mikey D

So many people asking about turbo stuff over here I thought i might post some of the info i wrote up at Mazspeed.com so long ago that no one here seems to know about.

maybe someone will sticky this seeing the questions are asked so often....
and remeber all parts and info are listed as a BUDGET so dont complain and tell me im wrong about HP numbers im stating. I know you can get more power
and I know you Cant do it without spending MORE money than Im noting down here.



Building a Turbo Rotary Engine on a Budget


Introduction

Let me start by telling you what this project wont do for you.
You will not get 300 or more WHP. Your engine wont last nearly as long is it would have before. You wont get to run 87 Octane gasoline anymore. You wont get better Gas mileage and you definitely wont pass smog.

Now that all the ugly stuff is out of the way here is what you will get.

What you will get is an awesome sports car that weights around 2500lbs and will have between 150 and 225 HP at the wheels. That gives you a very fast sports car with an 8-12lbs per 1 hp ratio, Very near or possible better in some cases than the stock 3rd generation RX-7! Your gas mileage will not be greatly affected, Possibly better under cruising conditions due to better carburetion than the Stock worn out Nikki provided. Under aggressive driving you will be competing with my 69 ford pickup to get to the gas pump.





The Parts List

The parts I’m listing are no frills Purpose only parts. No show car stuff here.
None of them are at any bargain price so YOU may be able to get better prices on comparable items and build your budget racer for even less money

Intake Components
2 choices of carburetion in my FAQ

IDA and DCO Webbers. down or side draft

Many have this stuff laying around or for sale cheep so I'm not going to go into this very much.

Mazdatrix sells kits for 800 to 900 bucks
12a cars need an entirely different manifold
IDA Weber Part#18102 $250.00
DCO Weber Lower Part# 8111 $168.00
DCO Weber Upper Part#18100 $130.00

13b cars can just use the weber upper

A 45mm Weber Carburetor will take good care of your boosted engine.
There are Many Many Many places to purchase these anywhere from 250-400 dollars.
Don’t forget you’ll need an IDA or DCO carb depending on your manifold type.

You will need a Hat or Plenum for your carburetor to feed the boost in
The lowest price pre made stuff I found was at CBPerformance.com

Turbo hat aluminum 50 bucks CBPerformance.com
7737t turbo hat gasket(rubber) 4.95 CBPerformance.com

rotaryshack.com sells carbs for a very reasonable price
and turbo hats but they are a little more pricey.



Fuel Control

Your turbo engine will require a lot of fuel and up to 30psi of it under max boost at high rpms. You now will have to use external EFI fuel pumps to supply your engine.
2 affordable fuel pumps that can do the job are

MSD-2225 External In Line High pressure electric fuel pump
$76.95 SummitRacing.com

7315t External In Line electric fuel pump
$104.95 Cbperformance.com
this pump will move way more fuel than you need so your return line may need to be modified.

Any Boost Referenced Fuel pressure regulator will work just fine.
How this works is as boost raises your fuel pressure will raise 1-2 psi per each 1lb of boost. This pretty much feeds enough gas to keep the motor happy and also keeps the boost pressure from pushing the gas away from where you want it, The ENGINE!

MAA-4309 3 Port Billet regulator $74.88 Summitracing.com

Aeromotive makes some very nice alternatives.


Exhaust Components

This is the part where you can save the most money if you just spend time and Look for good deals. Thepartstrader.com and ebay are a great source of used stuff.
Any sort of used turbo manifold for an rx7 can be modified to work for you.
12a’s will have it the toughest. I would suggest a tubular manifold for them.
Even a tubular manifold from a 13b because it can be modified much easier to bolt up to your engine.
A regular seller of 13b tubular manifolds for both 2nd and 3rd gen cars is Ssautochrome.com They sell nice manifolds on ebay for 150-200 dollars
Either one should work just fine. The external waste gate flanges they come with can be blocked off or removed. You don’t need them for the power level you will be at. Most tubular manifolds are prone to cracking over time because of heat.

13b exhaust manifolds $150-$200 Ssautochrome.com on ebay

for the down pipe from your turbo a 3 inch 90 mandrel bend would be perfect. 2 of them will easily make all you need to get your exhaust under your car smoothly

Hed-12007 3in OD 90 degree mandrel bend mild steel $22.39 Summitracing.com

2.5 inch will also be just fine. You are not making huge power to require a huge exhaust but a 3 inch will give you a little better power than the 2.5 but be a lot louder and harder to fit under your car nicely if its lowered.


Turbo

I know everyone says bad things about the stock TII Turbo but I say its BS!
An S5 88.5 and later turbo is a great starting point. It’s a good size turbo and is upgradeable for those on a budget. A 60 compressor on a S5 turbo is capable of nearly 300WHP at fairly low 10-14 psi boost levels depending on the rest of your setup.

12a guys
To feed oil to your turbo you will need

Oil Filter Relocation Kit Part#11820 $55.00 Racingbeat.com

You will need to tap a fitting into the front cover of your engine for the oil return.
I’ve been told be some reliable people the best place is the front cover just under the OMP. There should be a small depression or a cast area where you can clearly see circular shape. Drill and tap there. The oil return line should be fairly large. After the oil exits the turbo it is nothing but froth.

Gauges

I recommend a few gauges as a must have and a few that are nice to have.

Must Have

Autometer Fuel pressure gaugeATM-3363 $195.000 Summitracing.com
this one is great because its electonic and the gauge goes inside the car
without bring fuel inside with it!
Autometer Air/Fuel Ratio gauge TM-3375 $51.88 Summitracing.com
O2 sensor for the A/F gauge SUMJ-G2989 $29.95 Summitracing.com

The 3rd gauge to have is a boost gauge. Its not needed but is cool and is a must have for adjusting boost levels.

