Miata Turbo Forum - Boost cars, acquire cats.

Miata Turbo Forum - Boost cars, acquire cats. (https://www.miataturbo.net/)
-   MEGAsquirt (https://www.miataturbo.net/megasquirt-18/)
-   -   HELP! Blew engine, and am now paranoid. Need help/opinions. (https://www.miataturbo.net/megasquirt-18/help-blew-engine-am-now-paranoid-need-help-opinions-73338/)

nitrodann 06-13-2013 11:43 PM

No one has told him how to avoid it next time.
You need to actually watch an air fuel gauge as you tune it to ensure that the ecu is doing what you think it is.
Dann
Dann

Fireindc 06-14-2013 12:01 AM

I'm going to have to compare my timing map now, you guys got me paranoid. I just took the 99mspnp base timing map, took 2 degrees out of the entire thing, and ran it on 91 octane. I also live at elevation which is a det deterrent of its own, i made sure the (real) opg didn't fluctuate at the slightest, i didn't hear knock, and my afrs are excellent.

triple88a 06-14-2013 12:02 AM


Originally Posted by nitrodann (Post 1021674)
No one has told him how to avoid it next time.
You need to actually watch an air fuel gauge as you tune it to ensure that the ecu is doing what you think it is.
Dann
Dann

Set the overboost cut at what u want, then watch the gauge. Disconnect the wastegate flapper and start tunning that way. then ensure the map keeps flowing... you gotta get that shit close enough before you use auto tunner and keep ur eyes glued to the afr gauge.

27 degrees at 8psi is quite a bit.

Enginerd 06-14-2013 12:29 AM

You can feel out the fuel table before getting anywhere close to dangerous levels also. First tune should be very gradual and meticulous. If you see VEAL adding fuel down low, grab the whole table and bump up the cells a few points before tuning the next row up. As you found out, it's much safer to be more than a tad rich than to be more than a tad lean.

aaronc7 06-14-2013 12:45 AM

Stick? How to: blow up your engine??

richyvrlimited 06-14-2013 04:04 AM


Originally Posted by nitrodann (Post 1021674)
No one has told him how to avoid it next time.
You need to actually watch an air fuel gauge as you tune it to ensure that the ecu is doing what you think it is.
Dann
Dann

+1

And take logs and review them after every run, as great as VE analyse live is, you shouldn't trust it, all sorts of things can make it spew out incorrect adjustments.

Even better, get someone else to either drive, or watch the laptop - also have them listening with detcans - if the AFR's get too out of line, or det occurs that person can signal to back off the throttle.

jrmotorsports55 06-14-2013 06:36 AM

Thanks for the input, I'm definitely thinking this should have been a two person job while road tuning.

Jason

miata2fast 06-14-2013 07:33 AM

Do you guys not verify your timing??

jrmotorsports55 06-14-2013 07:35 AM

Base timing? Yes, was verified.

Jason

Braineack 06-14-2013 08:08 AM

I dont like when people ramp up timing near redline like that, especially when you've actually tuned your timing latency. I realize that additional rpms naturally add in knock threshold, but I still dont like the practice, especially on stock cams where the power is going to drop off regardless.

at 8psi, you were barely adding any ignition retard over the stock tables...which would be be around 27° or so.

nitrodann 06-14-2013 09:13 AM

But the injectors can handle 8psi.

Enginerd 06-14-2013 09:15 AM


Originally Posted by jrmotorsports55 (Post 1021715)
Thanks for the input, I'm definitely thinking this should have been a two person job while road tuning.

Jason

Meh, it's better as a one person job in my opinion if you're just using TS VEAL. At the very least, the driver must be able to safely and continuously monitor the boost and vac gauges. For me, street tuning, I don't feel safe glancing back and forth at my laptop in the passenger seat, so I have the boost and afr gauges on the A-pillar. I know if there is an issue instantly, and don't need to wait for my passenger to tell me to back off the gas.

triple88a 06-14-2013 09:27 AM


Originally Posted by nitrodann (Post 1021733)
But the injectors can handle 8psi.

Oh god here we go. :facepalm:

jrmotorsports55 06-14-2013 10:06 AM

I have afr and boost gauges in my pillar as well, and don't remember seeing issues. Guess I wasn't looking enough.

I'm going to figure out what size injectors to get, and work on putting together a revised timing map and mod my afr targets based on the feedback in this thread. I'll post what I come up with.

Thanks,

Jason

NiklasFalk 06-14-2013 10:17 AM

Ehm, wrong place to mention suggestions of course, but it would be helpful to noobs if VEAL could warn for injector duty cycle over a threshold.
Since VEAL is seductively easy to use, the temptation to get going (before having everything under control) is hard to resist.

Duty cycle is not only Req Fuel and VE table (and you have to know that you should do math to check if you're in trouble) so it would help to get a fast clue of an unsuitable setup (TS: "I can't reach AFR target regardless of how much I increase Duty Cycle. Stop trying you MORON!").

TS knows you are trying to do dumb things, why not let the noob know/learn?

If the function is there, it only shows how much I know (and that it's too well hidden)...
Changing to RX8 yellows this weekend :noob:

Enginerd 06-14-2013 11:17 AM

You can add one to your dashboard if you so incline.

TS, like most software, is a tool. The user is responsible for how that tool is used.

bcrx7 06-14-2013 02:27 PM

I just want to add something to this as well. Remember that the stock injectors are old in any given car and might not be in tip top condition. I have seen some to be even 10-20% difference in flow. That means possible cylinders that are leaner than you think they are and since the O2 picks up an average of all 4, it doesn't exactly show what happens.
At the least if someone is planning to use stock injectors, I would take them out and have them flow tested/cleaned!

Laur3ns 06-14-2013 02:51 PM

How come you have no logs but were still tuning?
27* is way over what Im running FWIW.

jrmotorsports55 06-14-2013 02:51 PM

I agree, and admit it's not something I thought about. My injectors have 155k on them, probably didn't help my cause.

Thanks,

Jason

triple88a 06-14-2013 02:54 PM

Are you still running stock injectors?

STOCK INJECTORS CANNOT SUPPORT MORE THAN 6PSI.


All times are GMT -4. The time now is 02:04 AM.


© 2024 MH Sub I, LLC dba Internet Brands