Jump to content
Ultimate Subaru Message Board

EA82T Tuning Genius's - Lets fix this problem


Recommended Posts

The car is pretty doggy. I put close to 120 miles on it this weekend, and i'm not very pleased. Basically, the engine has no torque. The cams come alive at about 3000 it seems, driving improves from there. At about 3500 the turbo hits and you are scooting along. Because of this, it leads to a driving style that is: wait for it, wait for it... go go go go go STOP, wait for it, wait for it... go go go go go.

 

It seems hard to slowly accelerate to a certain speed, simply because you have to flog the engine so hard to get it to go.

 

Starting on a hill... I'm done for. Just kinda crawl along.

So... it could be the delta cams and the wrx turbo, just not a good mix. Could be the exhaust. Could be timing. Could be a lot of things. Let me know your thoughts, ask questions, i'll do my best to answer them to the fullest. The dream is still alive, just wary I guess.

 

(yes, i posted this at the end of the other thread, but for the sake of staying on topic, i figured I'd start a new one and not clutter up the idle one, since it was at like 5 pages)

Link to comment
Share on other sites

Well the EA82T is not a torque motor to start with and I can imagin with cams it must be awfull crapy on the low end.

 

I would add a supercharger set up.

 

ok now that you have finished laughing Im serious. I have heard ov a guy who built a rally car back in the day out of an ea81 I think. with both a turbo and a supercharger. It however had a dificult time keeping the axles from snaping due to the masive amounts of torque and HP.

 

or your other option go with an EJ motor

Link to comment
Share on other sites

I don't have a problem having spent the money on the cams. It was worth a shot. I will undertake putting the stocker cams back in. Perhaps I'll put the delta cams in my brother's turbo XT. Perhaps too much for a 16 year old though...

 

I was going to call and ask delta what they could do for me. If they had a Torque ground cam for the EA82T. As the cam that I have is very horse power directed.

 

But, Corky Bell said it best in his book "Most stock turbo cams are as good as you are going to get."

 

And yes, i've been tinkering with this car for quite sometime, reluctant to post because of my results.

 

Lessons learned.

 

Side note: Shadow, could you PM me or post some links or info on why a new header (equal length) is needed. I just need some reading material on it. I'll look in Corky Bell's book on it too.

Link to comment
Share on other sites

well please keep me in the tuning loop. my stock turbo is going bad and I now have a TDO4 to install along with the wrx down pipe. I will be using the stock fuel system at stock boost levels. I am not looking for big perfomance gains just a better matching turbo.

I will be runing stock cams as my low end sucks as it is. I would really like to see how you guys plumed the turbo Air outlet to the IC. that is my biggest hang up right now.

Link to comment
Share on other sites

Well, another page to the story.

 

So there is the doohicky between the vaccum port on the turbo and the wastegate actuator. Its called a boost controller. For the hell of it, i cranked it up. Previously, it wasn't so cranked up, and i was running about 7-8psi. Now, its running about 10-11psi. However, turbo response has improved dramatically. Atleast tonight it has.

 

This evening is a lot colder that it was over the weekend, so maybe that had something to do with it. Also, adjusting the boost controller may have something to do with it. I might add, that I need to get me a real boost controller, as my homemade one is good... but hard to meter how much you turn it up. I put almost 5 full turns on it, and it only went up 3 psi.

 

I will continue driving, and fiddling, see what I can come up with.

Link to comment
Share on other sites

From what i remember..you are running the WRX intercooler..correct?

 

If so.. i guess that isn't too bad for having lots of intake restriction.

 

The car probably needs a really good tune.

 

What are you running for fuel management? Just a RRFPR??

 

I'd look into getting your Eprom programmed by someone, or using a piggyback computer to try and work out the flat spots.

 

From what you are saying. it seems like you are running very rich in the bottom end.

 

Seems like the computer is adding fuel as it's expecting the turbo to come in sooner, and it's going really rich, then when the turbo finally catches up it's starting to use that fuel and your feeling that with the kick in power. You really need a boost related fuel map

 

Another thing could be exhaust. What are you using for a manifold/header. assuming that you made something up to mount up the WRX turbo and not just hacked on a different flange.

