snips...

Also, I am sorry to say, those Seimans injectors do not fit the
injector holders or the fuel rail. My mistake. I'll buy them
from you
and keep them around. However you need four RX8 yellow fuel
injectors.

Paul Lamar

Paul,
Bill Bradbury described what's happening with his engine, and it sounds
pretty much the same as what's going on with mine. Below staging,
it'ssmooth, but above, it runs rich and in flight there's a lot
of poppingand surging.

He then reports that he has had good results by switching his
stock redand blue injectors to the yellow ones, that I 'm
assuming, but I'llcheck are yellow RX-8 injectors. Will they fit
my 93 13 BREW and wherecan I get them for as little $ as possible,
 and how much would that be?

On another note, I still have not gotten the last few pages of
the plansfor my RV off to you, I still have to get up to the
hangar and get themoff to you.

Brian Trubee

I have not researched the supply yet but Michael Hart is about to
dothat sohe will let us know.

Sounds to me like the trim map is wrong on the top end. You could
haveone or more partially clogged injectors. It takes a special circuit
and a burette to test injectors. The fuel coming out should be
directly proportional to the pulse width.

Here is a schematic of a DIY test device.

Also you could sample the air pressure in the runner with a couple
of pressure sensors and a data acq system. If my plate was not running
over I could come up and do that. It will be the end of April before
I am free enough to do that.

I don't think the RX8 injectors will fit your current injector holders.
You could get RX8 injectors and they might not change things. If not
it is the trim map. If they do you may currently have one or more
bad   injector. Getting them tested may be the first thing to do. There are some companies around that specialize in cleaning and
calibrating. Paul Yaw may still do it. http://www.yawpower.com/ New ones are getting socheap it might not be worth it.

Where are Bill's injectors mounted?

I see your secondary injectors are on the outer tubes a foot or so
from the port. What happens when you lean them out?

Is that a damper I see on the end of the secondary fuel rail?

Take some closer pictures of the EFI system.

Don't worry about the plans. Michael White kindly made me a gift
ofa set he was not using. Thank you Michael. They came in.

Paul Lamar

I had the injectors cleaned and flow tested just prior to engine start.
The thing you see on the end of the secondary rail is the fuel pressure
regulator.

The other day I went out and ran the engine up on the ground,
specifically looking at EGTs for a mis-match of EGTs above the staging
point. What I saw was that the EGTs were pretty consistent all
the wayup and down the RPM range. So, I'm thinking that I'm just
rich up in theareas above staging. Well, the EC2 should be able
to compensate if Itune it right, so I'll keep twiddling the
program knob. When it runssmoothly, it's like silk. I"m just a
bit tired of the tower gettingcalls from the local communities
about a plane in distress overflyingthem. Also developing a
crease in the bottom seat cushion from excessivepinching.

Brian Trubee

Well when I get time I am going to work on the engine monitoring
system that will read and store the history of the injector pulse
widths using a USB port to a PC. I think that is going to help
trouble shoot
these kinds of problems. Should be about the end of April.

Paul Lamar

Hi Paul,

Here is the story about the Denso injectors.The cheapest I can find
is the Denso 195500-4450 which is rated @ 450cc/min at 3 bar.These cost
$75.00 per injectors and $70.00 if you buy 4 of them.These can be found
at  www.fiveomotorsport.com/fuel-injectors/mazda/rx-8/  .The second
cheapest is the Denso 297-0041 and these cost $129.00 and can be
found at http://www.densoproducts.com/resultsSearch.asp.The problem
is that for the life of me I could not get the specs on the 297-0041,
I googled them in many ways but could not find the specs,however
they are listed as the original for Mazda RX8.So I do not know which
one to buy,can you take a look at these and let me know.BTW the
remote filter bracket is on the way.Thanks.

Michael

450 cubic centimeter = 0.118 877 423 56 gallon for the 195500-4450.
AKA 7 gallons an hour. 28 gallons per hour total for four.
3 bar is 45 psi.

Sounds like it will do the job at 45 psi.
Mazdatrix tells me the factory is charging about $150 each.

Paul Lamar


Paul,

Could you use a Ford injector for 5.0 engines. This injector converts to 42.8
pounds per hour. The ford racing and performance parts catalog has a 42#/hour
injector listed. The part # for a set of four is M-9593-F304. If you want a
flow matched set, add a F suffix. I don't know the price but a quick call to a
Ford racing dealer will answer in short order. They are not the skinny body
style though. 11-18 ohms. Ford also has adapters to change from connecter
styles EV1 to EV6 or the other way.

Dale Davies

Just about any injector with enough flow will work. However the physical shape
of the injector must be the same as the RX8 injector for this application.
The Seimans came close but not close enough.

Paul Lamar