Ciao

Hey guys
Had my car at the Dyno Today and encounted a huge power drop after 6200 RPM

I am thinking it might be the APV valve not opening so I got the pot. meter onto it and it seems to be opening at the right spot .Got the dealership to check it also for verification

I have seen pictures of the intale ports/AUx ports covered in Crap and think this might be stopping the ports from opening .However the meter tells me it is opening

Could this be that the comptutor thinks the Aux valves are opening but in actual fact they are'nt due to a mechanical function 'ie,a broken cog or linkage

Is it nesessary to remove the engine to take off the entire manifokd ? My RX8 maual tells me I have to Surely you can take the entire manifold off without removing the engine

The dyno figures show the lack of air after 6200 RPM .There is plent of fuel and the timing curve is good as well .The engine just chokes

By the way I have a custom turbo setup using A GT 35 style Garett

HAs anyone encounted this problem ?

Lastly ,If I remove the AUX ports alltogether Will my off boost driving be crap .I believe Manuel From PR removed his and drivability was unchanged

Thanx in advance

Ciao
Dave

swoope

iTrader: (5)

my guess is the photos you saw were mine.. but they still worked fine.. if they were not working / rototating open you would get a cel...

how many miles?

yes you have to remove the motor to take of the intake..

do you have a cat? if so is it stock?



beers

Ciao

30,000 kms

I have an aftermarket cat ( Metal CAt)

What could be causing the power drop off then .It makes 192 RWKW at 6100 rpm and then Drops bigtime ,the power curve is awesome untill then

I really dont want to remove the motor if I dont have to

Any suggestions what may cause the drop off in power ?

Ciao
Dave

swoope

iTrader: (5)

wastegate, bov. i know this is stupid stuff. but with only 30k km i doubt the ssvs are that clogged. the pics of mine were at 55k miles and still worked fine...

coils? how much boost are you trying to run...

beers

swoope

iTrader: (5)

and what ecu?

and is this the custom / greedy kit form you posts from days gone by?

beers

Ciao

Its based on the Mazda Aust .I owned the Greddy kit for a while and didnt like a few design things about it .My kit uses 2.5in piping throughout the entire kit and the turbo I use is superior and sized better .Then the management .........

The ECU is the Same as Maz Aust ....The Exede
Internal waste gate
Been runnung 10-14psi for the past year plus
The coils are stock as well .I have a set of Bosch ones but from what Ive learned it seems to gain nothing .

Ciao

One thing I failed to mention was the addition of the seventh injector in front of the intake .
This was to cool the intake charge down as well as fuelling it up .
Maybe this has something to do with it .
Having said tha,t RP has the NOS setup which essentially is the same ,fuel through the intake

Confusing times
Ciao
Dave

Ciao

I am trying to think how BOV and gate would effect this
The BOV is A plumb back generic unit and the internal gate has a 9 lb spring

swoope

iTrader: (5)

but you can tighten that spring.. the one on the waste gate..

that has been and issue.. as for the aus greedy.. i think it is the same thing..

if you have been running 10 to 14psi for the last year, you are right the problem is elseware, but you did not mention that at the begining....

the aus kit comes with an exedy???

check the coils..

good luck..

beers

ChrisRX8PR

iTrader: (1)

CIAO,
The problem is the APV. I am sure of it. I had the exact same thing happen to me first time at the dyno. Are u using a EMU?, if so the modification to open the APV may not be done correctly. Power drops off because the long/thin main runners can only support the air requirements up to that point, if the APV doesnt open the car is essentially starved of air. Your boost will still measure correctly right behind the throttle body but all that air wont reach the engine because of the restriction after teh intake manifolds main chamber. If you were to place a boost gauge right in front of the engine intake port fo the engine the pressure there would fall off. The plastic part of the manifold can be removed without removing the engine and that is all that needs to be taken off to fix this problem if at all. It can either be that the APV is fisically not working or there is a problem with its electrical connection. Find out with a scan tool. Hope this helps.

Esmeril...

mikeschaefer

He is not using the EMU, and the aux ports aren't supposed to open until ~7200 rpm

evilmiata

Sounds like the intake ports not opening. I'm also running a GT35R (top-mounted) and the manifold/downpipe don't allow me to keep the port motor installed. I originally kept the ports closed the car car had a nitrous-like surge of power but I found myself shifting around 7000rpm. Now we've tuned it with the ports open (easy to do. Just take the motor off and turn the plastic gear inside then disconnect the motor) and the car feels a ton slower and doesn't have nearly as much punch. Nevertheless, I now make more power at 5200rpm then the car did stock. Its probably important to note that I'm using the Interceptor-X and the CEL flashes a couple times around 6200rpm (most likely because the car is saying 'what the hell happened to my intake port motor?').

whoneedspistons

iTrader: (2)

i agree with these guys it deff sounds like the intake port isnt opening... evil was the piping to close to the port motor? how close was it... is there any chance to modify it to work to increase your torque?

rotorocks

Wait, I am confused, it sounds like some say the ports being open is a good thing, and some say it is not.
I too seem to loose power big time at around 6-7K the car sort of starts boggling and feels like it is too rich; like when I run the Zex Nitrous kit, and the bottle went empty, but I forgot to shut off the switch, so it kept pumping the fuel, while no Nitrous came.
(I say "Feels" because I still haven't gotten my wide band sensor installed)


ChrisRX.. have your getting ports to open has improved the power after 6200 RPM?