 

You may have gone too big on the tubing. which will lead to the air velocity being slower, and will have longer spool up. Smaller manifold pipes will give you more spool up and bottom end, but suffer on the top end.

 

I really think a proper tuning will make all the difference

Link to comment
Share on other sites

Hey Tex

 

I had a thought, are you running the stock "boost switch", the one that turns on the dash light? That same switch send a "heavy load" signal to the ECU that cancels the mixture feedback (02 sensor). I'm sure this affects fuel mapping, if you are running without it, it could cause trouble well below full boost, I checked mine with a gauge and it comes on right at 0 psi.

 

Gary

Link to comment
Share on other sites

 

This evening is a lot colder that it was over the weekend, so maybe that had something to do with it. Also, adjusting the boost controller may have something to do with it.

that may have a bit to do with it. When ambient temps here hit 100 , my car turns into a super slug.. gas mileage goes down, power goes down.. but when it gets dark and the temps drop back down into the 80s, everything goes back to normal. Haven't really figured oout what to do about it yet.

Link to comment
Share on other sites

I don't really fit the EA82T tuning genius requirements and I don't want to hijack by any means but I have a very similar set up to what subarutex has and I am having some of the same issues.

 

My set up

 

EA82T

Delta cams, torque grind

TDO4 turbo (thanks NASIOC)

WRX TMIC (Thanks NASIOC)

WRX pown pipe

custom intake, K&N cone

2.5 exhaust to cherry bomb muffler

Lightened flywheel by 6lbs (I'm sure this doesn't help idle)

 

I just got this thing running a couple of weeks ago and now I'm trying to get it to run well.

 

First, I have the same no idle at cold start issue. Plumbed the AAV and BOV correctly, AAV from metered air, Bov recirculating. Now it idles well on cold starts, at about 1100 then drops to 950 or so once warm.

 

The current problem seems to be some lag, I can deal with lag until I build a better header/uppipe. I may also have the tdo4 clipped a bit to get it to spool faster

 

Once the turbo kicks in at about 3000-3500, it starts acting like it's out of gas, hesitates, jerks, sounds mad at me so I let off. I have no boost or overboost switch" so perhaps what Alltalk has brought up is causing this. I imagine the ECU needs to know that the motor is being boosted and that it needs to change the AF ratio. I will try to get those damn switches and see if that helps.

 

Subarutex, are you using the boost and overboost switches?

 

My other thought on my situation is the quality of the turbo? I bought it second hand and know nothing about it's childhood, perhaps it was abused? It leaks a bit of oil out the hot side and has a tiny bit of shaft play. I suppose if it doesn't spin really easily that could cause the lag. perhaps the fuel system is working perfectly but the air is not smoothly increasing in flow....

 

My other wonder, my MAF (flapper style) is mounted sideways. To make the intake work I had to rotate the MAF 90 degrees so that the flapper is up/down instead of left/right. It seems to me that the flapper is spring loaded, not gravity affected but I may be wrong.

 

Subarutex, how is your MAF mounted or is it hotwire style?

 

I hate to think the cams are the problem, If I remember correctly, Dennisex24 was running Deltas and an other than stock turbo with good results. From my very limited understanding of valve trains and cams, the torque grind (I don't remember the number) is pretty mild and designed to add power throughout the whole power band, not just top end. I will try everything to make it work before going back to stock cams.

 

Anyway, this is not a happy subject, I know we'd rather be talking about how kick rump roast our cars are and how much rump roast they haul. I believe we can work through it and figure out whats going on

Link to comment
Share on other sites

all talk I do not belive the switch you are refering to effects fuel control at all. at least it does not on my car.I did not like that stupid boost light. I have not used mine for some time now and it does not seem to have changed any thing. under boost the o2 shows a fat mixture and at cruise it cycles like normal. I will be changing my o2 to a 4 wire today to get better readings at idle.

 

I am still on stock turbo as of now but am a little hesitant to gather the rest of the parts for the swap after reading all this.

