Okay I need your help in decidiing which direction to go with this set up. I'll start by saying I've always been a carb guy and found Holley's to be very tunable and makes for a very simple hassle free 4 barrel carb for a 13b motor.

However I also like the drivability and fuel economy of the stock fuel system. SO what direction to I go? Keep in mind that the electric omp has been removed and blocked on this motor (limp mode) and the air pump has been removed so the aux. ports wont work as they should if I keep it fuel injected.

I know I can get an R-tek and keep it simple but for the price I can also get an intake a Holley carb (not RB) and I already have everything else needed to convert to carb. Okay guys what do you think?

 

i guess it depends on how far you're willing to go, particularly with budget. given the choice between carbies and EFI, i'll choose EFI almost ALL the time!

 

If the car is stock.. dont waste your time doing a whole carb conversion etc.

If you are planning on modding for more power.. you can do a 48IDA and manifold from Mazdatrix for around 840 I think. Done. Installed.
Nab a FB Dizzy and call it a day. CHEAP.

If you want to make real reliable power, that doesnt need re-jetting.. and thinking.. hmmm its a cool day.. wonder if it will run better? Hmm its REALLY cold.. will it start?
Just go stand alone FI.
YES you will need to tune it. No it isnt as simple as some would have you believe. Is it really that hard? Nope. Will you make a lot more power N/A? Yes.. over the stock system yes. Over a Carb? Not until its tuned properly. Then you will. Why? Because if tuned properly it will perform properly across the RPM range, in ANY WEATHER. So if person A tunes a Carb for perfect performance today.. come next weekend they need a dyno to re-tune to correct for weather changes.. or they can guess..

If you are planning on doing a ported motor and the whole works... either will work. But again.. you need to tune them both Once initially. The Carb will need re-tuning for performance int he future for sure.

 

Like D1 said. What's your budget? The Weber or carb way is going to be alot cheaper but tunning needs to be done more often. The EFI is going to be alot more expensive but more streetable and less tuning once established. I have a Weber 48 IDA and I think they are great for street/strip but more for flat out racing. Once you get the hang of jetting and tuning it, it is very easy. The jet changing litterally takes seconds. If you are going to drive your car mainly around town and on the street and can afford it, then I would go with the EFI setup. Better all around driveability and better fuel mileage.

 

All else being equal FI is far superior.

A Weber setup isn't necessarily that cheap, you need the manifold, the carb, a low pressure fuel pump and regulator, jets, and all that stuff, so in the end getting a Megasquirt, the manifold and some TWM ITB's and hooking it all up will be about the same effort and will give you more power, better drivability, better economy and better tunability.

 

Believe me if I do go carby it wont be Weber IDA or DCOE. Been there done that....and you guys are right about tuning, I would go 4 barrel Holley. I already had a 600 cfm on an s5 and it ran beautifully. Now I got a street-ported (large) s4 and its going into an s5 chassis and thats the main reason why I think carb is the way to go.

 

www.megasquirt.info

 

Hey man, my 7 is carb and i am not going to deny that it is simpler to work with and everything, but if u wanna go all out racing , defenitly go carb, but if not, man dont waste your money on a conversion because they are a hassle at times.

 

I've already done the carb conversion on an s5 and yes its simple to work with. I'm new to this efi stuff and thats going to be the challenge. The motor is ported and if I go with stock efi system I'll get an r-tek w/ RB headers and prescilencer. Thats about it I guess.

 

But all else being equal EFI will make more power EVERYWHERE compared to a carb. They might make comparable peak power numbers, but the power delivery and off peak power will be better with EFI. If the rules allow it, then run FI, unless it's like Prod racing rules in the SCCA, where its a weber carb or stock manifold and TB EFI only, with no ITB's or anything equivalent to an IDA weber.

 

I say JUNK IT and get a FB

 

There's no other carb out there that is easier to change jets, chokes, etc than a Weber IDA. Like anything else, you have to learn and know how to tune them. Remember Holley carbs don't have chokes that you can remove and change and I don't even think they have idle jets to change- correct me if I'm wrong on the latter. Also, if you think Weber and DCOE's are hard to tune, then you're in a world of hurt if you think tunning a EFI is going to be easier, especially if you have never done it as this looks to be the case. Why do you think so many people pay big bucks for tunners to tune their EFI setups? Sure you can get it to run and probably run decent but to get the full potential is going to take alot of time, more so than a Weber for sure. Just something to think about.

 

Carb fuel economy is to be best found in the idle and progression circuits. Since the majority of street time is spent on those circuits.

Run the smallest idle fuel jet that does not make the motor kick and buck on the progression circuit. 65 is a tad rich and 60 is way too lean on 48 ida, 13b mild streetport fo example. Jet reamer kit comes in handy to get inbetween increments of 5.

Lastly, too big a accelerator pump kills mpg every time gas pedal is pushed.

EFI really is the way to go these days but carbs still work well. Just a dead technology is all.

 

Go to RacingBeat they have a pre-tuned carb for your setup, and a comparison chart between the Webber and Holley in power out put and different engines, and ports.

 

lol....c'mon Wacky, show a brotha some love!

 

I had bought a new RB Holley in the past and I wasnt impressed w/ they're old style carbs. Since then I learned much about Holleys and am very pleased w/ how easy the newer style carbs to tune.

**BTW this is for s street car driven weekends only.

 

Check out Paul Yaul I think thats how spell his name I hear he's good at tunning carbs that he sells and he stands by them and helps you set them up according to your area conditions. cARBS sound so good.

 

Paul Yaw isnt doing much rotary specific stuff these days, but if you are interested in fuel injection he is dealing in Motec and injector performance testing.

 

Still undecided but if I go fuel injected I'll go with R-tek w/stock efi or Megasquirt w/ throttle body IDA, If I go carbed its gonna be a Holley.

 

It took years for SuperStreet to convince Bisi to switch to fuel injection, he finally did it last year when he saw the results. He had reach the full potential of carbs. But his car is a race car and running meth.

 

a predaror carb is the easyist carb to work with no jets just a fuel curve cam it is 390 cfm-930cfm depending on how much air the motor needs one srew adjustment for afr and looks wicked just get the one with an idle curcite but that is my take on it