Omg! Twe!

[WJM]

For those who are still waiting...someone at Folgers is...well, SLACK. Im going to have to fix this in person pretty danmde soon....like MONDAY after I get back from the state Autox championship. :mad::mad::mad:

 

Anyhow...installed the TWE Header/DP on the RX today..left the intake stock (from the intake boot to throttle bosy that is..no IC yet....) and its 2.5 inches from the DP back with a 2.5 inch cherry bomb (its comming off tomorrow...hehehe..me want louder!) and i *DID* install theGReddy EBC i have...cuz the factory one is fubar'd and doesnt work right....and I wanted to play with some high boost stuff and see what happens...

 

Ok...STOCK boost...turbo spools and gets to full boost by 2200~2400...depends on if you are waiting around for it to spool...otherwise, you are going thru gears and busy going "WEEEEEEEEEEEE!!!!!!" to pay attention to spool. Low end is unaffected. Mid range is imporved. Top end is....well, it DOESNT end. you get to 5k and its pulling hard. 5.5k and its pulling harder. 6k and its still pulling hard. 6.5K its SUPER "WEEEEEEEEEEEE!!!!!" and you say, "Oh $H!T!!! SHIFT!"....but its still pulling HARD.

 

Its like an STi with a TBE.....but still slowAr... :-\ but fastAr than stock thats for SURE!

 

Soon I'll put the WRX IC on and paint the scoop'd hood white to match the RX....yeah yeah...i know I said light mods...this is still "light"....im not going dto do wackey things like spyder intake and XT6 TB, cams and such...the WRX IC setup will pretty much end the engine mods until I get MS+DIS stuff ready to plug and play. \

 

That and fix the stupid AT STOCK BOOST fuel cut.

[Myxalplyx]

Will,

 

This all sounds great. I'm excited to read about this. That 5500rpm power drop off is a mutha.

 

Do you or anyone else have any suggestions as to what cat converter to install? Actually, I'll be needing to order a muffler as well but I'm mainly concerned about a cat converter to use. I shoud've looked at the header/downpipe/exhaust setup on the RX. How is it setup as far as cat converters are concerned? I'm going to need at least one on the car but I forgot how many converters we have and were they are setup.

[Skip]

Kevin, I run a 3" high flow cat from Summit.

I have no muffler per say, just the cat on a 2.75 ID pipe system.

Seen here

Magna Flow Cats

I got a non stainless version for 65 GW's some time ago. Pass PA emissions with ease.

 

I don't have TWE parts but I do have a twin tube down pipe of my own design and some other parts that make you ill, one of which is a LP injector for boost pressures over 8 psi.

 

The ECU turns over the A/F control to the FPR at anything over 5 psi, so a RRFPR is wise.

 

I have monitored the injector pulse width via an onboard oscilloscope

I have seen them reach saturation at ~ 5 psi.

Thus all fuel control past

this point is done by the FPR.

 

BTW I have no trouble pulling 7 grand and more.

 

As for boost cut, try a voltage clamp modifier on

the signal wire from the MAF.

 

I modified a version found on a Mazda RX 7 site.

I do NOT have the diagram or site as a pooter crash wiped me out, sorry.

 

Be forewarned doing this with out other metering

(wide band A/F monitor) can lead to destruction of the detonation type.

 

Remeber my coined saying -

YP YP (pronounced "yip yip" ----

You Play - - You Pay

[WJM]

Kevin: Just get one basic 3 way cat/high flow and that will take care of emissions....and just install it soon after the downpipe comes down and levels out under the car. I had a 3 way on the wagon...combo of that and the cherry bomb made the car really quiet...

[Myxalplyx]

Kevin, I run a 3" high flow cat from Summit.

I have no muffler per say, just the cat on a 2.75 ID pipe system.

Seen here

Magna Flow Cats

I got a non stainless version for 65 GW's some time ago. Pass PA emissions with ease.

I will apologize ahead of time for the questions I will be asking.

 

Perhaps then I will go without a muffler if it's not too loud. As for the Magna Flow Cats, I don't see any non-stainless versions for $65.00 on that site. Do you recommend the oval or round type of cat on that site? Why? I think I will be going with a 2.5" cat and exhaust diameter piping. Also, on that site, there is a mention of cats 'with an Air Tube'. What's that?