 

Garner- I do belive that the mounting of the flaper maf is inportant. I had the one on my toyota truck mounted sideways at first and it really did not like it. It would stumble and conplain I changed it to mount level and it was much more happy with that.

Link to comment
Share on other sites

I'm no genius either, but I'll post some thoughts:

 

Turbo cams differ greatly from N/A cams, so like others have said, unless Delta (or others) have a turbo specific cam I’d stick with stock.

 

The TDO4 is a bigger turbo with a heavier turbine/compressor, it takes more flow to spool it, no way around that. Sure an open exhaust and more efficient up-pipe can buy back some of the “lag”, but I don’t know if you will ever get it all back. The stock turbo is very well matched to the engine (funny how millions of dollars in engineering will do that), and is reportedly good for around 12psi/200hp, unless you plan on going passed those numbers (unlikely on pump gas), I’d be prone to stick with the stock unit and optimize for modest power gain across the whole RPM range. True the TDO4 will make more power in the end, but there will be a price, I guess it really depends on what you want the car to do and how you’re going to use it.

 

Garner, I doubt its you're turbo, I had my stocker out a while back to change the lower coolant line and noted it had significant play (260,000 miles) and it still boosts right at spec. And like Russ said, I think the mount of the flapper does matter.

 

Hey Russ, I’m not sure how (or even if) the “heavy load” signal affects the fuel map, but the wording in the ’89 FSM seem to suggest it might (see pic). If the switch signal doesn’t modify the fuel map then the only boost controlled mixture adjustment would be the fuel pressure regulator (aside from the increased flow measured by the MAF). All other boost mapping would be assumed by the ECM based on relative inputs from the MAF, RPM, TPS and the like. I really wish we had more information on the ECM’s functionality, I suppose with an O-scope and enough time we could figure most of it out, I guess that’s a good argument for going to an aftermarket control system.

 

Gary

PressureSwitch.jpg

Link to comment
Share on other sites

:cool: I want to go play at shadows place. dam thats one hell of a plan. :slobber:

 

well keep us informed. Im not so sure about that saab 9000 IC idea. I think you could find a better fitting unit with better flow than that. I tried to stuff one in my car at one time and I decided that it was not going to happen without hacking the front of the car to bits and welding it back together in some other strange fashon.

along with a ~100 dollar rebuild kit for the stock turbo

you know where to get a rebuild kit?

 

Does anyone know off the top of thier heads at what point (RPMs) boost comes on (negative-postive transition) with the stock turbo, and at what point it is at full boost?

I would assume this would be tested from a stop at full throttle?

just pulling numbers out of my head here but my car goes into +boost before 1500 and full boost at 3000. I think.

I will check in the morning to get some real numbers.

this is with a worn stock turbo (oil burner) 2.5 exhaust with cat. VW IC on top. stock fuel control and boost levels.

this set up is prone to over boost at higher RPM(4800 to red line). I was hoping to eliminate that problem with the instal of the TDO4.

Link to comment
Share on other sites

What I think might be a really cool alternative is to send out a stocker unit for one of the Deadbolt monster port - with the extreme difference it makes on the TD04 I can only imagine what it would do for early on boost on this engine - as a 200 dollar service, along with a ~100 dollar rebuild kit for the stock turbo, someone has GOT to try this (might be me on one of my other RXs :D).

 

I was talking with Jerry (i.e. Deadbolt) recently about this very thing (i.e. acquiring a "Monster VF7" from him), and I know that Pleiades was at one point planning to get him to "monsterize" his VF7 turbo for his GRM $2004 challenge entry, but IIRC it didn't happen in time.

 

But after discussing turbo options with him (and having him propose some alternatives), I have decided on something a little more customized and a little more wild (which, if it works as expected, should spool much faster than a TD04, but still flow a good bit more air than a VF7). More details as the project progresses. :D

 

FYI: Those of you with TD04s might want to consider having him convert your turbos into "Monster TD04s" (maybe even with a bit of a clip) as the turbo spools quite a bit faster after this treatment is performed. (The "monsterizing" is essential a port and polish service, primarily of the exhaust side of the turbo. Several of the local guys are running Deadbolt "Monster" turbos (it helps that Jerry lives like an hour from here and attends the local autocrosses...LMAO) and absolutely love them.