Autometer Vacum/Boost gauge 30psi ATM-3303 $43.95 SummitRacing.com



Have fun folks. Its not the full article, just the bulk of part numbers and prices.
more to come soon.

mikey D

just keeping this up near the top.....

Dan_s_young

iTrader: (1)

seems to me like a helpful thread I think it should be put in the achive

red13brx7

A few things can be added to this.

www.tunertoys.com

Uses the same oil take off fitting as a rotary engine, same as a honda.. sorry had to put it.

And gaskets/flanges are pricey and can be had from racing beat.

Also a wideband is by far better than a stupid air fuel gauge that is a narrow band, they are just light shows.

www.plxdevices.com

Innovative LM-1 and Zetronics are good choices, just get one with a nice display.

Also, intercooler pipes, can be had from summitt, in the same way that you make your DP, and some nice intercoolers can be had at www.johnnyracecar.com

AND a boost gauge is most definitley needed, don't turbo your car without one.

rwatson5651

iTrader: (5)

Thanks for the linkd red, I have been using a narrow band o2 sensor to tune a carb and am interested in getting a wideband unit, thanks!!

kleinke

Thank you for the information. But one might ask why embark on this type of turbocharger project for such a small power gain. 150-200 hp at the wheels is within a conservative normal aspirated rotary's power range.

mikey D

id reccomend going to a dyno to tune your engine. they will provide a wide band o2.

you can play with your timing and mixture under a load that way and tune your car to max hp quickly.

the regular a/f gauge can get you at lest jetted and to the right fuel pressure close enough that you wont be wasting your money on ALOT of dyno time.

Intercoolers not needed for budget turbo cars...intercooling is expensive.


thanks for the links though. Allways nice to have other options available.

mikey D

to answer you kleinke
because this is a budget.

a streetport 12a NA isnt going to make 200hp at the wheels.

a streetported 4 port 13b with high compression rotars will be able to do that but
it is an expensive motor along with the components for the power were talking.

Bigger ports mean shorter engine life and loss of streetability and less torque.
certainly not a good auto x'er or great daily driver.

An NA rotary will never have the torque of a turbo rotary.
Nor will it make more power as easily.

a stock port TII block can make in excess of 250whp with very few mods.
a stock port 12a can make excellent power also with very low cost and be a very
cheep engine to replace if need be.

A stock port 12a modded out to its max 150 flywheel hp and gutted will still not equal what a stock TII engine can do with the heavier 2nd gen rx7 at 180-200 flywheel horsepower.

mpetersrx7

mikey,

nice writeup. what are your thoughts on keeping the stock nikki though? is it possible ot run low boost(6-7 psi) through it? I know some things need to be modified like the float and such, but seems a cheaper alternative since keeping the stock manifold.

Also how about using a se pump?

Thanks,
mark

red13brx7

I'd reccomend going to a dyno to tune your engine. they will provide a wide band o2.

where is the fun in that? Half the dyno places won't know how to tune the carb anyway.. the best place to tune is on the street for a street car.

you can play with your timing and mixture under a load that way and tune your car to max hp quickly.

On a dyno this is true.. but once you go outside.. you will always go leaner, it is best to have a wideband just for safety purposes.

the regular a/f gauge can get you at lest jetted and to the right fuel pressure close enough that you wont be wasting your money on ALOT of dyno time.

[b] I do agree with this, a narrow band a/f gauge is good enough to get you close to the right jets. The only problem is, under boost the narrow gauge reads rich even when the a/f is lean, not a big fan of them..[/b}

Intercoolers not needed for budget turbo cars...intercooling is expensive.

Intercooling is not expensive, it is all in choices.. Intercooling might just safe a tired old rotary, as well all know, the heat is a huge fator with them, and intercooler is almost a must with them.
www.johnnyracecar.com

They have some nice cheap intercoolers. Look good, and don't kill your wallet. I have one waiting to go on. It is a decent design, you can also check junk yards, and starion intercoolers work well.


Sorry for like jumping in on this thread and what not, just giving another opinion on things. I am actually going megasquirt on my car, I decided that a carb just will not cut it anymore. And if it works out, the full writeup will come here first. I am going to start on it very soon.

- John

mikey D

no probem at all.

I myself went efi also. Im in the process of setting up my car with a haltech.


I would like to respond to your dyno tuning comment.

I never said let the dyno tuner do the tuning to your carb. If you have the skill to get the jets dialed in close and put the car together you should be able to do the fine tuning on a dyno.

cant raise that fuel pressure or advance that timing at 3000rpms under full load on the street....

I agree that intercooling is a good investment. Its still not cheep.
intercooler cost of 200 bucks ok sure. How about the piping. the silicon connectors. to buy decent silicon your going to spend 12-18 bucks a connector.
having intercooler piping welded, bent or whatever isnt cheep either.

theres quite alot of work and money involved..

seanrot

iTrader: (2)

DP

seanrot

iTrader: (2)

Nice write up D, free bump from a fellow turbo'ed

red13brx7

That is the best thing to do on the dyno is tune the timing, I agree you are shooting in the dark doing it on the street. I completely agree with that. Not sure why I kept that out.

But for low boost setups, there isn't any reason to buy silicone connectors and stuff like that, you can go to the hardware store and get them for like 3 dollars a piece and they come with clamps.

You can pick up a good intercooler for $100-150 if you know where to look, and the piping can be had from summitt or from anything really. I made my intercooler piping from an old roll cage, my bro had in his car.

I agree EFI is the best way to do a turbo setup, you just can't beat it with the technology that is available.

Also a great place to learn how to tune is going to an EFI 101 class by Ben Stradler. I am probbaly going this summer, can't wait to go. Heard lots of good things.