Where can we see/hear the Decoupe motor ?
Survey Thread - Carbs or Megasquirt
- Thread starter bwalvoord
- Start date
decoupe
(deceased)
Clarification post
Whoa there guys - I don't have S38 ITB's (yet) on my engine. Never said that. Slowly working in that direction but right now it's the "squid" as I call the b35 intake manifold on mine.
Here's a link to a 535i (so its an m30 engine) with S38 intakes http://www.youtube.com/watch?v=DOuHMEw0Afo with the intakes at about 28 secs. Not crazy about the exhaust.
I put forward (after Kasbatts mentioned ITB's) using the S38 intake as the perfect FI solution to triple webers. If you want to hear them, find an m5 (pre 1992), take off the air box and dream.
Sorry to dash your (and my) hopes. Give me a couple more years.
Doug
Whoa there guys - I don't have S38 ITB's (yet) on my engine. Never said that. Slowly working in that direction but right now it's the "squid" as I call the b35 intake manifold on mine.
Here's a link to a 535i (so its an m30 engine) with S38 intakes http://www.youtube.com/watch?v=DOuHMEw0Afo with the intakes at about 28 secs. Not crazy about the exhaust.
I put forward (after Kasbatts mentioned ITB's) using the S38 intake as the perfect FI solution to triple webers. If you want to hear them, find an m5 (pre 1992), take off the air box and dream.
Sorry to dash your (and my) hopes. Give me a couple more years.
Doug
Interesting. The main developer of MS is based in the UK. I have been running it for 5 yrs now with no major problems. I have been keeping up with the latest test codes, so occasionally I run into bugs, which are fixed fairly quickly by the developers. The biggest issue is probably operator error in programming all the features correctly. Like any programmable system it has a learning curve. I have made my share of mistakes. Today it runs strong and reliably - but I am always tweaking things in that goal towards a perfect driving experience - and having fun along the way.
decoupe
(deceased)
Like Sven, I've been running with a programable engine management system - SDS (Simple Digital Systems) in my case.
It is a much less sophisticated product but for our m30 based engines works well, is very easy to set up and program and is very robust (the Israeli military use it on their prop driven drones).
The great thing about these programable engine management systems is the ease of getting the engine up and running well after any modifications whether it is a new cam, different head or in my case switching from b34 L Jet log intake to b35 intake and driving away after setting idle and switching to closed loop. How long after switching from zeniths to triple webers do you think that would take?
Now if I could stop fiddling with it I could concentrate on the scenery.
It is a much less sophisticated product but for our m30 based engines works well, is very easy to set up and program and is very robust (the Israeli military use it on their prop driven drones).
The great thing about these programable engine management systems is the ease of getting the engine up and running well after any modifications whether it is a new cam, different head or in my case switching from b34 L Jet log intake to b35 intake and driving away after setting idle and switching to closed loop. How long after switching from zeniths to triple webers do you think that would take?
Now if I could stop fiddling with it I could concentrate on the scenery.
I agree with Sven on this- only problems I have encountered have been not understanding how to do initial set ups. That was taken care of when they introduced the PNP
(Plug and Play) version. Only thing left to do is to finesse the map numbers now.
(Plug and Play) version. Only thing left to do is to finesse the map numbers now.
Donors
My mechanic tells me he has an 89 735 and an M6 (not sure what year, 88 perhaps) as donors in his lot so we have a few choices. I will report back in a few weeks once we reach a decision but it looks like engine goodies are on my Christmas list. I suppose I should start being nice! On a somewhat humorous note, I did mention to my wife that when I inquired from my mechanic if I might be able to assist in the assembly of the engine once we get all the parts, he replied "we mechanics typically try and avoid visitors" to which she replied with simply a "duh" look on her face. Oh well, that fantasy crushed!
