The MegaSquirt Thread

Re:The MegaSquirt Thread (Knightrous)

Tue, 16 Feb 2016 18:20:57 GMT

fredhoon
Aaron - How much time did you spend on the Dyno tweaking the tune, was it mainly WOT / high load tables that needed adjusting?

Approximately 2 hours on the dyno, this included:
- Fixing a big assed vacuum leak (Idled at 65kpa).
- Re-tuned the idle area to compensate for the lack of vacuum leak
- A quick rebuild of the AFR table (Simplified)
- Removing around 25% of the fuel from the VE tables, then using auto tune to get them dialed into the AFR table settings and then a couple of hand tweaks for a few cells.
- Tweaking the ignition table for more power/torque across the board in the high load sections while staying clear of detonation.
- Finding and fiddling with the boost controller
- Identifying the water to air intercooler was not keeping up after 6500rpm (MAT's rising rapidly)
- Added a MAT correction curve (Pulls timing once MAT's begin to exceed 65'c)

Re:The MegaSquirt Thread (fredhoon)

Tue, 16 Feb 2016 17:25:04 GMT

Knightrous
I recently helped the new owner tune it on a dyno and it has made it a bit more top end power (now makes 191RWKW) and is smoother on power delivery.

Aaron - How much time did you spend on the Dyno tweaking the tune, was it mainly WOT / high load tables that needed adjusting?



Dom - have you looked into the cost of hiring some Dyno time to tune yourself? From what I've seen of the EPA free lessons and read about the place basic tuning of an NA car does not appear to be a complex process, just iterative and time consuming. Personally my main concern would be not allowing enough safety margin while tuning / not being experienced enough to spot potentially fatal trends and responding fast enough (i.e. I keep reading about the importance of good knock detection, but never a definition of "good").

A quick Google reinforces Aaron's point above regarding the need for a Dyno Tune for ignition timing...

HaltechNotice I didn't mention ignition timing. The proper way to work out timing requires a dyno IMO. You can tune to the knock threshold on the road if you have a proper know detection system but it's still not as accurate as using the dyno. Regardless of dyno of road work start with timing figures known to be conservative, work out the fuel, then move to the timing. On the dyno you can advance timing until the power doesn't rise anymore or you find the knock threshold. If power quits rising before the knock threshold there is no need to add more timing and you are probably costing yourself power at that point with further advance. On the street you can't see the reaction between power and timing and can only (hopefully) know if you've reached the knock limit.
http://forums.haltech.com/viewtopic.php?t=1741

Re:The MegaSquirt Thread (Knightrous)

Tue, 16 Feb 2016 08:59:06 GMT

Domma_aw11
saying that, if u remember ken matsuda tuned his 4agte with out a dyno...

It ran pretty rough too.
I recently helped the new owner tune it on a dyno and it has made it a bit more top end power (now makes 191RWKW) and is smoother on power delivery. We were also able to identify the limitation of the intercooler setup and spot some areas in the torque curve that were able to be improved with timing changes.

Ken can chime in with his perspective on the car before and after the tuning since he drove it at the MTC2016.

Re:The MegaSquirt Thread (Domma_aw11)

Tue, 16 Feb 2016 06:39:47 GMT

not sure, I know they do some specials, there was $99 for the fundamentals of EFI and they threw in a couple more things, and forum access for a year.... just waiting for that to come back.. I signed up to 6 free lesson, all on different things, but still vague...

I have thought about what u said many times, but I dare say, the load in 4th gear at 7000rpm might be different than say 1st or second gear.. but its also been able to hold load points in certain rev ranges and realy needing the dyno to see the torque curve..

saying that, if u remember ken matsuda tuned his 4agte with out a dyno...

Re:The MegaSquirt Thread (fredhoon)

Mon, 15 Feb 2016 23:56:14 GMT

Can the cost of the HPA lessons be split - i.e. are they pre-recorded or online classroom style?

What's the engine load difference of road vs. dyno runs? Given a safe and/or discreet location, could it be tuned on the fly from the passenger seat with low gear pulls?

Re:The MegaSquirt Thread (Domma_aw11)

Mon, 15 Feb 2016 21:51:56 GMT

ive been waiting for the specials to come up for HPA, but on apprenticeship wages, things are tighter than ever and the same old chest nut, no tuner to touch the MS which means il have to learn the wiring so I can wire in one that someone can actually tune, the engine has power to make and no one to unleash it...

Re:The MegaSquirt Thread (Knightrous)

Sun, 14 Feb 2016 01:52:55 GMT

Domma_aw11
I cant believe I forgot out the AE92, my mate had that setup in his with a BT20v.. not bad idea.. the reason im more for road tuning is still cant find a dyno tuner, so trying to see stock afr maps and what kind of stock spark maps are out there to give me a reference. because on the stock ecu my car went bloody HARD!!!

Road tuning is fine for dialing in your fuel tables, but it's impossible to do ignition tuning. You need to get it on a dyno and have a look at the torque at each timing setting.

