My (fairly new-to-me) megasquirted '74 2L is running warm on the highway, and I suspect an overly aggressive ignition map might be to blame. As well, it's got some spots in the fuelling that are still rough around the edges, and I don't think I've got the patience to do anything but DRIVE the damned thing (who wants to fiddle around with the laptop when I could be enjoying the car?).

As a result, I think I'd like to buy some dyno time with a tuner that's familiar with both the type IV and the MegaSquirt... does anyone have any recommendations?

For reference, I'm tuned for ~14.5 at cruise and about 36 degrees of advance at 3100 RPM cruise on the highway. I'm seeing head temps settling around 360 with up to 385 on long uphill sections, and oil temps of about 230. Around town temps hang out at about 345 and 225.

Thanks in advance for the advice! This forum is a really great resource.

Are you running a MAP sensor? it sounds like you might be lean under load.

I took my MS to a dyno here. Cost me $200 for the day plus they let me use their wideband O2 to help.

Yeah, it's running in speed-density mode (MAP sensor) with a TPS. I've got a wideband installed (in the tailpipe - not optimal, but okay), but I turned off auto-tune mode as it was making the system do weird things.

I know some really good tuners in the area that do MS tuning, but the TIV seems to be a wholly different beast. I'd prefer a tuner who's at least used to tuning air-cooled engines!

hey, would be at all interested in sharing some 914 megasquirt info?
http://914megasquirt.ning.com/

pm me if you are interested.

I can give you my MSQ file for MS2 3.0 with 2.88 code. It runs, but could always be better.

I live in wodstock am I still trying to get my Megasquirt to run on my test
engine, boy am I finding problems.
Lets have a get together and share knowledge.

I'm a huge proponent of crank triggering for MegaSquirt. Getting the signal from the coil is yucky.

That may be, but you're also selling something, and my car runs quite well otherwise. More to the point, do you know of any Atlanta-area tuners that are familiar with the MS and the type 4?

I agree 100% with you on this, if you are running timing to. With fuel only it works fine.

for fuel only, you can get away with coil triggering because any fluctuations aren't nearly as pronounced as they are for ignition.


Once you're around here awhile, you'll understand that I'm not interested in selling anything you don't need. I was completely blown away with how much the signal improved when I switched from coil triggering to a VR sensor.

If you're car runs great without it, I'm just as happy. Your skepticism is healthy. Just keep in mind that coil triggering CAN cause erratic triggering signals, which can lead to mistimed spark events and improper fuel metering, especially at low RPM and idle.

No sh*t. Mine was so erratic, it took the teeth right off the flywheel. Went back to just fuel, and flip the key and pretty much go. I'm currently selling of a bunch o crap to help fund my 2056 build, that will have EIDS on it.

I'm running Megasquirt with a 36-1 tooth wheel, but I'm using a Hall efect
sensor (no VR sensor) and the timing works great using wasted spark mode.
No EDIS required to run this, less parts to worry about.

Agreed, but, with the eids system, no more Dizzy problems, no more cap and rotor. Actually less parts to worry about. A tooth wheel would for sure be better than the hall efect on the dizzy though. Since cranking speed of the wheel would be somewhere in the 250-350 rpm range, not reduced by half, i'd think you would get a much cleaner signal.

On the wasted spark system the only parts required are a 36-1 tooth wheel on the
crank, a Hall efect pick up to the Megasquirt and coils. Timing is adjusted in
Megasquirt timing table. Thats it. My dizzy used for cylinder location only which
is going to be used for twin plugs with the second set of plugs also control by Megasquirt.

Okay, well, if you think that mistimed spark events could be common enough at 3000-3500 RPM to cause no loss in power but slow heat buildup, I'll take that under consideration. Basically, I'm looking for someone to take the rough edges off my fuelling map and validate my timing. I'm especially not interested in pulling the engine to install a crank sensor. When I pull the engine, it's going to get replaced with a Suby. Thanks for the concern, though.

So... does anyone know of any tuners in or near Atlanta that will work with the MS? Apparently Jack Raby is in the area, but only works with SDS?

Thats all the eids system is. Just a coil pack.

Just as an observation you can take McMark at his word, he's 100 percent. He's also posted before about the problem of poor distributor ignition signals as a "for your information" offering to the Megasquirt inclined. Sharing his good experience with no strings attached.

I think you'll find most of the vendors around here (almost all) aren't hustling anything, they're mostly just advanced hobbists who are happy to help others. This group tends to heal itself, rejecting nasty foreign objects that would cause things to get infected and fester.

He's using COPs in wasted spark mode, no distributor.

Should be no trouble finding someone in Atlanta to help. You do know that Diyautotune is in Sawanee up by the Mall of Georgia. They are Megasquirt.
www.diyautotune.com

Bob

Type 4 like to run about 13:1 to stay cool at those rpm's

Is there a good repository of information like this? Just general guidelines for an otherwise stock application? My searches haven't turned up anything.

try this link

http://914megasquirt.ning.com/

I'm no fan of MS, but I'd be happy to assist you in tuning on my chassis dyno. Just up the road 80 miles or so and I am familiar with TIV tuning :-)

yes but don't expect miracles just yet as i'm in the same boat as you. :-)

but do share your experience on jakes dyno.

