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-   -   13b carbed turbo setup (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/13b-carbed-turbo-setup-825711/)

Turboroll 03-12-09 05:29 PM

13b carbed turbo setup
 
Ok, I am building a carbed 13b turbo. I know many of you dislike carbed applications, however, I am trying to do something a little different then most others with 2nd gens. I am going to post my basic setup with the hopes of getting some good feedback as to whether or not it will work well together. Thank you in advance for any help!!!!

S4 4port Full Bridgeported
Racing beat carb intake manifold
Holley 650 w/ vacuum secondaries (boost prepped)
Holset hx40 turbo
Custom built turbo manifold
large tial wastegate
FMIC with 2.5 inch piping
1st gen distributor, aftermarket coils, crane cams hi-6 ignition box
walbro 255 fuel pump
full 3" exhaust with N1 muffler

I will also be pre-mixing my gas/oil and this IS NOT a daily driver...


Thanks again!!!

S4GXL 03-12-09 05:33 PM

good luck. theres a reason you dont see many carbed turbo cars of any kind.

FrankV702 03-12-09 05:59 PM

1 Attachment(s)
This was my attempt at a blow-through carb setup.. I FAILED! :wallbash: But I should've known better, I know absolutely nothing about carbs, I just thought it would be cool and unique! :)

Attachment 709773

Aaron Cake 03-12-09 06:36 PM

Uh, that's not a Holley 650...

LargeOrangeFont 03-12-09 06:56 PM


Originally Posted by S4GXL (Post 9039274)
good luck. theres a reason you dont see many carbed turbo cars of any kind.

They can be made to work just fine, if done correctly. VW guys have been doing it for decades.

joeylyrech 03-12-09 07:16 PM

I owned one several years ago and it ran great,full bridgeported,60-1,holley 650 turbo prepped double pumper with mechanical secondaries and running a locked first gen dizzy ALA PUERTORICAN STYLE,people will tell you that they dont run good that it will not idle fine that you wont be able to run lost of boost not really,if the person building it knows his stuff it will drive fine and make good power without investing a chunk of money of a standalone in fact i seen turbo carbed cars killing fuel injected ones all they long.

arghx 03-12-09 09:39 PM

^^^ he never said it was. That pic is not from the OP's car.

I'm sure you can make it work but one of the biggest drawbacks is a lack of any precise timing control.

S4GXL 03-12-09 11:51 PM

and a lack of precision fuel control. two of the biggest issues when building a turbo motor. hence the general lack of high power turbo carb cars around.

iceblue 03-13-09 12:06 AM

And the boost floating the carb. Personally I cant stand them its decades old technology and for a reason. Flip side they can work if you set the carb up properly I just have a disgust for carbs think there anchant junk but whatever.

Turboroll 03-13-09 10:26 AM

I will never understand where total disgust comes from for carbs... To each his own. I do appreciate everyone's feedback though. As for fuel control, I will be using a nice boost sensitive FPR, not sure how precise it will be though because I have never used one. But it does sound like I will be doing most of my tuning by watching my wideband.

Aaron Cake 03-13-09 01:45 PM


Originally Posted by arghx (Post 9039856)
^^^ he never said it was. That pic is not from the OP's car.
I'm sure you can make it work but one of the biggest drawbacks is a lack of any precise timing control.

Yep, I'm an idiot. I scrolled down too quickly and the names ran together...

In reply to the OP, the total disgust of carbs comes from the fact that it is thoroughly antiquated technology. Now I suspect that a lot of people to say "carbs suck" are just parroting, but believe me, I totally mean it when I say "carbs suck". Having dealt with turbocharged carbureted rotary before, I say "good luck" to anyone who thinks they can make it run as well (or even close to as well) as a fuel injected car. Especially with a bridgeport.

teddyrx2 03-13-09 02:14 PM


Originally Posted by S4GXL (Post 9039274)
good luck. theres a reason you dont see many carbed turbo cars of any kind.

You are so cute and dumb at the same time...Tell the cats in florida, here in cali, Puerto Rico, Ausi, just to name a few, that this idea sucks and wouldn't work...and hp levels would never be reached!!! When this shit has been done countless times over the years...

Yeah it takes a little more tunning, but with propler jetting, porting, and mods to the carb, things will work just fine...

g14novak 03-13-09 03:10 PM


Originally Posted by teddyrx2 (Post 9041803)
You are so cute and dumb at the same time...Tell the cats in florida, here in cali, Puerto Rico, Ausi, just to name a few, that this idea sucks and wouldn't work...and hp levels would never be reached!!! When this shit has been done countless times over the years...

Yeah it takes a little more tunning, but with propler jetting, porting, and mods to the carb, things will work just fine...

QFT. Yeah, turbo setups are hard to do mainly because of the custom fab required.

I could be wrong, but you cant run that Walbro. It's going to push WAY too much fuel. Try a Holley blue pump.

Personally, If I were to make a turbo carb setup, the carb would basically be used as a TB... Custom intake manifold with 6-10 injectors depending on what turbo. :lol:

Are you sure you modified the carb correctly?

And to the people saying you can't make a carb run right. Want to come by and see my or my mechanics or all of my mechanics customers cars? I bet they run better than your efi cars. I can get in my car, ice cold or a hot summer day. Little tap of the gas pedal and it'll start on the first crank of the starter. Do that with your EFI system. Oh wait, you can't, it'll flood.

Turboroll 03-13-09 03:58 PM

I have not boost prepped the carb yet. Though I am fairly certain I can manage that. I have been reading that holleys need other modifications to work on a 13b, is that what you are talking about??

g14novak 03-13-09 05:47 PM


Originally Posted by Turboroll (Post 9042160)
I have not boost prepped the carb yet. Though I am fairly certain I can manage that. I have been reading that holleys need other modifications to work on a 13b, is that what you are talking about??

