anarchyx34

Just upgraded to MS2, and I had some ignition settings wrong that was preventing me from revving past 6k. Anyway I cleared that up and I'm noticing I have the exact same issue. Pulls great till 5k, goes flat, and then takes off like a bat out of hell at 6k again. Obviously it's not belt slippage since I'm running a turbo. I need to log it and post it. May or not be the same problem as you.

stav

exactly the same happens to me too (MK2.5, MP62 supercharged)...
the boost drops suddenly at about 4600rpm and then comes up again at 6k rpm...it is definetelly not belt slippage, because if it was, boost wouldn't come up again...I have attached a 3rd gear pull log, and the spark table I am running

GrahamA

All my new logs show fairly constant boost (tightened a few bolts and not getting any more dusting under the bonnet)
I've tried a run with the basic spark table from diyautotune's base map and had the same result. The switch to speed density has improved it but there is still this kick at 6k rpm.

Braineack

iTrader: (62)

ever thought about leaning it up? your VE table goes 7% richer in boost between 5400 and 6000 RPM, you logs looks like it dips into the high 10s for AFR. You shouldn't need to run so rich with a SCer at 8psi. I don't even run that rich at 15psi.

stav

One big difference in my case is that although there is a boost loss in the logs, I don't really feel it...So I talked over the phone with our MS guru here in Greece (Dimitris aka Reverant), and he told me that under certain circumstances there is a chance that the boost I see on the logs is "fake"...so I will check with my boost gauge to see if there is a drop there too....

GrahamA

Ve-analyze has been trying to lean it out for me. Trouble is I think I'm so rich that I'm burning fuel in the exhuast manifold and cooking my lc-1 which means an aborted run. I think I'll try a leaner map to start with and build up the revs slowly and let autotune do it's thing.

CRAIGO

Stav was your spark table set-up at a dyno or road-tuned? It dials in alot of timing around the peak torque curve area and then pulls timing towards the red-line when you could actually be adding it in lightly. The log shows a blip in boost exactly where your timing advance peaks. Have you tried smoothing your advance table?

Also your MAT's look heat-soaked? It reduces as you do your 3rd gear pull?

stav

the table was set-up on the road...and to be honest was meant for my previous setup (JRSC at 11psi)...I did play a lot with fuel and afr tables but I didn't touch the spark table after I fitted the MP62 2 weeks ago...I am not that familiar with tunerstudio yet

As for the temps, i didn't notice that before...I did the pull right after I spent a minute or two waiting to pay the tolls, so I guess that might was the reason for heatsoaking (btw I forgot to mention that I haven't currently connected the fmic, as I need to fab the piping)

GrahamA

Had another run today and started with a much leaner table but was still suffering the same flatspots and surges I then switched on the enhanced acceleration enrichment and the car was transformed. Smooth throughout the rev range, no sudden surges in power and just damn good fun to drive. Need to work on the eae settings as it will bog down now if I floor it in too high a gear but otherwise a great result.

stav

went out yesterday to check boost on the gauge...there is a drop there too...so it seems that its not a fake signal....
I read somewhere that a faulty PCV can cause that effect...leaking in relatively low rpm and the sealing (somehow!!!!) off at higher rpms .... has anybody heard anything about that before??
In any case I ordered a CUSCO oil catch can yesterday, which I am going to install along with a one-way valve and a new PCV valve ( i was lucky to find the can brand new for only $32 )...

Turbobarber

iTrader: (2)

Nice, right?? So... I would watch your tpsDOT(and mapDOT if you use blended enrichment) in your logs and try to taper down that flooding that occurs when you snap on the throttle. I pulled out some of the PW added by tpsDOT and the result was improved throttle transition, but with my clutch slipping now it's going to be near impossible to finish tuning until I get another clutch.

That said - I'm guessing you're happy with your VE table? It should be fine tuned before proceeding with the AE and EAE. There won't be much you can do about the power loss in those rpm ranges without it, but get it as close to the AFR's you want as possible, then move on to messing with the tpsDOT/mapDOT and the EAE. My results with the EAE involved no modification of the EAE settings themselves.... They seem to be working fine, for now.

Hope this helps


Otherwise tomorrow I'm going to *attempt* to braze my IAT bung onto my intake pipe.... should be fun lol just finished brazing up a throttle mount plate and tube fitting for my monster mower, so I've got some short practice in

Braineack

iTrader: (62)

I had to alter my Stuck-To-Walls table significantly. The Sucked-From-Walls, not as much, but I did need to alter the rpms corrections for it.

anarchyx34

I managed to eliminate my flat spot this morning by reducing maximum dwell to 3.2 from 5.0.