 

The ECU turns over the A/F control to the FPR at anything over 5 psi, so a RRFPR is wise.

 

As for boost cut, try a voltage clamp modifier on

the signal wire from the MAF.

Is there any particular RRFPR ('Rising Rate Fuel Presure Regulator' for those that do not know) that you recommend and where can I get it? I'm always down for something cheap but functional.

 

Any voltage clamp modifier you recommend and where can I get it?

 

I always have to ask for specifics being though I see how info flows at NASIOC and other boards. This way I don't get confused or assume the wrong things. I appreciate the info you provided Skip. Thanks!

[WJM]

Im going to skip the Fuel cut defender crap....and go stright to MS+DIS ASAP.

[All_talk]

one of which is a LP injector for boost pressures over 8 psi.

I'd love to know more about this, injected as a liquid or gas? Injection pressure? Hardware used?

 

The ECU turns over the A/F control to the FPR at anything over 5 psi, so a RRFPR is wise.

 

I have monitored the injector pulse width via an onboard oscilloscope

I have seen them reach saturation at ~ 5 psi.

Thus all fuel control past

this point is done by the FPR.

The stock ECU has no way to read boost pressure, the 5psi must just coincide with the point where other sensors tell it to go full pulse width. I'm assuming you've seen this on full throttle pulls? Or are you saying that it goes full pulse at 5psi under any condition, like part throttle or low RPM? I wonder how?

 

Gary

[Skip]

The auxiliary injector is mounted directly over the throttle

butterfly. It is a Bosch cold start injector from a CIS system.

 

The propane is liquid (thus the LP and not LPG) It is feed at

propane vapor pressure (~ 70 psi) and controlled with an electric

propane valve from a tow motor. The injector and

the solenoid valve open via a pressure switch and relay.

I use a small inverted propane bottle that I fill from a 20 lb tank.

I use it for it's anti detonation qualities at elevated boost pressures.

 

You are correct the ECU has no way to measure manifold pressure.

As you know, we do not have MAP sensors.

The pressure switch seems to only light the turbo light.

The full rich condition is the ECU going into it's boost map

and ignoring the 02 sensor output.

I have seen full rich conditions even when the light is not lit.

I believe the parameters for this full rich condition are based on the

MAF signal. The RPM and the FI temp sensor no doubt also have a say.

 

The saturation point is also brought about by the MAF signal, as is the

fuel cut.

[WJM]

Skip, I notice the 87+ MAF cars wont idle w/out the MAF hooked up....but, the 85-86 can run and do drive....but drive like crap at anything between 25% throttle and WOT...aka runs great at WOT and anything below 25%....so do the 85-86 have MAP and 87+ do not?

[All_talk]

The auxiliary injector is mounted directly over the throttle

butterfly. It is a Bosch cold start injector from a CIS system.

 

The propane is liquid (thus the LP and not LPG) It is feed at

propane vapor pressure (~ 70 psi) and controlled with an electric

propane valve from a tow motor. The injector and

the solenoid valve open via a pressure switch and relay.

I use a small inverted propane bottle that I fill from a 20 lb tank.

I use it for it's anti detonation qualities at elevated boost pressures.

 

You are correct the ECU has no way to measure manifold pressure.

As you know, we do not have MAP sensors.

The pressure switch seems to only light the turbo light.

The full rich condition is the ECU going into it's boost map

and ignoring the 02 sensor output.

I have seen full rich conditions even when the light is not lit.

I believe the parameters for this full rich condition are based on the

MAF signal. The RPM and the FI temp sensor no doubt also have a say.

 

The saturation point is also brought about by the MAF signal, as is the

fuel cut.

Just to clarify (sorry if I’m being slow), the LP enters the manifold as a liquid, or is expanded into gas between the tow motor valve and injector? The reason this is important is that expansion within the intake should provide significant charge cooling in addition to the supplemental fuel. Why did you find it necessary to use the tow motor valve, were there problems using the injector alone? The liquid pressure of the LP (at ambient temps) should be within the normal working range of the injector and I doubt the LP would be incompatible with the wetted parts, just curious.