ChrisRX8PR

iTrader: (1)

Actually the ports open at about 6200. Otherwise the car chokes and looses power. That is the reason there is a dip and then a spike on the OEM car's dyno sheet at this rpm. Power falls a little bit and then the APV kicks open and you get a slight surge. I had the same problem and ti was the wiring that was done wrong but I've heard of the motor going out as well. The best possible solution is to scan the OEM ecu because even if you're standalone if the motor's out or the wiring is messed up the apv wont open.

Esmeril

MadDog

I remember you saying this before. It sounds like you take this as a good thing. Can you clarify? Are you saying that the turbo isn't making boost until after 5200RPM and that below that point you make less power than a N/A? That's what its sounds like to me....

Flashing CEL indicates a misfire. You aren't igniting the mixture.

evilmiata

I'm saying that I make 180rwhp+ at 5200rpm verses the 8???rpm for a stock motor.

The CEL can indicate a misfire, but I don't believe it does in my case. There is no hesitation or AFR change at 6200rpm.

If I remember correctly, the intake port motor is 1.25" tall. My downpipe shares a small part of that space. I could try to change the downpipe configuration, but all I'd most likely do is put a big kink in the 3" pipe. In a worst-case, I'd melt the plastic motor housing anyway. The pipe is in there so tight that it would take me a couple days just to remove and reinstall parts.

As a back-handed concession, the car no longer absolutely withers the Azenis in first and second gear

Ciao

Thing is,I am getting nearly 250RWHP at 5200 RPM .Would that change If I remove/alter the ports you think?

Also can I leave the port open ,like you said ,without pulling the engine out ?
If so how?

It seems to me ,it can only be that APV Aux Port .The ignition ,AFR stats are all in check and fine .Its almost like you can hear the engine sort 'o' choking
The Exede can control the time when these suckers open but I strongly believe there is a malfunction with the opening gear ,or something .The scan tool shows no errors with the actuation of the motor ,,,,,but is it opening? Me think not

Thanks Esmeril.So taking the plastic manifold off will give me access to the APV motor .I was thinking of the possibility of physically opening the port and removing the opening rod so the computor thinks it is opening and shutting however staying open .On a reciprocating motor ,this is like adding cam duration and will make off boost driving a pig .Is this theory Valid? I believe the Exede can facilitate in the tune to overcome this but will there be too much air under say 4000RPM for the Exede to accommodate
Manuel I believe said doing this didn't effect off boost driving too much
Anyone else taken their ports out or left them open???

Thanks so much guys for your input .I think my initial sentiments are coming to fruition ,,,,,unfortunately

Ciao
DAve

Renesis_8

wow 250RWHP at 5200rpm............... the GT35 should be capable to flow to 9000rpm, I think you could be very near 400WHP...when you have everything fixed.
________
Live Sex Webshows

Ciao

I'm shooting for 300 RWHP .Thats all this car really needs .It's good for 12 sec quarters now ! Anymore would take away from the experience and make it a scary/unpredictable car to drive daily .The turbo is my own design and is not a Garret But is similar .I use ceramic nitride bearings .This turbo costs more than a Garet.

Ciao

Just thought I'd try and post a pic of my car .....Finally worked

rotorocks

Where is the pic?

dastallion951

ciao..........if u got a power loss......could be ur ignition system.........did u upgrade that..........i know turbod 8 r pretty much maxin the coils out around 300-350hp........if ur anywhere near that u might be too.........just a thought......

rotorocks

I just tuned it out on the Int-X.
Auxiliary ports stay closed. I took off quite a bit of fuel off the secondary injectors starting from about 5K and up. There is this screen in the Int-x (cant remember the name of it though, as I have bad memory for the names and titles and stuff) that controls the injectors based on the rpm (not boost) and the base map (as per Scott it is a similarly set up map as on EMU) inserts a huge amount of fuel starting at around 5.5K RPM increasing to max at 7K and all the way into 10K.
I smoothed it out, by gradually beginning to build up the fuel increase from around 3.5K going up. Now it runs beautiful. No power loss at all.

In the next couple of days , I'll try to take some screen shots from my laptop, to give you an Idea of what I am talking about and post them in my "...another turbo" thread.