I highly recommend that you sign up to HPA and watch this webinar.
https://www.hpacademy.com/previous-webinars/055-optimising-ignition-timing-mbt-timing-haltech/
It will give you some really good insight on the subject while giving you a live demo (350Z).

Re:The MegaSquirt Thread (Domma_aw11)

Sat, 13 Feb 2016 07:33:12 GMT

I cant believe I forgot out the AE92, my mate had that setup in his with a BT20v.. not bad idea.. the reason im more for road tuning is still cant find a dyno tuner, so trying to see stock afr maps and what kind of stock spark maps are out there to give me a reference. because on the stock ecu my car went bloody HARD!!!

Re:The MegaSquirt Thread (Knightrous)

Fri, 12 Feb 2016 10:32:44 GMT

Had a novel written up as a reply, but my web browser crashed, so here's the cliff notes version.

Domma_aw11
I remember you say something like this to me, and me not having a goddam clue, cayne was also telling me the same thing, I cnt go longer runners as il have to run them in the boot...

Get creative.

Seen a 20V AE92 with a 180 bend in the runner and the velocity stacks sat above the head. I think the runner was around 500mm in length.

Domma_aw11
but also, can I use det cans or is there no point?

They are good for tuning, but useless for street driving. In my opinion, easier to do a good tune on the dyno with some safety in it. Additionally you could always add something like a knock lite if your concerned.

Domma_aw11
and when we did that dyno run day, were u on the MS or the stock ecu? could u post that dyno chart up?

Stock ECU.

Re:The MegaSquirt Thread (Domma_aw11)

Fri, 12 Feb 2016 07:06:58 GMT

I remember you say something like this to me, and me not having a goddam clue, cayne was also telling me the same thing, I cnt go longer runners as il have to run them in the boot...

but also, can I use det cans or is there no point?

and when we did that dyno run day, were u on the MS or the stock ecu? could u post that dyno chart up?

Re:The MegaSquirt Thread (Knightrous)

Thu, 11 Feb 2016 08:59:09 GMT

Domma_aw11
oh, a lot of people told me 36deg was to high, mines down to 32deg, but its gone slower, but then I need to tweak my AFRS, but also, my car doent like making power over 7k... so ive been pondering shorter stack, from the head to the end of the stack is over 300mm

Each motor is different, some might fine 30-32 is the upper limit, others might take 36-38+. The only way you will know the best value is to get it onto a dyno and look at the Max Brake Torque (MBT).

I'm a little rusty on runner length calculations at the moment, but last time I was looking at 4AGE's the maths was showing a longer intake was needed. Tuning for a peak of 8000rpm and 285 duration cams, you needed a ~780mm runner (Valve to Bellmouth) to catch the 2nd order wave. A ~310mm runner will allow you to catch the 5th (3 orders weaker then the 2nd).

This is all just maths and theory, when applied to a car, you can get a different result due to a whole range of variables the maths cannot tell you. The best way is to make up a variable length slide runner to adjust while it's on the dyno and see what length produces the best results.

Re:The MegaSquirt Thread (Domma_aw11)

Thu, 11 Feb 2016 07:06:42 GMT

oh, a lot of people told me 36deg was to high, mines down to 32deg, but its gone slower, but then I need to tweak my AFRS, but also, my car doent like making power over 7k... so ive been pondering shorter stack, from the head to the end of the stack is over 300mm

Re:The MegaSquirt Thread (Knightrous)

Mon, 08 Feb 2016 00:29:02 GMT

Looking at the logs, it doesn't look like there are any major issues. The AFR's are reasonable, the fuel looks fine and there are no errors popping up. You have a few minor things like the TPS not being calibrated (showing 103.7% at WOT).

You could do with a little more timing from 3800 RPM on wards.
I found with my old 16V and 20V, both motors liked 36 degrees of timing for a large portion of the table in WOT.
Some similar chatter across the interwebz, but each motor is different.

I would set it to something similar to this. (You can ignore my OCD adjustments of the table rows values...)

See how it performs with the addition top end timing and see what the butt cheek dyno says.
However, ideally to find out where the motor can gain or lose, you need to get it on a dyno.

Re:The MegaSquirt Thread (xtimmyx)

Sun, 07 Feb 2016 22:20:47 GMT

Hi guys,
That tune is fairly old. I found a straightish piece of road earlier and did a few runs. It wasn't entirely but hopefully that shouldn't skew the logs too much. I've also attached my current tune in the zip file.
https://drive.google.com/file/d/0B4cSFMGRzbLtUzRYczlKd21USU0/view?usp=sharing
Log 1: Two pulls in 2nd gear, slight downhill in the first pull and slight uphill in the second
Log 2: Same route as Log 1 but in 3rd gear
Log 3: 2nd gear, slight uphill

Thanks a bunch!

Re:The MegaSquirt Thread (Knightrous)

Sun, 07 Feb 2016 16:52:35 GMT

Domma_aw11
would mine help him out?

Difference in compression and cams would probably make it easier to just run some TunerStudio generated maps.