I guess I didn't make myself clear too. I wasn't talking about a BOT KITs with piggyback and separate wiring loom and injectors like those sold by RPW in Australia for Proton. Those cost more than a standalone ECU on some kits. Usually piggybacks come into mind as a simple piggyback controllers without external kits. Those will not make it for BOTs.

Yes, there are very extensive piggybacks but I won't call them piggybacks anymore as you'd need to purchase a whole new set of wiring looms and sensors if the original ECU does have it. These are called conversion kits that are very popular overseas but not here.

Unfortunately, for the local scene, it is the other way around. Labour is cheap and engine conversions are the norm. Overseas, labour is charged per hour and engine conversions cost more. Here, it cost more to tune an ECU than to do an engine conversion. I got the quote to retune my ECU for RM3000 (without dyno as they get the maps from the internet too). What a rip off. I do it myself for less than RM400 (to get the cable). Mappings I can get from the internet and I find hundreds of cars with the exact same mods as mine and just use their tried and tested mappings.

Piggybacks (and conversion kits) suffer the same problem here. Cost too much and hence it is not popular. However, with the 4G93T engine fading into the history books and new Protons can't use them easily, the only option for most people now is to go BOT. Do hope that one day we do see the BOT kits hear other than the one offered by Proton a long time ago.

ok true in a way but i wasnt talk about those BOT kits that comes with piggybacks from rpw either... piggybacks are quite advanced these days, i was just specifically referring on ryan_hustlers case , a piggyback to support his hardware which would not require any external kits or wiring looms or whatever which would not cost more than rm1600 for the unit brand new.. advanced piggybacks dont cost that much.. its the dyno costs that is expensive thats all, installation and tuning on the dyno in his case would cost him from 550-1000rm depending on the quality of tune he is after... its also a once off investment.. there are ppiggybacks out there that are completely universal to all cars even diesel vehicles.. so ineffect u only pay once for a unit which would go with u anywhere even when u change cars =) ive moved on from safc to piggybacks to standalones, i now stick to piggybacks cause its so flexible, ez to remove and revert back to standard and also comes with me when i sell the vehicle.. whether i own a kelisa, or proton or ferrari it still uses the same unit =) cost me less to install and tune as well.. most importantly.. no headaches =)

rm3000 without dyno is ridiculous XD that is a rip off.. maybe its just that shop... maybe i recommend u a piggyback as well as direct u to the right ppl to tune XD kekek jk

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Added on November 6, 2008, 1:55 pmthat would cost too much, ur better off with a piggyback with the right tuner that can tune it =)as i said its been done b4 and it can be done =)

This post has been edited by FAibS: Nov 6 2008, 02:07 PM

I don't need piggyback. My ECU is based on open ecu programming that can be fully flashed with all the necessary mappings.

kekek as i said, i was kidding =)

those stock NA ecu can never read boost..above 0psi it will all go hairwire because it was never design to read above 0psi and it doesnt have map for above 0psi

what piggyback like safc do it to make them see less pressure..and by fitting in large injector you have some margin of tuning

let say for example stock injector is 150cc, you change it to 200cc which is a 33% increase in size, we assume fuel pressure can be maintained, you will need to set the fuel correction on your safc to run -33% on all rpm for it to inject SAME amount of fuel as stock.

so when running boost, the safc fuel correction can be change to higher value such as -20% -10% 0% so on depend on rpm and boost. this can effectively inject more fuel on 100% HI throttle because u know when the boost come on..let say 3krpm..pretty much consistent

but have you think on half throttle? high load low throttle? low load high throttle? low load low throttle? daily driving condition? the fuel is not accurate at all because boost doenst kick at 3krpm all the time under these condition..yea i know can set the LO throttle correction but still it is inconsistent

another point is, by reducing fuel (because u have switch to bigger injector, safc tell ecu the engine are on low load) from MAP/MAF sensor..most ecu automatically add ignition timing..as stock ecu doesn't read above 0psi..it wont reduce timing as boost come

big timing + boost + inconsistent fuel = ??

