Can't solve this detonation issue - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


E-Manage Post your questions about greddy e-manage installation and tuning here.

Reply
 
 
 
LinkBack Thread Tools
Old 02-15-2010, 04:01 PM   #1
Senior Member
Thread Starter
iTrader: (2)
 
Join Date: Jun 2007
Location: Shalimar, FL
Posts: 965
Total Cats: 7
Default Can't solve this detonation issue

This is a problem that I've gotten nowhere with since I bumped the boost past 6psi. My setup is as listed in my sig.

I can get the car to detonate, even with rich AFRs (10-11:1) and severely retarded ignition timing. This is how I can get detonation to occur and it is reproducible. Get to 5K+ RPMs or higher, in second or third gear, and punch it. There will be a small bit of audible ping immediately and that's it. Afterwards it'll pull like normal.

Doing a pull in third for tuning doesn't reproduce the issue. It is only when transitioning into boost rapidly at high RPM. Here's my current timing map (MAP sensor wired into TPS, 45% is 5 psi, 55% is 10 psi).



You can see how far retarded my timing is. I'm really at a loss with this. I will be installing a DO water injection kit soon so I can at least make it to some autocross events, but I know it'll only be serving as a stopgap. Any advice would be helpful. Thanks.

Edit: I think I will check my ignition timing this week (with a light and all). If it were way advanced, that would explain why I keep having to pull so much timing.

Last edited by messiahx; 02-15-2010 at 06:55 PM.
messiahx is offline   Reply With Quote
Old 02-15-2010, 06:37 PM   #2
Junior Member
iTrader: (4)
 
Join Date: Mar 2007
Location: Greece
Posts: 290
Total Cats: 4
Default

Your picture is tiny.
gianic is offline   Reply With Quote
Old 02-15-2010, 06:46 PM   #3
Elite Member
iTrader: (10)
 
Join Date: Oct 2008
Location: Seattle, Wa
Posts: 1,780
Total Cats: 30
Default

My bet is that your ecu isn't compensating properly for the rapid increase in pressure (acceleration enrichment) which in turn is causing a massive lean spike while in boost = knock. By contrast, starting at low rpm and doing a pull in a gear causes a much slower pressure increase which is easier to compensate for.
Jeff_Ciesielski is offline   Reply With Quote
Old 02-15-2010, 07:04 PM   #4
Senior Member
Thread Starter
iTrader: (2)
 
Join Date: Jun 2007
Location: Shalimar, FL
Posts: 965
Total Cats: 7
Default

I fixed the picture.

I went and got a timing light and the timing was advanced 2-3 degrees. Doesn't seem enough to cause these issues but I went and set it to 10 BTDC anyways.

Jeff, that would be exactly what is happening. I've never had much luck with the EMB's accel enrichment map. Maybe I need to keep trying. I haven't been able to see the lean spike in the emanage data logs or on my AFR gauge. Maybe the greddy software doesn't sample quickly enough.

Here's another thought: I have my MAP sensor and O2 clamp under the dash, tee'd off the line going to the boost gauge. That would put about 4-5ft of vacuum line between the sensors and the nipple on the throttle body. Do you think moving the clamp and MAP sensor out into the engine bay and putting as little line as possible would alleviate the problem?
messiahx is offline   Reply With Quote
Old 02-15-2010, 07:16 PM   #5
Elite Member
iTrader: (10)
 
Join Date: Oct 2008
Location: Seattle, Wa
Posts: 1,780
Total Cats: 30
Default

I doubt that the map sensor being in the cabin is the problem. All of the MS guys have their map sensor in the same case as the ECU with vac line coming through the firewall. Can you post some screenshots of the AE tables? I've never used the EMB software so I'm not familiar with what settings to change .
Jeff_Ciesielski is offline   Reply With Quote
Old 02-15-2010, 08:08 PM   #6
Senior Member
Thread Starter
iTrader: (2)
 
Join Date: Jun 2007
Location: Shalimar, FL
Posts: 965
Total Cats: 7
Default



I'm not sure the AE map will do much with the ECU wired as is (MAP wired into TPS on the EMB). I would have to wire the MAP sensor into the AFM input and reconnect the TPS. The reason I'm not using the normal MAP input is because it's being used for AFR. But if that'll allow me to resolve this problem, I'll do it ASAP.
messiahx is offline   Reply With Quote
Old 02-16-2010, 09:25 AM   #7
!!! NOT CONFIRMED !!!
 
Join Date: Nov 2007
Location: Virginia Beach, Va
Posts: 158
Total Cats: 1
Default

If you can't resolve the issue your having try these guys, I've gotten alot of infromation off this site all Emanage stuff :

DIYTuning Powered by TeamND - Powered by vBulletin
elderc is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Raleigh: Fiberglass headlight scope, 1.6L ECU, AFM, Hardtop latches, more bigmackloud Miata parts for sale/trade 13 09-22-2017 01:34 PM
Bizarre connection issue? nick470 MEGAsquirt 1 09-30-2015 11:32 PM
Bad head gasket or ? shooterschmidty Engine Performance 8 09-30-2015 11:28 PM
Odd Steering issue interestedofold Suspension, Brakes, Drivetrain 5 09-29-2015 02:42 PM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 03:40 AM.