 

Here is the Deadbolt Speed website if you are interested:

http://www.deadboltspeed.com

Link to comment
Share on other sites

To tell you guys the truth....I am shooting for a custom header...and place the turbo in like in one of my other posts....so its will be a custom 3 inch TBE.

 

A spyder intake with an XT6 (or same size or larger) throttle body bolted on. Stock ECU and engine management and timing system for now. WRX IC, and the BOV set for a factory style reciculation. Boost....12-16 PSI. Stock for a while tho. Also a new MAF/AFM to turbo pipe.

 

Anywho....Tex, I sent you a PM....if you go back to stock cams, and want to get rid of the ones on it now, I'll gladly take them off your hands.

Link to comment
Share on other sites

Oh, and it doesnt matter which way the MAF or AFM is....i will turn mine sideways just to prove it. :-p

 

Do you have a flapper style? If so, turn it 90 degrees clockwise so the hinge on the door is up and report back.....

 

garner

Link to comment
Share on other sites

Ok ok you have to tell us about the turbo you're going to use on your project now, there's no making claims without some more backup info at least! It could really help someone out that is looking at different options now - most of us here posting are already commited, but there could be more out there. Are you concerned with someone beating you to the punch, or are you just fond of this type of torture!?:-p

Muhahhahahahahaha...ahem...sorry... :D

 

It's actually a hybrid setup that I've never heard of being built before, so I want to see how it turns out before I divulge the details. :) I'll try not to keep you in suspense for too long...LOL ;)

Link to comment
Share on other sites

Oh, and it doesnt matter which way the MAF or AFM is....i will turn mine sideways just to prove it. :-p

yeah the car will still run but the flapper is now effected by gravity as well as air flow when sideways. this will cause some variations in mixture throughout the sweep. of course a hot wire unit does not care and can be mounted any way.

Link to comment
Share on other sites

I know subarutex is now dealing with some other issues but I thought I'd post on my progress. Since my last post I have:

 

Plumbed everything properly, aav, bov and disty to ported source. Very important

 

Reset my MAf to stock orientation. This was a huge improvemnet. Definately makes a difference on flapper MAFs.

 

Borrowed boost and boost cut switches form mudrat and plugged them in.

 

Went for several drives and here is the result:

 

Idle at cold start up is about 1100-1150 after warm, it drops to about 900-950. works for me!!

 

there is a bit of a "flat spot" from idle to about 2000rpm really strong from 2000 to as high as I dare rev it, I hit 7500 the other night, not trying to just looking for boost cut. not the recomender break in procedure I know..

 

while driving, once I rev up to 2000 through the "flat spot" she screams, tires smoke, back end gets squilley, neighbors give dirty looks. Good strong pull once boost hits at about 3000 pulls hard to redline and beyond.

Keep on it and WAM boost cut....at about 8-9 psi

 

shifting into second or third, occasionally and randomly, I hit what feels like boost cut well before I should. It is like the fuel is being cut out or just can't keep up. Fule pressure is exactly to spec under idle don't know what it does while driving and hitting boost (I have the guage mounted under the hood).

 

My suspects:

 

Fuel pressure regulator works at idle but perhaps does not rise the rate. It is a stock 1:1 rising rate and perhaps I have it to ported vac and it should be non-ported or vice versa (can't remember where I have it plumbed) If I remember correctly, the fpr uses vacuum to raise the flow rate. Also, if I remember correctly, ported vacuum raises consistantly with increasing engine speed, non ported raises then goes to pressure as boost kicks in?

 

disty vacuum advance is not advancing consistantly. I will test this tonight. It seems these vac advance units are prone to fail so it may be an issue.

 

 

Anyone else have any bright ideas? Its really close and fun as is but I've got to get it perfect by the show so I can really show it off

 

garner

Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
 Share

×
×
  • Create New...