This post has been edited by thelulz: Nov 6 2008, 06:53 PM

u driving evo engine sure feel useless to bot 4g15 ler....

nope...as i count the budget...it wayyyy over than convert....

agreed , unless u have good cash flow all the way ...

shame to those who doesnt understand TS' requirements. at the end of the day, it's the modding satisfaction that matters, its not about smoking vtec or mivec or GSRs.

most of the check points have already been mentioned by the sifus here. i hope they will continue to do so in a constructive and professional manner

may i suggest you hybrid your TD04? change your hot side to something smaller, as you might suffer tremendous turbo lag.
adding a wastegate will also be helpful. not for the sake of annoying other drives on the road, but for the sake of maintaining the boost from the risk of blowing up your hard work.
have your calculated what is the best CR? stacking up gaskets may help, but you'll need a trustworthy mech to do it. never ask a child to do an adult's job.

lastly, may i recommend you a book to read? Maximum Boost, by Corky Bell. its a good book and it took me 4 months for kinokuniya to ship for me. the book is really relevant of what you plan to do. you might be able to get some tips from the book. google it to look at the contents that he's covering.

Good luck.

yup,i have it

CR im not too sure bro.maybe you can advise.
Wastegate wise,my internal starts opening at 0.5 bar..im still meddling with the screw to get close to fully open at 0.3.if thats unsucessful,then an external is definitely necessary,only prob i cant find a 0.3 bar one! nobody runs boost that low..

may i know what is your stock CR?

oh no.. this thread is being abandoned?

9.2:1

time to use a stand alone or Emanage Ultimate .. if not mistaken, emanage have the ability to control ignition ..retard it on boost

just use a boost controller .. set it at 0.3bar ... even external wastegate dont hv that low boost spring.

nolah .. ppl still view it ma .. view count still increasing

Your boost controller depends on the turbines internal/external wastegate. Boost controllers let you adjust the boost above but not below the original spring tension. So if the stock boost is 0.7, you can't use a boost controller to set it below that. You'd have to adjust the wastegate or get one that is set lower.

owh ... dish . didnt think about that... silly mistake .. hahaha.

how about use the adjustable actuator ?

SVDO can't be tuned by people who are used to old piggybacks because they can't figure out closed-loop lambda-based ECU operation. Old MMC ECUs are lame. Misinformed people say they're "good" just because they're easy to be fooled by piggybacks. SVDOs are more advanced than MMC ECUs any day, that's why they're harder to fool and are "poorer" for tuning purposes.

MMC ECUs use mass airflow sensor to read the incoming air charge. Then, it determines the injector duty cycle based on the internal map. Easy as that. If you plug in higher flow injectors, your engine will run richer all the time. Plug in lower flow injectors, your engine runs leaner all the time. The mapping of MAF readout <-> injector duty cycle is static.

Traditional "tuning" on such ECUs involve only the interception of MAF output. An altered MAF signal is provided to the ECU to fool it into using a different injector duty cycle (by fooling the ECU into thinking there's more or less air than there actually is).

For SVDO ECU, it uses the lambda sensor for closed-loop operation at idle up to around 3500 rpm. Furthermore, it uses a MAP sensor that uses manifold vacuum to determine airflow.

If you intercept the vacuum signal to fool the ECU into thinking there's less air, the lambda readout will still see the actual air-fuel ratio. Within the closed loop mode, the injector duty cycle target is based on air-fuel ratio. If you wanna tune the SVDO ECU, you'll have to intercept the lambda sensor value from idle to 3500 rpm.

Above that, the SVDO ECU goes into open-loop mode, and functions similarly to the older ECUs.. by using a static injector duty cycle map for the MAP sensor inputs. It won't take into account the air-fuel ratio.

Hence, overall, you'll have to intercept the lambda sensor signal from idle to 3500rpm, and alter the MAP sensor signal above 3500rpm.