I think in your first post you said you were running 32 deg advance at 3500RPM I think that is your running hot problem. Listen to 904SVO, he's had his MS on a test stand for about a year and has a vast Knowledge of electronics. I agree with 904SVO lets get an Atlanta group together and learn about MS and other 914 issues, AL

Wow! I might just take you up on that, Jake. I'll give you a call tomorrow to talk rates and schedule. Luckily, I'm gonna have some time off in between jobs here soon...



Understatement of the year? I bet this record stands for a while.

I'm a member of Freeside ATL, a local hackerspace. That'd be a perfect place to host a meetup and we can all fix my ca- er, I mean, talk 914s!

I'll post another thread about that.

way to far advanced the T4 should only have a max of 26*-28 (stock, MAX adavance on the dizzy)at 3600 IIRC.

actually, with that ign. advance and the AFR, those arent "bad" head temps.

before you take it to the dyno, maybe try taking out 5* of timing first and see how it works. You may find that the other areas of concern get better also.

I agree.. Over-advancing is pretty easy to do, especially when tuners have experience with other engines.

If an engine wants more than 30 degrees of timing to be optimized the engine design is FUBAR or the engine is way too rich.

Call and set up a time with Dean, we should have chassis dyno time available in two weeks.

While I agree with both of you, 36 is too much, it also would depend on if we are talking timing with a timing light or what the MS has programmed in to it. The base timing of the MS could be off. That being said I run more timing at WFO at 5K, but I really don't care if my motor goes. I like explosions.

Cool - I've got an appointment with Dean @ Raby's shop set up. I'm still going to tweak the map so I know it's safe for the drive up there (holy crap is it far out of town!), so feel free to keep the tips coming. Sounds like I need to back the cruise and power timing out quite a bit. I haven't hit it with a light yet, but the PO wasn't a total 'tard so it's probably close enough for my work.

.
We'll see you then.


Have the engine tuned as well as possible.
Have all engine issues worked out, to include oil leaks and fuel leaks. We don't test engines with leaks as they are a fire hazard. To best use your time on the dyno have the tuning done as far as possible and ensure the engine and tranny are healthy and won't cost time and money.


Yep, on purpose.. We function in our own world where it is quiet and we don't get bothered.
I took these pictures out my office window yesterday morning...
Click to view attachment
Click to view attachment





You'll see what works and what doesn't work when tuning for power and efficiency on my dyno. Most engines leave my dyno with 20HP more than they came here with, hopefully you'll be another one of those.

Jake, are on lookers allowed to watch?

NO.

Tuning is serious work that requires total concentration. We'll be having a Dyno Day and all aircooled VW and Porsche show here in the fall for entertainment. Other than that these gates stay closed tight!

(They'll be closed tighter as soon as the damn weather allows us to finish the electric gates and keyed entry points)

Man, that was great! Jake let me invite all my friends, and I brought a keg in the passenger seat, and everyone watched as Jake tuned my car to 400 horsepower!



No, really, got back not too long ago from Jake's shop. I've gotta say it was worth the (very, very long) drive. 78 horsepower from my tired-ass 2L and a Megasquirt is acceptable! Jake was super-friendly, showed me around the shop, and gave me more than I paid for just in advice alone! He and I probably left a good bit of power on the table, but my goals are reliability, reliability, reliability, so a fairly flat timing map and tuning targetted for the 13s means my car is now smoother than it was before!

Thanks again, Jake.

Glad to see the car is better than it was when you drove it up..
I have to say, your tuning ability is better than most, other than a few dips in the AFR and some spikes the table was well tuned! I was impressed.

BTW- Here is a 500HP Beetle on my chassis dyno

http://www.youtube.com/watch?v=EgwnJsCaHtw

Did the tuning help with the head temps? Also, what are the AFR's we should be shooting for at WOT and cruise?

I ask because I am dealing with a similar issue where my head temps go way to high when cruising on the freeway. I don't have problems in stop and go traffic or even autocrossing, just freeway cruising.

I read somewhere that stock d-jet sets cruise to 13.7:1, i think i have my megasquirt at 13.5 when cruising. Should I be richer ~13:1?

Thanks
-James

If you are using a FI cam, you may have to rebuild the Fuel VE table, AFR table
and Spark table. They all use the MAP reading at Idle to calculate the information.
The FI cam has a LOW reading of 60 bars at idle, if you check your tables you might see it start at 20 bars if so try changing your table to show the correct MAP
reading.

James,

Based on my discussions with Jake, my temps are basically normal. I see 360-385 on the highway with slow rises to 390 on long uphills. I'm now tuned for low 13s and about 27 degrees advance and it didn't make a huge difference on the drive home, just much smoother power and less "spikeyness" in temps. I also kept a close eye on oil temps, and they never rose above 225... so basically I just don't do top-speed runs?

I'm not quite sure why that'd be the case - can you elaborate? We got good and consistent results with VEs that basically make sense for a 40-year-old design. Don't be afraid to get technical, I can handle it.

The tables are 12X12 or 8x8. If you don't use the correct MPA value you reduce
the size of the table to 6x6 or 4x4 for example, so you can't fine tune the engine
for the best values over the tuning range.

If I understand you correctly, you're talking about scaling the VE table MAP values across [idle pressure, atmospheric] instead of the more typical [zero pressure, atmospheric]. I can certainly see the resolution benefits, but that totally ignores overrun, and is entirely a matter of taste.

You must set the values in Megasquirt for your engine!!!! If the VE fuel table is wrong every thing else is wrong this includes the other tables that use the MAP
signature.

Call me.