LocostUSA.com

The problem comes later, when the parts, tools, and knowledge are needed to tune the carb. A full set of jets and venturis gets expensive and at that point, the EFI approach starts looking better, especially for idle and light-load conditions. The best you can hope for is either getting the jet sizes from someone who has successfully tuned the same engine in the same setup, or just take the whole mess to a hotrod shop and have them do it. However, once outsiders are involved, the price shoots up so fast that it may be cheaper to have used EFI in the first place. (I was at VW Paradise in San Marcos some time back and they had two used sidedraft Weber carbs for sale - but at around $1100, they cost about what an aftermarket EFI box does.)

That said, I will admit that from my book, "there's something to be said for connecting exactly two wires to the engine - ignition and starter - and being able to start it!" That assumes of course that the jetting is somewhere near correct, and that isn't always a slam dunk.

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Midlana book: Build this mid-engine Locost!, http://midlana.com/stuff/book/
Kimini book: Designing mid-engine cars using FWD drivetrains
Both available from https://www.lulu.com/

True....True. But (theoretically) once tuned, I can run my car in Daytona Beach or on Pike' Peak and don't have to re-tune anything. Aftermarket ECU's, especially the Megaquirt, takes a bit of learning. Even if you try to use the donor's ECU, it will most likely need to be "tweaked" to get by immobilizers and misc sensors that need to be tricked, let alone optimizing the tune for a new weight vehicle. There is learning there too. Or you can pay someone else to do it all for you. Where is the fun in that I ask?

So a carb and dizzy is both simple and enticing. It is just not that simple to retrofit on a late model cars where there is no place for a dizzy. They have crank and cam sensors (if your engine has a cam that is ) However, disty's are not trouble free. In my MGA I carried points, rotors, condensors, plugs disty cap, etc. And I have changed them all on the side of the road at one time or another. I never had to call for a tow. I would not be so lucky when something goes wonky with the Megasquirt or my antiquated coil packs from the RX7.

I had thought about DCOE Webers and DHLA Dellortos over the years. There is something so "classic" about them. However, the cost of trial and error for tuning, by the time you talk about venturies, jets, emulsifiers etc each multiplied x 4, just to ttry to get something "close enough" steered me away. With EFI, I can change my tune in the comfort of the driver's seat with my laptop and not even get my hands dirty. That is when things are working right.

At my very core, I hate having to redo something that has already been done before. But afterwards, I do enjoy having solved the problems.

Lonnie, Whichever method you decide to go with for fuel and spark, there are guys here that will help out.

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Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766

I like my twin SUs.

In the Miata world, no one leaves their engine stock and so aftermarket ECUs are common. You would think by now that tuning a Miata would be a breeze, with every possible map well known and easily programmed. But no. Tuning never stops.

My gf's supercharged Miata has been in tuning hell for over two years. Many Miata owners--and we know quite a few--claim to have a well-tuned engine with a steady idle and a smooth torque curve, but they still keep fiddling with it.

Car manufactureres obviously have dozens of engineers spending thousands of hours to perfect their stock ECUs, so it makes sense that individuals using an aftermarket unit are going to struggle a bit even to get close.

Me too. Nothing like a set of SU's and a simple point-driven ignition system. I always joked that, come the nukes and their EMP, My MGA will be one of the few cars still running. When I had SU's on my MGA's, I set them and forget them. But then they are a known entity running a known vehicle and engine so the "tune" is a given in the books. Not much to adjust with SU's, Float level (1 time), throttle balance (1 time) and jet depth (1 time). As I recall, that is about it. Then just let them be for the next 5 to 10 years. My experience with SU's is that 9 out of 10 SU problems can be traced back to ignition problems. Back in the day, few of us 'Mericans understood how SU's worked, (aka: Seldom Understood) they got a bad rap. usually because they got "adjusted".

ECU's are certainly a mixed bowl of nuts. If you give someone something to adjust, they will adjust it wrong, no matter if they understand it or not. I'm guilty of compulsive adjustment too. When the tuner recognizes that something is wrong, they adjust it (wrong) again. The cycle never ends. It is so easy to change and it costs nothing but time. I've seen the same symptoms throughout my career in electronics.

Back on subject, one of my favorite quotes from Colin Chapman : It is obvious that he never had to deal with a Megasquirt and a laptop!

_________________
Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766

It hurts to admit this since its against everything I should stand for but I'm really liking SU carbs. I really shouldn't since they're not electrical or complicated or modern or over engineered and they need oil in places cars shouldn't but they're so awesomely simple.

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-Andrew
Build Log
Youtube

I was fooled one more. This is getting to be a habit; and not a fun one at that! The newly sparking plug was ruse. Once the idle got back down to <1000 RPM, the sparking dropped out. So I've been communicating with the firmware writer and sent him my MSQ file and a log file. He could not find anything wrong. He set up his system-on-a-bench with my MSQ and had no problems. Back and forth trading videos and scope snapshots. I checked the signals with a scope and they appeared to be good. I tried a few things today and finally got working again. I'm not sure exactly why..... but if I set my ignition advance at idle up to 3 deg advanced, from 0 deg advanced, everything works just fine. I'm going to accept that and just move forward (again).

_________________
Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766

Yo Chuck-
I want to thank you for simplifying my decision about whether I want Mega-Squirt or not... Your story this last few weeks has made that stock Ford PCM in the Slotus look really good.

Good luck with your continuing adventure!

JDK

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JD, father of Quinn, Son of a... Build Log
Quinn the Slotus:Ford 302 Powered, Mallock-Inspired, Tube Frame, Hillclimb Special
"Gonzo and friends: Last night must have been quite a night. Camelot moments, mechanical marvels, Rustoleum launches, flying squirrels, fru-fru tea cuppers, V8 envy, Ensure catch cans -- and it wasn't even a full moon." -- SeattleTom

JD, Certainly, the easy way is to use the Ford ECU. But where is the fun in that? I ask.

