82streetracer

iTrader: (1)

I am in the proscess of building a streetported hybrid 13b (re-egi block with 91 hi-comp rotors, 74 rotor housings and 12 plate)

I am too the point of setting up the fuel system.

I am either looking at a 50 dco or or some kind of twin setup
cost: about $1000

or a atkins fuelie setup
I already have a cheap computer to run this with.
cost: about $3000

Is there a cheaper way to setup a FI system

I know of the drivability advantages and ease of tuning but what is the power advantages.

V8kilr

you can buy the weber setup im selling on ebay

here is the link

Manntis

carbureteur setups tend to be easier for the backyard mechanic to tune, as in the 12a parts car I have, but I prefer the EGI in my 13b. Zero flooding problems, much better cold start, etc.

When not in Los Angeles I live on the Canadian Prairies and with EGI I was able to start the engine first time, every time, with a simple twist of the key even when the temp was -40 C

82streetracer

iTrader: (1)

v8 killer - i am sure a 45 is too small for my application.
Although I am not that familiar with the setup.

how was your top end power.
I am shooting for about 220 and I dont think that carb would cut it.

thanks though.

renns

>Is there a cheaper way to setup a FI system

Get in on the group buy for the next MegaSquirt purchase. This is a well put-together kit with open-source software and ready-to-run programming applications for your laptop. Controller kit is $110.00, which indicates the margin (development cost?) the aftermarket companies require.

http://groups.yahoo.com/group/megasquirt/

I bought one on the first group buy. It is assembled and tested, awaiting some further FI bits before going into my '79 with 4-port 13B.

Roger

82streetracer

iTrader: (1)

what kind of a power advantage will I get with efi?

PaulFitzwarryne

EFI is marginally better. The car starts better, idles well, and with a good computer program you get the best air/fuel ratio. In terms of performance, the power output in the normal range of driving conditions is less than 5%.

The real problem is setting up an EFI, it can take hours of dyno time and a skilled tuner. A carb set up is relatively easy. Manufacturers go with EFI because the set-up costs are written-off over many vehicles.

Directfreak

iTrader: (2)

do some research and confirm. I could swear that you can't mix 86+ rotors with 85 and older housings. Something about the tolerences being different.

Ask one of the experience builders to confirm.

82streetracer

iTrader: (1)

look at the mazdatrix under engines. They have a setup exactly like mine and you can get it with 89 hi-comp rotors.
http://www.mazdatrix.com/eng13bsp.htm

Directfreak

iTrader: (2)

I stand corrected. Maybe it was the 93+ rotors?

82streetracer

iTrader: (1)

that megasquirt thing sounds kind of iffy. YOu have to build it yourself. I suppose it would work well for a rotary but it doesnt seam like there would be alot of suport for it.

diabolical1

iTrader: (3)

hey 82streetracer -

i know this may be a bit off the subject, but i just wanted to warn you about the engine you're planning to put together.
now i don't have the instruments to test this, but for what it's worth, here goes ...

it is suggested that you do not mix the different generations of 13B's. you plan to run '91 rotors in '84-'85 rotor housings. i read that MAZDA made slight changes to the peritrochoid shapes, which made three generations of 13B engines unable to interchange rotors. basically, they said that the old style 13B rotors should only be used with the old style rotor housings (cosmo, Rx-4, rotary P/U and Rx-7 GSL-SE) and the new style rotors should be used with only new style housings. it wasn't clear if the differences would prevent you from using the '86-'88 rotors with '89-'92 housings.

apparently the differences show up in high RPM use and basically the apex seals or corner seals exhibit the same kind of behavior when you blow an engine because of over-revving. i'm guess the differences in the peritrochoid shape take the tolerances out of spec (but that's just my guess - if anyone has more info please share, this is of interest to me, too)

but anyway ... just thought i'd give you heads up so you don't make an expensive mistake.

82streetracer

iTrader: (1)

I was thinking this too. I am looking at just installing a 2nd gen NA engine or something.

MAzdatrix makes there engines with the different housings and they know whats going on.

DriveFast7

iTrader: (1)

Hmmmmmm........

