Rx8 turbo lagging help please!!
09-21-2012, 09:18 PM
#27
HAVOC
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I also VTA during my turbo days, it would dump fuel and bog the engine down if i stuck it in neutral down to idle. PITA during traffic jams but i lived with it for the sound. In hindsight recirc would be better, but not a deal breaker. I know it's pretty user to user dependent on how well the tune handles it.
09-22-2012, 06:01 AM
#29
I divide by zero
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I drove mine VTA without drivability issues. 
And at night I could look in my rearview and see the bright flash reflecting off the cars behind me......who always inexplicably backed off. 
And at night I could look in my rearview and see the bright flash reflecting off the cars behind me......who always inexplicably backed off.
09-22-2012, 10:44 AM
#32
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Ok so i tried the pop can method and nothing. I changed out the coil packs. No diffrence either. I did notice that if i press on the gas a little like half a centimeter the car will build boost through 3500 to 5000 no problems but its really slow and during that range if i push the pedel down it will bogg down and stutter. I checked the functions of the vlaves and nothing seems to be wrong. Still throwing p2070. Any thoughts? Im in western ny if anyone know a good turbo installer to look at this for me.
09-22-2012, 11:56 AM
#33
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I don't think at this point that the BOV is the issue, it would be nice to see a data log, maybe invest in the access port right away then lots of people can help you by distance.
I've got the logs if you would like to see them Brettus, I'm not seeing any issue with my VTA setup, but someone with your experience may be able to point otherwise. My theory is went you close the throttle you close the throttle. Therefore the metered air is slightly irrelevant, and also if you recirculate the air then less air will be drawn in vs. if you VTA more air will be drawn through the MAF when the throttle re-opens. The only bad effect from a VTA setup is will idling or cruising under vaccum it will lean out if the BOV is not tuned properly, this is why I used a twin piston BOV. Simple to put this to rest all you need is a comperatives of 2 data logs.
Cheers
I've got the logs if you would like to see them Brettus, I'm not seeing any issue with my VTA setup, but someone with your experience may be able to point otherwise. My theory is went you close the throttle you close the throttle. Therefore the metered air is slightly irrelevant, and also if you recirculate the air then less air will be drawn in vs. if you VTA more air will be drawn through the MAF when the throttle re-opens. The only bad effect from a VTA setup is will idling or cruising under vaccum it will lean out if the BOV is not tuned properly, this is why I used a twin piston BOV. Simple to put this to rest all you need is a comperatives of 2 data logs.
Cheers
Last edited by jay_tibo; 09-22-2012 at 12:25 PM.
09-22-2012, 12:24 PM
#34
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E https://www.youtube.com/watch?v=ofIK...e_gdata_player
These are my compression tests. Both front and rear rotors have the same compression.
These are my compression tests. Both front and rear rotors have the same compression.
09-22-2012, 12:30 PM
#35
E https://www.youtube.com/watch?v=ofIK...e_gdata_player
These are my compression tests. Both front and rear rotors have the same compression.
These are my compression tests. Both front and rear rotors have the same compression.
You need to have special compression tester that will capture each compression cycle and the RPM
Then you need to normalize the compression value
09-22-2012, 01:52 PM
#36
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Yep this is right, keep in mind you have 3 different compression chambers per rotor therefore the pulses need to be read. There are specific rotary compression testers, mazda for sure has one.
09-22-2012, 02:46 PM
#37
I've got the logs if you would like to see them Brettus, I'm not seeing any issue with my VTA setup, but someone with your experience may be able to point otherwise. My theory is went you close the throttle you close the throttle. Therefore the metered air is slightly irrelevant, and also if you recirculate the air then less air will be drawn in vs. if you VTA more air will be drawn through the MAF when the throttle re-opens. The only bad effect from a VTA setup is will idling or cruising under vaccum it will lean out if the BOV is not tuned properly, this is why I used a twin piston BOV. Simple to put this to rest all you need is a comperatives of 2 data logs.
Cheers
Recirc is just way better from every point of view except the lack of a pssssssht noise.
09-22-2012, 03:06 PM
#38
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Just for the sake of experimentation (and to be a boy for a while) - I set mine up VTA yesterday . Had to put a heap of tension on the spring to make it acceptable to drive .So much so ,that I'm now getting a small amount of compressor surge at low throttle .
Recirc is just way better from every point of view except the lack of a pssssssht noise.
Recirc is just way better from every point of view except the lack of a pssssssht noise.
Lol yep I love the pssssht noise, your experiment proved a regular BOV doesn't work efficiently, try a twin piston one: Forge Motorsport | Alloy Fabrication
That's what I have, works like a charm, can I send you a PM Brettus, I have something I did different on my Greddy install based on things you suggest and would appreciate your feedback but feel it wouldn't add anything to this thread.
