[bendutro]

I would love to hear from you Megasquirt users what your impressions are of the difference between a stock Qjet/Dual plane and the EFI/single in a real world sense of drivability, not peak to peak dyno numbers.

Love the installations so far, great work!

[Junkyard Dog]

Originally Posted by krisr

Would you please explain your intriguing ignition system? It looks like no distributor and coil on plug, like an LS1?

[Ollie]

Originally Posted by Junkyard Dog

Would you please explain your intriguing ignition system? It looks like no distributor and coil on plug, like an LS1?

You are correct there is no distributor as such, only a cam position sensor to tell MS3X the position of #1 cylinder. Read through this forum. There is a lot of discussion regarding the MegaSquirt set up. Yes the coils are LS1 type. Fired by MegaSquirt.
The cam sensor can be a modified stock distributor to a custom fabricated sensor.
The stock distributor is modified by locking out the mechanical and vacuum advance. Then removing all but one pair of teeth on the reluctor
wheel. To a custom machined cam sensor. I believe Krisr modified a unilite distributor body. He posted the modification on this forum.

Photo 2 is a cam sensor using a Accel duel point distributor.

Photo 3,4,5 are a custom fabricated sensor using a Ford sensor.

This is a link to another post that will interest you.
http://forums.maxperformanceinc.com/...d.php?t=767925

[TheSilverBuick]

Originally Posted by bendutro

I would love to hear from you Megasquirt users what your impressions are of the difference between a stock Qjet/Dual plane and the EFI/single in a real world sense of drivability, not peak to peak dyno numbers.

Love the installations so far, great work!

I've never noticed a difference in drivability. I've ran four cams under this intake and megasquirt, ones pulling 9inHg at idle to 16-17inHg at idle. All of them I got tuned to drive the same. I went sequential injection with the 9inHg cam and could idle the engine down to ~750rpm in 4th gear and roll into the throttle to speed the car up without a hiccup. I have a cam pulling 16inHg in there now and it does the same.

I've ran 3.08, 3.23, 3.42, 3.70 and 3.89 gears behind the manual transmission and I was able to get all of them to drive just fine using the same intake. Including pulling small trailers with the car. With the big block, it was never lacking in torque. With the high vacuum cam it really has a bunch of low end torque.

I've been running a Megasquirt, with this intake, on my Buick engine since 2009.

[krisr]

Originally Posted by Junkyard Dog

Would you please explain your intriguing ignition system? It looks like no distributor and coil on plug, like an LS1?

It's a MS3X system. It's a machined a unilite distributor to take an MSD magnetic pickup because I am a huge fan of VR sensors because of their ruggedness and just modified the shaft so it only has 1 "pole" to provide a cam home signal and use a 36-1 (minus 1) wheel on the crank for engine position.

[BruceWilkie]

Nice Krisr!

Plan on doing something similar to an old iron body Delco points distributor but ground off points cam and mag pickup out of a mopar distributor.(which looks identical to an MSD pickup). I think I'll grind cam till its just a flag now that I've seen yours.

What sensor you running for the crank position?

[TheSilverBuick]

I agree, that is a very nice, and clean, distributor mod!

The only reason I like using hall sensors over VR sensors is because I have more digital inputs than VR wave filters into the MegaSquirt (only two built in VR filters in the MS3/3x). VR sensors though are definitely more rugged. In my Buick's case the TKO-600 has a built in VR speed sensor, so I use the built in cam VR signal filter for that and use a generic digital input for the cam sensor.

Here is the hall sensor set up I used on a modified OHC L6 distributor. Got the hall cam sensor from the junkyard off a mid-90's GM 4-cylinder. Some day I'll make a nicer cap, or maybe go to an internal setup like Krisr's!

[krisr]

The crank angle sensor is a VR from an "EA" series Ford over here. I snagged it off an inline 6 cyl car. This pic is from a LONG time ago but I just made a bracket where the mech fuel pump would normally go but I went to the RARE cover and just welded a bracket on the side instead. Thanks for the comments, I just build it as how I think it should come from the factory

@SilverBuick - Yeah that's fair enough. The sensor I put in my TH400 is a hall so I managed to send that signal to the PT4 input on the MS3X. The autometer sender behaves nicely on a +5V square wave there, just take the usual precautions and twist your wires to help with shielding etc... I've also got a JBPerf IOX in my car too running over CAN, his box has 4 x VR inputs too. I'm mainly using it for 0-5V pressure transducers (transmission line, fuel pressure, oil pressure) and have had no issues there either.

[krisr]

Oh forgot to add, with my distributor mod, the "pole" was simply one of the posts on the main shaft that the advance spring would anchor off. I just put a tack underneath to make sure it doesn't move.

[jonathonar89]

Nice work darbi, krisr, silverbuick, and others! I started this thread a while back and it's amazing to see everyone's various builds on here. You guys that are doing megasquirt make yourselves look like engineers.

My recent issue was contemplating where to put my IAT sensor. The Edelbrock super victor doesn't offer a port for this. I currently have my buddy working on installing it this week on the front side of my manifold plenum. Hopefully it goes well.

[krisr]

IAT sensor is an easy one. Get yourself a plastic LS1 sensor that looks like this;



Drill a hole in the base of your air cleaner, fit rubber grommet, then fit sensor in. It'll get enough airflow to be accurate and won't suffer from heat soak like the brass ones do.

[Ollie]

Purchase an open element sensor and install it in the air cleaner.
Yeah, like that ^^^^
Treed me Krisr

[TheSilverBuick]

This is an old picture when I was thinking of using a Q-jet for a throttle body (ended up going with holley without float bowls), but its the only picture I seem to have showing the IAT sensor. The plastic ones work, not sure where I got that one from. I usually just pocket them from the junkyard =P

[TheSilverBuick]

I went out and snapped a picture of the one on my Skylark.