How come my friends 13b peripheral port with 89-91 rotors and 12a plates and 84-85 GSL-SE 13b rotor housings is making 318 fwhp at 9700rpm (using smaller endurance size sleeves)????????? And he had 45 hours on that motor before it got refreshened. Some people only go 10-12 hrs.

I see guys use these parts on a streetport all the time. The GSL-SE rotos are cheaper.

-bp-

diabolical1

iTrader: (3)

well, all i can say is ... i'm just the messenger. i read it somewhere, and it just stuck with me. i've never tried to build a motor that mixed the housings and rotors.

i simply can't afford to confirm that mixing them is a mistake. i can't remember where i read it, and it could be gospel or utter CRAP! i just wanted to help 82streetracer out when i read what he was doing. the first motor i built didn't work (for different reasons) and that was about $ 2,000 down the tubes, and i didn't want to see him make a mistake if it could be prevented - that's all.

i mean, i'm sure there are just as many ways to explain why your friend's motor works as there are why it shouldn't ...

like i said, i'd like for someone to share as much technical info on the subject as they can - i'm very interested. i'm making plans to build another motor soon and i'd love to know what can be interchanged and what can't.

j

82streetracer

iTrader: (1)

Does a streetported 6 port make less horsepower than a streetported 4 port?

Like a second gen NA verses the engine I am building.

I have onlyh spent like $400 on this engine so changing my plans now is not a big deal.

I suppose if mazdatrix makes them there okay, but I think you guys are right. Its not really worth the gamble.

diabolical1

iTrader: (3)

well, i would suspect that a streetport would work a bit better in terms of overall horsepower on a 4-port engine (simply because there is one port to constantly inhale as the rotor sweeps by, as opposed to two ports) - but that's just my opinion. i don't have any horsepower figures to support this.

however, all you have to do is get the end plates from a T2 and you'll have a 4-port engine with the lighter parts. if you already knew that ... then i'm sorry for making myself seem like the messiah incarnate

but seriously, i would go for a 4-port over a 6-port, but that's because, like i said, i see the 4-port as having more potential power.

i guess the questions that REALLY need to be answered are what your ultimate setup is going to be?

however ... here's my 2 cents on the situation. if money is going to be a limiting factor at some point (whether now or down the road) go with the setup that matches what you're running now (4 or 6 - i don't know) ... here is my logic:
since you're getting a new EFI system that you've never used before, it would probably be best if you run your current stock intake setup on the motor for the break-in period. that way, the motor is broken in when you need to tune and dial in the EFI system. i'm not really familiar with the EFI systems that were mentioned earlier, all i know is the TWM systems used with Haltech - so i don't know how to answer your power questions. breaking the motor in first is the best way to know that your motor is seated and ready for high rpm tuning (under load) and that whatever demons that need to be exorcised, would be limited to playing around on the computer.

better safe, than sorry, eh?

good luck!

diabolical1

iTrader: (3)

oh yeah ... and for what it's worth, i had friend once that turned a 6-port into 4 by grafting the two ports on each end plate into one and then smoothing out the contours. the engine ran great! he had a Holley setup.

it didn't look all that great because the secondary ports looked a little slanted (since the 2 ports on the endplates did not sit exactly on top of each other) - it was kinda ghetto, but that thing ran like hell!



see if you can opinions from people on that avenue, in case you can't find T2 endplates.

82streetracer

iTrader: (1)

I hadnt thought of the TII side plates on a NA. Still I would like to know about the power differences. I could find a Jspec NA or something.

I hear about people pulling 230hp with 6 port 2nd gen engines. So what about that.

diabolical1

iTrader: (3)

well, if that's the case, then the 6-port just about matches the most powerful, "streetable" streetported, 4-port EFI engine i've ever heard of. that motor was pushing about 220 with a stock distributor and stock flywheel in place, so i'm sure it could get a few hp over 230 if those things were changed.

however ... i throw it out to the masses again ... anybody out there got some hard numbers on this topic?
4-port vs. 6-port? JDM vs. USDM?

diabolical1

iTrader: (3)

well?
anybody?

82streetracer

iTrader: (1)

I wonder If corksport could get a NA 13b from a jspec 2nd gen. That would be tight.

abeomid

GSL-SE Engine
+ Street-port
+ Racing Beat Dual exhaust collecting at rear axle
+ Stock EGI
= 220HP at flywheel