuel you run, the FI TECH unit will support 1200 HP on gas, not so on alcohol. My buddy has a 588 BB chevy that runs alcohol . The car slowed down .3 from 8.70 to 9.0 but it fires right off with the 15-1 compression and idles like a fairly stock car. If fi-teck would come out with a larger cfm body like a 1250 size I think the injection set up would run with the carbs. His thought on getting more cfm is to add another fi-tech on a dual four Holley Sniper sheet aluminum fabricated short tunnel ram. We'll see how that works in the early spring.

Do you carry around extra injectors, tpc, map, temp and o2 sensors when you take your modern daily driver down the road?

Nope.. no need to.. if something crapped out I
can buy it at the parts store.. mainly all GM
stuff

I have not done a back to back with the FI Tech but I've done back to back with the Holley EFI setup. No real power difference between carb and EFI but EFI allows you to "find" power much quicker. It can take a long time to figure out the correct jetting and ignition tune for an engine with a carb and distributor but EFI allows you to very quickly test different tunes.

On the dyno we are able to test a bunch of tunes in just minutes on the EFI engines. With an old school carb and distributor it can take all day to dial in an engine. Even with a distributor machine it is painful to try different timing curves. Also, if you need stuff like start retard, high speed retard, two step, nitrous control, etc. you have to add a bunch of modules if you have a carb and distributor. If you have a good EFI system that stuff is all built in. The good EFI systems also have built in data logger so that is even more stuff that you don't need to buy and wire in.

If its JUST a drag car yeah a carb would be fine and yep it'll work.
I'm sure the carb will change for temp, elevation, and density.
Actually won a "street class" truck pull event that I drove to against some big block Chevys Fords and a sweet little mercury/ford FE stroker truck in Gardnerville NV this year because of my EFI. It was hot 102 degrees and just before the pulls started it rained hard dropped temperature into mid sixties. Track was supper wet they bladed and let us go all the boys who were carbed and came from California's lower elevation ran like [censored]. The sweet little Mercury/Ford came from 4500 elevation as do I and his ran good but I'm sure it wasn't running as good as it could. I am into my Fitech around 1500 I'm going to build a custom tank and go intank pump soon, may try a single plane as well. I will do back to back wheel dyno tests to check results. Good luck and enjoy!

I'm a diehard carburetor guy and enjoy tuning them but I really like some of the positives about these new EFI systems.

One thing I've wondered about with EFI, can you set what RPM you want the motor to idle at in park and in gear? With a carb it can be quite a challenge to dial this in for us average tuners.

Yes you can set the idle speed and then the EFI system holds that speed by opening or closing the IAC (idle air port). Some systems will also adjust timing to control idle speed.

Nice. Thanks Andy.

With the idle air it holds the RPM dead on...
with the engine I am building now I will be
going a fair amount bigger on the cam and it
should control it easy but it will have a fair
amount of lope to it
EDIT
I wanted to go back to a roller cam that was in
the race car so I am(.695 lift on a 106 LSA

What EFI system are you using?

Holley HP.. its got all the stuff on it now..
its multi point and coil near plug.. I put the
coils on the valve covers

The Holley system will also increase the idle when the AC comes on. I think FAST might do that also. They have a sensor wire that connects to the AC and when it gets a voltage signal the idle speed will increase.

If you go to the Holley website and look over the features you'll be surprised at what the systems will do. They'll control the fans, control the nitrous system, control an automatic trans, allow you to use drive by wire, etc.

Yes the Fast system does that as well.

I lot of the power comes from the infinitely adjustable timing curve.
I run the fast xfi system and needs a laptop to tune.
Being able to see what is happening is a big advantage. My car is a procharged street strip so the EFI made a lot of sense, at least for me.

There are both advantages and disadvantages There is a learning curve for sure

Oh yeah there is a learning curve.. there is so
much data you can get you need to have that
learning curve.. when I started with the Holley
HP I was lost and needed some help with all of
the stuff on it.. way more than I figured.. hell
even working in the fuel lab and flowing injectors
for months I couldnt get a grasp of it .. love it
now and wouldnt change back