To Lock Or Not To Lock?

[altezzaclub]

The most I could ever get in mine was 28deg. Any more than that and it would not make more power.

 

Good man! Some solid info- So, you can retard the timing 8deg millaz, so it peaks at 28deg, or do something tricky to the slots in the plate that set max advance, like glue a stop in there. If you shorten the slots then you can run the idle timing as stock.

 

I assume its the same dizzy that I'm using.

 

http://www.rollaclub.com/board/topic/49927-how-to-fix-your-brand-new-ke-motorsport-electronic-distributor/page__pid__511594#entry511594

[Millaz88]

Yeh looks like the same one as you

I was wondering how much advance does the vac advance give? For egzample if I locked the mechanical and ran the vac from the intake side of the S/C would it give much advance over the revs?

[Mitch-12]

i know nothing about dizzys my 4k has sequential ls1 coils

[Millaz88]

Yeh this hole dizzy thing is doing my head in and seems like a pain in my a$$

What's mega squirt like to work with?

[Mitch-12]

where do you get megasquirt's from? mine has motec :D

[Millaz88]

I wouldn't have a clue hahaha

So this is te plan for tonight

Lock the mechanical advance in my old points dizzy and run the vac advance from the carby because it's suck through ad map out the advance it gets with just that

Then with rhe elec dizzy I'll just remove the vac line and see what advance rhe mechanical does n see what's best to run

[ke70dave]

http://www.diyautotune.com/

 

for all your megasquirt needs.

 

as well as a few other products, widebands and wiring stuff etc.

[altezzaclub]

As I understand it..... Having only owned one turbo car and I never touched the motor in that!

 

Vac and mechanical systems give advance at totally different times.

 

Vac gives advance when the inlet manifold has high vacuum, which is when the throttle is closed, especially on over-run and also on low-throttle cruise. That's because the flame front needs more time to burn the very thin mixture in the cylinder at those times. Ported vac is the same as manifold vac except at idle when the port is covered. Idle vac is zero for the ported system, and at it maximum for manifold vac systems.

 

Its all about emission control, not performance. When you accelerate to overtake someone at 100kph the vac advance drops to zero and retards the ignition back to the mechanical level.

 

The real advance for performance comes from the weights. The mechanical advance starts off a few degrees before TDC to give a smooth idle, then advances more and more up to 36deg or so as the revs rise, to give the flamefront more time to burn in an ever-decreasing cylinder filling cycle. The flame burns at a constant rate, but the compression stroke gets shorter and shorter in time, so you need to start the flame earlier at higher revs.

 

I suppose all you're really worried about is firing the spark plug too early into a high-compression fuel mixture so it burns too fast. That should only happen in the mid-range on light throttle when you'd normally need plenty of advance but with the S/C you don't.

 

Pre-igniition detonation has nothing to do with spark plugs, its when the motor compression fires like a diesel without using the spark plugs at all. I think that's what kills most turbo & S/C motors. That just depends on how hot the motor is and how much boost it has.

 

Map the ignition over the whole rev range and see what you're getting. It will be interesting to compare to what I found.

[Mitch-12]

http://www.diyautotune.com/

 

for all your megasquirt needs.

 

as well as a few other products, widebands and wiring stuff etc.

 

thats all in america land i couldnt be botherd really anyway just thought it might be fun to build an ecu ill just stick to motec and haltech will build one oneday though

[Millaz88]

Oh well I won't be doing that idea lol thanks for the explenation mate that helped out heaps now I no what they do cheers

 

Ecu looks alright but worried about doing the lot from scratch but if it comes down to it I will have to

Cheers guys

Miller

[ke70dave]

you can buy them pre built as well, add about $100 i think.

 

and whats wrong with America land?

 

i think they might have stuff on eBay too, so you can just use paypal etc.

[carbonboy]

If you've got the brand loyalty and/or the money, by all means stick with Motec.

 

"and a standalone fuel management system...not a bad way to spend ten thousand dollars..."

 

:lol:

 

Edit: Just taking the mickey, Motec is good but the prices... :o

 

The MegaSquirt stuff is available on eBay, it is tempting but so are the Haltech's :laff:

Edited July 21, 2011 by carbonboy

[Mitch-12]

i have made a haltech thread on rollaclub on my other account with prices in the sponsers section i also have a wolf 3d for sale $400 with hand controller and plug

[Millaz88]

Weill charger is on piped up and cars running with vac removed

But!!!!

There's always a but with these things

Huge flat spot from about idle to 3k under load so it's crap to drive

So I will look into the timing again see if that's te issue or it could be the carby

Any thoughts ?

Cheers

Miller

[Millaz88]

Ok well I half locked my old points dizzy so it only gets 10* mechanical advance now so I set the idle to 15* ad it hits 25* at full revs

I no not perfect but I wanted to see what it would do

Still huge flat spot so I put it down to badly tuned webber and the fact the webber stays ice cold constantly I mean like builds up condensation cold it's actually wet to touch the pipe that runs from the carby to the charger

I won't be tuning the carby as in a week or so the fuel system is getting gutted and going straight LPG with a gas research throttle body and getting tuned and might get the elec dizzy regraghed aat the same time

But just wondering your thoughts about getting around the anti-warming affect on the carby!!

Cheers

Miller