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-   -   fuel injection or carbureted turbo (https://www.rx7club.com/old-school-other-rotary-63/fuel-injection-carbureted-turbo-388354/)

sweet86 01-22-05 03:29 PM

fuel injection or carbureted turbo
 
I bought a turbo engine from my ex best friend and he took all of the fuel injection parts off of it. All i have is the engine block and the internal parts, plus the turbo and exhaust manifold. I was told that carbureted engines are more powerful then fuel injection. All i know is if fuel injection is better im gonna be spending some serious bread.

Crit 01-22-05 05:39 PM

Injection is typically the way to go with a turbo, just because it's that much easier to tune. I like using a carb, but I'm plumbing my RX-2 with a fuel return line when I start reassembly, just because I know there's a good chance I'll go EFI. By the way, if you're not going to use a Mazda injection setup, check out Megasquirt at www.megasquirt.info. It's a build it yourself, program it yourself, tune it yourself setup, but you can also just copy a FI program from someone with a similar setup if you want to just have an adjustable, turnkey setup.

sweet86 01-22-05 07:44 PM

so i guess that means im gonna have to find fuel injection parts for it? so you pretty much reckamend injection over carb? and thank you for helping me out.

drcoopster 01-27-05 10:44 AM

Fuel injection will give you better gas mileage for sure and a higher performance potential. A carb might be easier but far less efficient, though for a turbo I think FI is far easier.

Papasmurf 01-28-05 10:26 AM

Each has their pros and cons. Out of all honesty, fuel injection may be the better way to go, but then you spend a lot on the components, setting up the map, and it is not always the easiest to find a problem with the system if one was to arrive. People who say that carbs are not easy to tune, probably are just not familiar with carbs. There are a lot of cars out there running very competively with there carbs. One main advice I could give you is pick a quality carb. Holleys are great carbs to start out with, but if you pick one that has seen better days, it will never run right. The Demon carbs are basically the same thing, just better quality. Now you could do your own blow through carb, but a carb shop that specializes in this application can tailor the fuel curve for you so it is properly metered so it is smooth right through redline. I would check out www.csucarbs.com www.tpcracing.com and www.superiorairflow.com for some examples. I really like the tpc site. By the way, my rx2 is being setup with a blow through, but with the manifold that I am using, that doesn't mean that I can't use a throttle body someday.

Whizbang 01-28-05 10:37 AM

my TII i am working on now was carbed. dont do it!!!! BAD BAD BaD bAD BAD youll regret every moment of it.

rotary emotions 01-28-05 10:58 AM

Just take a look at modern race engines: they all use EFI. Or look at production sportscars. They make more power then ever, are cleaner then before, and have better milage.
EFI is just the way to go, if however, you can use the right bits and pieces! A good carb will be better then a bad EFI setup.
You say the engine was a EFI but had the EFI stuff removed, am I right? That'd mean you should be able to get stock parts fairly easy, to make it EFI again. Most RX-7 parts are not that hard to source, once you know the direction to look for them.

sweet86 01-28-05 04:24 PM

thats my only problem. i dont know of any place where i live to get the FI parts. if i could find a motor that is in a junk yard somewhere with all the FI parts i would do it. there is one place close to me that deals with rx7's but i really dont think he has FI parts. i was kinda leaning toward carb but i dont know yet. thank you for your help your input very helpful to me.

680RWHP12A 01-28-05 07:15 PM

i have fi parts if you need them..
as far as carburated turbo , its a cheap alternative to fuel injection. carb'd turbo works, ive made 550rwhp with a 12a carb'd turbo setup, i have since switched to f/i and at 15 psi both setups made the same amount of power, but, the f/i made a lot more power @20psi and up...
my daily driver is a blowthrough carb'd turbo setup and it smokes evo's and subaru's all the time!! good driveability , gas guzzler though ... here is some pics ...
http://www.rotaryshack.com/CustomPro...uto/84Auto.asp

Papasmurf 01-28-05 09:08 PM

Oh man, I knew I was in trouble when I jumped back on and saw a post from rotaryshack. Check them out! I love that 510 on there, any more info on that thing? Thanks Shawn

sweet86 01-29-05 04:00 PM

thank you for your help. i think im gonna go with carb if i can find a weber carb. is holley a good carb to use or something else?

Papasmurf 01-29-05 08:35 PM

A holley carb is not a bad carb, but I like the proform carbs and the demon carbs because of the billet metering blocks and such, it just seems that as old as some holleys are, they start to have porosity problems and don't meter right. But there are some people who swear by them and thats fine, but like when it comes to fuel injection for others, I would like to have the best. I am just recently learning how to do a blow through on the edelbrocks. I am sure for what you will be doing, the holley will work just fine. Any questions, just ask.

sweet86 01-29-05 09:22 PM

what about weber? ive heard they are better then holley when it comes to rotary engines?