 

According to the ’89 FSM the pressure switch that lights the “TURBO” light also signals the ECUs “heavy load” mode and cancels the O2 feed back. On my RX the pressure switch trips at 0psi, so I’m sure its doesn’t set the injectors to full pulse. So I would agree, the boost map doesn’t use the O2 feedback and the ECU controls the pulse width for some part of the boost map before handing A/F ratioing off to the FPR. It is also my understanding that the stock FPR is a 1:1 type with the fuel pressure set at 36psi above manifold pressure.

 

Gary

[Skip]

Yes the propane enters as a liquid for the exact reason you purpose.

 

The phase change from liquid to gas absorbs latent heat of phase change energy,

thus lowering the A/F charge temp. Icing of the cold start valve can become

problematic, thus the back up valve in the liquid phase.

 

As for the FSM saying the boost map is controlled by the pressure switch,

which indeed is triggered at any positive pressure. My empirical observations on an

87 system say different. I have disconnected mine to prove my theory and the

boost map still occurs at certain MAF flow signals.

Maybe they reprogramed the ECU ROM in later years.

 

Your FSM should also tell you that part of the programing when in a boost

condition is to ignore the 02 signal.

 

As for the FPR again you are correct - it raises the fuel pressure as

the intake manifold pressure rises. So at 10 psi manifold the FP should be

46 psi. A RRFPR uses different ratio when the manifold goes positive.

 

hope this helps,

Skip

[Myxalplyx]

The ECU turns over the A/F control to the FPR at anything over 5 psi, so a RRFPR is wise.

I'll try this again. This question isn't just to you Skip but anyone here that can answer. Are there any RRFPRs that any of you recommend using that will fit on our EA82-Ts? I don't want to go out and purchase just any ole RRFPR and have it not fit to my car. I'm not going to utilize it just yet. I have to get an intercooler in place and open up the exhaust. After these two mods and installing an air/fuel ratio and EGT gauge, then I'll play with boost.

 

Oh BTW: I am now reading this.....

http://www.ultimatesubaru.org/forum/showthread.php?t=6985&page=1&highlight=RRFPR

 

Seems to be a good read. I'm searchin'!

[archemitis]

I'll try this again. This question isn't just to you Skip but anyone here that can answer. Are there any RRFPRs that any of you recommend using that will fit on our EA82-Ts? I don't want to go out and purchase just any ole RRFPR and have it not fit to my car. I'm not going to utilize it just yet. I have to get an intercooler in place and open up the exhaust. After these two mods and installing an air/fuel ratio and EGT gauge, then I'll play with boost.

 

Oh BTW: I am now reading this.....

http://www.ultimatesubaru.org/forum/showthread.php?t=6985&page=1&highlight=RRFPR

 

Seems to be a good read. I'm searchin'!

there surely are ones that will work on our cars. i have never seen a universal inline unit like ours are. usualy they screw onto the fuel rail with pipe thread. buy a honda one, and make it fit, with screw on barbs. one hose in, one hose out, and one vac line. our fuel rails are very wierd,compared to other engines of the era, they might as well be rubber hoses =].

[archemitis]

Skip, I notice the 87+ MAF cars wont idle w/out the MAF hooked up....but, the 85-86 can run and do drive....but drive like crap at anything between 25% throttle and WOT...aka runs great at WOT and anything below 25%....so do the 85-86 have MAP and 87+ do not?

all the ea81/ea82/er27 maf sensors are that, maf, mass air flow. just flapper and hotwire styled.

a map sensor is operated off of a vac hose from the manifold. on na cars it is a 1 bar map, it can read pressure up to 1 bar 14.whatever lbs. it can measure -30lbs of vac, up to atmospheric pressure. on a turbo car it will be a 2 bar map, it can measure vac, 1 bar of pressure, then one more bar of pressure. so 14lbs is your boost limit. or you get a superduper map, and they are 3 bar. almost 30 lbs of boost is what this map can see.

 

so the map measures manifold pressure. the maf just measures volume, and temp.