i have searched, and no one seems to adress the problems assosiated with carburated turbo engines. my mechanic has discussed this with different people. saying one day it'll run fine, but with a climate change, you'll start to have problems.

so im wondering, if you run into the same problems with a draw through set up?


also, what has a lower compression ratio, 12a, or 13b?

 

As far the blow-thorugh turbo the positive pressure created more extreme enviroments on the carb i guess you could say. AS you talking about a turbo prepped carb or a stock carb?

I dont think a draw-through turbo exists, you you have to place you carb on the intake run all your fuel through the turbo,IC piping, The IC itself, and a ways back to the motor. it just wouldnt work.

A blower doesnt created and much heat because it doesnt use the exhaust which also lets it get much closer to the intake and save alotta room.

 

compression info:

http://www.mazdatrix.com/r-rtrwgt.htm

 

Draw through turbo's do exist and they're usually minus an intercooler. The atomisation(sp?) of the fuel in the carb creates a very cool charge. So it helps cool the turbo a little. I've seen one picture of a setup on a rotory, don't know anything about it. Try searching that might help.

 

I saw it on air cooled VW

 

https://www.rx7club.com/showthread.p...ght=draw+turbo
http://www.dune-buggy.com/turbo/carbureted.htm
That search feature is amazing look what I found for you...

 

Draw through turbo's are OLD! Why would anyone bother to spend the money and time on a turbo project and then choose an oudated setup?
Using an intercooler will allow to run higher boost at cooler intake temps, thus making more power. This is not possible with a draw through, as the fuel would start to become "fluid" again in the IC. This also happens in the turbo, btw: it's not uncommon for small pools of fuel being in the intake side of the turbo, thus upsetting the fuel mixture.

 

Though outdated, draw-through turbos are simple and can make alot of power. You can't use an intercooler so another form of charge cooling is needed like water/methanol injection. There used to be a few untubbed cars here running 9's with draw-through setups.

 

I've got an ad in my old *** Rotary Rocket magazine, with a draw through setup in it.

 

I am soon to be running a drawthrough setup. I am going to start on it during thanksgiving break. I will snap some pics. IT should be rather nice, I have been planning it for over a year!

 

I have a 79 with a draw trough set-up. It isnt the best set-up in the world but it is good and can put out great power. To switch from a draw through to a blow trough or even a fuel injection kit cost a lot. Go for the blow through system. Just try to keep the turbo as cool as possible. Run air ducts for it and stuff. I just got done runnign a air duct for mine. Seems to help a lot.

 

I am going to run the drawthrough just because it is different, with maybe some water/alch injection. I don't wan to be like everyone else and run blowthrough or fuel injection, I could if I really wanted seeing how this is a 6port motor and I have all the fuel injection stuff. I am just going for some unique, how many blow throughs look exactly the same, you won't see anyone with what I am doing.

 

ummm, draw-through turbo systems are the ****. My buddy built his 87 tII with the 13b large streetport/t4 and carb'd it. It runs constant 11.8 380rwhp, and has aintercooler. he has the sweetest plenium I have ever seen for a carb'd turbo.

 

Draw through with Fuel injection??? There is no advantage running a draw through with Fuel Injection. FI is perfect for blow through in all aspects compared to draw through.

 

he wants to be original...........

 

I believe he is carbing it.

 

did you read this thread?

https://www.rx7club.com/showthread.p...highlight=draw

btw, in the end he chose a haltech. whatever thats worth.
i think drawthrough is a pretty cool setup for 1stgens. although not ideal. it sticks to the simplicity design of the car. so i support you in your efforts. morally....

however, water or alchol injection would be manditory if you planed on driving it regularly. IMO

 

go for the draw through

 

i know this is a couple years late, but you guys have to get ur faces out of the magazines and internet. what u c on the screen and on pages is not all real world. open up ur mind. BRAND NAMES do not= performance. knoledge is where performance is. I saw in puerto rico a toyota 1.8("3tc") with the nikki carb from a mazda and yes it was bucking. life and the car scene is not about whos got the most horse power. @ ALL!! its about having fun. that should be everones prespective. Thats the mentality of the car scene in PUERTO RICO and that is the home of the fastest ROTARIES in the WORLD. not L.A. not australia but a small island measuring 100X35. over there there are 9-10-11 sec cars daily driven not "weekend cars" with full guts and rollbars so tight aroung the interior that they seem not to be there

 

I think it would be cheaper to go draw through to huh. i was thinking of doing it but couldnt find to much info on it. let me no how it works for you, And has any body seen this setup with a side draft carb?

 

The only problem I could forsee is your location. As a draw thru system could easily ice over up north, in the winter.

As far as simplicity/bang for the buck - nothing beats it.

As I posted in other threads recently - running e85 fuel alone could be the magic pill for a draw thru sytem. As the charge temps would be even cooler than traditional charge cooling. Much higher boost/power levels could be obtained without additional complexity.

Draw thrus have been done with all different carb combinations - it's all going to depend on your intake manifold design.

 

I've been running a Cartech drawthrough turbo system on my 12a for a year now and it's been as reliable as stock. I chose this route because it is simple and doesn't modify the car beyond the parameters available to it when it was new. Any of the Cartech systems including their later blow throughs should be ultra reliable since this was when Corky Bell was still part of the company.

It does require the engine to be fully warmed to idle consistently and in my Toronto climate I always plug in the oil heater hours before I start it to improve instant driveability. There are lines to add to the manifold that run coolant through it to improve very cold weather driveability but as I don't drive it in the winter it has not been an issue for me.

It's true that you don't really want to boost more than 9 psi with stock compression, I keep mine at 6 psi. That's good for 180 bhp.

Jim

 

About how much would it cost to run a drawthrough setup. I'm interested in doing it where would i start

 

actually its not that expensive i vave the home made recipe that will get u going.

1. u need an intake manifold from a jdm 12a.
2. u need a turbo setup from a second gen (dont matter the year turbo & manifold only, plus oil lines)
3. (close attention) u need an upper intake manifold from a 78-81 pontiac firebird turbo 301. the one where the carb sits in
4. the accelarator cable from a 1988-1991 honda crx (real long) because the carb will sit by the headlight motor upfront
5 then u simply make piping and flanges to accommidate the setup
6. must upgrade the fuel system either holley blue or malloery but u have to run lines.

as for prices-
1. intake manifold 60 on ebay
2. turbo 140 from a freind, about same on ebay
3upper intake manifold 70 from another friend probably cheaper on ebay
4 20 bucks on the metal needed for piping and flanges
5 7 for accelerator cable
6 about 150 for a rebuilt holley( although i have a holley had to get an adapter from carter to holley)

i had it in my STOCK PORT 12a and it pulled like a bat out of hell ( without any absolute tuning at ALL) no need for blow off valves or intercoolers

let me know i will try to take pics of the setups individual parts so u can c

 

you can pm robert from rotaryshak aka 680rwhp. he is selling a uesd draw through kit