High compression M20 on Sidedraught Carbs?

[nando]

Thanks for getting in on this discussion...
are you really familiar with Megasquirt? do you have to run coil on plug for best results of will the stock set up work just fine?
What would the down side be to tuning with just 2 injector outputs?
I have tuned cars with Autronic, AEM, Fast, Halltec and various piggy backs and flash software...does MS use a VE table or a pulse width table for fuel?
I think there is a guy on this forum called Ely who does a lot with MS...I think he is quite close to me in Chattanooga TN, maybe I will pick his brain.
I guess the smart thing to do would be to tune the car with MS on the stock set up (banana manifold) first and move on from there as you are right ITBs are a real PITA to set up with a MAP sensor, although when correct they sound GLORIOUS!!!!

no, you do not have to run COP - I wouldn't even recomend it realy, there isn't a big advantage and it uses a lot of output pins that could be better used elsewhere. the stock coil works fine for almost any M20 (even turbo), or a good compromise like wasted spark with 3 coils (which is nice to eliminate the mechanical wear you get with a cap/rotor system).

the only real disadvantage to tuning with 2 injector outputs is in low load/low RPM areas and idle. Especially as injectors get bigger, their pulswidths start to shrink making low-load tuning more difficult to control with batched injection. But it's not impossible - MS2/e supports semi-sequential at least, which is the same thing BMW used on the M20 (motronic 1.3), and it's plenty smooth. at higher loads and full throttle the injectors are mostly on all the time anyway, so the timing of them doesn't matter as much - basically it's not going to make any difference in peak power, only smoothness and economy/emissions. That said, I'd *love* to have 6 full sequential injector outputs, but my car is daily. if it were a track car, I wouldn't care at all.

MS does use a VE table for fuel, and there are a few ways to get around the MAP problem with ITBs. MS1/extra supports blended alpha-n/speed density directly, MS2/extra doesn't officially support it but there's a neat trick you can use with dual VE tables to blend the two together. I would definitely reccomend learning the system on a stock motor with the stock intake - cuts down on variables and makes it easier to tune while you are learning.

as far as ely - he's pretty knowledgable on MS. I'd definitely reccomend hitting him up, he even builds a trick plug and play setup that uses the stock wiring harness to cut down on setup time & troubleshooting.

[Dyno4mance]

Hi Madhatter
I priced new carbs with manifold right at $1500.00 USD the lot excluding trumpets and filters I can jet and tune myself not that tricky used to do it all the time on a Cosworth BDG with a set of 48's back in england in the old days...I do understand what you are saying though so I have decided to get the car running after the build on the stock manifold but using a MAP sensor w/MS....at that point I may hate it and throw in a LS1(joke)
Who knows
Do you have ITBs on your e21?....it must be early over there?

[nando]

you can run alpha~n and do away with a map sensor. Or as you have said, you can run a MAF sensor like M vehicles. What is the big restriction in a MAF sensor though? you only have a heating element contained inside and the body section is more than large enough. You would be mad to run open trumpets on a road vehicle so you need to run a plenum anyway, a maf at the front isnt going to be a problem. You will still get the throttle response and top end increase due to the throttles, you just need to make sure you size the plenum correctly.

there's more in a MAF sensor than just the heating element - there's usally a honeycomb/screen as well. a MAF is defintely more restrictive than using MAP, since MAP literally has NO restrictions in the intake. MAF has advantages of course, but generally MS doesn't support MAF sensors anyway (some support in MS1/e, future support in MS2/e).

[Dyno4mance]

no, you do not have to run COP - I wouldn't even recomend it realy, there isn't a big advantage and it uses a lot of output pins that could be better used elsewhere. the stock coil works fine for almost any M20 (even turbo), or a good compromise like wasted spark with 3 coils (which is nice to eliminate the mechanical wear you get with a cap/rotor system).

the only real disadvantage to tuning with 2 injector outputs is in low load/low RPM areas and idle. Especially as injectors get bigger, their pulswidths start to shrink making low-load tuning more difficult to control with batched injection. But it's not impossible - MS2/e supports semi-sequential at least, which is the same thing BMW used on the M20 (motronic 1.3), and it's plenty smooth. at higher loads and full throttle the injectors are mostly on all the time anyway, so the timing of them doesn't matter as much - basically it's not going to make any difference in peak power, only smoothness and economy/emissions. That said, I'd *love* to have 6 full sequential injector outputs, but my car is daily. if it were a track car, I wouldn't care at all.

