daily driving issues (with forged gtx2867r)

Discussion of tuning specific to CX-7 vehicles
pankrok
Posts: 14
Joined: May 13th, 2015, 8:12 am

daily driving issues (with forged gtx2867r)

Post by pankrok »

greatings to all

here is the setup so far (MANUAL transmission genI cx7)
a) k1 rds/ wiseco 88
b) 3.5" maf , 3bar map
c) autotech pump internals
d) decat dp , 200cell HJS cat, 3" exhaust
e) gtx2867r @ 1.6bar (23psi)
f) mishimoto j line fmic

and here are the goals

a) economy (more or less going well)
b) throttle response
c) mid range power (together with response)
d) transient response without knocking / hesitation from low loads
e) 380+ awhp (quite possible)

i have been playing around with great help from Teo ( the 800+awhp 3mps owner) but i m trying to elaborate things.

I will appreciate feedback on above.
I have been currently using a tune with a lot of advance timing in closed loop (up to 10deg from stock) which made tremendous difference in fuel consumption and throttle response however i thing the applied advance is excessive.
I m using torque for everyday observations and i get some stupid knock retard recorded (which i was getting also before - maybe not that obvious) in low loads (3rd gear 2000 rpm , light pedal position - makes no sense to me as these disappear when APP goes up) which is not always observed but might be up to 4deg. There are also some misfirelike event (without knock retard) were engine might rattle (as if misfiring) in partial load mid/low rpm

i m also using a bit lean afrs at closed loop (1.02 in most of the range) and 0.82 at open loop.

I believe I have gone too far with this ignition testing so i posting this for evaluation.
although each engine is different there should be a lot of common ground in this map
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cl base timing normal 231.zip
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Steve @ VersaTune
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Re: daily driving issues (with forged gtx2867r)

Post by Steve @ VersaTune »

I recommend starting with stock timing and incrementing by 1 or two degrees at a time and log. If you see frequent knock events above 1.05 try backing off a half degree and see if it helps. KR of 4 is bad news!
pankrok
Posts: 14
Joined: May 13th, 2015, 8:12 am

Re: daily driving issues (with forged gtx2867r)

Post by pankrok »

My question is if this is real knock or some noise picked up by sensor. I have read somewhere that ac compressor some times creates noise that is interpreted as knocking by ecu.

It is strange for me knock retard on low loads and mid rpm and not on wot .
Even stock timing was picking some knock retard now and then in similar condition.
Could this be related with balancer removal? To my understanding balancer removal is obvious on 800-900 rpm 1600-1800 and 2400-2700 rpm

I will start over anyway when I get back.
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Steve @ VersaTune
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Re: daily driving issues (with forged gtx2867r)

Post by Steve @ VersaTune »

Occasional random knock events are normal. When it's consistent and repeatable, that's typically real knock. Please also check your min load table for KR. The default is 0.4 load minimum. You may not be hitting that at cruise. VVT actuator failure is a common cause of false knock.
pankrok
Posts: 14
Joined: May 13th, 2015, 8:12 am

Re: daily driving issues (with forged gtx2867r)

Post by pankrok »

indeed occasional

min load is same as stock .

vvt is dcr version if this means anything and looks to work well during logging
mituc
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Re: daily driving issues (with forged gtx2867r)

Post by mituc »

The GTX2867 will get you to 380awhp but it's going to be a bit more difficult with just pump gas and no WMI.

To understand the issues that you're experiencing you should really capture those events in a log and post it here. No one will be able to figure anything out by just looking at your timing table (which BTW looks similar to mine).

2 weeks ago I made myself a tune with leaner AFRs (up to 1.035 in some areas) and I didn't see any notable fuel economy by doing that (only 0.1l/100). However, sometimes I had the feeling that the engine is pulling in waves in those situations when the load and RPM values were favouring the leaner AFRs in the tune. I just got back to the stoich AFRs and that weird behaviour I experienced for several hundred kilometers disappeared as well.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
pankrok
Posts: 14
Joined: May 13th, 2015, 8:12 am

Re: daily driving issues (with forged gtx2867r)

Post by pankrok »

i will try back to 1.00 to see what is happening.
recently replaced the first λ sensor as the old one was giving unreliable readings.

using a similar table like this without issues is helping - what spark plugs are you using and what is their gap?

the problem about logging is that i cannot reproduce what is happening when i have the chance to log. of course i could continue logging for long time but might not be easy to isolate the moment of the problem in the graph (unless readings are quite obvious).

about awhp i had not yet dynoed the car but if vdyno is to be trusted i was able to see nearly 375awhp before summer time on pump gas without meth.

i estimate to be back in 10-12 days to test few things so using this time to get some more ideas.
mituc
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Re: daily driving issues (with forged gtx2867r)

Post by mituc »

For this level of modifications and amount of power you should use one step colder sparkplugs (Denso ITV22 or NGK LTR7IX-11) gapped at 0.65 maximum 0.7mm.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
pankrok
Posts: 14
Joined: May 13th, 2015, 8:12 am

Re: daily driving issues (with forged gtx2867r)

Post by pankrok »

Ok checked few things

Ngk 7ix indeed but forgot to gap them properly. I was testing something with low boost in the past and used gap 1.0mm

Now gapped them at 0.65 and running significantly better. I have seen even 16.5 deg advance keeping up to 6000 but could not log it.

Also noticed that my new muffler resonance at 1600 and 3200 is not only audible to me but to knock sensor too. Everyone I hit 1600 with load above 0.4 o get 2deg retard and at 3200 it is possible to see 1 deg - not always thankfully.

I will add some damping to my exhaust and see if it gets better. But this certainly is not real knock.

My logs suck. For the moment I am using torque to watch the events as happening.
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: daily driving issues (with forged gtx2867r)

Post by mituc »

If you're using Torque then most probably you're using some ELM device which is slow. If you want proper monitoring you will have to dedicate it a bit of your time and log (with Versatuner) a longer drive (5-10 minutes of city driving) and get 1-2-3 WOT logs (also with Versatuner) on a less busy stretch of road.

Also, torque doesn't know how to interpret the MAP sensor voltage so you will never see the right boost values from your 3 or 3.5BAR MAP sensor (assuming that for your 23PSI goal you updated the factory MAP sensor).

So you continue doing it wrong... even though your setup has a lot of potential.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
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