I will eventually be rebuilding the ST205, when I do I plan to perhaps modernise the ignition system a little......what would be best?

1. Stop messingt with it and leave the dizzy cay system in place. its fine.

2. Fit a wasted spark system?

3. Fit Individual coil packs?

What are the pros and cons for each and which would eb the best.

I`ll be running near normal boost levels initially but may in the future run more (not sure yet).

The car will be far from standard (although the block will be a brand new Toyota item), but not aiming for that much above normal power.

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ST205

Hi Nial,

It's not easy to determine what's the best route forward. It's really a decision you need to make

I'm planning on going individual coilpack because I have all the bits to do it properly but the list to do it right is quite extensive

The main reasons to stray froma dizzy are high boost or high rpm
The main benefit of coil per plug is increased charging time for the coil before the big bang event. In the stock setup you have to charge the coil for every single firing event In our ingines there's a big bang every cycle so @6000 rpm you only get 10mS of coil charge. As rpm increaes this time decreases and as boost rises the charge time needed goes up as you need bigger sparks to light off the mixture
There is also a reliability benefit - in the stock system coil/igniter failure means you're parked. In a cop setup you just loose one cylinder

To do the job right (complete dizzy removal) you need
cop units (avensis, 2zzfe caldina etc)
a cam cover to suit with mounting points
a cam position sensor
a crank position sensor
ecu
A caldina engine is the best route to this imo as it's all set up
Sadly the bits are not an easy retrofit. The 215 head is bolt on but the crank sensor setup requires 215 oil pump, 215 upper sump, 215 crank sensor and 215 crank pulley. Possibly a 2.0 avensis donk might be a donor

The half bottomed but simple route it to replace the stock dizzy cap with a blanking plate and use the existing dizzy signals to drive cop - the stock dizzy provides cam position and (low res) crank position
This used to be what Adrian did, I'm not sure now


Wasted spark is much the same as cop and requires the same triggers but has the disadvantage that it can eat plugs

Pretty much what steve said... BUT
Wasted spark only requires crank position sensor. IMHO avoid with COP as COP is a little prone to overheating and running 2 sets of ignition events increases heat dissipation requirements for no reason.

It is pretty easy to nail on a crank trigger wheel to the stock crank pulley - adding the position sensor is a little more difficult but just requires a custom bracket made up. Not hard TBH and avoids the whole ST215 oil pump retrofit possible can of worms when fitted to a ST205 bottom end.

I would personally look at what ECU you intend to use before deciding on COP. For your power levels I doubt you will see much gain. I will eventually run COP with DTA S60 on a ST185 engine and again I don't expect to see any gain apart from ditching a load of Toyota sensors from the engine bay.

IIRC the st205 cam cover has obstructions that may preclude the fitment of COPs?

_________________
JP
GT4DC Treasurer

Grey St185 RC
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To be fair, the standard setup works well and is reliable provided you're not going for a seriously high power engine.

There are 2 sides to changing the standard setup, and with an aftermarket ECU they are effectively separate.

1. Sensing. The standard dizzy provides crank & cam signals and these can be used regardless of whether sparks are run through the dizzy. Putting a sensor direct on the crank will provide greater accuracy, although I don't have any data on how much flutter / drift you get going via cam belt. You can, if you wish, go for crank sensor and still use the standard coil / dizzy to produce the sparks and the cam sensor signal.

2. Making the sparks. My experience of the COP type things is from renault and they are the biggest pain out. About 3 failures per year on average milage. Wasted spark just never feels right to me, firing a spark into a cylinder during the overlap period with inlet valve open (unless I've misunderstood the operation) strikes me as a recipe for blowing the manifold apart if something goes slightly astray. Personally, I don't see a lot wrong with the standard setup unless you're running enough RPM/boost that it just can't cope.

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If at first you don't suck seed, try drier grain.

Hi,

i think it is better you drive the standart engine with standart ignition system in front of the price

i think you need:

ST215 head with Cam position sensor, intake cam and trigger
(possible Injecotrs and fuel rail if gen.3 doesn't fit)

St215 oil pump with crank sensor and trigger wheel

ST215 COP's

aftermarket ecu, wiring and clamp

but the real problem is the cam cover with the mountigs for the cops
meanshwile i stock a gen.3, 4 and 5 in hope to get one of these fit with the intercooler on top of the engine

3 = does not have mountings (possible a weld on, drill and cut job)
4= is to high and do not have the flat section for a center feed throttle body
5= possible fit nearly plug&play but i can't can say that yet

but all in all you spend a lot of bucks with no true advantage over the standart system on a oem engine

greetz

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KEEP COOL UNDER PRESSURE

street legal?.....perhaps in tschibuti

fair points by both of the above.

_________________
JP
GT4DC Treasurer

Grey St185 RC
Silver BMW E46 M3
Multicolour yawn Honda VFR400
Silver Honda Civic Type-R

I think sticking with the standard system is the way to go then.

many thanks for all the advice/help all. saved me alot of time/money and effort...cheers

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ST205

I run COPs, they rock.

I`m not sure of my aim anymore...the more I talk to people the more power I want, when you start from nothing it dosnt seem that much more expensive to go for moderate power over staying around he standard level....I`m probably wrong.....started off wanting a totally standard car like DT4s frog...now I`m thinking that 350-400 would be nice. I guess details like ignition systems will sort themselves out once i have got the engine built to a spec I want.......where will it ever end, I wish I was the type of person who once their mind is made up they stick to it....I`m so easily swayed its untrue.

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ST205

Then there's the unknowables to consider

Even a stock rebuild plan can go awry if the block needs boring beyond what stock pistons can accomodate. It's then almost the same price to forge as to buy a block

IMO if you're uncertain (any money isn't a consideration) rebuild it with low expansion forgies. That will give you more scope to up the power without the issues created by high expansion "bombproof" pistons.

My personal opinion is that for more than 350 you need to consider other mods too - garrett/borg warner turbos, cooling mods, exhaust manifolds, cams etc etc as you'll be pushing stock setups pretty hard above that sort of number.
Sure some people will claim it's not needed and it's sort of true. For eg, the often banged on about "stock exhaust manifold is good for > 400 bhp". This is true but the unequal and generally poor flow creates higher EGT than a decent design and will stress the engine
A good component choice will lead to good power relatively safely

Some very wise words by steve.

Build an engine for 350 and run it at 350 and it will be stressed. Build it for 400 and run it at 350 and it will last longer.

We are not in a race environment so longevity is a major factor.

_________________
JP
GT4DC Treasurer

Grey St185 RC
Silver BMW E46 M3
Multicolour yawn Honda VFR400
Silver Honda Civic Type-R