09-22-2012, 03:26 PM
#39
weeeeeeeeee
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The Synchronic with the anti-stall valve works well enough VTA ... but you still experience the fuel dump when it opens. Thee's no way around it in a MAF based system.
Perhaps I'll try it again one day now that I'm MAP based. Oddly enough, a couple weeks ago I experienced a coupler failure and it took me a good 10 minutes to even realize I'd lost boost...
Apparently there was still enough air traveling across the MAF to keep the ECU from throwing me into limp mode.
Perhaps I'll try it again one day now that I'm MAP based. Oddly enough, a couple weeks ago I experienced a coupler failure and it took me a good 10 minutes to even realize I'd lost boost...
Apparently there was still enough air traveling across the MAF to keep the ECU from throwing me into limp mode.
09-22-2012, 05:39 PM
#41
Ok so i tried the pop can method and nothing. I changed out the coil packs. No diffrence either. I did notice that if i press on the gas a little like half a centimeter the car will build boost through 3500 to 5000 no problems but its really slow and during that range if i push the pedel down it will bogg down and stutter. I checked the functions of the vlaves and nothing seems to be wrong. Still throwing p2070. Any thoughts? Im in western ny if anyone know a good turbo installer to look at this for me.
p2070 is SSV stuck open which means................ the SSV is stuck open .... so fix it
The SSV does a test cycle when you switch the engine off . Have a look at it while someone switches the engine off for you and see if it does this .
09-22-2012, 07:53 PM
#42
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If it isn't the BOV it could be a big boost leak somewhere else . Suggest you leak test the system - search " turbo leak test" on the net for how to do that.
p2070 is SSV stuck open which means................ the SSV is stuck open .... so fix it
The SSV does a test cycle when you switch the engine off . Have a look at it while someone switches the engine off for you and see if it does this .
p2070 is SSV stuck open which means................ the SSV is stuck open .... so fix it
The SSV does a test cycle when you switch the engine off . Have a look at it while someone switches the engine off for you and see if it does this .
09-22-2012, 08:28 PM
#46
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It occurs from 3500 to around 5000 rpm. And im not sure how to read those. My phone pulls the afr off both of the 02 sensors on the car. They are in a aa:bb:cc format how do i read those?
09-22-2012, 08:32 PM
#48
weeeeeeeeee
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dude... you really do need some dedicated gauges too....
Fuel Pressure
Wideband O2
Vacuum/Boost
Oil Temperature
Oil Pressure
Pretty much required. I didn't notice but did you log AFRs yet?
Fuel Pressure
Wideband O2
Vacuum/Boost
Oil Temperature
Oil Pressure
Pretty much required. I didn't notice but did you log AFRs yet?
09-22-2012, 08:48 PM
#50
You should be reading AFR's from the front O2 Sensor.
Read this:Air/Fuel Ratio tuning:Rich vs Lean | Turbobygarrett
That's a quick general explanation, those AFR's mentioned in that article do not apply to a boosted RX8 under WOT you should be seeing low 11's and cruising should be high 14's, there's a lot more to it than that though.
If you plan on keeping this car and expect it to last any length of time you seriously need to start doing some research regarding what's involved with owning a boosted car, getting everything setup properly and what you should be monitoring on a regular basis.
Like I said before, Ditch the E Manage, Get a Cobb Accessport and get it PROFESSIONALLY tuned and Recirculate the BOV, not doing this means you have air read by the MAF that's not making it to the Engine and you will get rich spikes.
Check all you coupler connections make sure they are tight to avoid boost leaks, and check all of your vacuum line routing, Jet Air, and OMP Lines
https://www.rx8club.com/major-horsep...uff-up-211884/
Read this:Air/Fuel Ratio tuning:Rich vs Lean | Turbobygarrett
That's a quick general explanation, those AFR's mentioned in that article do not apply to a boosted RX8 under WOT you should be seeing low 11's and cruising should be high 14's, there's a lot more to it than that though.
If you plan on keeping this car and expect it to last any length of time you seriously need to start doing some research regarding what's involved with owning a boosted car, getting everything setup properly and what you should be monitoring on a regular basis.
Like I said before, Ditch the E Manage, Get a Cobb Accessport and get it PROFESSIONALLY tuned and Recirculate the BOV, not doing this means you have air read by the MAF that's not making it to the Engine and you will get rich spikes.
Check all you coupler connections make sure they are tight to avoid boost leaks, and check all of your vacuum line routing, Jet Air, and OMP Lines
https://www.rx8club.com/major-horsep...uff-up-211884/
Last edited by kma5783; 09-22-2012 at 09:20 PM.