The SVDO MAP sensor in theory can detect up till 0.8 bar of positive pressure in the manifold. However, the output will be a full +5V back to the ECU. The SVDO ECU will see values like that as a fault condition. One solution is to clamp the output voltage with a zener diode so that the MAP sensor output never exceeds a certain point, e.g. 4 or 4.5 volts. That way, the ECU won't detect a fault condition. The disadvantage is that the MAP sensor response will be non-linear at higher manifold pressures, since we're cutting off the maximum output abruptly. Another solution is to use a voltage regulator at the MAP sensor input to reduce the input voltage from 5 volts to something like 4.5 volts. In effect, we're scaling down the entire range of output for the MAP sensor proportionately, so the sensor response will still be linear.

SVDO ECU has the added advantage of having a built-in knock sensor that ties back to the ignition advance mechanism (electronic ignition advance, not like in the older ECUs). Thus, engine knocking due to lean mixture can be mitigated by the SVDO ECU and it compensates by enriching the fuel mixture. However, I've heard that the knock sensor input isn't present on the 4G15, it's only on the Satria GTI's 4G93.

The closed-loop function can actually help somewhat. In theory, you can practically tune a turbocharged SVDO ECU without a piggyback and by using an AFR meter to check your air-fuel ratio. At above 3500rpm, the ECU goes into open-loop static map. During that time, adjust the fuel pressure regulator until the AFR shows a slightly rich value (e.g. 12:1 or 12.5:1 AFR). Some tuners will set the AFR as rich as 10:1 with piggybacks, which is quite unnecessary unless you're running big boost. With a low boost, a slightly rich AFR will do.

Below 3500rpm, regardless of the fuel rail pressure, the ECU will try and adjust the injector duty cycle to achieve a target AFR. In the case of SVDO ECU, its target isn't really stoichiometry.. it's a bit richer, at around 13:1 to 13.5:1 because a slightly rich mixture will burn cooler than a stoichiometric mixture. If the engine can handle the thermal load (which should not be a problem at low boost), you can just let the closed-loop mode sort out the injector duty cycle automatically.

SVDO tuning on a shoestring budget will thus probably only involve: MAP sensor clamp/regulator; adjustable fuel pressure regulator; uprated injectors (240cc should be fine for mild boost); and an AFR meter for ensuring your engine doesn't lean out.

For the BOV, venting off the excess air at such a low boost might hurt the engine response. And don't vent it into the intercooler piping, as that part of the air plumbing also has compressed air (roughly the same pressure as the vented air, so you'll just keep the intake side choked with no actual blow-off to relieve the pressure). Vent it back to the turbine's "cold" side (air filter side), i.e. send the vented air back into the air inlet of the turbine. This is the standard blow-off path used by stock turbo setups on light pressure turbo cars.

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Added on November 17, 2008, 6:50 am1 way is of course to use an external wastegate with a soft spring.. which I think is not so common. You'll vent off the excess exhaust gases into the atmosphere, so your car would be a pretty noisy machine with the wastegate dumping exhaust at 0.3 bar.. that would be pretty often!

The most cost-effective solution is to cut the stock actuator arm, and alter it. If you have a spring pressure gauge to accurately measure the amount of deflection required to produce the amount of wastegate opening (it's related to the actuator's diaphragm spring rate), then you can derive how much of the actuator arm you need to add to open the wastegate sooner. Longer arm = shorter travel to open wastegate = lesser pressure to open the wastegate = lower boost. Shorter arm = longer travel to open wastegate = more pressure to open the wastegate = higher boost.

Some people DIY to make the actuator arm length adjustable, by threading the cut actuator arms and then inserting nuts and an additional hollow sleeve.



This post has been edited by jswong: Nov 17 2008, 06:50 AM

sorry,TS has been overloaded with work! sleepwalker is staff? congrats

yeah .. thats what i did .. and when the arm karat edi ... die ...cannot adjust anymore ..

Heres the updates:
sourced rising rate fuel pressure regulator
imitation bov
trying to source a 0.3 bar wastegate spring
in process of getting a 240cc injector

im intrested in what you said by intercepting the lambda sensor or O2 sensor.Most basic piggybacks intercept the map/maf readings and either provide a higher value to run richer or lower value to run leaner.The latter is for better FC since the svdo has detonation sensor (confirmed,but how effective im not sure)
What do you use to alter the maf/map and the O2 sensor as well?