My mechanic tells me he has an 89 735 and an M6 (not sure what year, 88 perhaps) as donors in his lot so we have a few choices. I will report back in a few weeks once we reach a decision but it looks like engine goodies are on my Christmas list. I suppose I should start being nice! On a somewhat humorous note, I did mention to my wife that when I inquired from my mechanic if I might be able to assist in the assembly of the engine once we get all the parts, he replied "we mechanics typically try and avoid visitors" to which she replied with simply a "duh" look on her face. Oh well, that fantasy crushed!
I've have a coupe that's 3.5L MSII built by Don Lawrence. It is smooth, reliable, and powerful. I also have a stock CS with downdraft carbs. Downdraft Zeniths are nice on the stock motor, Weber downdrafts not as much (less umph, but less finicky I guess); sorry can't speak on the triples. In the end for me, the ease of use is paramount for me. I deployed overseas and I have my neighbor looking after my coupes. Guess which one he has to start and drive every week.
OK guys, so another 2 cents worth.
If you want individual throttle bodies at a an affordable cost (at least they are down here in NZ) may I suggest you get some of these from a 20valve 1600cc twin cam Toyota, everyone down here in NZ uses them on all sorts of stuff, they are cheep to buy, but will require some engineering to fit, so the cost of this unless you can do yourself may make them cost prohibitive.
http://www.speedhunters.com/wp-content/uploads/2009/04/20V-AE86-08.jpg
BUT
the ultimate route I guess for bwalvoord to go would be the look of the DCOEs with FI
So, sell the triples and get your hands on some Jenvey Throttle bodies and a management system. The Jenveys bolt right up to the DCOE manifold and look as close as possible to DCOEs as you will get.
http://www.jenvey.co.uk/home/twin-throttle-bodies/twin-bodies-dcoe-style-91mm-long
If you want individual throttle bodies at a an affordable cost (at least they are down here in NZ) may I suggest you get some of these from a 20valve 1600cc twin cam Toyota, everyone down here in NZ uses them on all sorts of stuff, they are cheep to buy, but will require some engineering to fit, so the cost of this unless you can do yourself may make them cost prohibitive.
http://www.speedhunters.com/wp-content/uploads/2009/04/20V-AE86-08.jpg
BUT
the ultimate route I guess for bwalvoord to go would be the look of the DCOEs with FI
So, sell the triples and get your hands on some Jenvey Throttle bodies and a management system. The Jenveys bolt right up to the DCOE manifold and look as close as possible to DCOEs as you will get.
http://www.jenvey.co.uk/home/twin-throttle-bodies/twin-bodies-dcoe-style-91mm-long
Polariscsl
Well-Known Member
Interesting views. Well all I can say from my experience is that a well set up set of webers are perfectly drive-able, and don't actually require much fiddling with once done. I do concede however that I have invested a considerable amount of time and money with the correct people to achieve my result. I now have a car that will start first time, idle at 1050 rpm when freezing cold before settling to a normal idle when warm, while still taking full throttle from idle without so much as a splutter. I guess my point is that with effort you can achieve a good result with carbs (in my opinion a very pleasurable one!) but it will most likely take more time to get sorted than an equivalent Injected setup.
I also feel that carbs are more period than fitting later injection - most historic racing csl's ran them outside the team cars and many road cars were converted by tuners and privateers.... But that's just me.
I think I may be the only one on here that has built a true mapped ignition setup with crank and throttle position - it does make all the difference so it may be worth consideration for those looking for more perfection from your triple webers. If others have done this however I would be interested to hear your experiences.
I also feel that carbs are more period than fitting later injection - most historic racing csl's ran them outside the team cars and many road cars were converted by tuners and privateers.... But that's just me.
I think I may be the only one on here that has built a true mapped ignition setup with crank and throttle position - it does make all the difference so it may be worth consideration for those looking for more perfection from your triple webers. If others have done this however I would be interested to hear your experiences.
I fall into this camp, fiddling with the old hardware is part of the charm and driving experience for me but I can definitely see how you wouldn't want to mess with it, it also took me a while to get them set up which is why I have posted my updates on another thread.
Polariscsl, I'd be interested in learning about your mapped system, can you post or pm me with the basics?
Polariscsl, I'd be interested in learning about your mapped system, can you post or pm me with the basics?