I just heard from the MS firmware guru. He has now been able to replicate my situation exactly on his test bench. It is good to know that my system is not acting weird. He knows why it is happening and has a proposed fix and will be testing it iver the next few days. That will be too late for me and The Gathering, but that is fine. What other aftermarket ECU company would be investigating software problems with only 1 person having a particular problem? I've got to hand it to these MS boys.

I went into this project with the express intention of learning about car building, rotary engines, ECU's and testing my perseverance. And I am still learning and testing. At least I'm not redesigning differential mounts, making new axles and replacing engines (yet). And my hands are still clean.

All in good fun. Come on JD. Jump into the Megasquirt Family. The water is fine (Cough....Cough):cheers:

_________________
Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766

Shouldn't that be Coo-laid?

In all seriousness the MS isn't that difficult if you're willing to sort through the manuals and spend a good amount of time researching what you need before firing up the soldering iron. In Chuck's defense, he is doing an engine that is sort of an odd-ball and it seems like some of the typical stuff just doesn't really apply to rotaries.

Heck there are engines like the LS that the MS3x is basically intended for. 8 sequential coil channels - check. 8 sequential injector channels - check.

I think it really comes down to what you're Megasquirting and how much time you're willing/able to spent. I spent hours researching before building mine and once I got the potentiometers for the crank and cam sensors set and figured out my crank trigger was 180 degrees out it fired right up - not much to it.

Its sort of like buying a built Caterham or building a Locost. One takes money, one takes time.

_________________
-Andrew
Build Log
Youtube

Forgive me Locosters, for I have sinned. It has been many months since my last update.

Not much to report. It took a few months to get new springs for the rear GAZ shocks. Then......once they were received, I was too lazy to do anything with them. So they sat in the driver's seat in the garage. That is until earlier this last weekend. I pulled the old ones out and replaced them. I went from 200# to 250# springs. I was finding some road conditions had the tires hitting the inside top of the rear fenders. Hopefully this will help to minimize the situation. I won't know until Spring! Blah! 0.0 degrees this AM when I woke up, on its way all the way up to 12. Tomorrow's high is forecasted to be -2degF. I hate Winter!

I will accept my penance of 5 Hail Colin's and will try to do better in the future.

I have made the beginnings of getting a semi-respectable tow vehicle. I might just give up the iron butt award attempts and tow the Locost to future Gatherings. I picked up a 2000 GMC Jimmy 2WD last Sept with 90,000 miles. The last few months I have been getting it into shape. Full head rebuild, Plugs, wires, rotor, disty cap, fuel pump, fuel regulator, fuel filter, tires, door hinges, etc. It is coming along, but still tracing down a slow coolant leak. I found a loose hose clamp this AM at the water pump. Hopefully that will take care of it. If not, it is a 6-8 hr job to replace the heater core, which I think may also be a problem. In the Spring, when I can get into the salvage yards without freezing, I'll get the interior pieces I will need to get it up to snuff. Then a good receiver hitch.

_________________
Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766

What are your plans for a trailer?

_________________
-Andrew
Build Log
Youtube

Beg, borrow, steal, rent, in that order. I have no interest in storing a 2nd trailer for 12 months out of the year or paying the added license fees. I already have a 4x8 foldup trailer that is good for ~1300#. Not quite good enough for the locost. I could rebuild / reinforce it, add brakes and still be able to use it for runs to the big box store or ????? Maybe I should just sell it and just buy/build a new one to take its place.......... decisions - decisions - decisions.

I found this site that lists max weight by state for trailers without brakes: http://www.towshop.com/trailer_supplemental_braking_laws.htmI could get away with no brakes but would feel better about having them if I build......

_________________
Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766

Chuck
If you do not want to store a trailer, how about flat towing your Seven. I recall a Locoster flat towing his car from Ontario all the way to Florida for several years, as a snow bird.
You could fab a custom tow bar in no time.
Dave W

Now that is an idea that I had forgotten about. I'll have to check if the RX7 trans can be flat towed or if I have to disconnect the driveshaft. Thanks for reminding me of that option.

BTW, are planning on going to the Gathering?

_________________
Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766

OK for you fellow Locoster's, I have searched the web and found several interesting web-facts. Which means take this all with a bit of skepticism.

Some have flat towed the RX7 and Miata for long distances with no issues. Tough to beat real world experience

The RX7 is not recommended for flat (aka 4-down) towing. I believe this is because the RX7 transmission is splash lubricated as well as the 1st gen Miata (I don't know about other MX-5's). The lay gear is the one the sits lowest in the trans and is submerged in oil. If it is not turning, there is no splash lubrication. However, looking at the FSM, if the trans is full, the output shaft may possibly contact the oil and provide some minimal amount of lubrication. If it was on a tow dolly, the car's angle would move the fluid to the rear of the trans and the output shaft would be deeper in the oil, providing more assurance of lube occurring. But without the gears turning, I think it would not get the oil everywhere it needs to be.

Alternatives are: 1) take my chances and just hookup and tow, 2)disconnect the driveshaft from the diff for either flat or dolly towing. 3) install an aftermarket lubricating pump. 4) tow on a dolly backwards.

Since I have already run ~50 miles with this trans and NO oil, I am pushing my luck already. I don't want to take further chances that the oil will get where it needs. And I don't want to add an external trans lubricating pump. That leaves me with options 2); 4) or just get a real trailer. Disconnecting the driveshaft wouldn't be that much work as I already have access from above. The other option is to just take my chances on the weather and drive the Locost like I have to 3 other Gatherings.

Choices, Choices, Choices!

_________________
Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766