MS does use a VE table for fuel, and there are a few ways to get around the MAP problem with ITBs. MS1/extra supports blended alpha-n/speed density directly, MS2/extra doesn't officially support it but there's a neat trick you can use with dual VE tables to blend the two together. I would definitely reccomend learning the system on a stock motor with the stock intake - cuts down on variables and makes it easier to tune while you are learning.

as far as ely - he's pretty knowledgable on MS. I'd definitely reccomend hitting him up, he even builds a trick plug and play setup that uses the stock wiring harness to cut down on setup time & troubleshooting.

Wow...Thanks for the info, Great to know there is some knowledge on the MS on this board...when I get closer to this part of the project I hope I can PM you with my stupid questions..
I still have cylinder head, Cam, Headers, Exhaust and clutch assembly and of course engine installation to address but the car as a chassis is generally finished...I wish I could figure out how to host some pics so I can share....oh well

[Aptyp]

Best suggestion:

Call Korman Autoworks.

Ask about Lou Mendola's m20 build. Exact same thing that you're going for and they got a whole lot of research and specs and everything you need, even manifold for webers. They NA engine run voided 320hp and 260 ft lb torque. They no longer build those engines, but shelves are full of parts and Ray/Jimmy could really save you a whole lot of time.

[Dyno4mance]

Best suggestion:

Call Korman Autoworks.

Ask about Lou Mendola's m20 build. Exact same thing that you're going for and they got a whole lot of research and specs and everything you need, even manifold for webers. They NA engine run voided 320hp and 260 ft lb torque. They no longer build those engines, but shelves are full of parts and Ray/Jimmy could really save you a whole lot of time.

I don't mean to talk badly of a company but I have called Korman 3 times now regarding a customers M3 and every time they have been extremely rude and non engaging..and they dont return calls
I know first hand things can get busy in a shop from time to time and I have my bad days like the next guy but when I begin to regard customers as not important and pat myself on the back for past achievements I may as well lock the doors and go and do something else.....
I am glad you have apparently had a good experience with them...

[Madhatter]

there's more in a MAF sensor than just the heating element - there's usally a honeycomb/screen as well.

Example;



Thats a fairly large element too, ones I used to have in the zed were much smaller, ive seen very few on my own vehicles which are covered by a honeycomb.

Do you have ITBs on your e21?....it must be early over there?

Havent finished building the engine yet, but yeah, I have a set.







Running an aftermarket ECU though. Will get the ecu running on the injected manifold, get it tuned and sorted, then fit the throttles and tune it again, then the new motor will go in.

[HST]

Ignore

[Dyno4mance]

Ignore

Ignore? What does that mean....I guess just trying to get that post count up eh?

[Kingb]

Has anyone had experience with "Extrudahone"

A few years back I was building a 88 VW GTI with a 2.0L block with a 1.8L GTI head. I was pretty much following my friends build. We had our heads built at the same shop at the same time. I had mine hand ported and polished and he had his extrudehoned. My P/P job was $550 his was $500 and took an extra 3 weeks. Mine flowed better on the flow bench.

[nando]

A few years back I was building a 88 VW GTI with a 2.0L block with a 1.8L GTI head. I was pretty much following my friends build. We had our heads built at the same shop at the same time. I had mine hand ported and polished and he had his extrudehoned. My P/P job was $550 his was $500 and took an extra 3 weeks. Mine flowed better on the flow bench.

yeah, way not worth it - because of the way the process works, there's basically little control over what actualy gets removed. small defects in the casting can turn into huge flow problems. hand porting is difficult and time consuming but much more consistant.

[Farbin Kaiber]

Example;



Thats a fairly large element too, ones I used to have in the zed were much smaller, ive seen very few on my own vehicles which are covered by a honeycomb.

Madhatter, Just for the record, that looks like an A/m Delphi unit that was modified ans sold by Jet. They are big on the lSx series engines, and have been making the modified meter you posted above.


Examples.


Modified



Oe screen

[Kingb]

yeah, way not worth it - because of the way the process works, there's basically little control over what actualy gets removed. small defects in the casting can turn into huge flow problems. hand porting is difficult and time consuming but much more consistant.

From what I was told exrutehone is a metalic gel that is flowed through the port to smoothen any rough areas. But like quoted can cause bigger problems if the cast has even a small defect.

[Farbin Kaiber]

IIRC, its more like play-doh.

[Dyno4mance]

A few years back I was building a 88 VW GTI with a 2.0L block with a 1.8L GTI head. I was pretty much following my friends build. We had our heads built at the same shop at the same time. I had mine hand ported and polished and he had his extrudehoned. My P/P job was $550 his was $500 and took an extra 3 weeks. Mine flowed better on the flow bench.

Doh....Sorry I meant extrudabody as in this company....

http://www.extrudabody.biz/servlet/StoreFront

Has anyone ever got these working correctly on an M20...or any e30 for that matter?