Yes, their are some tricks that you have to perform on the carb for it to work on a rotary and not lean out up top. Theirs also other tricks for setting it up correctly for boost. You might want to take it to a mechanic to modify or that motor will be toast pretty quick.

Not trying to say you cant do it, theirs just steps people forget when they modify the carb the first time.

iceblue 03-13-09 06:17 PM


Originally Posted by g14novak (Post 9041989)
Personally, If I were to make a turbo carb setup, the carb would basically be used as a TB... Custom intake manifold with 6-10 injectors depending on what turbo.

What? :scratch:

Evil Aviator 03-13-09 07:11 PM


Originally Posted by Turboroll (Post 9039263)
I am trying to do something a little different then most others with 2nd gens. I am going to post my basic setup with the hopes of getting some good feedback as to whether or not it will work well together.

As posted by the Puerto Rican forum members, your idea is not different, but rather it is so outdated that you rarely see it anymore in modernized nations. You may want to post in the 1Gen forum or on third world country websites to get help with your setup.

680RWHP12A 03-13-09 07:16 PM


Originally Posted by Evil Aviator (Post 9042599)
As posted by the Puerto Rican forum members, your idea is not different, but rather it is so outdated that you rarely see it anymore in modernized nations. You may want to post in the \ on third world country websites to get help with your setup.

that is where the fastest rotarys are :) P.R.

680RWHP12A 03-13-09 07:18 PM


Originally Posted by S4GXL (Post 9039274)
good luck. theres a reason you dont see many carbed turbo cars of any kind.


i guess you have never visited rotaryshack.com
my 12a turbo blowthrough made 540rwhp with a modified factory carb, a nikki :) this was back in 2000

680RWHP12A 03-13-09 07:20 PM


Originally Posted by Turboroll (Post 9042160)
I have not boost prepped the carb yet. Though I am fairly certain I can manage that. I have been reading that holleys need other modifications to work on a 13b, is that what you are talking about??

contact this place, they are the king of holley blow-thru


http://www.csucarbs.com/

1,200 hp blow thru setups are common and race competitively today :) fawk the haters

g14novak 03-13-09 07:21 PM


Originally Posted by iceblue (Post 9042504)
What? :scratch:

Not have the carb control the fuel, but rather injectors before the carb.

OP's setup will more than likely run once he gets done with it. I can't say how long, but it'll run. Carb, like previously said, is old technology. You'll never get the AFR's perfect and will either never get the power out of the car that it's able to make or it'll blow up.

Carb setup is easier to get running. EFI will always run faster though.


And I think OP was stating that he is trying to do something different and make a blow-thru on a 2nd gen. Most people just buy a T2 motor and do the swap. He's actually trying to be original and do a custom setup.

Super82 03-13-09 07:29 PM


Originally Posted by iceblue (Post 9040276)
And the boost floating the carb. Personally I cant stand them its decades old technology and for a reason. Flip side they can work if you set the carb up properly I just have a disgust for carbs think there anchant junk but whatever.

How can we take your opinion on carbs as truth when you can't even spell ancient?

They are old. But so are rotaries, the idea of internal combustion engines, and the idea of a car. The fact that we still talk about carbs in a performance aspect over 100 years after their invention says alot about their resilency and quality. The fact that you say 'I have a disgust for carbs think there anchant junk' leads me to believe you don't comprehend how a carb fully works. I'm not expert on carbs myself, not by a long shot, but once you start looking at the mechanics of a carburetor it is amazing how they work and how well (and simplisticly) they work.

While I have no experience on the subject, I've heard and I can imagine that there are severe limitations with a carb'd turbo car, and that they can be a pain to work with. But from what I know, if you aren't trying to push the limits and get it tuned right they can be a real simple way of turboing. That being said I know little about boosting or boosting with carbs, so thats all I have to say.

iceblue 03-13-09 09:35 PM


Originally Posted by Super82 (Post 9042631)
How can we take your opinion on carbs as truth when you can't even spell ancient?

While I have no experience on the subject, I've heard and I can imagine that there are severe limitations with a carb'd turbo car, and that they can be a pain to work with.

I think you said enough in your own post I really don't need to respond with anything besides another :newbie: crawls out of the wood works


Originally Posted by g14novak (Post 9042617)
Not have the carb control the fuel, but rather injectors before the carb.

It's all good I think my post just went completely over your head. Tip: google = ITB's

RXvedub 03-13-09 11:18 PM


Originally Posted by FrankV702 (Post 9039332)
This was my attempt at a blow-through carb setup.. I FAILED! :wallbash: But I should've known better, I know absolutely nothing about carbs, I just thought it would be cool and unique! :)

http://i56.photobucket.com/albums/g1...Picture001.jpg


what happened? that setup is great, it should work fine :)

Super82 03-13-09 11:24 PM


Originally Posted by iceblue (Post 9042859)
I think you said enough in your own post I really don't need to respond with anything besides another :newbie: crawls out of the wood works

You think you've gotten me, but if you read I'm not offering any help on boosting with a carb. I explictly said that. How does saying 'While I have no experience on the subject, I've heard...' make me a noob? I'm not claiming to any knowledge, but offering regurgitated info I've heard. I think that is a bit more admireable thing to do for a 'noobie', rather than just coming in here thinking I do have help to offer.

If you re-read my post, you will see that I didn't really make any points in the third paragraph. My third paragraph was solely my take on the subject, to contribute to the OP without derailing the thread. My thesis and my argument was in my second paragraph, which I stand by. Carbs are nothing but ancient junk, the are an incredible piece of technology.


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