Polariscsl
Well-Known Member
It's an omex mapped ignition system which allows full adjustment of the ignition map for every throttle position and engine load. The system is fitted fairly easily by hiding the 'ecu' box above the glovebox and feeding wires through the bulkhead. A weber throttle position switch was bolted to one of the carbs and the crank pulley was machined with 'teeth' and rebalanced before a sensor was fitted opposite on a small bracket. The distributor is effectively gutted and the weights removed and fixed - all it does now is direct spark at the relevant plug.
Once fitted the car spent a fair amount of time on a braked dyno to come up with the ignition map - the good thing about this is that the ignition curve can be used to smooth any transitions caused by changes in jetting and throttle angle.
Equally the omex also has a scatter spark system that effectively automatically over advances the ignition if the idle drops - it it this that enables the car to be started from stone cold and hold a steady idle with no choke.
All of these changes are almost invisible to the eye and easily reversed should the mood take me.
Bearing in mind i am running a fairly high lift cam, my idle is rock steady - this was not possible by tuning the curve in the stock dizzy.
Please let me know if you have any specific questions as I will do my best to answer.
Once fitted the car spent a fair amount of time on a braked dyno to come up with the ignition map - the good thing about this is that the ignition curve can be used to smooth any transitions caused by changes in jetting and throttle angle.
Equally the omex also has a scatter spark system that effectively automatically over advances the ignition if the idle drops - it it this that enables the car to be started from stone cold and hold a steady idle with no choke.
All of these changes are almost invisible to the eye and easily reversed should the mood take me.
Bearing in mind i am running a fairly high lift cam, my idle is rock steady - this was not possible by tuning the curve in the stock dizzy.
Please let me know if you have any specific questions as I will do my best to answer.
The mapped ignition is a really good idea. As you know even with the original FI these cars still had points, and not just 1 set, but 3 (2 to trigger the injectors)!
My next project when I get the car all finished (got to get the dam windscreen in first
)
will be a complete new engine rebuild with aftermarket computer, The system I plan to use is a locally made one and is very very tune-able with every conceivable option covered.
http://www.linkecu.com/products/engine-management-ecus/g4plus-xtreme#
At this stage I am going to be running standard FI with Plenum (modern high pressure)
Crank triggered ignition, triple twin HT output coils, with mapped everything.
More on this in the new year, I plan to do a full post on the whole project right up to and including dyno.
My next project when I get the car all finished (got to get the dam windscreen in first
)will be a complete new engine rebuild with aftermarket computer, The system I plan to use is a locally made one and is very very tune-able with every conceivable option covered.
http://www.linkecu.com/products/engine-management-ecus/g4plus-xtreme#
At this stage I am going to be running standard FI with Plenum (modern high pressure)
Crank triggered ignition, triple twin HT output coils, with mapped everything.
More on this in the new year, I plan to do a full post on the whole project right up to and including dyno.
i can not complete the poll, one option is missing,...
and what about keeping the old lady stock ? rebuild engine and carbs and that is all,...
asto the mechanic: ," he replied "we mechanics typically try and avoid visitors" " that is enough for me, find another one !
Polariscsl
Well-Known Member
Now where's the fun in that? Lol
it is a decent ammount of work too !
My mechanic doesn't seem to mind me popping in from time to time and I buy all of the parts so there is no markup. What he was politely objecting to was me spending a week in his shop helping out with the engine build.
I don't really want my customers on the floor of our pharmacy either, they tend to get in the way and ask too many questions and you can't really bill them for the time.
Lay mind was already made up to search for more power than what was provided by the original engine. I will hold onto it but since I have no plans of ever selling it, I would like to enjoy it as much as possible.
I don't really want my customers on the floor of our pharmacy either, they tend to get in the way and ask too many questions and you can't really bill them for the time.
Lay mind was already made up to search for more power than what was provided by the original engine. I will hold onto it but since I have no plans of ever selling it, I would like to enjoy it as much as possible.
Polariscsl
Well-Known Member
Yes that's the one