Papasmurf 01-29-05 10:45 PM

I don't know anything about the webers but Robert does at www.rotaryshack.com I like the cleaner look of the webers but like I said, I know absolutely nothing else about them.

rotary emotions 01-30-05 02:39 AM


Originally Posted by sweet86
what about weber? ive heard they are better then holley when it comes to rotary engines?

Webers and the like (Mikuni and Dellorto) are among the worlds best carbs. It's no wonder many racecars of the old days (before EFI) used them. Mikuni, which is more or less a weber-clone, was very popular in Japan. In Europe almost everyone who was serious about power was using Webers (not just for rotaries).
In europe some kitcars and low-volume cars (like Caterham) use a Weber-Alpha EFI system, which is Weber based, but throttle body instead of carb. Caterham made over 200 and later 250hp from a Vauxhall (Opel) 2.0l engine, and used that baby in a car called "Super Seven JPE", it did 0-60 in 3.6sec...
But, Webers tend to be expensive (you always get what you pay for...) and were becoming a bit rare too, although that should now be solved.
Also be aware that carefull tuning is required to get the thing really good (but EFI is not much less demanding), esp for cold start etc. My Mikuni setup (I used a 12A with full RB exhaust and Mikuni carb before I swapped in a 13B TII) did work perfect once warm, but the warming up was slightly... well, let's say entertaining.

sweet86 01-31-05 03:53 PM

which carb do you recommend? Holley or Weber? i wanna make sure i get the good one. not one that i will regret buying. im sure im not gonna regret buying either one but just to make sure

Papasmurf 02-02-05 10:42 PM

Seriously, checkout www.turbomustangs.com and look through the carb section. I started a thread there, my user name there is papasmurf. I think you will learn a lot from that site, and they welcome any turbo car for that matter. On your question on which carb is better, that is probably left to which one you want, I picked holley because that was the manifold that I bought at the time. Good luck on your decision and if you have anymore ?'s, just ask, thanks. -Shawn

bbmac 02-04-05 09:43 PM

personaly I would use weber as they have metal floats( to my knowledge) making the pressure differential of just a carb hat less dangerous. I am going to run a 48 ida with a 12a turbo for my set up in my datsun and will post results in a couple of months if you want some input. pm me!

SDRacer87 02-04-05 10:59 PM

With a turbo application, I would go fuel injection because it makes it much more easier to tune.

sweet86 02-27-05 03:34 PM

I think im gonna go with weber because i heard that you have to always adjust holley carbs. I would like to go with FI but i dont have the money to do that plus i really dont know how to hook FI back up. Carbs are easier for me. If i had the money i would get an upgraded FI system.

Papasmurf 03-02-05 11:59 AM

You can get that with any carb that is not up to par. Start with a good quality carb. I am getting mine from www.csucarbs.com one of the best in setting a carb up for turbo or blower applications.

Whizbang 03-02-05 01:56 PM

stilling de-cluster fucking a former carby TII and turning back into EFI so i will run. so my opinion on the idea is less than nice.

DEATH TO THE TII CARB!

680RWHP12A 03-02-05 08:47 PM


Originally Posted by Papasmurf
You can get that with any carb that is not up to par. Start with a good quality carb. I am getting mine from www.csucarbs.com one of the best in setting a carb up for turbo or blower applications.



yah, those guys have some fast blowthrough holleys but they are $$$$$$$$$$$
at $400.00 to turbo prep a holley, it better be the best blow-through holley!!!

id like to try a holley myself but i dont know enough about holley carbs

so........ weber it is!!

KaiFD3S 03-02-05 09:01 PM

Hey Robert,

tried PM you but you dont take pm's here is a link to what my car looks like, not done yet but will be done this sat and will tune on the 12th

https://www.rx7club.com/single-turbo-rx-7s-23/preview-my-single-398108/

Dont mean to hi-jack this thread...

gambone 03-03-05 02:46 PM

carbs and turbos do go to gether BUT you need the rite kind of turbo or you will blow oil BIG TIME, in them real olden days befor most of you where born there where thes cars called Corvairs, I had me four of them, blew the doors off of a off duty cop in his Olds 442, well back to the main story line, the turbo had seal on the compersser side that looked like a mini water pump seal, this was so it could had a vaccum, worked real good easy to tune, Steve Gambone 76 RX4 Twin Turbo Fuel Inject 2nd Gen sport supension


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